摘要 |
A method comprising:
plasticating polymeric material in an extruder;
introducing a first dose of blowing agent into the polymeric material while plasticating the polymeric material in a first plastication period of a molding cycle;
introducing a second dose of blowing agent into the polymeric material while plasticating the polymeric material in the first plastication period of the molding cycle; and
injecting a mixture of blowing agent and polymeric material into a mold. |