TW201501822A - Method for washing polyvinyl alcohol-based material containing iodine - Google Patents

Abstract

A method for washing a polyvinyl alcohol (PVA) -based material containing iodine comprises steps as crushing a PVA-based material containing iodine into debris, putting those PVA-based debris into a spiral transmission unit having an alkaline solution on the bottom thereof for dissolving iodine out of those PVA-based debris, delivering those debris into a washing unit for a cleaning treatment by use of water to remove iodine on surfaces of those PVA-based debris, and at last dehydrating the cleaned PVA-based debris in a squeezing manner for obtainment of polyvinyl alcohol without iodine. In such a case, the iodine contained in a polyvinyl alcohol-based material can be properly effectively dissolved out of and separated from the material, and the PVA material can be further recycled for environmental purposes and avoiding a waste of resources.

Description

Cleaning method containing iodine PVA

The invention relates to a cleaning method for iodine-containing PVA, in particular to a method for separating iodine contained in PVA (polyvinyl alcohol), so that the PVA can be collected and reused, and indeed achieves environmental protection and avoids waste of resources. The effect of the cleaning method of iodine-containing PVA.

According to the polarizing plate, there is a PVA (polyvinyl alcohol) layer which has good light transmittance and can generate a polarizing mechanism, and the PVA layer adsorbs iodine complex or dichroic dye by a light transmissive PVA film to make iodine Ions or dyes diffuse into the PVA film and are made by stretching the PVA film after micro-heating. Since the molecular arrangement is in a certain direction after stress extension, the specific wave is used for the light by the iodine complex and the dichroic dye. Absorbed, and can achieve the polarizing effect.

Due to the production of a PVA layer with a polarizing mechanism, a large amount of cutting waste and defective products are generated, and most of these wastes and waste products are currently treated by incineration or landfill, but the PVA layer having a polarizing mechanism contains iodine. Therefore, the way of incineration or landfill treatment will cause air and environmental pollution.

Therefore, if the waste iodine-containing PVA can be recycled, it can not only increase the utilization value of waste PVA and avoid waste of resources, but also avoid environmental problems caused by waste PVA.

The main object of the present invention is to provide a cleaning method for iodine-containing PVA capable of recovering iodine-containing PVA to increase the reuse value of PVA.

The above main object of the present invention is achieved by the following specific technical means:

A cleaning method for iodine-containing PVA, comprising the following steps:

Step 1: directly pulverize the iodine-containing PVA (polyvinyl alcohol) to form a plurality of female fragments of predetermined size;

Step 2: The mother chips are sent to the screw conveying unit, and the bottom of the screw conveying unit is left with an alkaline solvent, so that the mother pieces can be thoroughly immersed in contact with the alkaline solvent during the screw conveying process to PVA. Iodine dissolution

Step 3: Washing the mother fragments in the second step to wash the mother fragments in the second step to remove the dissolved iodine adhered to the surface;

Step 4: Finally, the mother pieces after the third step of washing are dehydrated to filter the washed mother pieces, so that PVA without iodine can be obtained.

The cleaning method of the iodine-containing PVA as described above, wherein, in the first step, the pulverized mother chips can be further concentrated and stored in the storage tank for use.

The cleaning method of the iodine-containing PVA as described above, wherein the alkaline solvent described in the second step is a biological alkaline solvent or a chemically basic solvent.

The iodine-containing PVA cleaning method as described above, wherein the chemically alkaline solvent is preferably one selected from the group consisting of sodium hydroxide, bleach, acetone or alcohol.

The method for cleaning iodine-containing PVA as described above, wherein the biological alkaline solvent is selected from the group consisting of plant alkaline solvents.

The cleaning method of the iodine-containing PVA as described above, wherein in the third step, the PVA mother chips which have completed the second step are sent to the cleaning conveyor for washing.

The cleaning method of the iodine-containing PVA as described above, wherein in the fourth step, the PVA mother chips which have completed the third step are sent to the filter press for dehydration by extrusion.

The beneficial effects of the invention are:

1. By pulverizing the PVA into a smaller size mother chip, the contact area can be increased to improve the processing efficiency.

2. The iodine in the PVA is dissolved by an alkaline solvent. After the PVA is washed, the PVA can be collected and recovered to increase the utilization value of the PVA and reduce the generation of waste.

For a more complete and clear disclosure of the technical content, the purpose of the invention and the effects thereof achieved by the present invention, it is explained in detail below, and please refer to the drawings and drawings:

Please refer to the first figure, which is a flow chart of the steps of the cleaning method of the iodine-containing PVA of the present invention. The steps of the cleaning method of the iodine-containing PVA of the present invention include:

Step one (S1): smash. PVA is pulverized to form a plurality of mother chips of a predetermined size; wherein, the PVA is preferably pulverized in a pulverizer; wherein the pulverized mother chips can be further collectively stored in a storage tank for use;

Step 2 (S2): Iodine contained in the PVA is separated. Feeding the female chips into a screw conveyor, the spiral conveyor injecting a little alkaline solvent to keep the alkaline solvents at the bottom of the screw conveyor; when the female chips enter the screw conveyor, The mother chips and the alkaline solvent are tumbled and agitated in the screw conveyor as the screw conveyor rotates, so that the mother chips fully react with the alkaline solvent, and the iodine contained in the mother chips is dissolved; Wherein, the alkaline solvent is a biological alkaline solvent or a chemical alkaline solvent; wherein the chemical alkaline solvent is preferably selected from the group consisting of sodium hydroxide, bleach, acetone or alcohol, and most preferably sodium hydroxide. Wherein the biological alkaline solvent is selected from the group consisting of plant alkaline solvents;

Step 3 (S3): Wash. The PVA mother chip which has completed the second step and dissolves the iodine is washed, and the PVA mother chip which dissolves the iodine is sent into a cleaning conveyor, and is directly rinsed with water to further complete the second step. The remaining iodine adhered to the surface of the PVA mother chip from which iodine is dissolved is removed, so that the iodine-free PVA mother chip can be obtained;

Step 4 (S4): Dehydration. The PVA mother chips which have not been iodine after the third step of cleaning are sent to a filter press for dehydration; the filter presses are pressed to remove the PVA mother fragments which are free of iodine. The moisture contained therein was filtered to obtain a PVA mother fragment which was free of iodine and which was slightly dried.

The iodine component contained in the PVA can be dissolved and separated by the cleaning method of the present invention to obtain a PVA containing no iodine and being slightly dried, so that the iodine-free and slightly dry PVA mother fragments can be recycled and reused, thereby reducing resources. Waste and waste generation meet environmental requirements.

The above is only a part of the embodiments of the present invention, and is not intended to limit the present invention. It is intended to be included in the scope of the present invention.

In summary, the embodiments of the present invention can achieve the expected use efficiency, and the specific technical means disclosed therein have not been seen in similar products, nor have they been disclosed before the application, and have completely complied with the patent law. The regulations and requirements, the application for invention patents in accordance with the law, and the application for review, and the grant of patents, are truly sensible.

<present invention>

(S1)‧‧‧Step one

(S2)‧‧‧Step 2

(S3) ‧ ‧ Step 3

(S4)‧‧‧Step four

First: Flow chart of the cleaning step of the iodine-containing PVA of the present invention

(S1)‧‧‧Step one

(S2)‧‧‧Step 2

(S3) ‧ ‧ Step 3

(S4)‧‧‧Step four

Claims (10)

A cleaning method comprising iodine PVA, comprising the following steps: Step 1: directly pulverizing iodine-containing PVA (polyvinyl alcohol) to form a plurality of female fragments of predetermined size; Step 2: feeding the female fragments into the spiral conveying unit The bottom of the spiral conveying unit is left with an alkaline solvent, so that the mother pieces can be fully tumbling contact with the alkaline solvent during the screw conveying process to dissolve the iodine in the PVA; Step 3: Step 2 The mother pieces are washed to wash the mother pieces from the second step to remove the dissolved iodine adhered to the surface; Step 4: Finally, the mother pieces after the third step of washing are dehydrated to be washed. After the net, the mother fragments are filtered, so that PVA without iodine can be obtained. The cleaning method of the iodine-containing PVA according to the first aspect of the invention, wherein in the first step, the pulverized female chips can be further concentrated and stored in the storage tank for use. The method for cleaning iodine-containing PVA according to claim 1 or 2, wherein the alkaline solvent described in the second step is a biological alkaline solvent or a chemically basic solvent. The method for cleaning iodine-containing PVA according to claim 3, wherein the chemical alkaline solvent is preferably selected from one of sodium hydroxide, bleach, acetone or alcohol. The cleaning method of the iodine-containing PVA according to the fourth aspect of the invention, wherein in the third step, the PVA mother chips which have completed the second step are sent to the cleaning conveyor for washing. The method for cleaning iodine-containing PVA according to claim 5, wherein in step 4, the PVA mother chip which has completed step 3 is sent to the filter press for dehydration by extrusion. The method for cleaning iodine-containing PVA according to claim 3, wherein the biological alkaline solvent is selected from the group consisting of plant alkaline solvents. The cleaning method of the iodine-containing PVA according to the seventh aspect of the invention, wherein in the third step, the PVA mother chip which has completed the step 2 is sent to the cleaning conveyor for washing. The cleaning method of the iodine-containing PVA according to the eighth aspect of the invention, wherein in the fourth step, the PVA mother chips which have completed the third step are sent to the filter press for dehydration by extrusion. The cleaning method of the iodine-containing PVA according to claim 1 or 2, wherein in step 4, the PVA mother chips which have completed the third step are fed into a filter press for dehydration.