Bubble assisted method for fast stripping plastic-aluminum composite material

Abstract

The invention discloses a method for bubble-aided quick peeling off of aluminum plastic composite materials. The method comprises: crushing the aluminum plastic composite material into pieces and placing the pieces in a separating agent; introducing gas into every liter of the separating agent at a flow speed of 50 to 500ml / min and heating to 80 to 90 DEG C; keeping the temperature for 10 to 40min to completely separate aluminum from plastic; then, respectively obtaining aluminum and plastic through filtration, floatation separation and drying; the gas is inert relative to the separating agent; and the separating agent comprises the following components in percentage by weight: 10 to 99.9 percent of organic carboxylic acid, 0.1 to 1 percent of surfactant and the balance being water. The method does not need special equipment and has simple operation and low cost; therefore, the method is propitious to industrial production and can realize respective reclaiming of aluminum and plastic, thereby not only improving the recycling value of the aluminum plastic composite material, but also reducing environmental pollution caused by wastes.

Description

technical field [0001] The invention relates to a separation method of aluminum-plastic composite materials, in particular to a method for rapidly destroying the force between aluminum foil and plastic in aluminum-plastic composite materials by using a chemical method and the combined action of air bubbles to realize automatic peeling of aluminum foil and plastic, and belongs to the field of environmental protection . Background technique [0002] The aluminum-plastic composite packaging material is a composite material with a multi-layer structure made of aluminum foil and plastic by heat pressing or bonding. The composite material not only utilizes the characteristics of soft texture, good ductility, easy processing, good barrier property, light and beautiful appearance of aluminum foil, but also utilizes the characteristics of easy processing, acid and alkali corrosion resistance and good strength of plastic. Aluminum-plastic composite packaging materials have the charac...

AI Technical Summary

Problems solved by technology

There are mainly: one, as described in the Chinese patent application with the publication number CN1337280A, using the principle that both metal aluminum and aluminum oxide can be dissolved in acid or alkali, the aluminum in the material is dissolved by an acid-soluble or alkali-soluble method, Thereby recycling plastics, and then making aluminum-containing waste liquid into polyaluminum chloride or aluminum sulfate, this method will not be able to obtain aluminum foil, which reduces the value of recycling, and this method has rarely been used to separate aluminum-plastic composite materials; the second is Use acidic substances to penetrate into the plastic layer, first dissolve the interface (aluminum oxide) between the plastic and aluminum, and then add a certain oxidant to protect the aluminum, so that part of the aluminum foil and plastic can be obtained. In this method, strong acidic substances are selected. Be that nitric acid is selected in CN1401443A Chinese patent application as publication number, be that sulfuric acid or phosphoric acid etc. are selected in CN101054446A Chinese patent application in publication number, in the aluminum-plastic separation research of document aluminum-containing waste plastics (Gu Guohua, Zhang Bo, mining and metallurgy engineering, 27 ( 5): 47-50, 2007) used hydrochloric acid. In these methods of selecting strong acids, because the acidity is too strong, the aluminum foil will react with the acid and the recovery rate of aluminum will become very low, which will also reduce the economy of recovery. sex

In the Chinese patent application with publication number CN1903965A, it is proposed to use slightly lower acidic aqueous acetic acid solution as the separating agent. The separation speed of this method is very slow under low-concentration acetic acid aqueous solution, and the separation efficiency is low. However, the separation cost is high for high-concentration acetic acid solution.

[0009] Looking at the aforementioned existing separation methods, there are disadvantages of low separation success rate, high separation cost, low recovery rate of aluminum foil and slow separation speed.

In addition, most of the separation methods have ignored a problem, that is, after the adhesive force between the aluminum foil and the plastic layer is destroyed, they are not actually peeled off, but stacked together. Due to the presence of a release agent in the middle, they still remain With a certain force, the aluminum foil and the plastic are still together when put into the water for flotation separation, and the peeling between the aluminum foil and the plastic is not actually completed