Both thermosetting resins and thermoplastic resins have special desireable properties that are possessed by one, but not the other. This investigation involved a study of the development of conjugated molded parts that possess both sets of desireable characteristics as well as a study of the molds necessary for making these parts. A new molding technique has been developed in which rapid heating and coolling is performed by means of high-frequency induction heating. In this study, we report on studies using a modified technique in which the mold is heated and coolled at arbitrary times during the molding process in an ordinary injection machine combined with a high frequency generator. A high-frequency heating inductor is embedded in the mold. The molding process that was developed is as follows: (1) An uncured solution of Diallylphthalate (DAP) is sprayed onto the mold cavity surface. (2) After closing the sprayed mold, a thermoplastic is injected at ordinary resin injection temperatures (to investigate their conjugation with DAP). (3) The mold is heated by high-frequency induction heating, which cures the DAP. (4) The mold is cooled and the molded part released from the mold.
The results that were obtauned are as follows: (1) The conditions for hardening the DAP were: mold temperature 140-150°C for 1-5mins. (2) The curing of the DAP: cured by heating after the conjugation. (3) Thermoplastics capable of conjugation with DAP: SAN and ABS resins.
This method has led to the successful development of a new conjugated molding process, in which a thermoplastic resin (such as DAP) reacts and cures in the mold, while being conjugated with an injected thermoplastic resin (such as SAN or ABS).

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The neck structure formed in polyethylene cylindrical rods under a tension-torsion combined stress was analyzed using wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC). The volume change of microvoids in the neck was investigated suing DSC and density measurements.
At the start of a neck, the crystal a-axis is oriented in the direction that is different from the equatorial direction. At the end of the neck, a fibrillar structure is formed. Bundles of fibers are oriented in the direction that is different from the axial direction due to the resultant force of the combined tensile and shear forces, which result sin a spiral orientation of the polymer chains. Microvoids are created during the plastic deformation as a fibrillar structure is formed. However, the volume of microvoids is reduced in the cold drawing region. As a result, it is suggested that the volume of microvoids created among the bundles of fibers is reduced with further twisting.

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The analysis of large deformation behavior of polymers is regarded as one of the most important subjects in the fields of film and fiber processing.
Neck formation and neck propagation as unique characteristics in large deformation of polymers was investigated by use of the finite element method (FEM). In the course of this study, a detailed analysis of the relationship between the criteria of the occurrence of neck propagation and an unique constitutive law for polymers was carried out.
From the analysis, the following results were obtained;
(1) Neck propagation occurs by a steep rise of the tangent modulus in the plastic deformation region.
(2) The occurrence of neck propagation was determined by the ratio of yield stress and tangent modulus just after the yield point.

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