CN109624360B

CN109624360B - Regeneration method of waste polyimide film

Info

Publication number: CN109624360B
Application number: CN201811435044.1A
Authority: CN
Inventors: 陈道明; 卢德明; 彭凯嘉
Original assignee: Sichuan Plasking Sci Tech Co ltd
Current assignee: Sichuan Plasking Sci Tech Co ltd
Priority date: 2018-11-28
Filing date: 2018-11-28
Publication date: 2020-12-08
Anticipated expiration: 2038-11-28
Also published as: CN109624360A

Abstract

The invention discloses a regeneration method of a waste polyimide film and a fabric, which comprises the following steps: firstly, cutting the collected polyimide film into pieces with the length and the width of about 5-10cm respectively by a cutter, and then sending the pieces into a normal-temperature washing tank for washing; feeding the polyimide film crushed aggregates after the impurities are removed into a double-screw extruder to be melted and extruded into an extrudate; thirdly, the extruded material is sent to a filter for hot filtration, and the filtered molten liquid is spun by a spinneret plate to form filaments; fourthly, the filiform substance is sent into a hydrolysis tower for hydrolysis; fifthly, feeding the crystallized mixed solution into a filter for filtering under the stirring state, drying the filtered crystal in a dryer, and then preparing a new polymer film by taking the dried crystal as a raw material, and rectifying the liquid in a rectifying tower to recover light components and heavy components. The invention prepares a new polymer film by taking the regenerated polyimide as the raw material again, reduces the environmental pollution and changes waste into valuable.

Description

Regeneration method of waste polyimide film

Technical Field

The invention relates to a regeneration method of a waste polyimide film.

Background

Along with the improvement of living standard of people, the plastic waste is more and more, and the environmental protection is greatly influenced.

Because the polyimide film cannot be degraded by adopting a burying method by abandoning the polyimide film, a reasonable method for utilizing the polyimide film by wastes is not found at present.

Disclosure of Invention

The invention aims to provide a regeneration method of a waste polyimide film, which regenerates polyimide and then takes the regenerated polyimide as a raw material to prepare a new polymer film, thereby reducing environmental pollution and changing waste into valuable.

The technical scheme is as follows: a regeneration method of waste polyimide films comprises the following steps:

firstly, cutting the collected polyimide film into pieces with the length and the width of about 5-10cm respectively by a cutter, and then sending the pieces into a normal-temperature washing tank for washing;

feeding the polyimide film crushed aggregates after the impurities are removed into a double-screw extruder to be melted and extruded into an extrudate;

thirdly, the extruded material is sent to a filter for hot filtration, and the filtered molten liquid is spun by a spinneret plate to form filaments;

and fourthly, the filiform matters are sent into a hydrolysis tower for hydrolysis, the filiform matters enter from the upper left part of the hydrolysis tower, water vapor enters from the bottom of the hydrolysis tower, the temperature of the hydrolysis tower is controlled to be 250 ℃, the pressure is controlled to be 35-40 atm, the hydrolysis time is 1.5 hours, and the water: the weight ratio of the filaments is 10:1, feeding the hydrolyzed solution into a crystallization tower from the upper part of the right wall of the hydrolysis tower for crystallization after hydrolysis, and returning insoluble substances at the bottom of the hydrolysis tower to a double-screw extruder for melting and extruding again;

fifthly, feeding the crystallized mixed solution into a filter for filtering under the stirring state, drying the filtered crystal in a dryer, and then preparing a new polymer film by taking the dried crystal as a raw material, and rectifying the liquid in a rectifying tower to recover light components and heavy components.

Preferably, the melt extrusion exit temperature is about 260 ℃.

Preferably, the mesh number of the spinneret plate is 100-150.

Preferably, a separation plate is arranged in the hydrolysis tower, the separation plate is vertically arranged, the separation plate has a certain distance from the top of the tower and the bottom of the tower, and the distance between the separation plate and the left tower wall is smaller than the distance between the separation plate and the right tower wall.

Preferably, the distance between the partition plate and the left tower wall is: the distance between the partition plate and the right tower wall is 1: 2.

Preferably, the quaternary ammonium type cationic polymer compound is added into the hydrolysate of the hydrolysis tower.

Preferably, the quaternary amine type cationic polymer compound is added in an amount of 0.1 wt% based on water.

Compared with the prior art, the invention has the following principle and beneficial effects:

the invention prepares a new polymer film by taking the regenerated polyimide as the raw material again, reduces the environmental pollution and changes waste into valuable.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The invention will be further explained with reference to the drawings.

A recycling method of waste polyimide film as shown in fig. 1, comprising the steps of:

firstly, the collected polyimide film is cut into the sizes of 5-10cm in length and width by a cutter 1, and then the crushed materials are sent into a normal-temperature washing tank 2 for washing, so that dust and oil impurities are removed.

And feeding the polyimide film crushed aggregates after the impurities are removed into a double-screw extruder 3 for melt extrusion and extrusion, wherein the temperature of a melt extrusion outlet is about 260 ℃.

Thirdly, the extruded material is sent to a filter 4 for hot filtration, the filtered melt liquid is spun by a spinneret plate 5 to form filaments, the mesh number of the spinneret plate 5 is 100-plus 150, if the mesh number is too large, the subsequent decomposition is influenced, if the mesh number is too small, the melt liquid can be remained on the spinneret plate 5, and if the mesh number is 100-plus 150, the subsequent decomposition is sufficient and the spinneret plate 5 cannot be blocked.

And fourthly, the filiform matters are sent into a hydrolysis tower 6 for hydrolysis, the filiform matters enter from the upper left part of the hydrolysis tower 6, and the water vapor enters from the bottom of the hydrolysis tower 6. The temperature of the hydrolysis tower 6 is controlled to be about 250 ℃, the pressure is controlled to be 35-40 atmospheric pressure, the hydrolysis time is 1.5 hours, and the weight ratio of water: the weight ratio of the filaments is 10:1, the hydrolyzed solution is sent to a crystallization tower 7 from the upper part of the right wall of a hydrolysis tower 6 for crystallization after hydrolysis, and insoluble substances at the bottom of the hydrolysis tower 6 return to a double-screw extruder 3 for melting and extruding again.

Be provided with the division board in the tower of hydrolysising 6, the division board is vertical to be established, and the division board all has certain distance from the top of the tower and the bottom of the tower, and the distance between division board and the left tower wall is less than the distance between division board and the right tower wall, the distance between division board and the left tower wall: the distance between the partition plate and the right tower wall is preferably 1:2, and the arrangement is favorable for decomposition, so that the decomposition is more complete.

During hydrolysis, a small amount of quaternary amine type cationic polymer (commercially available) can be added into the hydrolysate, and the quaternary amine type cationic polymer is used for removing pigments in a hydrolysis reaction liquid on one hand and is helpful for flocculation and degradation of insoluble substances on the other hand, so that the yield of products in the whole process is improved. The addition amount of quaternary ammonium type cationic polymer compound is 0.1% of water.

Fifthly, feeding the crystallized mixed solution into a filter 8 for filtering under the stirring state, feeding the filtered crystal into a dryer 9 for drying, then taking the dried crystal as a raw material for preparing a new high molecular film, and feeding the filtered liquid into a rectifying tower 10 for rectifying and recovering light components and heavy components.

Through the process, only less than 1.5% of residues are finally taken as final waste materials by using the dry polyimide film crushed material (namely drying the polyimide film crushed material without impurities to remove water) without impurities, and the final waste materials are treated by the prior art.

Claims

1. A regeneration method of waste polyimide films comprises the following steps:

firstly, cutting the collected polyimide film into crushed materials with the length and the width of 5-10cm respectively by a chopper, and then sending the crushed materials into a normal-temperature washing tank for washing;

thirdly, the extrudate is sent into a filter for hot filtration, and the filtered melt liquid is spun by a spinneret plate to form filaments;

and fourthly, the filiform is sent into a hydrolysis tower for hydrolysis, the filiform enters from the upper left part of the hydrolysis tower, the water vapor enters from the bottom of the hydrolysis tower, the temperature of the hydrolysis tower is controlled at 250 ℃, the pressure is controlled at 35-40 atmospheric pressure, the hydrolysis time is 1.5 hours, and the filiform is converted into water vapor: the weight ratio of the filaments is 10:1, feeding the hydrolyzed solution into a crystallization tower from the upper part of the right wall of the hydrolysis tower for crystallization after hydrolysis, and returning insoluble substances at the bottom of the hydrolysis tower to a double-screw extruder for melting and extruding again;

fifthly, feeding the crystallized mixed solution into a filter for filtering under the stirring state, drying the filtered crystal in a dryer, and then preparing a new polymer film by taking the dried crystal as a raw material, and rectifying the filtered liquid in a rectifying tower to recover light components and heavy components.

2. The recycling method of waste polyimide films according to claim 1, wherein: the melt extrusion exit temperature was about 260 ℃.

3. The recycling method of waste polyimide films according to claim 1, wherein: the mesh number of the spinneret plate is 100-150.

4. The recycling method of waste polyimide films according to claim 1, wherein: the hydrolysis tower is internally provided with a separation plate which is vertically arranged, the separation plate has a certain distance from the top and the bottom of the tower, and the distance between the separation plate and the left tower wall is smaller than the distance between the separation plate and the right tower wall.

5. The recycling method of waste polyimide films according to claim 4, wherein: distance between the partition plate and the left tower wall: the distance between the partition plate and the right tower wall is 1: 2.

6. The recycling method of waste polyimide films according to claim 1, wherein: and adding a quaternary amine type cationic high molecular compound during hydrolysis.

7. The recycling method of waste polyimide films according to claim 6, wherein: the addition amount of the quaternary ammonium type cationic macromolecular compound is 0.1 wt% of water.