A method and apparatus for the reclamation of inorganic fibers from waste continuous strips of inorganic fibers. A binding agent, such as an organic binder, must be removed before the fibers can be reused or further processed. One or more layers of continuous strips are conveyed to a heating zone where the strips 42 are supported along a predetermined path as a heating fluid is drawn rapidly through the strips. The heating fluid is controlled as to temperature, pressure and mass flow rate to insure that the binder is properly decomposed and that the products of decomposition are rapidly carried away from the strips to prevent heat buildup which could cause a temperature increase to the fusion point of the fibers. Process temperatures are thus suitably controlled to below the fusion temperature of the fiber material. The reclaimable fiber may be directly recycled, further processed as desired or, in the case where binder is still present on the fibers in unacceptable levels, these non-reclaimable fibers may be dumped for subsequent disposal. Products of binder decomposition are incinerated and form part of the heating fluid drawn through the strips.
A method of removing coatings from glass fibers in which the fibers are introduced into a bed fluidized by a gas at elevated temperatures, the gas converting the coatings to substances which leave the bed with the gases.
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.
The waste material processing system of the present invention includes a (1) waste material supply; (2) shredder; (3) moisture reducing device; (4) crusher having a rotatable screw auger positioned within a cavity of the crusher for crushing and conveying waste material and a pressurizing device such as a conduit attached to the discharge end of the cavity for exerting a backpressure upon a portion of the waste material positioned about the second end of the auger such that a portion of the scrap glass fibers in the waste material is crushed; (5) dryer; and (6) separating device for separating waste material having a mean average length of less than about 5 millimeters from oversized dried waste material. Also provided by the present invention is a process for recycling waste material using the system.
Systems and processes of the present invention for recycling glass fiber waste into glass fiber product include a supply of scrap glass fibers having a mean average length of less than about 5 millimeters; a crusher having at least one pair of rotatable rollers which rotate at essentially the same speed, the rollers having intermeshing protuberances for crushing scrap glass fibers passing therebetween; and an air separating device for separating a first portion of crushed glass fibers having a mean average length of less than about 3 millimeters from a second portion of oversize glass fibers.
