A method for preparing cellular plastic particles comprising the steps: providing a plastic material in the form of pre-expanded plastic material particles, loading of the pre-expanded plastic material particles with a blowing agent under the influence of pressure, expanding the pre-expanded plastic material particles loaded with a blowing agent for the production of cellular plastic particles, in particular cellular plastic particles with lower density, under the influence of temperature, wherein the expanding of the plastic material particles loaded with blowing agent under the influence of temperature is carried out by irradiating the plastic material particles loaded with blowing agent with high-energy thermal radiation, in particular infrared radiation.

A method for producing polyethylene-based resin foamed particles includes a first-step foaming process. The first-step foaming process includes: producing an aqueous dispersion by dispersing polyethylene-based resin particles in an aqueous dispersing medium in a sealed vessel, adding a carbon dioxide-containing foaming agent to the aqueous dispersion in the sealed vessel, heating and pressurizing the aqueous dispersion in the sealed vessel, and releasing the aqueous dispersion in the sealed vessel to a pressure region where a pressure is lower than an internal pressure of the sealed vessel. The foaming ratio in the first-step foaming process is 10 to 18 times. The polyethylene-based resin particles have a polyethylene-based base resin and a melting point of 105 to 125 C., a tan of 0.3 to 0.7, and a complex viscosity of 5000 to 20000 Pa.Math.s.

The present invention relates to a process for the production of an expandable thermoplastic polymer comprising water as blowing agent, comprising at least the step (A) of storage of the thermoplastic polymer in water, so that water is absorbed by the thermoplastic polymer, in order to obtain an expandable thermoplastic polymer, to expandable thermoplastic polymer, obtainable via the process, to a corresponding expanded thermoplastic polymer, to a process for the production of a foam via foaming and fusion of the expanded thermoplastic polymer, and also to a foam, obtainable via said process.

A staple cartridge assembly is used with a surgical stapler. The staple cartridge assembly includes a staple cartridge including a cartridge body, a cartridge deck, and a plurality of staples deployable from the cartridge body through the cartridge deck. The staple cartridge assembly includes a compressible adjunct positionable against the cartridge deck. The compressible adjunct includes a plurality of unaltered fibers and a plurality of altered fibers that are melted and resolidified. The unaltered fibers include a first fiber including a first fiber portion and a second fiber including a second fiber portion extending over the first fiber portion. The compressible adjunct further includes a node which comprises the first fiber portion, the second fiber portion, and at least a portion of the plurality of altered fibers, wherein the at least a portion of the plurality of altered fibers affixes the first fiber portion and the second fiber portion.

A method of making a foamed article, for example a foamed component for an article or footwear, comprises depositing an unfoamed, thermoplastic polymer onto a support surface in a three-dimensional printing process to form an unfoamed article; heating the article to soften the article and infusing the softened article with at least one inert gas at a first pressure greater than atmospheric pressure that is sufficient to cause the at least one inert gas to permeate into the softened article; and reducing the pressure to second pressure below the first pressure while the article is softened to at least partially foam the article, wherein a surface of a partial mold limits foam expansion in at least one direction but less than all directions. The article or a part of the article may be made by printing a thermoplastic polymeric material with a three-dimensional printer in a structure of interconnected, unfoamed, thermoplastic polymeric members spaced to define openings between the thermoplastic polymeric members.

Disclosed, among other things, are ways to manufacture reduced density thermoplastics using rapid solid-state foaming and machines useful for the saturation of plastic. In one embodiment, a foaming process may involve saturating a semi-crystalline polymer such as Polylactic Acid (PLA) with high levels of gas, and then heating, which may produce a reduced density plastic having high levels of crystallinity. In another embodiment, a foaming process may produce layered structures in reduced density plastics with or without integral skins. In another embodiment, a foaming process may produce deep draw structures in reduced density plastics with or without integral skins. In yet another embodiment, a foaming process may utilize additives, blends, or fillers, for example. In yet another embodiment, a foaming process may involve saturating a semi-crystalline polymer such as Polylactic Acid (PLA) with high levels of gas, and then heating, which may produce a reduced density plastic having high levels of crystallinity.

A method of making a foamed article, for example a foamed component for an article or footwear, comprises forming a structure of interconnected, unfoamed, thermoplastic polymeric members spaced to define openings between the thermoplastic polymeric members. The structure may be made by printing a thermoplastic polymeric material with a three-dimensional printer. The thermoplastic polymeric members are heated to a first temperature to soften the thermoplastic polymeric members and the softened thermoplastic polymeric members are infused with at least one inert gas at a first pressure greater than atmospheric pressure. The first pressure is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic polymeric members. After being infused with the inert gas, the pressure is reduced to at least partially foam the thermoplastic polymeric members.

Aspects hereof provide methods for molding a single-phase solution comprised of a polymer composition and a gas. The polymer composition and the gas are maintained under pressure during the molding operation to prevent a cellular structure from being formed by the dissolved gas in the polymer composition coming out of solution. The mold cavity in which the single-phase solution is introduced for molding purposes is pressurized to a mold pressure that is sufficient to maintain the single-phase solution as a single-phase solution as the mold cavity is filled. Subsequent to filling the mold cavity with the single-phase solution under pressure, the resulting article may solidify entrapping the compressed gas, or the article may be exposed to a reduction in pressure causing the entrapped gas to form a cellular structure.

A producing method for producing a foam-molded product by using a plasticizing cylinder having, from an upstream side in the following order: a plasticization zone, a flow rate adjusting zone and a starvation zone, the producing method includes: plasticizing and melting a thermoplastic resin into a molten resin in the plasticization zone; adjusting a flow rate of the molten resin in the flow rate adjusting zone; allowing the molten resin to be in a starved state in the starvation zone; introducing a pressurized fluid containing the physical foaming agent having a fixed pressure into the starvation zone so as to retain the starvation zone at the fixed pressure; bringing the molten resin in the starved state in contact with the pressurized fluid in the starvation zone in a state in which the starvation zone is retained at the fixed pressure; and molding the molten resin into the foam-molded product.

A monolithic injection molded plastic part including an interior core, a surface formed as a monolithic structure with the interior core, and a distribution of hollow cells formed within the interior core during an injection molding process from a blowing agent and methods for making the same are provided. Such methods include preparing a mixture of unmelted plastic resin, filler agent, and blowing agent, melting the mixture into a viscous combination using a standard injection molding machine, injecting a set amount of the viscous combination into a hollow cavity of an injection mold secured within the standard injection molding machine, and holding the set amount of the viscous combination in the hollow cavity at a low pressure for a hold time until the viscous combination sets into a monolithic structure at least partially filling the hollow cavity and the blowing agent forms a distribution of hollow cells throughout the monolithic structure.