The invention relates to a method for producing a tube by injection molding a thermoplastic molding compound by using an injection-molding device with an article cavity, which defines the outer contour of the tube, and with an injection device, which is designed to drive a profile through the article cavity filled with the thermoplastic molding compound and thereby displace a liquid core of the molding compound, wherein the method envisages closing an opening of the article cavity with a mould core, which with the article cavity forms a hollow mould space and which has a secondary cavity that can be filled with the molding compound. After the filling of the article cavity and the hollow mould space with the thermoplastic molding compound, a projectile is driven through the article cavity, wherein the projectile displaces the molding compound into the secondary cavity. Subsequently, the mould core with the filled secondary cavity is pulled, wherein the displaced molding compound is separated from the molding compound forming the tube. The invention also relates to an injection-molding device for carrying out the method.

A holding portion having a diameter larger than that of a cavity is formed in communication with the cavity, in an area of a two-part type mold, the area including a portion corresponding to an annular groove. Subsequently, an insert member formed in a cylindrical shape and provided with, on an outer circumferential surface, the annular groove having no step in a groove surface is fitted to the holding portion, and then the mold is closed. On an inner circumferential surface of the insert member, a surface treatment layer having a surface roughness rougher than those of other portions of the insert member is formed. Molten resin is injected into the cavity; thereafter, an assist material is injected into the cavity to mold the resin into a desired pipe body. Then, the insert member and the pipe body are integrated along with curing of the resin.

A holding portion having a diameter larger than that of a cavity is formed in communication with the cavity, in an area of a two-part type mold, the area including a portion corresponding to an annular groove. Subsequently, an insert member formed in a cylindrical shape and provided with, on an outer circumferential surface, the annular groove having no step in a groove surface is fitted to the holding portion, and then the mold is closed. On an inner circumferential surface of the insert member, a surface treatment layer having a surface roughness rougher than those of other portions of the insert member is formed. Molten resin is injected into the cavity; thereafter, an assist material is injected into the cavity to mold the resin into a desired pipe body. Then, the insert member and the pipe body are integrated along with curing of the resin.

Provided is a pipe joint including a cylindrical hollow, wherein the wall thickness of a part having the largest wall thickness of the pipe joint is 2 to 7 mm, the ratio of the length of the hollow in the axial direction (L) to the diameter of the hollow (D), (L/D), is 5 or less, the pipe joint contains a copolymer containing tetrafluoroethylene unit and a fluoro(alkyl vinyl ether) unit, the content of the fluoro(alkyl vinyl ether) unit of the copolymer is 2.8 to 6.0% by mass with respect to the whole of the monomer units, the melt flow rate at 372° C. of the copolymer is 4.0 g/10 min or higher and lower than 11.0 g/10 min, and the number of functional groups of the copolymer is 50 or less.

The invention relates to a method of manufacturing a plastic frame for a two-wheeler having at least one hollow space in the interior by means of plastic injection molding having a series of method steps, wherein a fluid is injected to displace the plastic core from the component cavity after the injection of a preferably thermoplastic plastic melt into a closed injection molding tool.

The invention relates to an injection-molding device for producing multi-component moldings from a thermoplastic molding compound, comprising a mold, forming a first article cavity, comprising means for filling the first article cavity with the thermoplastic molding compound, comprising an injection device for injecting a fluid against a projectile to be driven, wherein the injection device comprises a projectile carrier with at least one injection nozzle and with at least one projectile receptacle for a projectile as a displacer for the molding compound. The injection-molding device also comprises a mold insert, which forms a continuation of the first article cavity and encloses the projectile carrier, wherein the projectile carrier forms with the mold insert a second article cavity that can be filled with the molding compound, wherein the mold insert has a separate sprue and wherein the second article cavity of the mold insert can be sealed off for a time with respect to the first article cavity by means of movable mold parts. The invention also relates to a method for producing multi-component moldings by using the injection-molding device.

To further improve hollow resin molded article manufacturing technology, a hollow resin molded article manufacturing method includes: injecting a melted resin material into a cavity of a mold; injecting gas and liquid into the cavity in which the resin material has been injected, via an injector connected to the cavity, to form a hollow portion in the resin material in the cavity; and discharging the liquid in the cavity to outside of the cavity. The hollow portion forming step includes injecting the gas in a compressed state into the injector and then injecting the liquid pressurized at higher pressure than the gas. The injector is connected to a vertically lowermost end of the cavity. In the discharging step, the liquid is discharged via the injector.

The invention relates to a method for producing a tube by injection molding a thermoplastic molding compound by using an injection-molding device with an article cavity, which defines the outer contour of the tube, and with an injection device, which is designed to drive a profile through the article cavity filled with the thermoplastic molding compound and thereby displace a liquid core of the molding compound, wherein the method envisages closing an opening of the article cavity with a mould core, which with the article cavity forms a hollow mould space and which has a secondary cavity that can be filled with the molding compound. After the filling of the article cavity and the hollow mould space with the thermoplastic molding compound, a projectile is driven through the article cavity, wherein the projectile displaces the molding compound into the secondary cavity. Subsequently, the mould core with the filled secondary cavity is pulled, wherein the displaced molding compound is separated from the molding compound forming the tube. The invention also relates to an injection-molding device for carrying out the method.

A method for manufacturing a hollow part with a branch, including a resin filling step of filling a mold, the mold having a main cavity in which a hollowing piece is placed, and a branch cavity to communicate with the main cavity, in which a slide shaft is inserted to advance and withdraw, and that forms a branch pipe portion in an annular space between the branch cavity and the slide shaft, a step of forming a hollow main pipe portion by moving the hollowing piece to force excess resin out of the main cavity, and a shaft removing step of withdrawing the slide shaft to form a branch hollow portion, the hollow part with a branch being made of a resin and having the branch pipe portion integrally connected to the main pipe portion such that the main hollow portion and the branch hollow portion communicate with each other.

A method of producing a structure for a component for a vehicle interior may comprise providing a mold with an insert in a cavity, providing resin into the cavity, providing water into the cavity to push a projectile element through the insert into resin in the cavity, pushing the projectile element through the insert and resin across the cavity. The structure may comprise the insert and molded resin. The insert may comprise a metal insert (pipe, tube, etc.). The projectile element may comprise a multi-stage projectile element with a base stage separable from a front stage during forming of the structure. The structure may comprise a second section and a first section with a larger inner diameter than the second section. The insert may be provided in the first section. The base stage may remain in the formed resin structure between the first and second section.