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A kind of method for preparing microporous waste polyester particles by gas foaming

A technology of gas foaming and waste polyester, applied in the direction of plastic recycling, recycling technology, etc., can solve problems such as residues, achieve the effects of reducing impurities, increasing yield, and accelerating the rate of depolymerization reaction

Active Publication Date: 2022-03-08
ZHEJIANG SCI-TECH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the added chemical blowing agent will inevitably have residues, which leads to the need to consider removing the chemical blowing agent in the subsequent impurity removal process

Method used

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  • A kind of method for preparing microporous waste polyester particles by gas foaming

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Add the recovered polyester (PET) bottle flakes, polyester (PET) slurry blocks, etc. into the screw granulator, and blow nitrogen gas together for melt granulation. The heating temperature of each zone of the screw granulator is 250°C, 260°C, 270°C, 280°C, 275°C, 275°C, 270°C, the feed percentage of the screw is 15%, the speed is 45rpm, the pressure is 75Mpa, the gas input It is 0.1 L / min, and the filter specification is 100 mesh. Nitrogen gas is selected for the formation of micropores, and the gas flow rate is 0.1L / min. The position of the gas is the fourth heating zone of the screw. After the extruded strip passes through the cooling water tank, the micropores are formed stably, and finally cut into pellets.

[0028] The micropore-containing waste polyester granules prepared by the waste polyester granulation step above have an average cell diameter of 115 μm and a relative density of 0.70.

[0029] Put the waste polyester (PET) pellets containing micropores into a ...

Embodiment 2

[0035] The recycled and sorted polyester (PET) film and polyester (PET) fiber products (curtains, carpets, clothing, etc.) are densified by thermal friction molding process at a temperature of 220°C, a pressure of 3MPa, and a time of 10 minutes. Foam material is formed, and then the foam material is melted and granulated in a twin-screw extruder. The heating temperature of each zone of the twin-screw extruder is 265°C, 270°C, 275°C, 280°C, 275°C, 270°C, 270°C, the feeding percentage of the screw is 30%, the screw speed is 60rpm, and the pressure is 4.5Mpa. The device specification is 200 mesh. Micropore formation selective access to CO 2 , the gas feed rate is 0.3 L / min, and the feed position is the fourth heating zone of the screw. After the granulation is completed, the micropore formation is stable after passing through the cooling water tank.

[0036] The microporous waste polyester granules prepared by the microporous waste polyester granulation step have a cell size of...

Embodiment 3

[0043] After cleaning and drying the recycled and sorted polyester (PET) bottle flakes and polyester (PET) pulp blocks, they are melted and granulated in a twin-screw extruder. The heating temperature of each zone of the twin-screw extruder is 260°C, 270°C, 280°C, 285°C, 275°C, 270°C, 270°C, the screw feeding percentage is 45%, the speed is 80rpm, and the pressure is 75Mpa. The percentage is 12%, the screw speed is 65rpm, the pressure is 7.5Mpa, and the filter device specification is 100 mesh. Micropore formers select N 2 :CO 2 It is a 1:1 mixed gas, and the gas feed rate is 0.5 L / min.

[0044] The average cell diameter of the microporous waste polyester granules prepared by the microporous waste polyester granulation step is 113 μm, and the relative density is 0.60. For the average cell diameter test, the average value of 100 average cell diameters was continuously measured by an optical microscope as the cell diameter. The test method for the relative density of micropor...

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Abstract

The present application relates to the field of regeneration and utilization of waste polyester, in particular to a method for preparing micropore-containing waste polyester particles by gas foaming. A method for preparing waste polyester granules containing micropores by gas foaming, the method comprising the following steps: 1) sorting the recovered waste polyester according to color, quality, and shape; 2) melting in a twin-screw extruder Granulation, gas is introduced during the granulation process, and micro-holes are formed on the surface and inside of waste polyester particles after cooling; the average cell diameter of waste polyester particles is 30-200 μm, and the relative density is 0.3-0.7. This method can not only make the waste polyester particles contain a large number of microporous structures, have a higher bulk density, increase the contact surface between the solvent and the solid particles, improve the depolymerization efficiency, but also avoid the introduction of impurities and improve the final performance of the product. .

Description

technical field [0001] The present application relates to the field of regeneration and utilization of waste polyester, in particular to a method for preparing micropore-containing waste polyester particles by gas foaming. Background technique [0002] Polyethylene terephthalate (PET) is polymerized from terephthalic acid or dimethyl terephthalate and ethylene glycol. Due to its good physical and chemical stability and processability, it is widely used in textiles, clothing, decoration, food packaging and other fields. However, due to the strong chemical inertness of PET under natural conditions, it is difficult to be biodegraded, and a large amount of waste polyester has caused great pressure on the environment. Therefore, recycling waste polyester products can achieve effective recycling of resources and reduce environmental pollution. Pollution has become an important issue in the polyester industry. [0003] At present, there are mainly physical and chemical methods fo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J9/12C08J11/24C08L67/02
CPCC08J9/122C08J9/0061C08J11/24C08J2203/06C08J2367/02C08J2300/30C08J2203/182C08J2205/044Y02W30/62
Inventor 王秀华王勇花泓静温馨邓倩倩曹宇恒
Owner ZHEJIANG SCI-TECH UNIV