Abstract: New coated nonwoven fibrous mats having properties particularly suited for a facer on gypsum wallboard and other substrates and in laminates of various types, and the method of making the coated mat is disclosed. The mat preferably contains a major portion of glass fibers and a minor portion of a resinous binder. The coating is preferably permeable and reduces fiber dust and abrasion experienced in the past with relatively coarse, relatively inexpensive glass fibers in the mat. Contrary to previous coating methods, the 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.

Abstract: A method and apparatus for chopping long unwound items like fiber, fiber strands, yarn, etc. The chopper has a backup roll, a blade roll and an idler roll. The improvements include one or both of a shield having an air jet at or near its upper end, the shield being upstream of the blade roll and spaced from the blade roll, a lower end of the shield being spaced from the working surface, the air jet communicating with a source of compressed air, to prevent a buildup of fuzz or chopped item(s) upstream of the blade roll, and a shield having an air jet at or near its upper end, the air jet being located close to the working surface and the shield angling or curving downward from a location spaced from the working surface beginning between about an 8 O'clock and a 10 o'clock position on the backup roll and transitioning generally downward ending at a location below and spaced from the idler roll to protect the idler roll from chopped item(s).