Method of making foam coated mat online and coated mat product

Abstract

A new foam coated nonwoven fibrous mat having properties particularly suited for a facer on gypsum wallboard, laminates made therefrom and the method of making the mat is disclosed. The mat preferably contains a major portion of glass fibers and a minor portion of a resinous binder. The foam coating is permeable and reduces fiber dust and abrasion experienced in the past with relatively coarse, relatively inexpensive glass fibers in the mat. Contrary to previous methods, the foam coated fibrous mat is made in-line on a wet mat forming production line by applying a wet foam binder onto a wet, fibrous web followed by drying and curing in-line.

Description

BACKGROUND OF THE INVENTION [0001] The present invention involves a process of coating a non-woven fiber glass mat with foam or froth on the same wet process line used to make the mat, as an intermediate step in the mat manufacturing process, and the foam coated fiber glass mat products that result. These coated mats have many uses, but are especially useful as a facing on a gypsum wallboard for exterior application and on which stucco is applied. [0002] Fibrous non-woven mats are often formed into a wet mat from an aqueous dispersion of fibers such as glass and / or synthetic organic fibers can include other fibers such as cellulose fibers, ceramic fibers, etc. and can also include particles of inorganic material and / or plastics. Usually a solution of urea formaldehyde resin, usually modified with a thermoplastic polymer, or one of many other known resin binders is applied to a the wet non-woven web of fibers and then, after removing excess binder and water, the bindered web is dried...

AI Technical Summary

Benefits of technology

"The present invention provides a foam coated non-woven fibrous mat that can be used as a facer on gypsum insulating board. The mat has improved handling characteristics, flame resistance, flexibility, and produces less dust when the board is cut. The mat can be made using a wet process and a conventional binder, and it contains a major portion of less expensive chopped glass fibers. The invention also includes a method for making the mat and a laminate containing the mat and other materials such as gypsum wallboard or insulating boards. The foam coating on the mat is permeable, allowing air to penetrate the mat and cure it. The invention also includes a foam coated fibrous non-woven mat that has improved handling characteristics, flame resistance, flexibility, and produces less dust when the board is cut."

Problems solved by technology

The fiber glass mat (Johns Manville's 7502 Mat—2 lb. / 100 sq. ft.) made using a binder of urea formaldehyde performed good in the process disclosed in U.S. Pat. No. 4,647,496 to make a faced insulating gypsum board, also disclosed in that patent, but the mat was not as strong as desired which caused process breakouts adding to production costs.

This mat was also more rigid than desired which made it difficult to fold around the edges of the board and also irritated the hands and arms of the workers handling and installing the insulating board product.

Further, when the faced insulated gypsum board was cut, the dust from the mat was excessive and further irritated those it contacted, particularly if the workers bare arms, etc. were sweaty and exposed to the dust.

Skin abrasion and irritation was also a problem for those handling the mat and the faced board when not wearing gloves and long sleeve shirts.

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