HU184400B - Method for utilizing fibreglass reinforced plastic waste - Google Patents

Abstract

The present invention relates to a method of recovering laminate waste from glass fiber reinforced plastics (mostly polyester or epoxy resin) by cutting the waste with a high shear rotary knife. Due to the shear force, the laminate breaks down into glass fibers with a relatively narrow boundary that can be clamped. The resulting resin coated glass fibers can be used in the applications of normal cut glass fibers. The procedure consists of the following main steps: - classification of waste - crushing of waste - grading of chips and - finishing of chips with adhesion enhancing and / or dispersing agents. The steps in the process depend on the characteristics of the processed waste and the area of application of the generated glass fiber. The process according to the invention can be used to produce pressed resins based on synthetic resin, preferably containing from 20 to 50% by weight of regenerated laminate waste. The characteristic feature of these presses is that they contain partially or wholly regenerated waste as a reinforcing material. It is also possible to produce glass fiber reinforced thermoplastic molding materials by this process. -1-

Description

The present invention relates to a process for the utilization of laminate waste (e.g., Edging waste) formed in the production of glass fiber reinforced plastic (mostly polyester or epoxy resin) products.

As is known in the art, most technologies for manufacturing fiberglass-reinforced resin products are, for technological reasons, larger pieces than the finished product, which are cut to size when gelled or completely cured. This results in a significant amount of deburring waste, which can be further increased by the amount of irreparable waste products. Disposal of this waste. destruction is usually a serious problem. The most common method of disposal is the incineration of waste, which however heavily pollutes the environment.

The use of thermoset plastic waste is described in U.S. Pat. No. 2,550,879. s. USSR disclosure document stating that waste is disposed of and reused in 50% fresh material. However, the use of frame or fiber-reinforced materials is not mentioned.

The object of the present invention was to provide a process for producing a recyclable raw material from waste. Because the resin cross-linking is an irreversible chemical process, it has proven expedient to recover the glass fiber content and make it reusable, which naturally results in the most economical recovery of wastes from the manufacture of high glass containing products (e.g.

The essence of the process is to cut the laminate waste into a high-shear rotary chopper. Due to the high shear force, the laminate is broken into glass fibers with fiber lengths that can be clamped within relatively narrow limits. However, a significant part of the resin is ground to a powder or small particles which can be separated from the system if necessary. Of course, the glass fibers are coated with synthetic resin.

The procedure consists of the following main steps:

1. Laminate waste classification.

Classification is based on the glass content. Another important consideration is whether the laminate surface is gelcoat coated.

2. Laminate waste shredding.

Shredding is done with a simple rotary knife grinder that can be used to regenerate thermoplastics, but with special knife inserts and knife adjustment to suit the application. The length of the resulting glass fibers can be controlled by the size of the shredder insert. This can also be done with mobile equipment, so the shredded waste can be easily transported to a recycling site.

3. Classification of the chips; separation of large resin particles based on specific gravity difference (eg by centrifugation).

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4. Surface treatment of chips with tackifiers and / or dispersants.

Each step of the process may vary slightly depending on the characteristics of the waste processed and the area of application of the recovered fiberglass.

Applications of regenerated fiberglass are the overwhelming majority of technologies that use cut or milled fiberglass, such as polyester premix presses (BMCs), high strength outer plasters and θ chassis coatings, reinforcement of PU foams and thermoplastics, reinforced paper production.

Application examples:

1. Preparation of resin based pre-mix:

With intensive mixing (eg with Z-lever mixer) we prepare the following ₅ mixtures:

wt% unsaturated polyester resin (2% wt based on resin with BP-50 catalyst) wt% filler (eg talc) q 35 wt% regenerated laminate waste (max. fiber length 15 mm) produced by the process of the present invention.

From the mixture thus produced, various products are obtained by hot pressing (120 ° C to 150 ° C), e.g. pipe fittings (loose and rigid flanges 25) can be produced. In order to achieve a higher mechanical strength during pressing, the press mass described herein can be combined with a conventionally prepared prepreg or a press compound. with fiberglass reinforcing materials (roving, quilt, roving)

2. Improving the mechanical properties of thermoplastic materials. It is known that during the processing of thermoplastic materials (mainly by injection molding), in order to increase the mechanical properties (in particular, bending stiffness), during the manufacture of granules, cut or milled glass fibers are mixed with the raw material.

To the injection molding material (e.g., polyamide) is added in the known manner, similar to the use of fiberglass, 5 to 30% by weight of reclaimed laminated waste 40 produced, graded and surface treated according to the invention. The granulate thus produced is then injected into the final product in a known manner.

Claims (1)

PATENT CLAIMS A process for recovering fiberglass from fiberglass reinforced resin waste by pre-sorting the waste into a max. It is ground to 50 mm length of fibrous material, then dispersant and tackifier 50 is added and finally graded according to specific gravity and fiber length.