Process for reclaiming thermally strained polyester scrap material
First Claim
1. A process for reclaiming thermally strained polyester waste materials comprising the steps of:
- a) shredding a mixture of polyester waste materials, said mixture comprising polyesters of different molecular weights and different degrees of conversion, so as to form a shredded polyester mixture,b) melting said shredded mixture so as to form a molten material,c) filtering said molten material down to a particle size of about 5 to 10 microns, by removing those impurities having a particle size of equal to about 5 to 10 microns and removing those impurities having a size of greater than 5 to 10 microns, so as to produce a filtered melt,d) increasing by about 12 to about 150% as compared to the initial molecular weight of said filtered melt, the average molecular weight of said polyesters, by post-condensation, so as to produce a condensed mixture, ande) recovering said condensed mixture.
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Accused Products
Abstract
Reclaiming of polyester waste material for re-use in the production of high-quality PET plastic material comprises shredding, cleaning, sorting and postcondensing said waste materials. The shredded scrap material comprises polyester waste materials of various molecular weights and degrees of purifying. The shredded material is molten and filtered The filtered melt is either post-condensed in the molten state and then granulated or is first granulated and then subjected to a solid phase post-condensation. The granules obtained in each case are preferably fed into an extruder and extruded together with virgin raw material so as to produce a useful film or article.
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Citations
24 Claims
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1. A process for reclaiming thermally strained polyester waste materials comprising the steps of:
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a) shredding a mixture of polyester waste materials, said mixture comprising polyesters of different molecular weights and different degrees of conversion, so as to form a shredded polyester mixture, b) melting said shredded mixture so as to form a molten material, c) filtering said molten material down to a particle size of about 5 to 10 microns, by removing those impurities having a particle size of equal to about 5 to 10 microns and removing those impurities having a size of greater than 5 to 10 microns, so as to produce a filtered melt, d) increasing by about 12 to about 150% as compared to the initial molecular weight of said filtered melt, the average molecular weight of said polyesters, by post-condensation, so as to produce a condensed mixture, and e) recovering said condensed mixture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification