A method of injection molding a building product includes providing an injection mold with a plurality of gates located adjacent a perimeter of the injection mold. The method further includes commingling a first material and a second material into a flow, the second material comprising a color that contrasts with a color of the first material and injecting the commingled flow into the plurality of gates to form a building product. Thereafter, the method includes removing the building product from the injection mold. The second material extends through an interior of the building product and appears as contrasting streaks on an exterior of the building product to form a variegated grain appearance. The method also includes notching a portion of the building product, such that the building product has a substantially linear grain in an exposed portion thereof.

A method of forming a thin-walled skin includes coating at least one side of a mold cavity of a molding tool, evacuating air from the mold cavity, and filling the mold cavity with a molten polymeric resin. Among other optional variations of the disclosed method, an inert gas is injected into the molten polymeric resin simultaneously with the step of filling the mold cavity with a molten polymeric resin. As a result, high quality, large, thin-walled skins are produced by the teachings of the present disclosure.

After the injection shaft moves backward and the gas is supplied into the injection chamber, it is desired to accurately control the gas supply amount in the injection device in which the injection shaft is moved forward to compress and dissolve the gas in the molding material in the injection chamber. An injection device of the disclosure supplies a gas into an injection chamber via a gas supply hole which passes through an injection shaft and is opened at a tip surface of the injection shaft. The injection device and a gas dissolution method thereof according to the disclosure perform backward and forward movement of the injection shaft for a plurality of cycles. The injection device of the disclosure has at least one seal ring and at least one piston ring aligned in an axial direction on an outer circumferential surface of the injection shaft.

Provided is an injection molding method for resin that contains reinforcing fiber, the method being capable of easily eliminating uneven distribution of added components. The injection molding method is provided with: a plasticizing step for supplying resin pellets P and added components to a cylinder equipped with a screw 10, which has a rotating axis as the center is capable of rotating normally and in reverse, and generating molten resin by rotating the screw 10 in the normal direction; and an injecting step for injecting the molten resin M comprising the added components into a cavity. In the plasticizing step, a reverse rotation operation for reversing the rotation of the screw 10 is performed or a screw-stopping operation of stopping the normal rotation of the screw 10 is performed with a prescribed timing and for a prescribed period.

A mechanism for mixing a supercritical fluid and a polymer raw material melt provided by the present invention includes a hot-melting unit, a mixing unit, and a supercritical fluid supplying unit. The mixing unit, independently of the hot-melting unit, receives a polymer melt from the hot-melting unit and a supercritical fluid from the supercritical fluid supplying unit, respectively, and mixes the polymer melt and the supercritical fluid into a homogenous single-phase solution. The hot-melting unit is provided with a pushing member for pushing a polymer raw material. The mixing unit is provided with a mixing rotor for mixing the polymer melt and the supercritical fluid.

A masterbatch (C) containing thermally expandable microcapsules (A) and a carrier resin composition (B) is provided. The carrier resin composition (B) contains a carrier resin (B1) and a plasticizer (B2), the carrier resin (B1) being an acrylic resin having a weight average molecular weight of 8,000 or more and 350,000 or less, and the plasticizer (B2) being an acrylic plasticizer having a weight average molecular weight of 1,000 or more and 20,000 or less. The carrier resin composition (B) is substantially compatible with a polycarbonate resin and has a shear viscosity of 1.0 Pa.Math.s or more and 1.510.sup.6 Pa.Math.s or less at 80 C. The occurrence of whitening is suppressed and a good appearance can be obtained in an injection molded foam made with the masterbatch. A polycarbonate resin composition, an injection molded foam, and a method for producing an injection molded foam are provided.

A method for producing an injection molded article including a highly-filled fiber-reinforced resin composition includes a step of charging a first resin feedstock including a thermoplastic polymer into an injection molding machine through a first inlet port; a step of charging a second resin feedstock into the injection molding machine through a second inlet port disposed downstream of the first inlet port, the second resin feedstock including a masterbatch that includes long fibers impregnated with a resin mixture including a thermoplastic polymer and an acid-modified polyolefin; a step of melt-kneading the first resin feedstock and the second resin feedstock together in the injection molding machine to give a fiber-reinforced resin composition melt; and a step of injection molding the fiber-reinforced resin composition melt in a mold, the first resin feedstock being charged intermittently or continuously from the start to the end of the charging of the second resin feedstock.

An injection moulding machine makes a long fiber length of reinforcing fibers contained in a resin moulded article to produce a high strength, rigidity, and wear and fatigue resistant resin moulded article. In a screw fiber kneading stage in an injection moulding machine, a longitudinal cross-sectional area between first flights feeding a base resin and reinforcing fibers in a feeding direction in conjunction with rotation of the screw while suppressing passage of the base resin and the reinforcing fibers is made greater at an upstream side than a downstream side in the feeding direction. In an article production method, an elongated roving containing the reinforcing fibers is continuously supplied as it is in the elongated state to the base resin plasticized inside the cylinder of the injection moulding machine to prepare a fiber-reinforced resin and the prepared fiber-reinforced resin is made to fill a mould internal space of a mould.

An additive feeder system is presented which is operable for use in a plastic injection molding machine including an injection component and a clamping component. The additive feeder system includes a feeder control unit, a feeder supply mechanism and feeder dosage control mechanism. The additive feeder system is operable to provide a specific dosage of the additive materiel in real-time for mixing with the raw material to achieve desired product characteristics. The additive feeder system may be applied to injection molding and extrusion, such as molding processes, plastic molding processes, blow molding, compression molding, extrusion molding, injection molding and laminating, and comprising additive feeders, for example for color mixing and nutrient supplements.

Blowing agent introduction polymeric foam processing methods and systems are described herein.