Ppg Industries, Inc.

Joe B Lovelace

Donald L Motsinger

Charles E Nalley

Dennis S Postupack

Harry Makitka

Curtis L Hanvey, Jr

Thomas C Bour

John W Cotton

Timothy G Mathis

James V Shivers

E Charles Watkins

Timothy Smith

Stanley C DeGreve

The process and apparatus of the present invention enable the production of glass fiber product from scrap glass fibers. The process includes: feeding the scrap glass fibers having an average length up to around 12 inches to a glass melting tank having a pool of molten fiberizable glass, melting the scrap glass fibers without the presence of non-vitrified glass forming materials in an oxidizing environment, conditioning the melt to a formable viscosity, and forming the glass fiber from the conditioned melt where for a given glass fiber product there is a near constant pull of the melted glass from the melter. The rate of feeding of the scrap glass to the melter is sufficient to maintain the pool of melted glass with a level within the range of .+-.0.35 inch (9 mm.) over a period of eight hours. The scrap glass fibers have a similar fiberizable inorganic composition to that of the desired glass fiber product and generally include fibers with organic-containing sizes and/or coatings. The apparatus of the present invention has a refractory-lined glass melter, engaged for supply of scrap glass fibers to a positive supply means, a conditioning means to receive formable melted glass, and one or more bushings to form the glass fiber product. The glass melter has a high length to width ratio with a finite-sided melting containment area which holds a pool of molten glass that receives the scrap glass from the feeder without any non-vitrified glass forming material. The feeder supplies the scrap glass at a rate sufficient to maintain the pool of melted glass with a level within the range of .+-.0.35 inch (9 mm.) over a period of eight hours.

Production of glass fibers from scrap glass fibers

A glass fiber forming size utilized to produce glass fiber strands is described in which the forming size is an aqueous mixture of polyvinyl acetate, fatty acid lubricant, methacrylato chromic chloride and gamma (ethylene diamine) propyl trimethoxy silane, the mixture being adjusted to pH between 6.1 and 6.5. The size composition is applied to glass fibers during forming. The strands produced utilizing this forming size find particular utility when formed into roving and produce a particularly effective gun roving product.

Forming size for glass fibers

Forming size of aqueous polyvinylacetate

Growing community of inventors

Forest City, NC, United States of America

Joe B Lovelace