US 6,432,482 B1Granted

Method of making a multiple layer nonwoven mat

AssigneeJohns Manville International, Inc.

InventorsAlan Michael Jaffee, Richard Emil Kajander

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Abstract

The invention includes fibrous nonwoven multiple layer mats having at least two layers with a body portion layer and a surface portion layer having fine fibers and/or particles therein, both layers being bonded together and to each other with a same resin binder. Preferably most or essentially all of the particles and/or fibers in the surface layer are larger than openings between the fibers in the body portion of the mat. The mats produced according to this invention are useful as a facer for all types of boards such as wood boards, wood product boards, insulating boards and hard boards of all types, and also as reinforcement and dimensional stabilizers for making a large number of novel laminate products and for a myriad of other uses. These mats are made an a wet laid nonwoven mat machine with a modification to the binder preparation system, an inventive step in the preparation of the binder and in the selection of ingredients for a binder slurry.

Claims8

Dependent claims

A method of making a multiple layer mat having a fibrous body portion and a surface portion, said body portion containing fibers and said surface portion containing fibers and/or particles, the body portion constituting a major portion of the mat, the body portion and the surface portion being bonded together with the same resinous binder, the method comprising:

a) forming the body portion by building up fibers in a random orientation to the desired thickness,
b) applying a resinous binder slurry to a top surface of the body portion, the binder slurry containing fibers and/or particles such that the fibers and/or particles in the binder slurry build up a surface layer on the top of the body portion while the resinous binder flows through the body portion, the binder content of the mat being between 5 and 35 wt. percent of the multiple layer mat, the resinous binder having been applied as an aqueous slurry wherein the fibers and/or particles in the surface portion were applied as part of the binder slurry, the amount of fibers and/or particles in the surface portion being about 0.5-20 wt. percent of the fibers in the body portion of the mat and wherein the fibers and/or particles in the slurry and in the surface portion are large enough that more than 99 percent of these particles and/or fibers are larger than the openings between the fibers in the body portion, and
c) drying and heating the mat to cure the resinous binder in the body portion and in the surface portion.

Dependencies are inferred from the claim text.

Facts

Application: 09/665,735Filed 20 Sep 2000 · division
Priority: 31 Dec 1998
Granted: 13 Aug 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

B32B 5/26
One layer being a fibrous or filamentary layer: another layer next to it also being fibrous or filamentary
B32B 5/022
Characterised by structural features of a fibrous or filamentary layer: non-woven fabric
B32B 5/24
Characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed: one…
D21H 27/38
Multi-ply: at least one of the sheets having a fibrous composition differing from that of other sheets