Abstract: A process for forming a molded article having a multilayer structure which comprises successively injecting melts of at least two materials into the cavity portion of a mold, solidifying a part thereof in the cavity portion to form the multilayer structure, characterized in that as a first step, one of the molten materials is injected into the cavity portion and the portion of the injected molten material contacting with the mold surface is solidified to a predetermined thickness to form a skin layer; as the second step, the next molten materials is fed into the cavity, the unsolidified portion of the molten material previously fed is pushed out of the cavity and a part of the thus fed molten material is cooled and solidified from the surface of the mold to form the next layer; and the procedure of the second step is successively repeated using the remainder of the molten materials alternately, and the molded article produced by the above molding process.

Abstract: An injection moulding process for moulding a material in a mould having a mould cavity and at least one channel communicating with the mould cavity, each channel entering the mould at a respective mould inlet includes the steps of heating inner surface areas of the mould to a temperature above the heat distortion temperature of the material; supplying the molten material into the mould by way of at least one channel and subjecting the molten material to a propelling force, sufficient to propel it through the channel into the mould; causing the molten material in the mould to solidify; applying periodic forces to the material in the mould at a plurality of spaced-apart regions, first and second of the regions being located either side of molten material in the mould cavity, the periodic force being applied with a difference in phase so as to cause shear of molten material within the mould cavity between the first and second regions; cooling the mould below the heat distortion temperature of the resin while or