Composite facer for wallboards

Abstract

A composite facer material for use with cementitious wallboards, where the composite facer is embedded in a top and bottom face thereof. The composite facer material, in a most preferred embodiment, comprises two layers. The first layer is preferably a carded polyester nonwoven mat, which is bonded to a second layer comprising preferably a tri-directional laid scrim fabric reinforcement layer made of continuous glass fibers. The two layers are preferably bonded together using an acrylic adhesive, which offers superior adhesion between the layers as well as superior adhesion between the composite facing material and the cementitious core.

Description

[0001] This application is a continuation of pending U.S. patent application Ser. No. 09 / 833,358, filed on Apr. 12, 2001. This reference is hereby incorporated herein in its entirety by specific reference thereto.[0002] The present invention relates to facers for wallboards and methods for making wallboards containing such facers. More specifically, the present invention includes a composite facer for wallboards comprising a nonwoven mat that is adhesively bonded to a scrim fabric reinforcement.[0003] Traditional wallboard contains a cementitious material, such as gypsum or plasterboard, and paper facing on one or both sides thereof. This type of wallboard has various disadvantages. First, the paper facing is generally flammable, which is not usually a desirable quality for wallboards used in building construction. Secondly, if the paper facing gets wet, it tends to peel away from the gypsum or plasterboard core and the structural integrity of the paper decreases, which ultimately a...

AI Technical Summary

Benefits of technology

"The present invention provides a composite facing material for wallboard that improves strength, fire resistance, and water resistance of the wallboard. The composite material comprises a nonwoven mat bonded to a reinforcement scrim fabric layer, which is oriented outwardly towards the face of the wallboard. The nonwoven mat is bonded to the reinforcement fabric layer using an acrylic adhesive, which allows for easy modification of strength characteristics without changing the nonwoven mat. The composite material is reinforced, but does not contain exposed reinforcement fibers on the face of the wallboard, which prevents skin irritation. The composite material can be embedded in the core of the wallboard without requiring extensive modifications to the existing wallboard assembly line. The nonwoven mat is preferably a carded polyester nonwoven mat, but other suitable materials may also be used. The reinforcing scrim fabric material should be strong enough to survive the rigors of board manufacture and should be open enough to allow gypsum to flow through. The composite material should be able to withstand the adhesive used to bond the nonwoven mat and the reinforcement fabric layer."

Problems solved by technology

First, the paper facing is generally flammable, which is not usually a desirable quality for wallboards used in building construction.

Secondly, if the paper facing gets wet, it tends to peel away from the gypsum or plasterboard core and the structural integrity of the paper decreases, which ultimately allows degradation of the entire wallboard.

Further, the paper facing does not impart much strength to the wallboard when wet.

The method for making this product includes the step of vibrating the layer of slurry in contact with the tissue until the slurry penetrates the tissue until it is completely embedded, thus requiring extensive and expensive modification of existing wallboard manufacturing lines.

A disadvantage to this arrangement is that the glass fiber mat is exposed on the outer face of the board, which is an irritant to the skin of workers and others who come into contact with the facing thereof.

None of the prior art discloses a composite wallboard facing material made from a nonwoven polyester carded mat bonded to a reinforcing laid scrim layer made from continuous glass fibers, which allows a gypsum slurry to penetrate and embed the composite in a face of the wallboard.

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