Abstract: A thin-wall deep drawn container having a molding depth vs. aperture caliber ratio of 2.0 or more, having a mean wall thickness of 0.1-0.6 mm at the sidewall and bottom of the hollow part and having a flange part of 1.4 mm or less in thickness at the aperture end can be produced from a thick sheet of a thermoplastic resin, preferably a crystalline plastic, having a thickness of 2 mm or more by plug-assist pressure forming.

Abstract: A cup-shaped deep-draw-formed article is formed by thermoforming a thermoplastic resin sheet characterized in that a concave forming mold and an ancillary mold which are in opposition to each other are used, said ancillary mold being equipped with a molding assist movable vertically to the opening face of the ancillary mold; the molding assist is first moved toward the opening of the ancillary mold; a preheated thermoplastic resin sheet interposed between said forming mold and ancillary mold is then expanded into the ancillary mold while moving the molding assist in contact with the sheet by introducing a pressured fluid into the forming mold; and when the molding assist reaches a predetermined position, a pressured fluid is introduced into the ancillary mold to press the sheet against the interior surface of the forming mold, thereby forming the sheet into the desired shape. This method can be applied to deep draw forming where the depth to opening diameter ratio is greater than 0.

Abstract: This invention provides a simple and advantageous method for producing plastic moldings with good surface gloss, very excellent transparency and high stiffness from crystalline polypropylene sheets manufactured by a generally employed industrial method without adversely affecting mechanical strength, shape retention at high temperatures and other properties according to a thermoforming process. This invention, more specifically, concerns a method for producing transparent polypropylene molded articles, characterized by heating a polypropylene sheet at a temperature higher than the melting point thereof, stretching it by more than 5%, rapidly cooling it to a temperature of not more than 120.degree. C., and then subjecting the thus treated sheet to thermoforming at a temperature below the melting point of the sheet.

Abstract: This invention provides a simple and advantageous method for producing plastic moldings with good surface gloss, very excellent transparency and high stiffness from crystalline polypropylene sheets manufactured by a generally employed industrial method without adversely affecting mechanical strength, shape retention at high temperatures and other properties according to a thermoforming process. This invention, more specifically, concerns a method for producing transparent polypropylene molded articles, characterized by heating a polypropyleneretention at high temperatures and other properties according to a thermoforming process. This invention, more specifically, concerns a method for producing transparent polypropylene molded articles, characterized by heating a polypropylene sheet at a temperature higher than the melting point thereof, stretching it by more than 5%, rapidly cooling it to a temperature of not more than 120.degree.