Method of making a multiple layer nonwoven mat

摘要

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.