摘要 |
<p>The procedure consists of homogenizing and/or mixing a polymer material and raising its temperature in an extruder. The basic material is injected with at least one gas and an optional colorant before it is passed through the die to form a bar of the required diameter. The bar goes through a cooling tunnel to form a surface skin, and cut up to make stoppers. The stoppers are finished by polishing their surfaces and chamfering their ends. The procedure consists of homogenizing and/or mixing a basic polymer material and raising its temperature in an extruder (10) with a hopper (12), single barrel, a screw (14) and a die (16). The basic material is injected with at least one gas at a pressure of 0.2 - 0.6 g/cc and an optional colorant before it is passed through the die to form a bar of the required diameter. The bar goes through a cooling tunnel (22) where it is sprayed with water to form a surface skin, and cut up to make a series of stoppers of the same diameter. The stoppers are finished by polishing their surfaces and chamfering their ends.</p> |