JPH0378466B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD This invention relates to loose-lay flooring structures, and more particularly to loose-lay flooring structures suitable for use on stable or unstable surfaces. Decorative floor coverings made of elastic materials have been used for many years. Generally, these floor coverings have been adhered to the subfloor with adhesives, but installation of such coverings is time consuming and expensive. Therefore, it is desirable to place the floor covering on the subfloor without the use of adhesives, ie, to lay the cover loosely (without sticking) on the subfloor. Under such an environment,
Loose-lay floor coverings tend to be held in place by the weight of the floor covering, although they can also be secured to the subfloor with furniture, appliances, and items placed over the floor covering. Loose-lay floor coverings must have the following properties: not expand or contract over time or under the influence of environmental changes; remain in place under rolling loads; and support the subfloor without buckling. To withstand or adapt to movement (the expansion and contraction of the subfloor caused by changes in temperature and relative humidity between seasons). The term "rolling load" refers to the lifting and tearing of loose-lay flooring structures as objects such as washers, refrigerators, and furniture on wheels roll over the loose-lay flooring structures. means resistance to The latter problem poses a particular challenge because subfloors range from dimensionally stable (eg, concrete) to dimensionally unstable (eg, particle board). Another problem arises depending on the type of subfloor over which the loose lay flooring structure is placed. Accordingly, the flooring structure industry has devoted much time and effort to developing loose lay flooring structures with the aforementioned characteristics. There is a variety of prior art documents relating to loose lay flooring structures. U.S. Patent No. 3,821,059
A piecewise compliant loose lay flooring structure is disclosed that is comprised of a plurality of rigid bodies that distributes stress within the matrix of the flooring structure so as to appear as a series of small curvatures. U.S. Pat. No. 3,364,058 discloses a composite floor consisting of a base support, a release coat, a water-resistant coat, an abrasion coat, and a protective (top) coat, which avoids damage caused by subfloor movement. It is designed to. U.S. Patent No. 4,066,813
A method is disclosed for reducing the elongation of elastic flooring structures having fibrous cellulose backings by incorporating small amounts of anti-elongation agents. Additionally, various patents address the problem of stress relief by including a series of deformable geometric shapes in the matrix. For example, U.S. Pat.
No. 4146666, No. 4049855, No. 4035536 and No.
No. 4020205 is exemplified. However, none of the prior art documents adequately teaches how to make flooring structures that are loosely laid on the surface of a subfloor, either stable or unstable. Therefore, one of the objects of the present invention is to provide a loose subfloor that accommodates unstable subfloor movements (expansion and contraction due to changes in temperature and humidity) without buckling.
An object of the present invention is to provide a method for designing and manufacturing a lay floor structure. Another object of the present invention is the design and construction of loose lay flooring structures that can accommodate any type of subfloor movement without buckling, bulging or curling and that do not move under rolling loads. The purpose is to provide a manufacturing method. A further object of the invention is to provide a loose lay flooring structure having the above-mentioned characteristics. It is also an object of the present invention to provide a method by which a product comprising one or more reinforcing layers can be processed on-site to provide suitable buckling properties. These and other advantages of the invention will become apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings. In summary, the present invention relates to a loose lay flooring structure comprising at least two reinforcing materials and a method of designing and manufacturing the loose lay flooring structure. Loose lay flooring structures are suitable for use over stable subfloors or are designed to accommodate the movement of highly unstable subfloors. Loose-lay flooring structures made in accordance with the present invention have the ability to resist buckling, curling and bulging, and can resist movement under rolling loads. DETAILED DESCRIPTION OF THE EMBODIMENTS In one embodiment, the present invention relates to a method of manufacturing a resilient loose lay flooring structure for use over a subfloor that exhibits certain measurable changes. The method consists of selecting a dimensional change value of ^the subfloor that corresponds to the dimensional change of the subfloor on which the elastic loose lay flooring structure is laid;
Selecting the basis weight of the flooring structure within the range of 10lbs/ ^yd2 ); bending stiffness value from 0 to 10.4cm-Kg
(0 to 9 in-lbs), and the relaxed compression stiffness value is changed from 0 to 1785 Kg/cm (0 to 9 in-lbs) per unit length width.
10,000 lbs/in); drawing a predetermined critical buckling strain curve for said selected basis weight;
The process of determining compressive stiffness values in a range defined by minimum and maximum relaxed compressive stiffness values corresponding to bending stiffness values of 10.4 cm-Kg (0.1 and 9 in-lbs), respectively; Loose Lay Flooring At least one matrix material and at least one reinforcing material, which are constituent materials of the structure, are selected such that the sum of relaxed compressive stiffness values of all the matrix materials and all the reinforcing materials is within the determined range, and The sum of the relaxed compressive stiffness values of all reinforcing materials used in a loose-lay flooring structure is greater than the relaxed compressive stiffness values of all matrix materials used in a loose-lay flooring structure. and the basis weight is 1.1~
Selecting a flooring structure with a bending stiffness value of 0.1 to 10.4 cm-Kg (0.1 ^{to 9} in-
lbs) and at least one of the layers of reinforcing material is disposed over the neutral bending surface of the loose-lay flooring structure. at least 1
From the process of causing the critical buckling strain of a loose-lay flooring structure to be greater than the strain due to dimensional changes in the subfloor by placing the layer below the neutral bending plane of the loose-lay flooring structure. It is characterized by becoming. In the second embodiment, 1.1 to 5.4 Kg/m ² (2
The flooring structure has a basis weight of ~10 lbs/yd ² ) and is comprised of a matrix material and at least two layers of reinforcing material disposed within the matrix material, at least one of the layers of reinforcing material being a loose-lay flooring structure. and at least one layer is below the neutral bending surface, and the sum of relaxed compressive stiffness values of the plurality of reinforcing layers is greater than the relaxed compressive stiffness value of the matrix material, and 0.1 to An elastic loose lay with a bending stiffness of 10.4 cm-Kg (0.1 to 9 in-lbs) and a critical buckling strain greater than the strain due to dimensional changes in the subfloor overlying the loose lay flooring structure. A lay flooring structure is provided. The main terms used in this specification will be explained below.
The term "loose-lay flooring structure" means a structure that lies flat on a stable or unstable subfloor and does not bulge, curl, buckle, or move under rolling loads and that: A flooring structure that has a rather low structural stability value, as defined in , and does not need to be held in place with adhesives. The term "conformable flooring structure" is a loose-lay flooring structure that conforms (or changes) in size and shape to conform to the size and shape of an unstable subfloor. The term "subfloor dimensional change" is a measure of the change in length of a subfloor under environmental conditions, expressed as change per unit length. The term "critical buckling strain" is the strain at which a loose-lay flooring structure compressed in a planar manner buckles. The term "relaxed compression stiffness" refers to the compressive force expressed as the compressive force per width of unit length divided by the resulting strain, and the load (stress) decreases when a certain strain is applied. Obtained by extrapolating the curve up to 1000 hours.
Relaxation here refers to a phenomenon in which when a certain strain is applied to a material and left unattended, the resulting stress decreases over time. The compressive force is then applied in a plane and measured on the straight line portion of the stress-strain curve. The term "relaxed tensile stiffness" is the tensile force per width of unit length divided by the strain that occurs, and the value of relaxed tensile stiffness is the decrease in load (stress) with a constant strain applied. The tensile force, obtained by extrapolating the curve to 1000 hours, is applied in a plane and measured in the straight part of the stress-strain curve. The term "basis weight" is the weight per unit area (Kg/m ² or lbs/yd ² ) of a loose lay flooring structure. The term "matrix material" comprises all components of a loose-lay flooring structure excluding reinforcement. The term "bending stiffness" is the bending resistance of a loose lay flooring structure measured by methods such as cantilever measurement and is expressed in cm-Kg or in-lbs. The term "bending resistance" is a material parameter used in the theoretical derivation of the potential energy representation and describes the bending resistance properties of a flooring structure. The term "structural stability" refers to the stability of a loose-lay flooring structure and refers to the amount of allowable shrinkage that results in an acceptable gap between the edge of the loose-lay flooring structure and the wall. A value of 0.5% to 0.1% was arbitrarily chosen for this purpose. The term "neutral bending plane" for a strip of material subjected to downward bending forces at both ends is an imaginary line within the strip above which the strip is under tension and below which it is under compression. be. A loose lay flooring structure must be kept within the tolerances of the shape and dimensions of the room in which it is placed, and must not shrink away from the walls leaving unsightly gaps. This requirement applies regardless of the nature of the subfloor. Therefore, a desirable feature of the flooring structure is to have a structural stability of less than 0.5%, preferably less than 0.1% under normal conditions. If the subfloor on which the loose-lay flooring structure is placed is stable, the characteristics that must be exhibited by the loose-lay flooring structure are those of the flooring structure provided that the dimensional changes in the subfloor are small. Since the amount of plane compression is also smaller, it is less severe than in the case of unstable subfloors. Nevertheless, the bulge
Problems arise related to expansion and contraction of the subfloor under curling and rolling loads. Conversely, unstable subfloors such as particle board tend to expand and contract depending on temperature and relative humidity conditions within the structure in which they reside, making loose-lay flooring structures dramatically increases the requirements for In winter, the dry air from furnace heating tends to cause unstable subfloors to contract, whereas in humid summer months, subfloors tend to expand. Loose-lay flooring structures that are placed in the maximum expansion position on top of such subfloors and are pinned, attached, or restrained by heavy objects such as appliances may vary as the subfloor dimensions change. subject to stress. Loose-lay flooring structures made according to the prior art and having the necessary structural stability are often unable to accommodate these stresses, resulting in bulging, buckling or curling of the flooring structure. . Surprisingly, we have found that loose lay flooring structures consisting of at least two layers of reinforcement can be constructed to meet all of the aforementioned criteria. In general, increasing basis weight and bending stiffness and lowering compressive stiffness results in loose lay flooring structures with superior compliance properties. Accordingly, the method described below allows for the production of loose lay flooring structures that have predictable properties when used over subfloors that have certain measurable dimensional changes. The first factor that must be considered is the amount of variation that can be expected from a given subfloor. For example, when a loose lay flooring structure is compressed in a plane due to expansion and contraction due to changes in the subfloor's environmental conditions, the contraction of the subfloor can cause distortion in the loose lay flooring structure. is expected.
If the flooring structure is configured with a critical buckling strain corresponding to the expected dimensional change of the subfloor, and the flooring structure is compressed by the maximum expected contraction of the subfloor, the floor The tensioned structure will buckle. Therefore, the critical buckling strain of the flooring structure must be greater than the expected strain resulting from the largest dimensional change in the subfloor. Loose-lay flooring structures will experience maximum compressive strain when installed over a subfloor under conditions of maximum expansion and must therefore be designed to withstand this strain without buckling. Three important parameters influence the buckling tendency of loose lay flooring structures. Those parameters are basis weight, bending stiffness and relaxed compressive stiffness as previously defined. The basis weight of commonly used elastic flooring materials is approximately 1.1~5.4Kg/ ^m2 (2~10lbs/ ^yd2 )
It is. Generally, the increased weight of a flooring structure requires greater compressive force to cause it to buckle, so the more unstable the subfloor, the greater the basis weight must be used to prevent buckling. The second parameter is the bending stiffness of the loose lay flooring structure, which is a measure of the bending and buckling of the flooring structure. Resilient sheet flooring structures are usually very soft (i.e. approximately 0.12 cm
(i.e., having a bending stiffness of approximately 9 in-lbs). Sheet flooring structures rarely have bending stiffnesses exceeding the latter value (10.4 cm-Kg) because they are transported on rolls. If the bending stiffness is greater than 10.4 cm-Kg, cracking, bending, and folding problems will occur when the flooring structure is rolled into small diameter rolls. The third parameter is relaxed compressive stiffness, which is discussed in more detail below. The essence of the invention is that once the engineer knows the amount of dimensional change in the subfloor, he can have a critical buckling strain that is greater than the strain imposed on the loose lay flooring structure by the subfloor. The ability to design and manufacture loose lay flooring structures. It is desirable that the loose lay flooring structure have adequate structural stability. One or more critical buckling strains can be determined by varying the relaxed compressive stiffness and bending stiffness values, or separately the bending resistance values, for a given basis weight using formulas derived from buckling theory. You can draw a graph of For convenience, the illustrated graph shows the relationship between bending stiffness and relaxed compressive stiffness at a constant basis weight and a constant critical buckling strain value. By determining the range of applicable compressive stiffness values from the curve, appropriate matrix materials and reinforcement materials can be selected. Next, the bending stiffness values of the flooring structure are determined for these materials, and a suitable flooring structure is constructed by suitably placing at least two layers of reinforcement within said matrix material. can be made. The relaxed compressive stiffness of a loose lay flooring structure approximates the sum of the relaxed compressive stiffnesses of the flooring structure components. Therefore, the matrix material and at least two
By obtaining a relaxed compressive stiffness value of a material whose layers consist of reinforcing layers disposed within the matrix material,
A suitable material can be selected such that the sum of the respective relaxed compression stiffness values falls approximately within the range of relaxed compression stiffness values indicated by the curve. The actual relaxed compressive stiffness value is then determined by building a test flooring structure, and this value is used to determine the bending stiffness value from the curve. Alternatively, the sum of relaxed compressive (or tensile) stiffness values can be used to theoretically predict the required bending stiffness. Theoretical calculation results for flooring structures depend to some extent on experimental measurements as well as other variables that are difficult to predict. Therefore, it must be recognized that there may be variations from theoretically predicted results. Therefore, this latter method is insufficient. Once the desired bending stiffness is determined, a reinforcing layer is placed beneath the matrix material to provide a bending stiffness essentially equal to the desired bending stiffness. The loose lay flooring structure thus obtained should have a critical buckling strain capable of withstanding the strain caused by the subfloor. Stiffness is a well-known property that can be measured in a variety of ways. For example, American National Standards Institute/American Society for Testing and Materials D747 (also known as the Olsen Stiffness Test) describes a standard method for determining the stiffness of plastics using a cantilever beam.
For this invention, a satisfactory value is 1 inch (2.54 cm)
Obtained by measuring at a bending angle of 20° using a span of . The bending moment determined by the Olsen stiffness test is equal to the bending stiffness. It is even more difficult to obtain relaxed compressive stiffness data for the materials used to make loose lay flooring structures. For matrix materials, such measurements can be easily made using conventional methods, taking into account the stress drop with time in the material under stress. Relaxed compressive stiffness values obtained by extrapolating load drop curves up to 1000 hours under constant strain using well-known methods are used in the practice of the present invention. Conversely, thin and lightweight reinforcements are generally not suitable for such measurements. Therefore, the data can be calculated by measuring the relaxed tensile stiffness of the material and considering the decrease in stress with time under stress. The relaxed tensile stiffness of a desired material, when properly measured, will be approximately the same magnitude as the relaxed compressive stiffness. Therefore, the relaxed tensile stiffness value can be substituted for the relaxed compressive stiffness value. The aforementioned graphs can be derived by conventional mathematical means. Theoretical models that determine buckling characteristics are well known. For example, Kerr (ADKerr)
The paper describes vertical track buckling in the High Speed Ground Transportation Journal.
Journal), Volume 7, Page 351 (1973). Loose lay flooring structures can be subjected to such theoretical studies as well. Therefore, the potential energy π of the sheet-like flooring structure after buckling can be calculated from the following equation. π=3Cθ ² /L _p +QL ² _p (1-E)Tanθ+KL _p [1
-(1-E) Secθ〕 ² -KL _p E ² where C = bending resistance θ = lift-off angle of buckling Q = basis weight K = relaxed compression (or tensile) stiffness L _p = resulting in buckling 1/2 of the length of the buckled part before strain is applied E = Compressive strain applied to cause buckling Bending resistance C is calculated using the following formula from the bending stiffness measured by Olsen's stiffness test. Calculate: C=M _w S/bφ where M _w = Measured bending stiffness S = Span used for the test b = Width of the test specimen φ = Angle at which the measurement was made (in radians) Critical buckling strain can be calculated mathematically by applying the principle of minimum potential energy. The bending stiffness value M _w is converted into a bending resistance value C. By setting π with respect to θ and the derivative of π with respect to L _p to zero, determining the values of E and Q, and varying C and K within a known range, the answer is obtained where E becomes the critical buckling strain. It will be done. For example, this can be obtained using the Newton-Rathson method of solving a nonlinear system of equations. The answers obtained by varying these bending resistance and relaxed compression (or tensile) stiffness values within known ranges give a table of critical buckling strain points. From these, one or more graphs at constant critical buckling strain are plotted as described below. As mentioned above, the graphs described herein are illustrated in terms of bending stiffness M _w and relaxed compressive stiffness K rather than bending resistances C and K. The value of C used for calculation is converted from the value of M _w . A flowchart for the computer program used to obtain this data is shown in FIGS. 1A and 1B. Of course, the parameters that can be ascertained with reference to the various curves can also be determined by purely mathematical means. The use of the mathematical means described above to generate the data necessary for the practice of the invention is a matter of choice of the engineer. Accordingly, terms in the specification and claims that relate to the depiction of curves or the like are deemed to include such mathematical selections. In the practice of the present invention, loose lay flooring structures are constructed for use over specific subfloors that have certain measurable dimensional changes. or can be made to be used over an underlayment that undergoes expected dimensional changes. The expression "a certain measurable subfloor dimensional change" as described herein is considered to include all of these options. In any event, the objective is to create a loose-lay flooring structure with sufficient critical buckling strain to accommodate anticipated subfloor dimensional changes. At one extreme are extremely stable subfloors, such as concrete, where the dimensional change in the subfloor (and thus the critical buckling strain) is minimal, and at the other end is the maximum dimensional change in the subfloor (and thus the critical buckling strain). There are extremely unstable subfloors, such as particle board, which have a critical buckling strain of approximately 0.003. Once the desired critical buckling strain of a flooring structure is known, an approximate basis weight for the flooring structure can be selected. polyvinyl chloride resin, acrylic resin,
Any suitable resilient flooring structure can be used, including vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, and the like. In addition, the flooring structure has a wear layer,
A makeup layer and the like may also be included. Flooring structures made of these materials typically weigh approximately 1.1 to 5.4 kg/m ² (2
~10 lbs/ ^yd2 ) (lighter or heavier may be required). Since the basis weight is not important when the loose lay flooring structure is placed on a stable subfloor, the basis weight for such applications should be approximately
A range of 1.1 to 2.7 Kg/m ² is desirable. Conversely, a basis weight of approximately 2.7 to 5.4 kg/m ² is desirable for unstable subfloors. However, these values are merely approximations and are not intended to limit the scope of the invention. Next, using the basis weight you selected, set the bending stiffness value to approximately 0.
From data points obtained by varying the relaxed compressive stiffness values over a range of approximately 0 to 1700 kg/cm wide, A graph of the desired critical buckling strain is drawn. As mentioned above, the bending stiffness of resilient flooring structures is typically limited to be within the range of about 0.1 to 9 in-lbs. However, as the dimensional variation of the subfloor increases, it is desirable to increase the bending stiffness value. Thus, for an unstable subfloor with a dimensional change of 0.0015 (in which case accommodation is required for large dimensional changes in the subfloor), a higher value, e.g.
−lbs) is desirable. A bending stiffness of approximately 2.3 to 10.4 cm-Kg for subfloors with a dimensional change of 0.0025 or more, and approximately 3 to 9 in-lbs for subfloors with a dimensional change of 0.0030 or more. Bending stiffness is desirable. The range of actual relaxed compressive stiffnesses that can be applied to flooring structures can be seen from the graph above, and once this range is known, the matrix material and at least two layers of reinforcement can be adjusted to accommodate the relaxed compressive (or tensile) stiffness of these materials. The value can be chosen to be within the indicated range. The sum of these values also gives the target bending stiffness of the flooring structure from the curve. Reinforcements can thus be placed within the matrix material to achieve the desired bending stiffness. Reinforcements are often made of conventionally used fibrous materials. Such materials include, for example, glass,
A fiber mat made of polyester, nylon, rayon, etc., or a combination thereof. about 17
Materials that are extremely lightweight, at 0.5 oz/yd ² (g/m ² ), are desirable. Reinforcement materials used in loose lay flooring structures should have a relaxed compressive stiffness that is as uniform as possible in all directions. Textile materials also tend to have direction-dependent strength changes depending on whether they are compressed or stretched in the direction through which they are made or perpendicular to the machine. Such direction-dependent strength variations (anisotropy) are minimized by nonwoven materials. Therefore, non-woven materials are desirable. Special reinforcement materials with unique properties can also be used. Such nonwoven materials include, for example, glass mats consisting of binders that dissolve or soften in the presence of plasticizers found in typical matrix materials. The use of such materials is also advantageous, although it makes prediction of relaxed compressive stiffness values significantly more difficult. For example, reinforcement materials that include soluble binders are actually heavier and easier to handle in manufacturing environments than materials that do not include such binders. They are therefore used where handling is an issue, but are also desirable for the production of flooring structures with low relaxed compressive stiffness. In normal cases, most of the relaxed compressive (or tensile) stiffness of an entire flooring structure is provided by the reinforcement. Elastic plastic matrix materials are usually dimensionally unstable and in most cases stretch or compress quite easily. However, reinforcement does not easily compress or stretch. The relaxed compressive stiffness of the reinforcement material is approximately 5 of the value of the matrix material.
1x, optimally 10x. Suitable flooring structures are made of reinforcement and matrix materials having similar relaxed compressive stiffness values. However, the sum of the relaxed compression stiffness values of the reinforcement should be greater than the sum of the relaxed compression values of the matrix material. The bending stiffness of loose lay flooring structures made in accordance with the present invention will vary depending on the placement of the reinforcing layer within the matrix material. In most cases, it is desirable for the reinforcement to be disposed substantially planarly within the matrix material. However, as shown below, it may be desirable to arrange the reinforcement in a non-planar manner. Although suitable loose lay flooring structures may be manufactured using more than one reinforcing layer, the use of two reinforcing layers is preferred. Generally, the further apart the two layers are, the greater the bending stiffness. Therefore, if one of the reinforcement layers is placed near the top surface of the matrix material and the other layer is placed near the bottom surface, the bending stiffness will be reduced as both reinforcement layers are placed near the neutral bending surface of the composite. larger than the case. Combinations of reinforcements can also be used. Instead of using two layers of the same reinforcing material in the matrix material, a light reinforcing layer and a heavy reinforcing layer are used in combination. The heavier reinforcement layer can be placed closer to the neutral bending plane, yet still provide a bending stiffness comparable to that of a lighter stiffener placed closer to the surface of the matrix material. However, when using heavy materials, care must be taken not to exceed the desired relaxed compressive stiffness of the final product. The use of such combinations becomes important, for example, when embossing the surface of matrix materials or when providing wear layers. When the lightweight reinforcement is placed close to the surface of the matrix, embossing tends to deform the reinforcement so that it is no longer planar. Accordingly, it reduces its contribution to the relaxed compressive stiffness of the flooring structure. However, if a slightly heavier reinforcement is used, the reinforcement can be placed further away from the surface of the matrix, thereby reducing the effect of embossing. Similarly, if a wear layer with a high compressive stiffness is provided, the neutral bending plane will be higher in a composite flooring structure than when the wear layer is not a component of the original matrix material. In such cases, it is necessary to place lightweight reinforcement in the wear layer to obtain adequate bending and relaxed compressive stiffness. Nevertheless, this problem can also be avoided by arranging a heavy reinforcing layer on the matrix material. Other methods of improving the properties of flooring structures are also available. For example, a reinforcement has a maximum relaxed compressive (or tensile) stiffness when it is in a planar structure. When the reinforcing layer is placed non-planarly in the matrix material, or so that a significant portion of the reinforcing layer is not in the same plane, the relaxed compressive/tensile stiffness is reduced. The former is obtained by arranging the reinforcing layer in a wave-like manner within the matrix (although improvements are also possible in various ways). For example, the reinforcing layer can be deformed from its planar shape by embossing or other similar processes. Another way to reduce the relaxed compressive/tensile stiffness of a reinforcement is to process the material in a way that does not affect planarity. For example, such processing may include drilling, cutting, etc., or folding to separate the fibers and flattening the reinforcement again. "Processing" as used herein for changing the relaxed compressive stiffness properties therefore includes all of the aforementioned possibilities and combinations thereof, as well as the use of reinforcing agents with soluble or softenable binders. These treatments can be done before or after incorporating the reinforcing layer into the flooring structure. Therefore, reinforcing materials with too high relaxed compressive stiffness values should be pretreated to reduce the relaxed compressive stiffness to a satisfactory value before being placed in the matrix material, and flooring. The relaxed compressive stiffness and/or bending stiffness are measured after the structure is fabricated and then adjusted by in-situ modification of one or more reinforcing layers. In this manner, flooring structures unsuitable for use over a given subfloor are treated to provide the required bending stiffness and/or relaxed compressive stiffness values. In most cases, the measured relaxed compressive stiffness does not correspond to the value curve calculated from the Kell equation above, especially when the flooring structure contains very heavy reinforcement.
However, the measured bending stiffness can be used in conjunction with the curve to determine the relaxed compressive stiffness of the desired final product. Therefore, if the resulting flooring structure is processed in the field so that it has a relaxed compressive stiffness that approximates that determined from the curve, the critical seat of this resulting product is The bending strain should allow the flooring structure to be used over the intended subfloor. It has been found that by applying such a method to flooring structures with inadequate buckling properties, flooring structures with very good properties can be obtained. Although in-situ processing results in a substantial reduction in relaxed compressive stiffness values, in most cases bending stiffness values are relatively unaffected. Therefore, the required relaxation compression stiffness can be predicted from the curve using the initially determined bending stiffness value. In cases where the bending stiffness shows a significant change (for example, when cutting one layer of a two-layer glass reinforcement layer), the required relaxed compressive stiffness value will vary depending on the fabricated flooring structure. It can be determined from the curve using the measured bending stiffness values. The present invention has the advantage of providing a relatively reliable method for predicting the properties of loose lay flooring structures. It also provides guidance on how various parameters can be varied to predictably alter the properties of such flooring structures. The following examples are illustrative of the advantages of the invention and are not intended to limit them. EXAMPLES Example Flooring Structure Comprising at least Two Reinforcement Layers 1 This example shows how to design a loose lay flooring structure for use over a subfloor with a dimensional variation of 0.001. The target critical buckling strain for the desired flooring structure is 0.0016, and the basis weight of the flooring structure is approximately
2.5Kg/m ² (4.6lbs/yd ² ). Therefore, for calculation, let E be the value of the target critical buckling strain (0.0016), and let Q be the basis weight (2.5 Kg/m ² ). Using those settings in the equations presented herein, the bending stiffness
The bending resistance C is changed so that M _w changes between 0 and 10.4 cm-Kg, and the relaxed compressive stiffness K is set to 0 per 1 cm width.
~1700 Kg/cm and by solving the resulting equation, a series of points of constant critical buckling strain corresponding to varying values of M _w and K is obtained (see Figure 2). From the curve, the relaxed compression stiffness corresponding to a bending stiffness value of 0.1 is 34Kg/cm (200lbs perinch of
width (hereinafter referred to as ppiow) and 10.4cm−Kg
(9in−lbs) corresponds to 158Kg/cm
(930 ppiow). International paper for evaluation
A reinforcement material with registration number IPO42081-2 from International Paper Co. was selected. This material is a nonwoven mat consisting of 50% glass and 50% polyester fibers and having a weight of 17.8 kg/m ² (0.524 oz/yd ² ). The relaxed tensile stiffness of this material is measured as follows: Cut a sample 5.1 cm wide x 30.5 cm long (2 in wide x 12 in long) so that the jaws are 20.3 cm (8 in).
Tighten it to the jaws of the Instron tensile tester so that the distance is . Next, the jaw part is 0.05cm/min.
The sample is separated at a speed of 0.3%, that is, the strain of the sample is 0.003. Stop moving the jaw and monitor the load on the sample for 90 minutes. Next, the load reduction curve over time was extrapolated up to 1000 hours using a well-known method, and the relaxed tensile stiffness was 38.6Kg/cm (227ppiow).
get. Prepare PVC plastisol matrix material with the following formulation: Ingredient parts by weight PVC homopolymer resin (molecular weight = 106000) 100 Primary plasticizer 45 Secondary plasticizer 15 Organotin stabilizer 2 Silica gel thickener 1 Instron tensile tester The relaxed tensile stiffness value measured using this method is 12.6 Kg/cm (74 ppiow). Therefore, the ratio of the ppiow value of the two reinforcing layers to the ppiow value of the matrix material is 454:74 or
The ratio is 6.1:1. The sum of the relaxed compressive stiffness of the two layers of reinforcement and matrix material is 89.7Kg/cm ² (528ppiow), and from the curve the bending stiffness corresponding to this value is 1.9cm−Kg
(1.65in-lbs). Therefore, 2.5Kg/cm ²
A flooring structure with a basis weight of (4.6lbs/yd ² ) is
One reinforcing layer is placed above the neutral bending plane of the resulting flooring structure and the other is placed below the neutral bending plane so that the bending stiffness is 1.9 cm-Kg (1.65 in-lbs). should have a critical buckling strain of greater than 0.001 when made from said material. To prove this, flooring structures are experimentally fabricated using a high-velocity air impingement furnace and a reversible roll coater. A layer of reinforcement is placed on top of the matrix material and saturated, then the composite is heated in a furnace to 135
Gel for 2 minutes at a temperature of °C. After cooling, 0.18cm
A second layer of matrix material (0.07 in.) thick is applied to the surface of the gelled sample, and the composite structure is gelled in an oven at 135° C. for 2 minutes.
A third layer of matrix material 0.025 cm thick is added to the gelled substrate and a second layer of reinforcement is placed in the wet plastisol and saturated. After saturation of the mats, the composite structure is
After gelling for 2 minutes at a temperature of 135°C, 193°C
Melt for 2.5 minutes. After cooling, the molten composite structure is pressed between platens at a temperature of 160°C to solidify to a gauge (thickness) of 0.20 cm (0.08 in). pressure 30
A material with a basis weight of 2.48 kg/m ² (4.58 lbs/yd ² ) and a bending stiffness of 1.9 cm-Kg (1.65 in-Kg) as measured by ANSI/ASTM D747 was obtained when held for 2 seconds. In order to confirm its suitability, a sample of the flooring structure is placed on top of a sample piece of particle board subflooring with a dimensional change of 0.001 in an environmental test chamber with high temperature and high humidity similar to the summer environment. The sample of the flooring structure adheres to the subfloor as it is pressed by the furniture. Next, the particle board sample with the flooring structure sample attached is placed in a cold, dry environment for 1000 hours to simulate the seasonal change from summer to winter.
This environmental change causes the particle board sample to shrink. The flooring structure is distorted by the contraction. The ability of a flooring structure to accommodate an applied strain without buckling indicates that it has a critical buckling strain of 0.001 or greater. The proof can also be made by using the measured basis weight, bending stiffness and relaxed compressive stiffness values of the resulting flooring structure and then calculating the critical buckling strain mathematically. Example 2 This example illustrates the construction of a flooring structure using an initial test structure to determine the bending stiffness of selected materials. An expandable polyvinyl chloride (PVC) plastisol matrix having the following composition and viscosity of 1000 cps is prepared in a known manner. Ingredient parts by weight Dispersion grade PVC homopolymer resin, M _w t=
105000 36.00 Dispersion grade PVC homopolymer resin, M _w t=
80400 36.00 Mixed grade PVC homopolymer resin, M _w t=
81000 28.00 Epoxy type plasticizer 1.00 Dioctyl phthalate 50.00 Blowing agent activator 0.20 Stabilizer 0.15 Azodicarbonamide blowing agent 0.66 Feldspar filler 18.00 For use over subfloors with an expected dimensional change of 0.0015 Prepare flooring structures. The target critical buckling strain of this flooring structure is 0.0018
and select. Expected subfloor dimensional change by 0.0015
indicates that the subfloor is of neutral stability. Therefore, a basis weight of 2.2 Kg/m ² (4.1 lbs/yd ² ) is chosen for the sample. Using these data, create a graph as shown in Example 1 (where E is
0.0018, Q is 2.2 Kg/m ² , M _w and K are varied between 0 and 10.4 cm-Kg and 0 and 1700 Kg/cm, respectively). From the obtained curve (Figure 3), the bending stiffness is 0.1
The range of relaxed compressive stiffness values corresponding to 10.4cm−Kg is
25.5 and 127.5Kg/cm. A reinforcing material consisting of 50% glass fiber and 50% polyester fiber with a basis weight of 17.8 g/m ² was selected, and the matrix material was as described above. The relaxed tensile stiffness value of the foam matrix is 7.1 Kg/cm (42 ppiow) and that of the reinforcement is 38.6 Kg/cm (227 ppiow). Therefore,
Since two reinforcement layers are used, the calculated total relaxed tensile stiffness value is 84.3Kg/cm as shown below:
(496ppiow):

[Table] This value is calculated from the curve and ranges from 25.5 to 127.5.
It is within the range of Kg/cm. Furthermore, the sum of the two reinforcing layers is 77.2Kg/cm, which is the measured value of the matrix material 7.1Kg/cm.
approximately 10 times larger than cm (this is the desired relationship). The actual relaxed compressive stiffness of the composite flooring structure is determined experimentally by fabricating test structures according to the following method. A layer of matrix material 0.051 cm thick is applied onto the releasable carrier, and a layer of reinforcing material is placed substantially planar over the wet surface. The reinforcing layer is saturated and the material is gelled at 138° C. for 1.5 minutes. After cooling, a second layer of plastisol matrix material, which will form the core of the final composite flooring structure, is applied to a thickness of 0.074 cm over the gelled substrate. A second layer of reinforcement is placed in the wet plastisol and saturated, after which the material is gelled at 138°C for 1.5 minutes. After cooling the complex, plastisol 0.05
A third coating, cm thick, is placed on top of the gelled surface. This complex was gelled at 138°C for 15 minutes to obtain a thickness of
Obtain a structure of 0.19 cm. When melting at 216℃,
Activate the foam to expand the structure to its final thickness
Make it 0.297cm. This structure is shown in FIG. 4, where R ₁ and R ₂ are reinforcing layers, and S ₁ and S ₂ are the bottom and top surfaces, respectively. The relaxed compressive stiffness value for this structure was determined to be 91.5 Kg/cm (538 ppiow) compared to the expected relaxed tensile stiffness value of 84 Kg/cm (496 ppiow). In Figure 3, the relaxed compression stiffness value is 538lbs/in.
The bending stiffness of the final fabricated sample (91.5Kg/cm) was 3.3in.
-lbs (3.8cm-Kg). However, the bending stiffness of the test flooring structure was measured to be 0.81 in-lbs (0.93 cm-Kg), which is significantly lower than the desired value, thus creating a second composite. The spacing between the reinforcing layers in this sample shown in FIG. 5 is widened to increase bending stiffness. The following steps are essentially the same as those described above.
A layer of matrix material is 0.025 cm on top of the releasable carrier.
The layer of reinforcing material R ₁ is placed approximately flat on the coated surface. When saturation is complete, the material gels for 1 minute at 138°C.
After cooling, a layer of matrix material having a thickness of 0.127 cm is applied onto the gelling material and gelling is performed by heating at 138° C. for 2 minutes. A third coating of plastisol with a thickness of 0.038 cm is then placed on the gelled surface;
A second layer of reinforcing material _R2 is applied to the wet plastisol.
Lay out the layers. After saturation is complete, the material is gelled to obtain a 0.19 cm thick composite flooring structure. The resulting flooring structure is then melted at 216° C. to activate the foam and expand the final flooring structure to a thickness of 0.297 cm between S ₁ and S ₂ . The measured bending stiffness of this flooring structure was 3.79 cm-Kg (3.29 in-lbs). As previously stated, this flooring structure is intended for use over a subfloor with an expected dimensional change of 0.0038. To demonstrate this compatibility, a sample was placed on and attached to the subfloor in its maximum expansion position. The flooring structure sample-subfloor composite was tested for 1000 hours as shown in Example 1.
When subjected to treatments simulating summer-winter seasonal changes, it does not buckle, thus indicating that it has a critical buckling strain greater than 0.0015. The structural stability of this flooring structure was determined by measuring the length of the sample, heating it at 82℃ for 6 hours, and heating it at 23℃ for 50 minutes.
% relative humidity for 1 hour and the length determined by measuring again. The rate of change in length (structural stability) was -0.02%. This is a desirable value indicating that the flooring structure is dimensionally stable. Example 3 The following additional flooring structures were prepared to demonstrate the change in bending stiffness caused by varying the location of the reinforcement within the matrix. The flooring structure of Figure 6 is prepared in a single step identical to that described in Example 2, except that a 0.19 cm thick monolayer of plastisol is placed on a releasable carrier. The expansion gives a thickness of 0.299 cm between surfaces S ₁ and S ₂ , and the measured bending stiffness of this flooring structure is 0.50 cm − Kg.
(0.20 in-lbs). A flooring structure similar to that of FIG. 5 was prepared, except that Manville glass fiber mats with a basis weight of 20 g/m ² were used as R ₁ and R ₂ . The flooring structure had a bending stiffness of 6.52 cm-Kg (5.66 in-lbs) when expanded to a thickness of 0.299 cm. The flooring structure of FIG. 7 is prepared by the method used to prepare the flooring structure of FIG. 5 (Example 2), except that the material is not heated to expand the plastisol. The resulting unfoamed matrix had a diameter of 0.196 cm, and the spacing between R ₁ and R ₂ was 0.137 cm. The bending stiffness of this flooring structure is 1.72cm−Kg
(1.49 in-lbs), which is significantly smaller than the value of 3.79 cm-Kg (3.29 in-lbs) obtained for the flooring structure of FIG. Comparing the results obtained with these flooring structures, there are a few general rules. First, the absence of two reinforcing layers results in extremely low bending stiffness values. Second, comparing Figures 4 and 5, the bending stiffness increases as the distance between reinforcing layers R ₁ and R ₂ increases. The same result is also obtained when replacing relatively lightweight reinforcement with heavier materials. Finally, comparing FIG. 5 and FIG. 7 shows that bending stiffness can also vary depending on the amount of expansion of the matrix material. Example 4 A flooring structure similar to that of Figure 5 of Example 2 is prepared. The difference between the two is that a wear layer of solid PVC prostisol is added to the top surface of the flooring structure. This flooring structure is shown in Figure 8 and is designed for use over a subfloor having a dimensional change of 0.0015, so the target critical buckling strain for this sample is 0.0018. The basis weight of this sample was 2.5Kg/m ² (4.7lbs/
^yd2 ). A graph obtained with these parameters as shown in FIG. 1 is shown in FIG. From this curve,
The relaxed compressive stiffness value range of 2.7 to 134 Kg/cm (160 to 790 lbs/in) is the bending stiffness range of 0.1 to 10.4 cm-Kg.
(in-lbs). Relaxed tensile stiffness value of reinforcement layer 39Kg/cm (227lbs/in),
7.1Kg/cm (42lbs/in) of matrix material and
Using 1.7 Kg/cm (10 lbs/in) of a 0.025 cm thick wear layer, the sum of relaxed tensile stiffness values for the proposed flooring structure is expected to be 89 Kg/in (506 lbs/in). A test flooring structure was made essentially identical to that shown in Example 2, except that it included a wear layer. The 1000 hour relaxed compressive stiffness value of this flooring structure is 97 Kg/cm (572 ppiow). The curve in Figure 9 has a bending stiffness of 3.9 that corresponds to this relaxed compressive stiffness.
Indicates cm-Kg (3.4in-lbs). This value is comparable to that obtained for the flooring structure described in FIG. 5; therefore, the flooring structure of _FIG . ) is placed and a 0.025 cm reinforcing layer is placed below the surface S ₂ . The bending stiffness of this flooring structure was 3.9 cm-Kg (3.40 in-lbs). When this flooring structure was tested as described in Example 1,
No buckling occurred, indicating that it is suitable for use on subfloors with a dimensional change of 0.0015. Furthermore, the structural stability measured as shown in Example 2 is -0.06%, indicating that the present flooring structure is dimensionally stable. Example 5 In this example, the side containing the wear layer is mechanically 0.0127cm
A sample identical to that prepared in Example 4 is prepared except that it is embossed to a depth of . The relaxed compressive stiffness measured for this flooring structure was 93 kg/cm (572 ppiow) compared to the value of 97 kg/cm (572 ppiow) for the non-embossed flooring structure.
Kg/cm (546 ppiow). When this flooring structure was tested in the manner of Example 1, no buckling occurred. This indicates that the predicted dimensional change is suitable for use over a subfloor of 0.0015. The structural stability was -0.04%. Example 6 This example demonstrates the use of a reinforcement with a dissolvable binder that allows the properties of the reinforcement to be altered in situ. A flooring structure is required to be used over a subfloor with a dimensional change of 0.002. Therefore, if the basis weight is 3.5Kg/cm ² (6.0lbs/yd ² ), the target critical buckling strain is 0.0026. Each of these values is E
and Q, and the relaxed compression stiffness K is 0 to 1700.
Kg/cm (0~10000ppiow) and bending stiffness M _w from 0~10.4cm-Kg (0~9in-lbs)
A graph like the one described above is created by changing between . From the curve (not shown), the applicable relaxed compressive stiffness values range from 23 to 102 Kg/cm (135 to
600ppiow). The matrix material used in Example 2 contains 34 parts by weight of butylbenzyl phthalate plasticizer and 5.1 kg/cm
A matrix material having a relaxed tensile stiffness of (30 lbs/in) was selected and used with SAF50/2 reinforcement obtained from Manville. The reinforcement has a measured relaxed tensile stiffness value of 59.8Kg/cm
(352 ppiow) and therefore the expected relaxed compressive stiffness of a flooring structure consisting of two reinforcing layers and said matrix material should be 125 Kg/cm (734 ppiow). However, the reinforcement material is vinyl.
It can be seen that when placed in a matrix, the reinforcing agent loses some of its stiffness contribution due to the softening of the binder in the presence of plasticizers present in the prostisol. A test flooring structure consisting of a matrix material and two layers of reinforcing material is prepared as follows. A plastisol layer as described above containing butyl benzyl phthalate is applied on top of the chrome steel to facilitate softening of the binder.
1 of the reinforcement material SAF50/2 coated to a thickness of 0.038 cm
Place the layer on wet plastisol. When the reinforcement is saturated, the material is gelled and cooled at 204° C. for 1 minute. Thereafter, a layer of plastisol approximately 0.114 cm thick is placed over the gelled material and gelled by heating at 204° C. for 1.5 minutes. A third layer of plastisol 0.038 cm thick is added to the gelled surface and a second layer of SAF50/2 reinforcement is placed within the wet plastisol and saturated. The sample is then heated at 215° C. for 3.5 minutes to melt the product. The resulting flooring structure had a thickness of 0.33 cm and a measured basis weight of 3.2 Kg/m ² . The measured relaxed compressive stiffness value of this flooring structure was 96 Kg/cm, which is significantly lower than the previously calculated sum for this flooring structure. From that curve, the bending stiffness corresponding to the relaxed compressive stiffness value of 96 kg/cm is 8.6 cm-Kg (7.5 in-lbs). The measured bending stiffness of the structure was 8.6 cm-Kg (7.47 in-lbs). The above values are within the expected range. Therefore, to determine its suitability, the samples were subjected to a 1000 hour summer-winter heating season test as described above. No buckling was observed and therefore it is suitable for use on subfloors with a dimensional change of 0.002. Structural stability is +
It was 0.06%. EXAMPLE 7 This example demonstrates how the reinforcement placed within a flooring structure has its relaxed compressive stiffness and therefore the relaxed compressive stiffness and bending stiffness of the flooring structure reduced by external means. This shows that improvements can be made by twisting and cutting. Since a flooring structure is required to be used on a subfloor with a dimensional change of 0.001, the target critical buckling strain is 0.0015 since the basis weight is 1.63Kg/m ² (3.0lbs/yd ² ). do. Draw a graph in the usual way,
From the curve (Figure 10), the range of applicable relaxation compression stiffness values is 26.4 to 131 Kg/cm (155 to 770 ppiow)
It can be seen that it is. The following materials were selected for making the flooring structure:

[Table] Reinforcement material
PVC plastisol 5.1
30 1.55 2.85
These materials are used to create flooring structures with reinforcements of similar weight to the backing material. A 0.038 cm thick plastisol coating is placed on a suitable releasable carrier and the plastisol is saturated with a reinforcing layer of SH-50/10. After saturation of this reinforcement, the material gels for 1 minute at 138°C. A second coating of the same plastisol composition is placed on top of the gelled substrate to a thickness of 0.081 cm. A layer of SH-20/1 reinforcement is placed on the top surface of the plastisol, saturated, and melted at 218° C. to expand the final thickness of the flooring structure to 0.38 cm. After cooling and separating the flooring structure from the removable carrier, the weight was 1.6Kg/
^{A basis weight of 3.0 lbs/yd 2 was} obtained. The flooring structure exhibited a relaxed compressive stiffness of 221 kg/cm (1303 ppiow) and a bending stiffness of 6.34 cm-Kg (5.50 in-lbs). From the above ranges, it is clear that the relaxed compressive bending stiffness of 221 Kg/cm is too high and that this flooring structure does not exhibit the desired critical buckling strain. To reduce the relaxed compressive stiffness of this flooring structure, the sample was inserted into the press upside down so that the surface in contact with the SH-50/10 reinforcement was facing up. A section of plastic material having a prismatically oriented surface with a pattern depth of approximately 0.127 cm is placed over this flooring structure. Pressure is applied to the flooring structure and plastic to press the prismatic surface into the flooring structure to the depth of the prismatic pattern, thereby disrupting the properties of the SH-50/10 reinforcing layer. The relaxed compressive stiffness of the improved sample of the flooring structure is
93Kg/cm (547ppiow) and bending stiffness is 3.7cm−
Kg (3.21cm-lbs). The critical buckling strain of this flooring structure is 0.0015 from the curve, so it is
Indicates suitability for use over subfloors with a dimensional change of 0.001. Furthermore, the structural stability is −0.06
%, indicating that the flooring structure is dimensionally stable. Example 8 This example shows the fabrication of a flooring structure consisting of a wear layer, a decorative layer, expanded plastisol and reinforcement. Use particle board subflooring with a dimensional variation of 0.0025. Therefore, since the basis weight is 3.7Kg/ ^m2 , the target critical buckling strain of the flooring structure is
Set to 0.0036. Create a graph using the usual method and use the curve (Figure 11) to determine the applicable compressive stiffness range.
It can be seen that it is 15.3 to 71.4 Kg/cm (90 to 420 ppiow). The following components are used to create this flooring structure.

[Table] The foamable plastisol composition of Example 2 is applied to a thickness of 0.025 cm on a releasable carrier, and the nonwoven reinforcing layer of Example 1 is placed on the surface of the plastisol and saturated. The material is then gelled at 138° C. for 1 minute and cooled to room temperature. 0.088cm on the surface of the gelled layer
Add a second layer of thick plastisol and heat at 218°C, expand the foamable plastisol to 0.25 cm thick and cool to room temperature. The basis weight of this composite material is
It is 1.62Kg/ ^m2 . A 0.005 cm thick urethane adhesive composition coating is placed on top of the cold flooring structure, and then the coating is
Evaporate the solvent by heating at 121°C. The urethane dressing consists of 10% by weight urethane block copolymer, 88% by weight methyl ethyl ketone and
% by weight of silica gel thickener. The binder/chip makeup layer is made by cutting the filled PVC composition into fine particles and mixing the resulting chips with a binder composition to create a fine particulate material suitable for deposition using a stencil. The composition of the chips is as follows: Ingredients by weight extrusion grade PVC homopolymer 100 Primary phthalate plasticizer 32.5 Epoxy type plasticizer 7.5 Zinc stearate 0.7 Limestone 328 Binder/chip composition is Chip Composition 1225 parts by weight, 250 parts of solution polymerized PVC resin, and primary plasticizer.
79.5 parts of epoxy-type plasticizer and 4.5 parts of stabilizer. Mixing is done using a Houbert mixer equipped with a wire whip and the mixing time is approximately 5 minutes. The 0.25 cm thick foam sample on the previously prepared releasable carrier is punched with a pin roll that drills holes through the structure at 0.32 cm intervals. The cosmetic binder/chip composition is stenciled onto the perforated foam surface forming a layer approximately 0.216 cm thick. The basis weight of this layer is 1.77Kg/ ^m2 . A second reinforcing layer, identical to that used previously, is placed on the surface of the stenciled layer, and a perforated PVC wear layer on a releasable carrier consisting of a mounting agent is placed in contact with the reinforcing layer above. Place on top of the chip layer as shown.
The entire flooring structure is placed in a flat press whose upper plate is heated to 146°C and whose lower plate is water-cooled.
Close the press and apply minimal pressure for 8 seconds to solidify the stenciled decorative layer from 0.216 cm to 0.132 cm thick. Then open the press
Insert the embossing plate preheated to 135°C into the press. Close the press for 8 seconds and remove the flooring structure.
Apply enough pressure to embossing to a depth of 0.04 cm. The composite sample is then removed from the press and cooled to room temperature, after which the upper and lower carrier layers are removed. The relaxed compression stiffness of this composite flooring structure is 61Kg/
cm (358 ppiow). For this measurement, the graph shows that a bending stiffness of 6.3 cm-Kg (5.5 in-lbs) is required. The flooring structure measured 6.33 cm-Kg (5.50 in-lbs), so no modification of the flooring structure is necessary. To evaluate the sample, it was placed in an environmental sample chamber for 1000 hours, where it was subjected to summer-winter environmental changes as described above. As a result, no buckling occurs and the test results therefore indicate that the flooring structure is suitable for use on subfloors with a dimensional change of 0.0025. The present invention is not limited to the matters explained above,
It covers all changes and modifications contemplated by the claims.

[Brief explanation of drawings]

Figures 1A and 1B are flow diagrams of computer programs used to calculate graphs of the relationship between relaxed compressive stiffness and bending stiffness of the present invention. Figure 2 is a graph of Example 1. Figure 3 is a graph of Example 2. FIG. 4 is a sectional view of the flooring structure shown in Example 2.
FIG. 5 is a sectional view of the flooring structure shown in Example 2. 6th
The figure is a sectional view of the flooring structure shown in Example 3. FIG. 7 is a sectional view of the flooring structure shown in Example 3. Figure 8 shows example 4.
A cross-sectional view of the flooring structure shown in FIG. FIG. 9 is a graph of Example 4. FIG. 10 is a graph of Example 7. Figure 11 shows example 8.
graph.

Claims (1)

[Claims] 1. Selecting a dimensional change value of the subfloor that corresponds to a dimensional change of the subfloor on which the elastic loose lay flooring structure is laid; 1.1 to 5.4 Kg/m ² (2 to 10 lbs/yd ² ) Selecting the basis weight of the flooring structure within the range of; bending stiffness value from 0 to 10.4 cm-Kg (0 to 9 in-lbs);
by varying the relaxed compressive stiffness value from 0 to 10,000 lbs/in (0 to 10,000 lbs/in) per unit length width. Step of drawing 0.1 and 10.4 cm− from the critical buckling strain curve
Determining compressive stiffness values in a range defined by minimum and maximum relaxed compressive stiffness values corresponding to bending stiffness values of Kg (0.1 and 9 in-lbs), respectively; The constituent materials, at least one matrix material and at least one reinforcing material, are arranged such that the sum of relaxed compressive stiffness values of all the matrix materials and all the reinforcing materials is within the determined range, and the loose lay selected such that the sum of the relaxed compressive stiffness values of all reinforcing materials used in the flooring structure is greater than the relaxed compressive stiffness values of all matrix materials used in the loose lay flooring structure; And the basis weight is 1.1 to 5.4
Kg/m ² (2 to 10 lbs/yd ² ) of the flooring structure; and the bending stiffness value of the loose lay flooring structure is 0.1.
at least two layers of reinforcing material are disposed within the matrix material such that at least one of the layers of reinforcing material is within the range of 0.1 to 9 inlbs.
by placing a layer above the neutral bending surface of the loose lay flooring structure and placing at least one layer below the neutral bending surface of the loose lay flooring structure;
A method for producing an elastic loose-lay flooring structure, comprising the step of making the critical buckling strain of the loose-lay flooring structure larger than the strain caused by dimensional changes in the subfloor. 2 The bending stiffness value is 1.1~10.4cm-Kg (1~9in
-lbs) and the subfloor has a dimensional change of 0.0015 or more. 3 The bending stiffness value is 3.4~10.4cm-Kg (3~9in
-lbs) and the dimensional change in the subfloor
The method according to claim 2, wherein the value is 0.0030 or more. 4. The ratio of the sum of relaxed compressive stiffness values of the reinforcing material to the sum of relaxed compressive stiffness values of the matrix material is at least 5:1.
The method described in Section 3 or Section 3. 5. The method of claim 4, wherein said ratio is at least 10:1. 6. The method of claim 1, 2 or 3, wherein the plurality of reinforcing material layers have the same composition. 7. The method of claim 1, 2 or 3, wherein the plurality of reinforcing material layers have different compositions. 8 The bending stiffness value of the resulting flooring structure is 1.1~
of at least one of the reinforcing material layers such that the critical buckling strain of the resulting flooring structure is greater than the dimensional change in the subfloor. Claims in which the relaxed compressive stiffness value is processed by embossing, drilling, cutting, bending apart the fibers of the reinforcing layer, using a softening binder, or filling the interstitial spaces of a given area with a saturated material. The method according to item 1, item 2, or item 3. 9. The method of claim 8, wherein said processing is performed on site. 10 The bending stiffness value of the resulting flooring structure is 1.1
~10.4cm-Kg (1-9in-lbs),
and the reinforcing material layer by processing means such as embossing plates or rolls, knives, punches, folding tables or presses such that the critical buckling strain of the resulting flooring structure is greater than the dimensional change of the subfloor. A method according to claim 1, comprising the step of processing at least one layer of. 11 having a basis weight of 1.1 to 5.4 Kg/m ² (2 to 10 lbs/yd ² ) and consisting of a matrix material and at least two reinforcing material layers disposed within the matrix material, at least one of the reinforcing material layers The first layer is loose.
and at least one layer is above the neutral bending plane of the lay flooring structure, and at least one layer is below the neutral bending plane, and the sum of the relaxed compressive stiffness values of the plurality of reinforcing layers is greater than the relaxed compressive stiffness value of the matrix material. and 0.1~10.4cm
- an elasticity characterized by having a bending stiffness of between 0.1 and 9 in-lbs and a critical buckling strain greater than the strain due to dimensional changes in the subfloor overlying the loose-lay flooring structure; Loose lay flooring structures. 12 The bending stiffness value is 1.1 to 10.4 cm-Kg (1 to
12. The resilient loose lay flooring structure of claim 11, wherein the subfloor has a dimensional change of 0.0015 or more. 13 The bending stiffness value is 3.4 to 10.4 cm-Kg (3 to
13. The resilient loose lay flooring structure of claim 12, wherein the dimensional change of the subfloor is within the range of 9 in-lbs. 14. Claim 11, wherein the ratio of the sum of relaxed compressive stiffness values of said reinforcing material to the sum of relaxed compressive stiffness values of said matrix material is at least 5:1,
Elastic loose lay flooring structure according to clause 12 or 13. 15. The resilient loose lay flooring structure of claim 14, wherein said ratio is at least 10:1. 16. Claim 11, 12 or 1, wherein the plurality of reinforcing material layers have the same composition.
The elastic loose lay flooring structure according to item 3. 17. Claims 11, 12 or 1, wherein the plurality of reinforcing material layers have different compositions.
The elastic loose lay flooring structure according to item 3. 18 The bending stiffness value of the resulting flooring structure is 1.1
~10.4cm-Kg (1-9in-lbs),
and the relaxed compressive stiffness value of at least one of said reinforcing material layers is determined by embossing, drilling, cutting, fibers of the reinforcing layer such that the critical buckling strain of the resulting flooring structure is greater than the dimensional change of the subfloor. Claims 11 and 12 are processed by bending and breaking apart, using a softening binder, or filling interstitial spaces in predetermined areas with a saturated material.
14. The elastic loose lay flooring structure according to item 1 or 13. 19. The resilient loose lay flooring structure of claim 18, wherein said processing is performed on site.