method for making flexible , noncarpeted thermoplastic articles , including floor mats . the method includes placing a flat slab of thermoplastic material in a cavity between first and second mold sections with each mold section having a mold surface for contacting a respective surface of the slab . the mold cavity is placed under vacuum and the mold sections are heated under compression to cause the thermoplastic material to heat and flow against the mold surfaces . the process further involves cooling the mold sections under compression and removing the floor mat from the mold sections . vacuum is maintained in the mold cavity by way of a check valve device during transition from the heated compression apparatus to the cooled compression apparatus and during the cooled compression step . in this general manner , a floor mat formed with a class a , textured finish and with a variable cross sectional thickness may be manufactured in a short cycle time .