Abstract: On a folding section of the thermoplastic sheet there is provided one or more thin-walled section, extending in a longitudinal direction of the folding section, whose minimum thickness is not less than 1/10 and not more than ? the thickness of the thermoplastic resin sheet. Thus, it is possible to provide a box in which rebound of the folding section is reduced and an operation efficiency upon setting up the box and putting goods into the box can be improved.

Abstract: On a folding section of the thermoplastic sheet there is provided one or more thin-walled section, extending in a longitudinal direction of the folding section, whose minimum thickness is not less than {fraction (1/10)} and not more than ⅔ the thickness of the thermoplastic resin sheet. Thus, it is possible to provide a box in which rebound of the folding section is reduced and an operation efficiency upon setting up the box and putting goods into the box can be improved.

Abstract: A process for manufacturing thermoplastic resin moldings in a short molding cycle but with good appearance, nearly free from resin and deformation, and free from weld lines on the surface. The process uses a mold assembly which includes a pair of male and female molds, either of which has two or more freely opening and closing resin feeding gates open to the cavity surface. Also, there is a mechanism for controlling the quantity of resin to be fed from each gate and the timing of the initiation of resin feeding.

Abstract: A process for producing a multilayer molded article in which a skin material is laminated to the surface of a thermoplastic resin core material which comprises feeding the skin material to the cavity of a pair of female and male molds which are not closed, subsequently feeding the molten thermoplastic resin to the cavity of the molds through a resin passageway provided in the molds, clamping both molds to shape the molten resin in the cavity of the molds and then cooling the resin under pressure, characterized in that the cooling under pressure is conducted so that the temperature for feeding the molten thermoplastic resin to the cavity of the molds is in the range of from 175.degree. to 195.degree. C., the clamping pressure at completion of the shaping is in the range of from 30 to 95 kg/cm.sup.2 and the product of the clamping pressure and the pressing time is in the range of from 100 to 1,500 kg/cm.sup.2.sec.