CN104114342A - Nonwoven, flame retardant, moisture resistant panel and method of construction thereof - Google Patents

Abstract

A nonwoven, fire retardant, moisture resistant panel and method of construction thereof is provided. The panel includes a bonded nonwoven sheet of bast fibers bonded with polymeric binding fibers. Further, the panel includes a single coating of a dried and cured solution. The dried and cured coating includes a binder, a Ph stabilizer and a single flame retardant. The binder is cross-linked with the bast fibers to form a moisture resistant barrier that reduces the moisture absorption of the bast fibers.

Description

Non-woven flame-retardant and moisture-proof panel and method of construction

Cross References to Related Applications

This application claims the benefit of U.S. Provisional Patent Application Serial No. 61/569,975, filed December 13, 2011, and U.S. Provisional Patent Application Serial No. 61/703,613, filed September 20, 2012, by This reference is hereby incorporated in its entirety.

technical field

The present invention relates generally to nonwoven panels, and more particularly to flame and moisture resistant nonwoven structural panels and methods of construction thereof.

Background technique

It is known to construct structural panels, that is to say those panels that can be used as structural members such as office partition panels, from fiberglass composite materials formed by combining glass fibers with resin. However, the formaldehyde content in the resin used to construct the fiberglass panels is high, which is harmful to humans, and since the new regulation CAL1350 states that the formaldehyde content must be less than 0.04ppm, the fiberglass panels are not compliant . Additionally, fiberglass panels are not environmentally friendly due to their relatively high carbon footprint during manufacture and are often formed from non-renewable materials.

In addition to fiberglass panels, panels of construction comprising natural fibers combined with resins are also known. However, the known composition of these panels readily absorbs moisture, which would compromise the structural capabilities of the panels themselves. As a result, natural fiber panels generally do not meet the requirements for humidity impact testing and panel stiffness testing in office divider tackable board applications. Furthermore, the processing of these panels is often very expensive, eg including the necessary multiple coating processes. Thus, their expensive construction often makes them not cost-effective and, thus, unsuitable for many applications. Also, natural fiber-based wall panels often exhibit a brown color, which is undesirable in see-through office panel applications.

Contents of the invention

According to one aspect of the present invention, there is provided a non-woven flame-retardant and moisture-proof panel. The panel comprises a bonded nonwoven sheet of bast fibers combined with polymeric binder fibers. Additionally, the panel includes a single coating formed from a dried and cured solution. The dried and cured coating includes a binder, a pH stabilizer and a single flame retardant. The binder cross-links the bast fibers to form a moisture barrier reducing the water absorption of the bast fibers.

According to another aspect of the invention, the panel complies with the regulation CAL1350 for a formaldehyde content of less than 0.04 ppm.

According to another aspect of the invention, the panel is formed as an office divider panel that passes the ASTM E-84 flame resistance test.

According to another aspect of the invention, the mixture comprises 50-80% by weight of bast fibers and 15-50% by weight of polymer binder fibers.

According to another aspect of the invention, the bonded nonwoven web is from 150 gsm to 1500 gsm.

According to another aspect of the invention, the dried and cured coating has a dry pick weight of 30 gsm to 300 gsm.

According to another aspect of the invention, a formaldehyde-free scrim layer is bonded to at least one side of the panel.

According to another aspect of the invention there is provided a method of constructing a nonwoven flame retardant moisture barrier panel. The method includes forming a homogeneous mixture of bast fibers and polymer binder fibers; forming a web of the homogeneous mixture; melting the polymer binder fibers and combining the bast fibers with the polymer binder fiber material to form a bonded non-woven fabric. A woven sheet; soaking (saturating) the combined nonwoven sheet in a solution comprising an adhesive, a pH stabilizer and a flame retardant; drying the soaked combined nonwoven sheet to make the binder crosslinks the bast fibers and cures the solution; and compresses the nonwoven sheet.

According to another aspect of the invention, the method includes maintaining the formaldehyde content in the panel below 0.04 ppm.

According to another aspect of the invention, the method includes compressing the nonwoven sheet while curing the solution.

According to another aspect of the invention, the method includes cooling the nonwoven sheet while compressing the nonwoven sheet.

According to another aspect of the invention, the method includes using a modified polycarboxylic acid and polyol binder.

According to another aspect of the present invention, the flame retardant is a single flame retardant.

According to another aspect of the invention, the method includes bonding a formaldehyde-free scrim layer on at least one side of the panel.

Description of drawings

Below in conjunction with present preferred embodiment and the detailed description of best mode, claims and accompanying drawing, those skilled in the art understands these and other aspects of the present invention, feature and advantage more easily, wherein:

Figure 1 is a process flow diagram showing the steps in constructing a panel according to one aspect of the invention.

Detailed ways

Referring to the accompanying drawings in more detail, Figure 1 shows a non-woven flame retardant and moisture-resistant panel constructed in accordance with the present invention, hereinafter referred to as a panel 10, 10', 10", and also shows a construction in accordance with another aspect of the present invention Panels 10, 10', 10" way. The panels 10, 10', 10" comprise a bonded nonwoven sheet 12 and a dried and cured coating 14 which is dried and cured in a single process from a single solution 16, thereby making the manufacturing process Space requirements and process steps are minimized in. The sheet 12 is formed from a mixture of bast fibers 18 and polymer binder fibers 20 bonded to each other by a process of at least partially melting the polymer binder fibers 20. The solution 16 includes a solution-based binder, a pH stabilizer and a single flame retardant. The binder in this solution 16 cross-links the bast fibers 18 to form a moisture barrier or a substantially moisture barrier that greatly reduces the propensity to absorb water. Thus, even in the presence of moisture, the structural integrity of the bast fibers 18 and the panels 10, 10', 10" made in part of them are maintained during use such that the panels 10, 10', 10" meets the strict requirements of ASTM E-84 Class A office partition wall panels that can be nailed with thumbtacks, and further passed the humidity impact test and wall panel stiffness test. Therefore, panels 10, 10', 10" have high strength and high rigidity are suitable for use as structural members, such as office partition panels. Additionally, the panels 10, 10', 10" are environmentally friendly because the materials used to construct the panels 10, 10', 10" are recyclable and renewable, mostly natural and biodegradable, and further, The formaldehyde content is less than 0.04ppm, hereinafter referred to as "low formaldehyde content", and therefore, the panels 10, 10', 10" are suitable for applications that need to pass the regulation CAL1350, which requires the formaldehyde content of office partition wall panels to be less than 0.04ppm.

The bast fibers 18 are shown by way of example and not limitation to be provided by a variety of natural fibers such as jute, kenaf, hemp, flax or mixtures thereof. The bast fiber 18 is typically provided with a content of about 50-85% by weight, and in one example is set at 80% by weight kenaf.

The polymeric binder fibers 20 are shown by way of example and not limitation as being made of a variety of thermally bondable materials, including polypropylene, polyethylene, copolyester, nylon, polylactic acid (PLA), and bicomponent fibers. (sheath/core fibers, where the sheath is typically a low melting point polymer material and the core is a higher temperature polymer material). The polymeric binder fiber 20 is typically provided at a content of 15-50% by weight, and in this example is provided as a 20% by weight bicomponent comprising a polyester core and a modified polyester sheath.

In this example, the solution-based adhesive is provided as a modified polycarboxylic acid and polyol diluted with water. The polyol is primarily used as a crosslinking agent when the modified polycarboxylic acid coexists with the natural fibers of the bast fibers 18 to form good crosslinks between the natural fibers and the molten resin of the polymer binder fibers 20, thereby having It is beneficial to form a moisture-proof barrier or a basic moisture-proof barrier to greatly reduce the water absorption tendency of the bast fiber 18 . It is very important that the adhesive is a solution based adhesive as typical dispersion based latex adhesives have been found to burn in the ASTM E-84 test method and therefore do not qualify for a Class A rating . The content of binder is 10-20% by weight, in this example 14% by weight of binder is used.

The flame retardant is supplied as a single flame retardant and applied in a single process, minimizing manufacturing process complexity and cost. Flame retardants are shown by way of example and not limitation as boron-based, phosphorus-based and sulfur-based components. Since polycarboxylic acids have a low pH, pH stabilizers are used to blend the flame retardant into the adhesive. The flame retardant used in this example is shown by way of example and not limitation as disodium octaborate tetrahydrate. The flame retardant content may be provided at about 5-25% by weight, and in this example a content of 15% by weight based on 30% by weight of dry extract in the chemical solids was used.

The method of constructing the panel 10 includes the steps of: forming a homogeneous mixture 22 of bast fibers 18 and polymer binder fibers 20; forming a web 24 of the homogeneous mixture 22; heating the web 24 to at least partially melt the polymer binding fibers 20 and combining bast fibers 18 with molten polymeric binding fiber 20 material to form a bonded nonwoven sheet 12; providing a solution 16 comprising a binder, a pH stabilizer and a barrier Combustion agent; soak the combined non-woven sheet 12 in solution 16, by drying the soaked combined non-woven sheet 12, the binder in the solution 16 is cross-linked with bast fibers 18; solidifies the solution 16 and compress the nonwoven sheet 12, and optionally, if desired to provide enhanced stiffness and change color from natural fibers, the method further includes bonding a formaldehyde-free scrim layer 25 to the sheet 12 on at least one side (panel 10') or both sides (panel 10").

In more detail, the method involves blending bast fibers 18 and polymer binder fibers 20 first in a mixer and then in a fine opener until a homogeneous mixture 22 is obtained. This uniformity provides an even distribution of the polymeric binder fibers 20 that is required for maximum and uniform stiffness throughout the finished panel 10 .

Next, after forming a homogeneous mixture 22 of bast fibers 18 and polymeric binder fibers 20, the mixture 22 is processed on a web forming machine to create a nonwoven web 24. The weight of the web 24 can vary between about 150 gsm-1500 gsm (grams per square meter), with samples formed therein having a weight of about 700 gsm.

Next, after forming the web 24, the web 24 is heated, such as in an oven 26, to a temperature suitable to at least partially melt the polymer binder fibers 20, thereby bonding the bast fibers 18 to the polymer. Binder fibers 20 are bonded together to form bonded nonwoven sheet 12 .

Next, the bonded nonwoven sheet 12 is soaked in solution 16, such as by passing through a solution bath 28 of solution 16, which solution 16 includes a solution-based binder, a pH stabilizer, and a flame retardant, the binder With a lower pH, the pH stabilizer compensates for the low pH of the adhesive and, as mentioned above, if the flame retardant is not used as a pH stabilizer, it is further diluted with water. The amount of impregnation provides 10-40% by weight of the extracted dry weight of solution 16, wherein the total binder extract in this example is about 30% dry extract and the total disodium octaborate tetrahydrate extract is 30% dry extract in solids about 5-25% by weight.

Next, the saturated bonded nonwoven sheet 12 is heated sufficiently to dry the sheet 12 and cure the solution 16 , such as in a continuous compression belt oven 30 by way of example and not limitation. During the heating process of drying and curing, the water in the solution 16 is first substantially evaporated, and the remaining moisture content in the bonded nonwoven sheet 12 is about 8-10%. Next, after reaching the desired moisture content, the temperature is raised to about 180-200° C., at which temperature the binder of the solution 16 cures and cross-links with the bast fibers 18 . As the adhesive cures, the bonded sheets 12 are compressed to a predetermined finished thickness under force F, such as by way of example but not limitation, between high compression belts 32 . Additionally, the resulting panel 10 is cooled while being compressed between the belts 32 and after being fully cured, wherein the heating, compression and cooling can all be performed in a continuous compression belt oven 30 .

The cooled and compressed panel 10 may be further passed through a scrim press 34 to laminate at least one formaldehyde-free scrim layer 25 onto one side of the panel if necessary to meet the requirements of the intended application (10') or on both sides (10"), the scrim layer 25 is, for example, by way of example and not limitation, fiberglass or polypropylene. The resulting finished panel 10, 10', 10" complies with ASTM E-84 Class A flame retardant requirements, while the panels 10', 10" also obtain enhanced wallboard stiffness, even in the presence of moisture, due to the solution-based adhesive, bonding fiber 20 and scrim layer 25 synergistic effect, the panel also has a very low formaldehyde content. Of course, if it is not necessary to be used in the intended application, the panel 10 may not have the scrim layer 25, although this will make the panel 10 less strong than the panel 10' , 10" strength. From the beginning of the process until after compression, curing and cooling, or if the scrim layer 25 is involved, until after lamination of the scrim layer 25, the sheet 12 remains a continuous Sheet of material. The panels 10, 10', 10" may be cut to desired lengths in a cutting operation 36, which is shown after compression and, if involved, after lamination.

According to the above teachings of the present invention, various improvements or variations are possible, therefore, it should be understood that the present invention can be implemented in other ways than those specifically described, and the scope of the present invention is defined by the finally authorized claims.

Claims (29)

1. a nonwoven flame-proof damp-proof panel, is characterized in that, this panel comprises:

In conjunction with nonwoven sheet material, the nonwoven sheet material of described combination comprises the mixture being combined by bast fiber and polymer-bonded fiber; And

Single coating, this coating is by being dried and curing solution forms, and described solution comprises adhesive, pH stabilizing agent and single fire retardant, the crosslinked water imbibition that reduces bast fiber to form moisture barrier of described adhesive and described bast fiber.

2. nonwoven flame-proof damp-proof panel according to claim 1, is characterized in that, described panel also comprises the scrim layer at least one side that is bonded to described panel.

3. nonwoven flame-proof damp-proof panel according to claim 2, is characterized in that, described scrim layer is not containing formaldehyde.

4. nonwoven flame-proof damp-proof panel according to claim 3, is characterized in that, described panel also comprises the described scrim layer on the relative both sides that are bonded to described panel.

5. nonwoven flame-proof damp-proof panel according to claim 1, is characterized in that, described mixture comprises the described bast fiber of 50-80 % by weight and the described polymer-bonded fiber of 15-50 % by weight.

6. nonwoven flame-proof damp-proof panel according to claim 1, is characterized in that, the nonwoven sheet material of described combination is at 150gsm-1500gsm.

7. nonwoven flame-proof damp-proof panel according to claim 1, is characterized in that, described dry and curing coating has the extraction dry weight of 30gsm-300gsm.

8. nonwoven flame-proof damp-proof panel according to claim 1, is characterized in that, the content of formaldehyde of described panel is lower than 0.04ppm.

9. nonwoven flame-proof damp-proof panel according to claim 1, is characterized in that, described fire retardant selects free boryl compound, at least one in the group of phosphorio compound and sulfur-based compound composition.

10. nonwoven flame-proof damp-proof panel according to claim 9, is characterized in that, described fire retardant is four water eight borate two sodium.

11. nonwoven flame-proof damp-proof panels according to claim 9, is characterized in that, described fire retardant is about 5-25 % by weight.

12. nonwoven flame-proof damp-proof panels according to claim 11, is characterized in that, described fire retardant is approximately 15 % by weight.

13. nonwoven flame-proof damp-proof panels according to claim 1, is characterized in that, described panel is that panel is separated by office.

14. nonwoven flame-proof damp-proof panels according to claim 1, is characterized in that, the requirement of following closely the wallboard of getting with available drawing pin is separated by the A level office that described panel meets ASTM E-84.

The method of 15. 1 kinds of nonwoven flame-proof damp-proof panels of structure, is characterized in that, the method comprises:

Form the homogeneous mixture of bast fiber and polymer-bonded fiber;

Form the net of homogeneous mixture;

Melt this polymer-bonded fiber and bast fiber is combined to form the nonwoven sheet material of combination with polymer-bonded fiber;

The nonwoven sheet material of this combination is soaked in solution, and this solution comprises adhesive, pH stabilizing agent and fire retardant;

By nonwoven sheet material curing this solution of dry this combination of soaking into, adhesive and bast fiber are crosslinked; And

Compress this nonwoven sheet material.

16. methods according to claim 15, is characterized in that, compress this nonwoven sheet material when being also included in curing this solution.

17. methods according to claim 16, is characterized in that, cooling nonwoven sheet material when being also included in this nonwoven sheet material of compression.

18. methods according to claim 15, is characterized in that, further comprise and use the polycarboxylic acids of modification and the adhesive of polyalcohol.

19. methods according to claim 15, is characterized in that, further comprise by dilute with water adhesive and by the mixture of single fire retardant and adhesive and water and are compounded to form described solution.

20. methods according to claim 15, is characterized in that, are also included in the adhesive that uses about 10-20 % by weight in solution.

21. methods according to claim 15, is characterized in that, also comprise that lamination scrim layer is at least one side of described panel.

22. methods according to claim 21, is characterized in that, described scrim layer is not containing formaldehyde.

23. methods according to claim 15, is characterized in that, the content of formaldehyde of described panel is lower than 0.04ppm.

24. methods according to claim 15, is characterized in that, described fire retardant selects free boryl compound, at least one in the group of phosphorio compound and sulfur-based compound composition.

25. methods according to claim 24, is characterized in that, described fire retardant is four water eight borate two sodium.

26. methods according to claim 25, is characterized in that, described fire retardant is approximately 15 % by weight.

27. methods according to claim 24, is characterized in that, described fire retardant is about 5-25 % by weight.

28. methods according to claim 15, is characterized in that, the requirement of following closely the wallboard of getting with available drawing pin is separated by the A level office that described panel meets ASTM E-84.

29. methods according to claim 15, is characterized in that, further comprise until compress that to keep described nonwoven sheet material after this sheet material be continuous material piece always, then cut this sheet material to form the required length of panel.