An optical element is configured to transmit a light flux emitted from a light source having a single light source wavelength, and is formed from a material in which resin and glass fillers are mixed. A difference between respective refractive index change rates (dn/dT) of the resin and the glass fillers relative to a temperature change at least in a vicinity of the light source wavelength becomes 10.5×10.sup.5 or less.

Injection molding utilizing targeted heating of mold cavities when in a non-molding position, thereby facilitating enhancement of the appearance and strength of injection molding parts in a manner that does not significantly increase cycle times or energy consumption.

A method of manufacturing an optical component having micro-structures is described. The method detects a crystallization temperature within a crystallization temperature interval for fully filling the molding material into a mold cavity to rapidly produce the optical element having a micro-structure with a large area.

Techniques are described for injection molding. When material inside a cavity of a tool is solidified into a molded part, the tool imparts a finished surface onto the part, including sidewalls with a zero or low-draft angle. To allow separation from the cavity without using sleeves or sliders, the cavity is widened, just prior to the part being ejected. The tool is made from metal with a high coefficient of thermal expansion, so the size of the cavity can be manipulated using temperature control. Heat applied to an outer portion of the metal surrounding the cavity pulls the metal away from the part creating an air gap within the cavity. Carefully applied cooling to an inner portion of the metal blocks the heat and keeps the surface temperature under control, which preserves the finished surface on the part. When the air gap allows, the part releases from the cavity with the finished surface intact.

The present invention relates to a method for the production of injection-moulded, reinforced moulded parts, the fibre orientation of which is specifically adjusted on a local basis. Via suitable, dynamically controlled supplementary heating in the wall of the injection mould which is used (variotherm heatable channel), a local cavity region is hereby heated at the time of injection to a temperature in the region of or above the solidification temperature (in any case above the crystallisation temperature in the case of partially crystalline plastic materials or above the glass transition temperature in the case of amorphous plastic materials) of the polymer (plastic material moulding compound).

An injection molded article obtained by injection molding a thermoplastic resin composition comprising 100 parts by mass of a thermoplastic resin and 50 parts by mass or less of at least one of a filler and a colored metallic pigment, wherein at least one weld exists, and a long diameter of 95% by mass or more of the filler existing within a cross-sectional depth of 50 μm or less from a surface of the weld is parallel to the surface of the weld.

Disclosed are: a polypropylene-based resin composition comprising 100 parts by mass of polypropylene-based resin (A) (provided that, when the polypropylene-based resin includes other resins and/or inorganic filler, the total amount of the polypropylene-based resin and other resins and/or inorganic filler is taken as 100 parts by mass), 0.80 to 5.0 parts by mass of on or more types of aluminum flakes (B) having an average particle size of 5 to 90 μm, and 0.005 to 0.06 parts by mass of carbon black (C); and a molded article obtained by injection-molding this polypropylene-based resin composition. The polypropylene-based resin composition and the molded article obtained from this are excellent in a flip-flop metallic feeling, a heavy luxury feeling, light resistance and a feeling of luminance.

Techniques are described for injection molding. When material inside a cavity of a tool is solidified into a molded part, the tool imparts a finished surface onto the part, including sidewalls with a zero or low-draft angle. To allow separation from the cavity without using sleeves or sliders, the cavity is widened, just prior to the part being ejected. The tool is made from metal with a high coefficient of thermal expansion, so the size of the cavity can be manipulated using temperature control. Heat applied to an outer portion of the metal surrounding the cavity pulls the metal away from the part creating an air gap within the cavity. Carefully applied cooling to an inner portion of the metal blocks the heat and keeps the surface temperature under control, which preserves the finished surface on the part. When the air gap allows, the part releases from the cavity with the finished surface intact.

A thermal management system that provides metal mold surface temperature control using cyclic process thermodynamics to enhance plastic material flow and curing conditions making it possible to produce resin rich molded plastic surfaces without micro cracks or fissures to which contaminant particles can adhere or to which dirt can attach.

Methods for preparing thermoplastic automotive appliques include applying heat from an auxiliary heater to a tool cavity of a forming tool. The auxiliary heater is activated for a period of time until a temperature of the heated tool cavity is heated to less than or equal to about a melting temperature of the thermoplastic. The heated tool cavity is filled with the thermoplastic, and a cooling fluid is pulsed through the forming tool. The thermoplastic applique is then removed, and the supply of cooling fluid is turned off.