JP2523523B2 - Gypsum board with matte side of fiber - Google Patents

Description

The present invention relates to improved structural components for use in fire resistant applications, such as elevator shafts and hollow shaft wall assemblies of the type used to construct stairwells in buildings. . More particularly, the present invention relates to gypsum board having a matte surface of fibers with improved fire resistance and its use in various structural applications.

Although the present invention is first described with respect to its use in a shaft wall assembly, its use has broader applicability, as will be described below.

Shaft wall assemblies are typically used to line shafts that typically extend through multiple floors in a building. An example of such a shaft is
Elevator shafts, air shafts, and stairwells. The widely used shaft wall assembly is
It consists of a panel of gypsum board with a paper side supported in place from a metal skeleton. The assembly design is
The panel of gypsum board, which includes the panel lining the shaft and comprising the surface thereof, has one side, namely:
It is such that it can be installed away from the enclosed shaft. Such an assembly is configured in place by an operator supported on the floor through which the shaft extends.
This eliminates the need to construct a scaffolding or other support structure inside the operator within the shaft.

It is essential that the shaft wall assembly have certain properties in order to be commercially acceptable. For example, it is particularly important that the gypsum board used in the shaft wall assembly have a fire resistant quality that allows the assembly utilizing it to meet the strict fire protection regulations of national law. Still further, in elevators, the gypsum board panels used to line the elevator shafts can withstand the considerable forces imparted to them by the compressed air generated by moving the elevator boxes up and down. It should be borne in mind that it must be possible. Such a force is 1.1 kg / cm ³
May include the addition of air pressures as high as (15psi).
Soundproofing properties are also desirable at the shaft wall.

The present invention relates to improved shaft wall assemblies and also to such assemblies, as well as gypsum boards having improved refractory fiber matte surfaces that can be used in other types of structural applications.

Currently used shaft wall assemblies also include therein a structural gypsum board consisting of a set gypsum core sandwiched between paper cover sheets. The shaft wall assembly currently in widespread use consists of a metal skeleton that supports multiple plies of a plasterboard panel. Such an assembly is detailed below. Briefly, one wall of the assembly, which encloses a shaft that is itself open, is a pair of horizontally arranged metal J-tracks (J
-Track) (one of the tracks in the pair is fastened to the ceiling and the other of the pair is fastened to the floor)
And a plurality of vertically spaced metal "I studs (I") frictionally retained within the J track.
-Stud) ". Gypsum board panels for lining the enclosed shaft are J track and I
Supported by studs. One or more face material layers of the gypsum board panel are fastened to J-tracks and I-studs on the side of the opposing metal assembly of the enclosed shaft. By increasing the layer of face material and / or the thickness of the gypsum board, the fire resistance of the assembly can be improved.

Gypsum board cores used in such commercial shaft wall assemblies usually contain chopped glass fibers as an additive to improve the fire resistance of the gypsum board.
However, in order to achieve the required flame rating for assembly, such gypsum plates have a relatively high density. This increases transportation costs and makes installation more difficult. Moreover, the amount of chopped glass fibers in the core is considerable and adds to the cost of the gypsum board. Moreover, sheets with a paper side, when exposed to the heat of a flame, produce smoke and ultimately burn.

A shaft, in which a sheet of flammable paper face material is excluded, instead a glass fiber mat or chopped glass fibers is embedded in the plasterboard and covered by the solidified plaster of the surface layer of the plasterboard, Gypsum plates for use in wall assemblies are described in US Pat. No. 4,195,110 and US Pat. No. 4,265,979. It is believed that the gypsum board described in these patents has never been used commercially for a variety of reasons.

U.S. Pat. No. 4,195,110 discloses a gypsum board formed from a set product of a gypsum slurry sandwiched between two surface layers of a set gypsum composition containing glass fibers. The glass fibers can be in the form of rovings, continuous strand mats or chopped glass. The single example of gypsum board that is the subject of this patent exhibits a relatively high density, ie, 833 kg / m ³ (53 pounds / cubic foot) of board. This is about 0.45-0.91 more than the conventional paper-faced plates referred to in U.S. Pat.No. 4,195,110.
Only 1 kg (1-2 lbs) higher. This patent also discloses that the subject matter of the patent, the plate, has improved flexural strength and does not produce smoke when exposed to the heat of a flame.

U.S. Pat. No. 4,265,979 discloses a gypsum board having concentrated chopped glass fibers on the surface portion of the gypsum board. In making these plates, a mixture of chopped glass fibers and gypsum is hydrated and formed into sheets. Before the sheet sets, the "conventional" gypsum slurry is sandwiched between unset sheets and the resulting three layer composite is compacted and dried. This patent also
"Highly fire and smoke resistant" and "relatively light weight"
In addition to that, it has been disclosed to have improved flexural strength over conventional paper faced plates. As is apparent from this disclosure, this patent considers a relatively dense gypsum board, and the surface sheet has a density of 1298 kg.
It is reported to be / m ³ (81 pounds / cubic foot).

Each fabrication of the gypsum board that is the subject of the aforementioned patent requires special handling of the glass-containing surface layers that sandwich the core, eliminating the fabrication of gypsum board with conventional gypsum board making equipment.

In accordance with the present invention, there is provided an improved shaft wall assembly including a gypsum-based structural component and also a gypsum board having improved fire resistance.

The present invention comprises a solidified core comprising at least about 85% by weight gypsum dihydrate and about 0.03 to about 0.3% by weight glass fiber, and a porous glass mat facing at least one side of said core. Wherein the core has a density of less than 753 kg / m ³ (47 pounds / cubic foot), the glass mat has an outer surface that is substantially free of solidified gypsum from the core, and the gypsum board is 1.59 cm ( A at a thickness of 5/8 inch)
Provided is a gypsum board having a surface of a glass mat, which is characterized by achieving a flame rating of at least 1 hour according to STM E-119.

Further, the invention comprises a refractory skeleton and a gypsum board having a surface of glass mat supported by the skeleton, wherein the gypsum board is at least about 85% by weight gypsum dihydrate and about 0.03 to about 0.3. It comprises a solidified core containing, by weight, glass fibers and a porous glass mat facing at least one side of the core, the core having a density of less than 753 kg / m ³ (47 pounds / cubic foot). The glass mat has an outer surface substantially free of solidified gypsum from the core, and the gypsum board has a thickness of 1.59 cm (5/8 inch) A
A shaft wall assembly is provided which is characterized by achieving a flame rating of at least 1 hour according to STM E-119.

Still further, the present invention provides a shaft wall assembly comprising a refractory frame and a gypsum plate supported by the frame, the gypsum plate having fiber mat faces and spaced horizontally from one another. A fireproof track and a fireproof stud arranged in a vertical direction located between the tracks, and including a panel on the side of the assembly and a panel on the opposite side of the assembly. At least said shaft side panel faces a solidified core comprising at least about 85% by weight gypsum dihydrate and about 0.03 to about 0.3% by weight glass fiber, and at least one side of said core. consists of a porous Garasumatsuto, the core has a density of less than 753kg / m ³ (47 pounds / cubic feet), said Garasumatsuto solidifies from the core gypsum An outer surface which is substantially free, gypsum board A in the thickness of 1.59 cm (5/8 inch)
A shaft wall assembly comprising a plasterboard having a face of glass mat that achieves a flame rating of at least 1 hour according to STM E-119.

As will be described below, the improved heat resistant board of the present invention can be used to great advantage in shaft wall assemblies, as described above, and, in addition, the board is a conventional gypsum board having a paper surface. It can be used very advantageously in the many and various applications in which it is used. Such applications include, for example, the use of plates as structural components such as walls, ceilings, partitions and the like.

The advantages resulting from the provision of the improved refractory plate of the present invention are numerous and significant. For example, it provides the fabrication of gypsum-based products with refractory properties that have hitherto not been obtained in gypsum plates of commonly used thickness and of relatively low weight. Further, such advantages are achieved by using existing plaster making equipment to make the board of the present invention.

To describe an improved gypsum board that can be used in the improved shaft wall assembly of the present invention, it includes a set gypsum core having a matte surface of fibers. Gypsum cores are basically the molds used in gypsum structural products known as gypsum wallboards, dry walls, gypsum boards and plaster canopies. The core of such products is water-powdered anhydrous calcium sulfate or calcium sulfate hemihydrate (CaSO ₄ 1/2
H ₂ O), also known as calcined gypsum, and then hydrate this mixture, ie solidify it to give calcium sulfate dihydrate (CaSO ₄ · 2H ₂ O), a relatively hard material , Is formed. The gypsum core will generally consist of at least 85% by weight solidified gypsum.

The composition used to make the set gypsum core is
It may include any of the components, such as those commonly included in plaster canopies. Examples of such components include setting accelerators, blowing agents, and dispersants.

The set gypsum core has a matte side of fiber. The fiber mat is sufficiently porous to allow water in the aqueous gypsum slurry used to make the gypsum core to evaporate through it. As will be explained in more detail below, gypsum board having a matte side of fibers can be efficiently made by forming an aqueous gypsum slurry containing excess water and placing a mat of fibers thereon. After the calcined gypsum solidifies, excess water evaporates through the porous mat, which evaporation is accelerated by heating.

The fiber mat is made of a material capable of forming a strong bond with the solidified gypsum that makes up the core. Examples of such materials include mineral type materials such as glass fibers and fibers of synthetic resins. The mat can consist of continuous or discrete strands or fibers, and the morphology can be woven or non-woven. Nonwoven mats, such as mats of chopped strands and mats of continuous strands, can be used satisfactorily, and they are cheaper than woven materials. The strands of such a mat are joined together by a suitable adhesive. The mat can have a range of thicknesses, for example from about 0.38 to about
1.0 mm (about 15 to about 40 mils), about 0.64 to about 0.89 mm
A thickness (about 25 to about 35 mils) is preferred. Mats of the aforementioned fibers are known and are commercially available in many forms.

A preferred fiber mat is a glass fiber mat consisting of glass fibers oriented in an irregular pattern and bound together with a resin binder. This type of fiberglass mat is commercially available, for example under the trademark DURA.
−GLASS (Manville Building Materials Corporatio
n) and those sold by ELK Corporation such as BUR or Single Matte.

The improvement can be achieved by the use of a gypsum core, the only surface of which faces the mat of fibers described herein, but it is preferred that both sides of the core have substantially identical faces of fibrous material. If the surface of the core has surfaces of materials with different coefficients of expansion, the core will tend to warp. Fibrous mat−faced gypsum boa
rd) and methods of making it are known, for example, as described in Canadian Patent No. 993,779 and US Patent No. 3,993,822.

In accordance with the invention, a gypsum board consisting of a solidified gypsum core having a matte surface of fibers, preferably a gypsum board consisting of a solidified gypsum core sandwiched between two porous glass mats, Used as one component of a shaft wall assembly or similar assembly. In such applications, a board having a matte side of fibers can be advantageously used in place of a board of gypsum core having a conventional paper side or a liner panel of a shaft, the core generally being a refractory additive. including. A shaft wall assembly including a plate having a matte side of fiber has improved flame resistance with respect to an assembly including a plate of gypsum core having a paper side. As mentioned above, this type of assembly generally includes metal frames or columns for supporting gypsum panels, which form the walls of elevator shafts, stairwells, air shafts, and the like. An example of such an assembly is U.S. Pat.
335, U.S. Pat.No. 4,324,082 and U.S. Pat.
No. 212. The matte faced plate of fibers can be used in the liner panels of the assemblies and shafts described in the aforementioned patents, and / or as panels of face material, as described herein.

In these types of applications, where fire resistance is considered important, the core of the gypsum board with the matte side of the fiber is of a solidified gypsum composition that maintains its integrity when exposed to the heat of a flame. Includes one or more additives that improve performance. Examples of materials reported to be effective for improving the fire resistance of gypsum products are mineral fibers such as glass fibers, asbestos fibers, and calcium sulfate whiskers. One or a mixture of two or more of such fibers can be used. Other typical materials known for use in conventional refractory gypsum boards are unexpanded vermiculite, clay, colloidal silica and colloidal alumina. Typically, favourite fibers, especially glass fibers, are used in admixture with one or more of the aforementioned typical materials. For example,
Assigned to the same assignee as the present invention, U.S. Pat.
See 173.

Preferred materials for use in improving the fire resistance of plasterboard having a matte side of fiber are described, for example, in the aforementioned U.S. Pat.No. 3,616,173, the disclosure of which is incorporated herein by reference for glass fibers. Like,
Made of chopped glass fiber. Briefly, the glass fibers are a type of drawn texitile glass fibers manufactured as individual continuous filaments and having a diameter of about 0.0051 to 0.0254 mm (0.0002 to 0.001 inch). The individual filaments are usually grouped into strands, the filaments having a relatively weakly bound material, such as starch or other water-softenable or water-soluble coating material coated thereon. The binding material helps prevent wear between the filaments of several groups of each strand. Prior to adding the loosely bonded textile fibers to the core composition, the strands were e.g.
Cut to a short length of 0.32 cm to 2.54 cm (1/8 inch to 1 inch). Once added to the aqueous slurry composition used to make the core, the binder or coating material dissolves and the strands separate into individual fibers that are evenly distributed throughout the slurry when the slurry is mixed. It will be distributed.

The presence of mineral fibers in the core of a plasterboard having a matte side of fibers according to the invention results in a product with unusually high refractory properties. For example, the presence of a predetermined amount of chopped glass fibers in the core of a plasterboard having a matte side of the fiber of a predetermined thickness results in a similar amount of glass fibers and a similar thickness in the core. Provided is a product having fire resistance properties significantly superior to that of a conventional paper sided plasterboard. The effects obtained from this development are significantly significant and can be exploited in a number of different ways if desired. For example, this development can be used to produce plasterboard with the face of a glass mat, which has a lower density than that of glass-fiber-containing plasterboard with the face of conventional paper, without sacrificing fire resistance. . Similarly, significantly lower amounts of glass fibers can be used in a plate having a face of glass mat without sacrificing fire resistance.

The amount of glass fibers in the core should be at least about 0.03% by weight, and over a wide range, for example,
It can range from about 0.03 to about 0.3 wt% based on the total weight of the components that make up the core, i.e., the total weight of the components prior to combining with water to prepare the aqueous slurry used to form the core. . In the preferred form, the amount of glass fibers comprises from about 0.07 to about 0.2% by weight.

A plate core with a matte surface of fibers for use in refractory applications can be made to a desired value of density according to available techniques. A relatively thick plate, for example
For plates over 1 inch, core densities can be as low as 35 pounds per cubic foot (560.7 kg / m ³ ). In plates having a relatively low density paper surface, the bond between the gypsum core and the paper surface is generally unsatisfactory due to the low density of the core. Preferably,
Core density is approximately 752.9 kg / m ³ (47 pounds / cubic foot)
Should not be exceeded. About 640.7kg / m ³ (40 lb / cubic foot) to about 752.9kg / m ³ (47 lb / cubic foot)
Within the range of density is believed to be the most widely used. About 656.8 kg / m ³ (41 pounds / cubic foot) to about 720.
Plates having 8 kg / m ³ (45 lbs / cubic foot) have a particularly good combination of properties including excellent fire resistance and relatively low weight.

Another aspect of the invention comprises a gypsum board having a surface of a glass mat having a core of calcium sulphate solidification product and at least about 0.03% by weight of glass fiber, said core having a surface area of about 656.8 kg / m ^3. Pounds / cubic feet) to about 75
It has a density in the range of 2.9 kg / m ³ (47 pounds per cubic foot), and the amount and nature of the components that make up the core are such that when the core has a thickness of about 2.54 cm (1 inch), .
The shaft wall test area, including the 54 cm (1 inch) core, has a fire endurance rating of at least about 3 hours.
rating). The method for evaluating the flame endurance rating is detailed below in the Examples section.

Also, as long as the density of the core falls within the above range, as long as the core contains the components listed above, and the particular core formulation contained is a 2.54 cm (1 inch) plate portion
It is understood that gypsum board having a face of glass mat having a thickness of less than or greater than 1 inch (2.54 cm) is included within the scope of the present invention, so long as the resulting graded board has a density. Should. 2.54 cm
Plates having a thickness less than (1 inch) are as good as 2.54 cm (1 inch) plates even when the density of the cores and the components used to form the cores and their amounts are the same. It will be appreciated that there is generally no fire resistance. On the other hand, a plate having a thickness greater than 2.54 cm (1 inch) has a core of 2.54 cm (1 inch), even if the density of the core and the components and the amounts used to form the core are the same. It will generally have better fire resistance.

Approximately 2.54 cm (1 inch) for use as a shaft liner panel in a shaft wall assembly
Thickness of about 656.8 kg / m ³ (41 lb / ft ³ ) to about 752.9 kg / m ³ (47 lb / ft 3), preferably greater than about 720.8 kg / m ³ (45 lb / ft 3). It is recommended to use gypsum board with the surface of the glass mat, prepared from a formulation having no core density and containing about 0.03 to about 0.3% by weight glass fiber.
In such an assembly, the surface of the glass mat of the gypsum board facilitates conducting heat away from the frame supporting the board, thus leading to improved flame endurance of the assembly.

A plasterboard having a face of glass mat, as described herein and also including such a plate having a glass fiber-containing core, also comprises one or two of the plies of the layer of face material that make up the shaft wall assembly. In the above, it can be used as a panel of plates. Moreover, this board can be used to advantage in applications of the type in which conventional refractory gypsum boards are commonly used. Plates have widely used thicknesses, eg 1.27 cm (1/2 inch), 1.59 cm (5/8 inch), 1.91
It can be manufactured in thicknesses of cm (3/4 inch) and 2.54 cm (1 inch).

Advantages are obtained when using a form of plate in which at least one of the surfaces of the plate has gypsum set over a substantial area thereof. This solidified gypsum appears to promote heat dissipation as heat is consumed as it expels the solidified gypsum water.

Both refractory additives and refractory additives may be included in the core in applications where both fire resistance and improved weathering properties are desired.

The use of certain refractory additives can reduce the fire resistance of the board. When this happens, such a reduction in fire resistance can be offset by making the core more dense. In the case of this type, ASTM E-11
To provide a 1.58 cm (5/8 inch) plate that achieves a 1 hour flame rating according to 9, the core density is about 768.9 kg / m
³ to be (48 lbs / cubic foot) to about 881.0kg / m ³ (55 lb / cubic foot) is recommended.

A preferred means of imparting water resistance to the gypsum core is to prepare one or more additives that improve the ability of the set gypsum composition to resist degradation by water, eg, resist dissolution, to make the core. It is to be included in the gypsum composition used for. In a preferred form, the water resistance of the core is
It is such that it absorbs less than 10% water, preferably less than about 7.5%, and most preferably less than 5% when tested according to ASTM Method C-473 with only the lip exposed.

The fiber mats used in the present invention have a water resistance that is substantially better than that of conventional paper surfaces on gypsum wallboards or canopies. Nevertheless, evaluations have shown that the bond between the fiber mat and the gypsum core can degrade relatively rapidly under the influence of water. For example, samples exposed outdoors showed loosening in the face of the glass fiber within 1-2 months. In contrast, evaluation of a water resistant gypsum core with a matte side of fiber according to the present invention has shown that the bond between the mat and the core resists water degradation for an infinite period of time.

Examples of materials reported to be effective in improving the water resistance of gypsum products are: poly (vinyl alcohol) with small amounts of poly (vinyl acetate); resin acid Metal salts; waxes or asphalts or mixtures thereof; waxes and / or asphalts and also cornflower and potassium permanganate; water-insoluble thermoplastic organic materials,
For example, petroleum and naturally asphalt, coal tar, and thermoplastic synthetic resins, such as poly (vinyl acetate), poly (vinyl chloride), and copolymers of vinyl acetate and acrylic resins; mixtures of metal resin soaps; water-soluble alkalis. Earth metal salts; and residual fuel oil; petroleum wax in the form of emulsion and residual fuel oil, pine tar (pineta)
r) or coal tar; a mixture consisting of a mixture of residual fuel oil and rosin; aromatic isocyanates and diisocyanates; organohydrogenpolysiloxanes; potassium sulfate, alkali metal and alkali metal aluminates, and Portland cements. Wax-asphalt emulsions with or without such materials; oil-soluble, water-dispersible emulsifiers added to blends of molten wax and asphalt, and containing alkali sulfonates of polyarylmethylene condensation products as dispersants A wax emulsion prepared by mixing a solution of casein with it.

A preferred material for use in improving the water resistance of gypsum cores consists of wax-asphalt emulsions, and these species are commercially available. The wax of the emulsion is preferably paraffin or a microcrystalline wax, although other waxes can be used. Asphalt generally must have a softening point of about 46 ° C (115 ° F) as determined by the ring and ball method. The total amount of wax and asphalt in the aqueous emulsion is generally about 50-60% by weight of the aqueous emulsion.
And the weight ratio of asphalt to wax is about 1: 1.
~ About 10 to 1. Various methods of preparing wax-asphalt emulsions are known, for example, US Pat. No. 3,935,021 (DRGre, assigned to the same assignee as the present application.
ve and EDO'Neill). Commercially available wax-asphalt emulsions that can be used in the compositions of the present invention include United States Gypsum Company (Wax Emulsion), Monsei Products (No. 52 Emulsion) and Douglas Oil Company. (Docal No.1034). The amount of wax-asphalt emulsion used is about 3 to about 10% by weight, preferably about 5 to about 7% by weight, based on the total weight of the components of the composition used to make the set gypsum core. Yes, said component comprises the water of the wax-asphalt emulsion, but not the additional amount of water added to the gypsum composition to form the aqueous slurry.

Particularly preferred materials for use in improving the water resistance of the gypsum core are materials of the type described above, namely:
It consists of a mixture of poly (vinyl alcohol) and wax-asphalt emulsion. The use of such additives to improve the water resistance of gypsum products is described in the aforementioned US Pat. No. 3,935,021.

The poly (vinyl alcohol) source is preferably a substantially fully hydrolyzed form of poly (vinyl acetate),
That is, polyvinyl acetate that is approximately 97-100% hydrolyzed. Poly (vinyl alcohol) is insoluble in cold water and at high temperatures, for example about 60 to about 96 ° C (about 140 to about 205 ° C).
F) Must be soluble in water. Generally, 20 ° C
A 4% by weight solution of poly (vinyl alcohol) in 1 has a viscosity of about 25-70 cp as determined by the Hoeppler falling ball method. Commercially available poly (vinyl alcohol) for use in the compositions of the present invention
Is a trademark of DuPont "Elvanol" and Monsanto
It is sold by the company under the trademark "Gelvatol". Examples of such products are Elvanol, grades 71-30, 72-60 and 70-05, and Gelvatol, grades 1-90, 3-91, 1
-60 and 3-60. Air Products Corporation also sells this product as WS-42.

The amount of poly (vinyl alcohol) and wax-asphalt emulsion used should be at least about 0.05% and about 2% by weight, respectively. The preferred amounts of poly (vinyl alcohol) and wax-asphalt emulsions are about 0.15 to about 0.4% by weight and about 3.0 to about 3.0%, respectively.
It is about 5.0% by weight.

Unless otherwise stated, the term "wt%", as used herein, is the weight percentage based on the total weight of the components of the composition used in making the set gypsum core,
The components include water of the wax-asphalt emulsion or water associated with other additives, but not the additional amount of water added to the gypsum composition to form an aqueous slurry.

The plasterboard fiber mats described herein are also a significant factor in reducing sound transmission, which can be utilized in elevator shaft wall assemblies, as well as other structural assemblies where reduced sound transmission is desired. This is a desirable property. For example, in a partition assembly in which a board having a matte side of fibers provides a supporting surface for a layer of face material secured to it by adhesive, the adhesive interface between the layer of board face material is acoustic. It provides an elastic connection that tends to dissipate the energy of the, thus providing a sound resistant assembly.

An attractive feature of the present invention is that gypsum board having a matte surface of fibers can be made using existing wallboard manufacturing lines, such as the one shown somewhat diagrammatically in FIG. Is. In the conventional method, the dry ingredients (not shown) used when forming the gypsum core are premixed,
It is then fed into a type of mixer commonly called a pin mixer 2. Water and other liquid ingredients (not shown) used to make the core are weighed into the pin mixer 2 where they are combined with the dry ingredients to form an aqueous gypsum slurry. Foam is generally added to the slurry in the pin mixer to control the density of the resulting core. Slurry 4 is dispersed through one or more outlets in the bottom of mixer 2 onto a moving sheet of fiber mat 6. The sheet of fiber mat 6 is of infinite length and is supplied from a roll of mat (not shown).

As is commonly practiced in the fabrication of conventional paper-faced plasterboard, two opposing edge portions of a mat of fibers 6 are flexed progressively upward from the mean plane of the mat 6, and then A coating is provided on the edges of the plate 40 that is folded back inward at the edge. In FIG.
The gradual flexure and shaping of the edges of this mat 6 is shown only for the edges on one side of the mat, and the usual guides normally used for this purpose have been omitted from this drawing. FIG. 7 shows the lip of the set gypsum core 42 covered by the lip portion 6A overlying the mat 6. In addition, FIG. 7 shows the markings of the mat 6 (ncore
mark) 10 and 10A, these indicia of inscriptions permit the formation of good edges and flat surfaces. The nick marks 10 and 10A are made by an ordinary knurling wheel 12. The advantage of using the preferred form of glass fiber mat is that it can be nicked and edged like a plain paper surface.

Another sheet of mat 16 of fibers is fed from a roll (not shown) onto the top of the slurry 4 to form the surface of the solidified gypsum core 42 formed from the slurry 2.
The slurry is sandwiched between a sheet of moving fiber mats. The mats 6 and 16 sandwich the slurry 4 therebetween and enter the nip between the upper and lower forming or shaping rolls 18 and 20 and are subsequently received on a conveyor belt 22.
Conventional edge guides, such as those shown at 24, shape and maintain the edge of the composite until the gypsum has fully set and retained its shape. Eventually, a plate of continuous length was cut and treated by further exposure to heat,
Accelerating the drying of the board by increasing the evaporation rate of excess water in the gypsum slurry.

Referring to FIG. 7, the solidified gypsum of the core 42 satisfactorily forms a bond with the mat and a bond between the lip of the overlying mat 16 and the overlapping lip 6A of the underlying mat 6. And thus using a bond improver (bon, improver) in the slurry,
Alternatively, it has been observed to be unnecessary to use a lip paste to form the aforementioned bond.

The preferred form of mats 6 and 16 shown in FIGS. 2 and 3 comprises glass fiber filaments 30 oriented in an irregular pattern and bonded together with a resin binder (not shown).

A preferred form of gypsum board 40 having a matte surface of glass fiber is shown in FIGS. It is the solidified gypsum of the core 42 that penetrates substantially through the thickness of the mat 6 over a portion of its substantial area, and the solidified gypsum of the core 42 partially penetrates the mat 16, thus The surface of the gypsum is substantially free of solidified gypsum. The plaster-free surface of mat 16 has a high degree of texture (high texture, as seen in FIG. 8).
ly textured), and as long as it contains many interstices into which the adhesive composition can flow and bond, provides a very good substrate for adhering the overlying components.

As used herein, the phrase "solidified gypsum has substantially penetrated" means that the solidified gypsum of the core extends from the mat surface adjacent to the core to the outer mat surface and the glass line outline solidifies. Means coating the outer glass fibers with a thin film of hardened gypsum to the extent that it is visible through a thin film of plaster of gypsum. The phrase "over a substantial area of the exterior surface" as used herein means that about 30 to about 75% of the exterior surface area of the mat is substantially impregnated with gypsum. Preferably, about 45 to about 55% of the outer surface area of the mat is substantially impregnated with gypsum. The gypsum-coated surface of this preferred embodiment of the gypsum board therefore has a roughened or textured appearance; it does not consist of a smooth continuous coating of set gypsum. This preferred form of gypsum board can be formed with a relatively small amount of gypsum slurry deposited on the underlying support surface,
This minimizes the need to clean the surface.

The need for such cleaning requires that the slurry be partially passed through the underlying mat of fibers, for example, about its thickness.
Up to 50% can be substantially avoided by adjusting the viscosity of the slurry to penetrate. Thus, this preferred form of gypsum board has a surface with two gypsum-free fiber sides.

Fabrication of the aforementioned preferred forms of gypsum board can be accomplished by adjusting the viscosity of the slurry in such a way that the aqueous slurry of calcined gypsum penetrates the underlying mat and the overlying mat to the desired degree. it can. In making each of the preferred forms of plasterboard described above, the viscosity of the slurry should be such that the slurry penetrates about 10-50% of the thickness of the overlying mat over its entire surface area.

The recommended means of adjusting the viscosity of the slurry is to add viscosity modifiers to it. Such viscosity modifiers are known in the gypsum board manufacturing field. The preferred viscosity modifier is paper fiber. Examples of other viscosity modifiers that can be used are cellulosic thickners, bentonites and starches.

The particular viscosity values used in manufacturing operations can vary from one application to the next depending on the porosity of the mat and the desired penetration of the slurry. Therefore, the viscosity value is best determined experimentally for a particular application.

When using the preferred form of glass fiber mat, as described above, to produce the preferred form of gypsum board, development studies have shown that a slurry of gypsum having a viscosity in the range of about 5000-7000 cp is used. It was shown that satisfactory results can be achieved by using it. As used herein, viscosity value refers to Brookfield viscosity measured using a No. 3 paddle at a temperature of 21 ° C (71 ° F) at 10 rpm. It should be understood that the amount of viscosity modifier added to the slurry to obtain the desired viscosity will vary depending on the particular viscosity modifier used and the specific viscosity desired.

Fabrication of a core of predetermined density can be carried out using known techniques, for example by introducing the appropriate amount of foam into the aqueous gypsum slurry used to form the core. In refractory applications that utilize fiber mats that are lighter in weight than conventional paper face materials, the weight advantage achievable by using gypsum board with fiber mat faces is obtained. For example, the weight of a paper face material that is widely used in the fabrication of conventional plaster canopies is about 0.596 kg / m ² board (120 lbs / 1000 square feet board), but glass fiber for use in the present invention. The preferred form weight of the mat is 0.195 kg / m ² board (40 pounds / 1000 square foot board).

Referring to FIGS. 10, 11 and 12, there is shown one example of a typical commercial shaft wall assembly in which the plasterboard having the matte face of fiber described herein may be used. Shaft wall assembly 100 is a ceiling and floor mounted J to support gypsum panel.
It consists of a metal skeleton consisting of truck 101 and I-stud 103. The J-track 101 is fastened by bolts 104 to the ceiling C and to the floor F adjacent to the shaft S to be enclosed. Each J-track has a short leg 106 and a long leg 107, the long leg 107 lying substantially flush with the shaft side 120 of the shaft wall assembly 100. I-stud 103
Is located vertically between the J-tracks 101 on the ceiling and floor. The ends of the I-stud 103 are friction fit between the J-track feet 106 and 107 on the ceiling and floor. Generally described, the I-stud 103 consists of flanges 109 and 109 'that extend vertically from an intermediate portion 114 of the body.

The tab T is cut and bent from the metal plate from which the I-stud is made. The formation of such a tab is
Form a hole 140 in the portion 114 of the body of the I-stud.

A gypsum panel 110, which comprises the shaft liner panel of the assembly, is located between the J-track feet 106 and 107, the vertical edge of which is a friction fit between the tab T of the I-stud and the flange 109. Has been done. The layer of face material of the panel 112 of gypsum board is fastened to the face side of the shaft wall assembly 130 by screw fasteners 113. Although two face material layers or plies of a gypsum board panel are illustrated, it should be understood that additional face material layers of the gypsum board may be applied as desired. The layer of plasterboard face material can also be applied to the shaft side of the assembly in the stairwell, where a finished wall surface is desired.

In the embodiment shown in FIGS. 10-12, gypsum board panel 110 (assembly shaft liner panel).
Is intended to be shown as consisting of a core of gypsum sandwiched between glass mats and having a surface of glass mats as described herein, and panel 112 of the gypsum board (of the shaft of the assembly). Liner panel)
Is intended to be shown as consisting of a gypsum core sandwiched between papers and having a glass matte surface.
Another exemplary embodiment involves the use of a panel of gypsum cores having only one side with the matte side of the fiber in the assembly and being oriented, the "matt" facing the shaft. , And gypsum boards with matte surfaces of fibers have been used in one or more plies of layers of facing material.

EXAMPLES In the following examples, plasterboard with a matte surface of glass fiber which falls within the scope of the invention was installed and tested for flame endurance in the test section of a conventional shaft wall assembly of the general type shown in the drawings. Was evaluated.

The metal components of the metal framework of the shaft wall are based on Georgia Pacif
ic Corporation) and made from 25 gauge hot dip galvanized steel. The component has four J-tracks with a 6.35 cm (2.5 in) wide base and from which 5.72 cm (2.25 in) and 2.54 cm (1 in) feet extend, and a 3.81 cm (1.5 in) wide. ) And a depth of S 6.35 cm (2.5 inches) of a single I stud. The J-track was fastened by bolts to the horizontal and vertical edges of the masonry framing structure. For convenience, the side of the assembly defined by the mean plane of the long legs of the J track is hereinafter referred to as the "shaft side"; the side of the assembly defined by the mean plane of the short legs of the J track is hereinafter referred to as the "face side". Call.

Dimensions of 38.1 cm (15 inches) x 167.6 cm (66 inches) each on each of the shaft wall assemblies tested
And two 2.54 cm (1 inch) thick gypsum boards with 61.0 cm (24 inches) x 167.6 cm (66 inches).
The plates were inserted between the feet of the upper and lower horizontal J-tracks on either side of the I-stud, and their longest dimension was oriented vertically. A vertical lip of the plate located adjacent to the I-stud was friction fit between the tab and flange of the I-stud, thereby sandwiching the I-stud between the edges of the plate. 3.18 cm (1.25 inch) S-screws, 60.96 cm (24 mm) on opposite vertical edges of the plate to the long legs of the J track, which is vertically positioned so that the long legs overlap the plate on the shaft side.
Fixed by an on-center (OC) of inch.

Each of the tested fiberglass matte sided gypsum boards had a side substantially free of gypsum and a side having gypsum over its substantial area. Each of the plates was placed in its test assembly with its gypsum-free surface exposed on the shaft side of the assembly. After placing the gypsum board with the glass fiber matte side in the metal assembly, the layer of face material of the gypsum board with the paper side was fixed to the side of the metal frame. The layers of these face materials are detailed below.

The resulting assembly, located in the Masonry frame described above, formed one wall of the test furnace. A number of gas burners were burned in the furnace, where the gas burners were arranged such that the yellow glowing flame of each burner impinged on the surface of the specimen, thereby maintaining a uniform temperature thereon. The furnace temperature was set to gradually increase according to the standard time curve in ASTM E-119, as shown below. Time (min) Temperature, ° C (° F) 5 538 (1000) 10 704 (1300) 30 843 (1550) 60 927 (1700) 120 1010 (1850) 180 1052 (1925) 240 1093 (2000) Temperature of test assembly Was measured by eight Chromel-Alumel (type K) thermocouples, four of which were located on the exposed side of the furnace and the remaining four of which were exposed to the assembly. Not located on the side.

The flame endurance of each tested assembly was (1) as the average temperature on the unexposed side reached 121 ° C (250 ° F) above ambient temperature as measured by four thermocouples. It was measured as the time required, or (2) the time required for either individual thermocouple to reach 163 ° C (350 ° F) above ambient temperature. Once either of these two types of gypsum was reached, the test was completed and the time measured from the start of the test was recorded.
During each test, each assembly was observed for plate degradation, cracking, strain and failure of metal components.

The evaluation included a 2 hour flame endurance test and a 3 hour flame endurance test as described below.

Two-Hour Test Five two-hour flame durability tests were conducted as described below. Thickness of 2.
A gypsum board having a 54 cm (1 inch) glass fiber matte side was placed in the test section of the conventional shaft wall assembly described above. For comparison purposes, two other trials were conducted with Georgia-Pacif.
ic Corporation) trademark shaft liner (SHAFTLI
Conventional thickness sold by NER) 2.54 cm (1 inch)
It was carried out using a plasterboard with a paper side of.

In each of the shaft wall assemblies tested, two face material layers (inner and outer layers) of the gypsum board were fastened to the faces of the metal frame. These two layers consist of 1.27 cm (0.5 inch) gypsum board, the composition of the core of which is described below. Two such plates, each having a dimension of 83.8 cm x 99.1 cm (33 inches x 39 inches), with their longest dimension oriented horizontally, a 2.54 cm (1 inch) S A mold screw was used to form a layer of inner face material. These two
The joint formed between the edges of the plates ran horizontally and was not complete. The outer facing material layer consisted of a single gypsum board having dimensions 99.1 cm x 167.6 cm (39 inches x 66 inches), with the longest gypsum board dimensions being vertically oriented. The board is 4.128 cm above the board of inner facing material
(1.625 inch) S-type screw, 40.64 cm (16 inch) O.
Signed using C.

The previously mentioned 1.27 cm (0.5 inch) refractory gypsum board was used by Georgia-Pacific Corporation (Ge
Orgia-Pacific Corporation) is sold under the trademark "FIRESTOP" and "XXX" type.
Such a plate has a density of 48 pounds per cubic foot (768.9 kg / m ³ ) and has a core solidified from the following composition.

The shaft side of each assembly was exposed to a gas flame in a furnace in three of the two hour tests performed. The face side of the assembly tested faced the outside of the furnace and was not exposed to flame. Table I below includes a description of the 2.54 cm (1 inch) plate used in the shaft wall assembly and the flame endurance rating for each of the tested assemblies.

A gypsum board having a matte surface of glass fiber, referred to in Table 1 below, i.e. a board within the scope of the present invention, is a non-bonded piece bonded together by an adhesive which the manufacturer calls "modified urea-formaldehyde resin". It was made utilizing a non-woven mat constructed from a fibre-ment of glass fibers oriented in a regular pattern. The mat had a thickness of 0.84 mm (33 mils) and was more porous than the type of paper used as a cover sheet for gypsum wallboard. The air permeability of this mat was 700 CFM / square foot (Test Method FT 436-910). This mat is DURA-GLASS 7
502-2 lbs is commercially available and is one example of a preferred mat of fibers for use in the practice of this invention. A conventional wallboard machine was used to make continuous length boards from an aqueous slurry of the plaster formulation set forth in Table 1 below. The slurry was fed onto the moving mat sheet as it was unwound from the roll onto the moving support surface. The mat had a width of about 130 cm (51 inches) and was continuously scored with a conventional scoring blade before depositing the slurry thereon. Make two score marks on each edge of the mat, and each outer edge is approximately one from each edge of the mat.
It was 2.54 cm (1 inch) and each of the inner notches was about 3.8 cm (1.5 inches) from its respective lip. After the slurry was deposited on the mat, the lip was folded at the indicia of indicia and overlaid on top of the slurry. (The gypsum core formed from this work has a width of about 122 cm (47 7/8 inches) and about 1.27
It had a thickness of cm (1/2 inch). ) Approximately 120.6 cm (47 1 /
Mats from another roll having a width of 2 inches) were fed onto the lip portion overlying the mat above and below the gypsum slurry. The gypsum slurry penetrated into the overlying lip and helped bond the lip of the overlying mat to the lip overlying the overlying mat. The viscosity of gypsum slurry is 21 ℃ (70
It was about 5900 cp at ° F). At this viscosity,
The slurry penetrated through a portion of the underlying mat to form a thin film on about 40-50% of the mat's outer surface area. As the gypsum in this film solidified, a substantial portion of the outer surface of the mat was covered with a thin film of solidified gypsum. The surface has a roughened appearance,
The contours of the glass filaments could be observed under a thin coating of plaster covering them. However, at the aforementioned viscosities, the slurry passes through the thickness of the overlying mat, but part of it [about 5 mil]
Through the entire area and no slurry was observed on the outer surface of the mat. When the slurry solidifies gypsum in the middle part of the infiltrated mat, the slurry mechanically interlocks with the solidified gypsum core.
k) was formed. About 2.4m continuous length plate
Cut it to a length of (8 feet). The gypsum board is dried in a furnace at 177 ° C (350 ° F) until it is almost dry, which accelerates the drying of the gypsum plate. Heat in F).

As the calculations show, the cores of plasterboard boards G-1 and G-2 with a matte side of glass fiber are 63% less glass than board P, ie the core of a board with a conventional paper side. Contains fibers. Board G-1 is 10 more than conventional boards
Although less dense by%, the shaft wall assembly containing plate G-1 showed a 9% improvement in flame durability over the assembly containing plate P. Although board G-2 is 17.5% lighter and 26% less dense than board P, the shaft wall assembly containing G-2 showed a 5% improvement in flame durability over the assembly containing conventional boards. . Thus, the plate G-1
And G-2 have lower glass fiber content and lower density in their cores than the conventional paper-faced plates, the test assembly containing the former plate is better than the assembly containing the plate P. It showed an average improvement in flame durability of 7%.

In contrast to the three tests of the means, the following two tests were performed on the shaft assembly, where the face side of the assembly was exposed to the gas flame in the furnace and the shaft side was exposed to the outside of the furnace. Faced and not exposed to flame. Table 2 below includes a description of the 2.54 cm (1 inch) plate used in the shaft wall assemblies tested and the flame endurance rating for each of the tested assemblies.

As the calculations show, the core of plate G-3 contains 63% less glass fiber than the core of plate P-1, and plate G-3 is 11% lighter and 20% less than plate P-1. Low density.
Nevertheless, the shaft wall assembly containing plate G-3 showed a 14% improvement in flame durability over the assembly containing plate P-1.

3-Hour Test A 3-hour flame endurance test was conducted as described below. A plate having a 2.54 cm (1 inch) thick fiberglass matte surface having a density of 42 pounds per cubic foot (643 kg / m ³ ) was placed in the test section of the conventional shaft wall assembly described above. The composition of the core of the plate, referred to herein as G-4, is described below.

The face side of the assembly tested included three layers of conventional gypsum board face material having a thickness of 1.59 cm (5/8 inch) and the composition described below. The innermost face material layer is formed from two such plates having dimensions of 38 cm x 168 cm (15 in x 66 in) and 61 cm x 168 cm (15 in x 66 in) respectively, and their longest dimension is Oriented vertically. These boards are the short legs of the J track and the I
It was fastened to the stud flange by using 2.54 cm (1 inch) S type screw and 61 cm (24 inch) OC. The joint was not completed. The plates forming the middle and outer face material layers have the same width and width dimensions and are positioned in the same orientation as the inner and outer face material layers of the assembly described above for the 2 hour test. Let The outermost layer of face material was fastened in place using 5.7 cm (2.25 inch) S-type screws. The face side of the test assembly was exposed to the flame of the furnace glass and the shaft side was left unexposed to the flame.

A plasterboard with a paper side is available from Georgia-Pacific Corporatio.
It was an "X" template sold under the trademark FIRESTOP by n). The plates of these face materials are
It has an average weight of 11.48 kg / m ² (2350 lbs / 1000 cubic feet) and a composition of the core described below.

During the test, the temperature of the flame-exposed surface of the assembly was ramped at a rate of approximately 49 ° C (88 ° F) during the first 15 minutes of the test and approximately 5 ° C (9 ° F) during the second 15 minutes.
At the speed of, and 1 for the remaining 2 hours and 45 minutes
C. (1.8.degree. F.) ramp rate is reached and after 3 hours and 15 minutes an average temperature of about 1,061.degree. C. (1,910.degree. F.) is reached. The average temperature measured on the unexposed side of the assembly is 3
Approximately 25 ° C (77 ° F) over 15 minutes (ambient temperature)
From 164 ° C (327 ° F). The maximum temperature measured on the unexposed side reached 206 ° C (402 ° F). The temperature was reached in 3 hours and 12 minutes. Thus, a 3.2 hour flame endurance was achieved with the test assembly. Immediate integrity failure, as evidenced by the appearance of cracks or strains, is exhibited at any time during the test, either on plates with glass fiber mat surfaces exposed to the furnace or on plates of face material. Was not done. The I-stud showed some signs of buckling after 3 hours.

In a conventional 3-hour grade shaft wall assembly, a 1.9 cm (3/4 inch) "X" type gypsum board is identical to a board with a 2.54 cm (1 inch) glass fiber matte surface described here. Positioned in a way and four layers of 1.59 cm (5/8
An inch "X" type FIRESTOP plate was applied to the face of the assembly to maintain a space between the third and outermost fourth layer of the plate. Thus, the gypsum board with the matte side of fiberglass described herein is 1/4 inch thicker than the board with the conventional paper side, even though it is a shaft wall assembly including board G-4. Included a 1.59 cm (5/8 inch) "X" type FIRESTOP plate with only 3 layers (instead of 4 layers) to achieve flame endurance of better than 3 hours.

As can be seen from the above tests, the plasterboard with the matte face of glass fibers described herein has a significantly lower density in their core and a significantly lower amount of refractory agent, i.e., glass fibers. Despite the fact that it contains, it shows a significant improvement in flame durability over its conventional paper-faced counterpart.

The following example was prepared according to the technique described for the gypsum board having the composition of the core described below and having the matte side of the glass fiber of the previous example, thickness 1.59 cm.
Includes flame test rating of gypsum board with (5/8 inch) glass fiber matte side.

The core density of this board was 849 kg / m ³ (53 lbs / cubic foot). This plate was evaluated for flame resistance and hose flow resistance according to ASTM E-119 for 1 hour.
A flame rating of 30 seconds was achieved. It should be noted that due to the use of water resistant additives in the core, the board had very good water resistant properties, those additives were wax-asphalt emulsions and poly (vinyl alcohol). .

As is apparent from the above examples, excellent fire resistance properties were achieved by the present invention. In the examples and other parts of the present invention, shaft wall assemblies have been specifically described that include a metal skeleton of a particular design. It should be understood that the gypsum board with the matte side of the fibers described herein can be used in other types of shaft wall assemblies, such as assemblies made from refractory materials, such as refractory plastics. It should also be noted that the example compositions included the use of calcium sulfate hemihydrate to form a set gypsum product. Alternatively, calcium sulphate can be used and the term is used in the claims to generically include both calcium sulphate and calcium sulphate hemihydrate.

In summary, it can be said that the present invention, in a practical way, provides significant functional improvements in structural assemblies intended to have fire resistant properties designed to ensure the safety of life and property. .

[Brief description of drawings]

FIG. 1 is a somewhat schematic partial side view of a production line for producing a plaster board of a type suitable for producing a plaster board prepared for use in accordance with the present invention. FIG. 2 is an enlarged partial cross-sectional view of the underlying glass fiber mat used to manufacture the gypsum board, as shown toward the left side of FIG. FIG. 3 is a partial plan view taken as indicated by line 3-3 in FIG. FIG. 4 is an enlarged cross-sectional view taken as shown to the right of FIG. 1, and is an overlying glass fiber mat sandwiched with gypsum composition for use in making gypsum board. And both of the underlying glass fiber mats. FIG. 5 is a partial plan view taken as indicated by line 5-5 in FIG. FIG. 6 is a partial bottom view taken as indicated by line 6-6 in FIG. 4 and shows the bottom surface of the mat lying under the plasterboard. FIG. 7 is a cross-sectional view of the lip portion of the completed gypsum board, this drawing taken as indicated by line 6-6 in FIG. Figure 8 was taken as shown towards the top of Figure 4,
It is another enlarged sectional view. Figure 9 was taken as shown towards the bottom of Figure 4,
It is another enlarged sectional view. FIG. 10 is an enlarged view showing the installation of a typical shaft wall assembly surrounding a shaft between floors of a building. 11 is a schematic vertical cross-section taken along line 11-11 through the shaft wall assembly shown in FIG. FIG. 12 is a schematic horizontal cross-section taken along line 12-12 through the shaft wall assembly shown in FIG. 2 …… Pin mixer 4 …… Slurry 6 …… Fiber mat 6A …… Overlapping edge 10 …… Indicator mark 10A …… Indicator mark 12 …… Car to carve 16 …… Fabric mat 18 …… Upper part Molding or shaping rolls 20 …… Lower forming or shaping rolls 22 …… Conveyor belts 24 …… Hedge guides 30 …… Fiber filaments 40 …… Gypsum board with matte surface of glass fibers 40A …… Glass fibers Plasterboard with a matt side 41 …… Gypsum-free surface of glass fiber 41A …… Gypsum-free surface of glass fiber 42 …… Cured gypsum core 43A …… Gypsum-covered surface 80 …… External Insulation system 81 …… Buildings 82 …… Fabs with a matte side of fiber 84 …… Nail 86 …… Timber frame 88 …… Expanded polystyrene panel 90 …… Glue 92 …… Glass fiber scrim 94 …… Final finishing material 96 …… Adhesive 100 ...... Shaft wall assembly 101 …… J track 103 …… I stud 104 …… Bolt 106 …… J track short leg 107 …… J track long leg 109 …… Flange 109 ′ …… Flange 110 …… Gypsum board Panel 112 …… Gypsum board panel 113 …… Screw fastener 114 …… Middle part of main body 120 …… Shaft side 130 …… Shaft wall assembly 130 …… Surface side 140 …… Hole C …… Ceiling F …… Floor S: Shaft T: Tab

 ─────────────────────────────────────────────────── ───Continued from the front page (72) Inventor Giofj Fouler Giunia, State of Giozia, United States 30093 Norcross Chitpendale Rain 940 (72) Inventor Ray Dobriyu Hinkel, State of Giosia, United States 30083 Storn Mountain Cedar Glen 4457 (56) Bibliography Sho 49-116446 (JP, U) JP 54-18049 (JP, B2)

Claims (13)

(57) [Claims] 1. A solidified core comprising at least about 85% by weight gypsum dihydrate and about 0.03 to about 0.3% by weight glass fiber; and a porous glass mat facing at least one side of said core. The core has a density of less than 753 kg / m ³ (47 pounds / cubic foot), the glass mat has an outer surface substantially free of solidified gypsum from the core, and the gypsum board is 1.59 cm. A at a thickness of (5/8 inch)
A plasterboard with a glass matte surface characterized by achieving a flame rating of at least 1 hour according to STM E-119. 2. A board according to claim 1 containing from about 0.07 to about 0.2% by weight of glass fibers. 3. The plate of claim 1 wherein said solidified core has a density of about 641 kg / m ³ (40 pounds / cubic foot) to about 753 kg / m ³ (47 pounds / cubic foot). 4. ASTM at a thickness of about 2.54 cm (1 inch)
The plate of claim 1 which achieves a flame rating of at least about 2 hours in accordance with E-119. 5. ASTM at a thickness of about 2.54 cm (1 inch)
The plate of claim 1 which achieves a flame rating of at least about 3 hours in accordance with E-119. 6. A method according to claim 1 having a core which also contains a water resistant additive in an amount sufficient to improve the water resistance of the core.
The plate described in paragraph. 7. The board of claim 1 wherein said glass mat has a plurality of solid gypsum-free internal voids. 8. The board of claim 1 wherein said core comprises paper fibers. 9. A gypsum board having a refractory skeleton and a glass mat surface supported by the skeleton, wherein the gypsum board is at least about 85% by weight gypsum dihydrate and about 0.03.
A solidified core containing about 0.3% by weight of glass fibers and a porous glass mat facing at least one side of the core, the core having a weight of less than 753 kg / m ³ (47 lbs / cubic foot). The glass mat has a density, the glass matt has an outer surface substantially free of solidified gypsum from the core, and the gypsum board is ASTM 9 at a thickness of 1.59 cm (5/8 inch).
A shaft wall assembly characterized by achieving a flame rating of at least 1 hour according to E-119. 10. A shaft wall assembly comprising a refractory frame and a gypsum plate supported by the frame, wherein the gypsum plate has fiber mat faces and is horizontally spaced from each other. A mold that includes a flexible track and a fireproof stud disposed vertically between the tracks, and including a panel on the shaft side of the assembly and a panel on the opposite side of the assembly at least, The shaft side of the shaft is at least about 85% by weight of gypsum dihydrate and about 0.03%.
It comprises a solidified core containing about 0.3% by weight of glass fibers and a porous glass mat facing at least one side of said core, said core having a density of less than 753 kg / m ³ (47 pounds / cubic foot). And the glass mat has an outer surface that is substantially free of solidified gypsum from the core,
Gypsum board is ASTM E at a thickness of 1.59 cm (5/8 inch)
Shaft wall assembly, characterized in that it consists of a plasterboard with a face of glass mat that achieves a flame rating of at least 1 hour according to -119. 11. The refractory frame comprises a metal frame,
11. The horizontal track is comprised of metal J tracks spaced apart from each other, and the vertically aligned stud is comprised of metal studs.
A shaft wall assembly according to paragraph. 12. The shaft wall assembly of claim 11 wherein said metal stud comprises an I-stud. 13. The shaft wall assembly of claim 11 wherein said opposite panel comprises a fire resistant gypsum board having a paper side.