| 摘要 |
A method for separating a polymer such as polypropylene from a layered plastic material that includes a layer of polypropylene together with a layer of vinylidene chloride is provided. The layered plastic material is agitated in a bath of water and sand to wet the surfaces of the material. The layered plastic material is then agitated in a wash liquor of hot water, caustic, sand, and a surfactant to crack and strip the vinylidene chloride material from the polypropylene material. Sufficient caustic is included in the wash liquor to raise the pH of the wash liquor to pH 12 or greater. Agitation is by reversibly rotating a perforating basket containing the layered plastic material and the wash liquor at 10-20 revolutions per minute and by blowing air into the basket. The wash liquor and stripped vinylidene chloride are then drained away from the polypropylene. The polypropylene is rinsed with water to wash away residual wash liquor and stripped vinylidene chloride. Water is extracted from the rinsed polypropylene, which then may be extruded for reuse.
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