Lightweight and strong components may be manufactured using self-skinning foam material compositions by the processes described herein. One or more mandrels may be inserted into a molding tool, and a self-skinning foam material composition may be injected into the molding tool. After closing the molding tool, the self-skinning foam material composition may expand and cure to form a component, and one or more skins may be formed on exterior and/or interior surfaces of the component. For example, an external skin may be formed on an exterior surface of the component in contact with surfaces of the molding tool, and one or more internal skins may be formed on one or more interior surfaces of negative space spars of the component in contact with surfaces of the one or more mandrels.

Lightweight and strong components may be manufactured using self-skinning foam material compositions by the processes described herein. One or more mandrels may be inserted into a molding tool, and a self-skinning foam material composition may be injected into the molding tool. After closing the molding tool, the self-skinning foam material composition may expand and cure to form a component, and one or more skins may be formed on exterior and/or interior surfaces of the component. For example, an external skin may be formed on an exterior surface of the component in contact with surfaces of the molding tool, and one or more internal skins may be formed on one or more interior surfaces of negative space spars of the component in contact with surfaces of the one or more mandrels.

A method for producing a heat-shrinkable product is provided. First, a polymer composition containing a polymer, a crosslinking agent and a micro-encapsulated foaming agent uniformly dispensed therein is melt mixed. The foaming agent has a peak activation temperature which is higher than a temperature of the melt mixing. Next, the polymer composition is injection molded into a molded product. This carried out at the peak activation temperature to activate the foaming agent. Then, the molded product is crosslinked within the mold.

A method for producing a heat-shrinkable product is provided. First, a polymer composition containing a polymer, a crosslinking agent and a micro-encapsulated foaming agent uniformly dispensed therein is melt mixed. The foaming agent has a peak activation temperature which is higher than a temperature of the melt mixing. Next, the polymer composition is injection molded into a molded product. This carried out at the peak activation temperature to activate the foaming agent. Then, the molded product is crosslinked within the mold.

Method of forming an article from a molten plastic composition including a polymer and a blowing agent. The method provides that during an injecting step (c) and a packing step (d), the injection pressure and the packing pressure, respectively, are maintained above a minimum pressure threshold in at least one second region of the cavity to maintain the physical blowing agent as a gas dissolved in the polymer so that substantially no gas bubbles are formed in the at least one second region, during a mould opening step (e), at least some of the molten plastic composition is exposed to an external pressure lower than a minimum pressure threshold to form in the article at least one first portion having expanded cellular foam formed from the plastic composition, and prior to the opening step (e), the plastic composition in the at least one second region of the cavity has been cooled so as to be fully solidified to form in the article at least one second portion having a substantially homogeneous, solid phase, unexpanded plastic composition

Method of forming an article from a molten plastic composition including a polymer and a blowing agent. The method provides that during an injecting step (c) and a packing step (d), the injection pressure and the packing pressure, respectively, are maintained above a minimum pressure threshold in at least one second region of the cavity to maintain the physical blowing agent as a gas dissolved in the polymer so that substantially no gas bubbles are formed in the at least one second region, during a mould opening step (e), at least some of the molten plastic composition is exposed to an external pressure lower than a minimum pressure threshold to form in the article at least one first portion having expanded cellular foam formed from the plastic composition, and prior to the opening step (e), the plastic composition in the at least one second region of the cavity has been cooled so as to be fully solidified to form in the article at least one second portion having a substantially homogeneous, solid phase, unexpanded plastic composition

A molding method includes providing a molding device, wherein the molding device includes a first mold and a second mold corresponding to the first mold; moving the first mold towards the second mold to form a first mold cavity; supplying a gas to the first mold cavity; injecting a material into the first mold cavity; and moving the first mold away from the second mold to form a second mold cavity and discharge at least a portion of the gas out of the molding device, wherein a first volume of the first mold cavity is substantially less than a second volume of the second mold cavity.

A foaming and dyeing integrated production method for a polymer material product includes steps of putting a polymer material preform into a foaming and dyeing kettle, and loading dye into a dyeing circulation module; gasifying CO.sub.2 and injecting the CO.sub.2 into the foaming and dyeing kettle, stopping pressurization when the CO.sub.2 reaches a supercritical state; performing a dyeing circulation process in which the CO.sub.2 in the supercritical state enters the dyeing circulation module and dissolves the dye in the dyeing circulation module, when the dyeing process is finished, injecting CO.sub.2 and/or N.sub.2 pressurized in the fluid pressurization delivery module and heated in the fluid heating module into the foaming and dyeing kettle, stopping pressurization and starting foaming operation when requirements of a foaming process are met; and when the foaming process is finished, taking out a foamed and dyed polymer material product in the foaming and dyeing kettle.

A molding machine includes: a tie bar connected continuously to any one of a stationary platen and a movable platen, and including an engagement groove; a first engagement member configured to engage with or move away from the engagement groove of the tie bar; a second engagement member configured to engage with or move away from the engagement groove of the tie bar, and configured to be displaceable in an axial direction of the tie bar; a force transmission member located opposite the first engagement member across the second engagement member, and including a pressure surface to press the second engagement member and a through hole in which the tie bar is inserted; and a drive mechanism configured to use the force transmission member to cause the second engagement member to be displaceable in the axial direction of the tie bar with respect to the first engagement member.

Non-time dependent measured variables are used to effectively determine an optimal hold profile for an expanding crosslinking polymer part in a mold cavity. A system and/or approach may first inject molten expanding crosslinking polymer into a mold cavity, then measure at least one non-time dependent variable during an injection molding cycle. Next, the system and/or method commences a hold profile for the part, and upon completing the hold profile, the part is ejected from the mold cavity.