Importance

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Abstract

A nonwoven web of polymer fibers bonded with from about 5 to about 30 wt. percent of a cured binder composition, based on the weight of the web or mat. The web is a spunbonded web of polymer, such as polyester, fibers bound with a binder containing one or more formaldehyde fortified polymer resins that normally emit substantial formaldehyde at high temperatures, but in this invention the binder also contains up to about 7.5 wt. percent of a bisulphite compound, preferably ammonium bisulphite. This binder is applied in latex form to the fibrous web after the fibers are made and collected in a known manner and then the wet web is dried and heated to cure the binder in a known manner. The resultant nonwoven webs have good hot strength and low formaldehyde emissions and reasonable costs, something not heretofore attainable with these types of formaldehyde containing binders. The webs of the present invention are useful for making various roofing products such as built up roofing products and for other uses.

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First Claim