Abstract: Thermoplastic objects are manufactured by placing an extruded thermoplastic blank while still in a substantially molten state within a mold cavity defined on all sides by rigid walls with at least one of the walls being movable relative to the other walls. The movable wall extends substantially completely over the entire area of one side of the article to be formed and it is moved to apply pressure to the article while also simultaneously applying heat to the one side against which the wall is pressed. The other walls forming the mold cavity are cooled during the forming process.