The invention relates to a process for manufacturing a copolymer foam containing polyamide blocks and polyether blocks, comprising the following steps: mixing the copolymer melt with a blowing agent, said copolymer having a coefficient of thermal diffusivity a and a crystallization temperature T.sub.c; providing a mold of thickness h at a temperature T.sub.m; injecting the mixture of the copolymer and of the blowing agent at a temperature T.sub.p, into the closed mold; foaming the mixture by opening the mold;
in which the maintenance time between the injection of the mixture of the copolymer and of the blowing agent into the closed mold and the opening of the mold is within the range extending from (t.sub.opt−25%) to (t.sub.opt+25%),
t.sub.opt being expressed in seconds and obtained by equation (I):

[00001]$\begin{array}{cc}{t}_{\mathrm{opt}}=-\frac{1}{{\pi }^2}\frac{h^2}{a}\ln \left(\frac{\pi }{4}\frac{T_m-T_c}{T_m-T_p}\right),& \left(I\right)\end{array}$

in which a is expressed in m.sup.2/s, h is expressed in m and T.sub.m, T.sub.c and T.sub.p are expressed in ° C.

A method of manufacturing a midsole includes placing first and second preforms into a midsole recess of a mold, with first and second portions of the mold defining a first overflow chamber connected to the first recess; closing the mold by positioning the first and second portions in contact with one another; heating the mold for a predetermined period of time at a predetermined temperature such that the first and second preforms melt and bond together to form a midsole, with a portion of each of the first and second preforms flowing into the first overflow chamber to form a first overflow portion; removing the midsole from the mold; allowing the midsole to expand; and cutting away the first overflow portion.

Methods of forming an article from a molten plastic composition comprising a polymer and a blowing agent. The methods include injecting the molten plastic composition into a mould, allowing the plastic composition to form a first solid skin adjacent to an in contact with a first cavity-forming surface of the mould and a second solid skin adjacent to and in contact with a second cavity-forming surface of the mould, and then opening the mould before the molten plastic composition between the first and second solid skins in at least one portion of the circumference of a region of the mould cavity defining an annular cross-section of the cavity has solidified.

A closure (750) is provided and comprises a top plate (755) and a sidewall (760) depending from the periphery of the top plate. The closure includes a sealing member (765) which depends from the top plate within the sidewall. The top plate includes a foamed region which is restricted to being within a boundary defined by the sealing member; the sealing member being substantially unfoamed.

Methods of forming an article from a molten plastic composition comprising a polymer and a blowing agent. The methods include injecting the molten plastic composition into a mould, allowing the plastic composition to form a first solid skin adjacent to an in contact with a first cavity-forming surface of the mould and a second solid skin adjacent to and in contact with a second cavity-forming surface of the mould, and then opening the mould before the molten plastic composition between the first and second solid skins in at least one portion of the circumference of a region of the mould cavity defining an annular cross-section of the cavity has solidified.

This disclosure relates to a foam-molding mold having channels formed therein and a physical foaming process using the same, and more specifically, the foam-molding mold is characterized by comprising a cavity formed therein for accommodating mixed resin for foaming, and having channels formed therein for guiding gas to the cavity.

A baffle or reinforcement element for sealing and/or reinforcing a cavity, in particular a cavity of a vehicle, including a carrier element and an expandable element supported by the carrier element, the expandable element including an expandable material, incorporating a plurality of gas bubbles forming a microcellular structure. Further presented is the process of manufacturing such a baffle or reinforcement element and its use.

Expanded rubber articles and processes for making such, comprising: partially curing an expandable rubber formulation by heating it in a first mould cavity to form a moulded blank; releasing the moulded blank from the first mould cavity and allowing the moulded blank to expand to form an expanded moulded blank; and further curing and expanding the expanded moulded blank by heating it to form the expanded rubber article comprising an expanded rubber part, wherein the expanded moulded blank is heated in a second mould cavity. Optionally, the expanded moulded blank is contacted with a further rubber formulation and a substrate comprising a base material and an elastomer bonding layer in the second mould cavity to form an expanded rubber article additionally comprising a solid rubber part and a substrate.

A method of making a foamed article comprises (a) injection molding a molten thermoplastic elastomer to form an precursor; (b) crosslinking the thermoplastic elastomer; (c) heating the thermoplastic elastomer to a first temperature to soften the thermoplastic elastomer; (d) infusing the thermoplastic elastomer with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic elastomer; and (e) while the article is softened, reducing the pressure to a second pressure below the first pressure to at least partially foam the precursor into a foamed article, wherein the foamed article is substantially the same shape as the precursor.

A method of making a foamed article comprises (a) injection molding a molten thermoplastic elastomer to form a precursor; (b) crosslinking the thermoplastic elastomer; (c) heating the thermoplastic elastomer to a first temperature to soften the thermoplastic elastomer; (d) infusing the thermoplastic elastomer with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic elastomer; and (e) while the article is softened, reducing the pressure to a second pressure below the first pressure to at least partially foam the precursor into a foamed article, wherein the foamed article is substantially the same shape as the precursor.