Abstract:
Disclosed is a method for producing a microcellular foam polypropylene thick board, by foaming a polypropylene motherboard by a flat foaming equipment, wherein the polypropylene motherboard bears a core structure and a pore canal structure in the core of the foam polypropylene motherboard, shortening a diffusion path of supercritical carbon dioxide into a polypropylene matrix, thus reducing the saturation time required for diffusion equilibrium and significantly increasing the production efficiency. Also provided is a method for preparing the foam polypropylene motherboard bearing the pore canal structure in the core, by extrusion molding, from general polypropylene as the raw material. The method described in the present invention may be used to produce the microcellular foam board with small cell size, high cell density and high thickness.
Abstract:
Disclosed is a solid state foaming method for the creation of nanofoams (about or less than 100 nm) by saturating thermoplastic polymers with liquid carbon dioxide, optionally, at low saturation temperatures of below room temperature and lower.
Abstract:
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.
Abstract:
A method for manufacturing a foam shoe material includes the following steps. (a) A plate prototype is formed, wherein the plate prototype is composed of thermoplastic polyurethane. (b) The plate prototype is foamed by a supercritical fluid to form a foam shoe material including a plurality of microporous structures and an average aperture of the microporous structures is smaller than 100 micrometers.
Abstract:
Foamed polypropylene-resin particles are obtained by dispersing polypropylene-resin particles containing polyethylene glycol and/or glycerin together with an aqueous dispersion medium in a pressure-resistant container; introducing carbon dioxide gas as a foaming agent into the pressure-resistant container; impregnating the polypropylene-resin particles with the foaming agent under a heating and pressure condition; and then discharging the polypropylene-resin particles into an area having a lower pressure than an internal pressure of the pressure-resistant container and having an atmosphere temperature of higher than 80° C. and not higher than 110° C. The foamed polypropylene-resin particles can yield an in-mold foam molded body at a low heated water vapor pressure for molding, do not lose moldability at a high heated water vapor pressure for molding, have a wide heated water vapor range for molding, exhibit good moldability even when a mold with a complicated shape, a large mold, or a similar mold is used.
Abstract:
A resin foam having excellent dustproofness not only at ordinary temperatures but also particularly at high temperatures as well as having excellent flexibility. The resin foam has a thickness recovery ratio at high temperatures as defined below of not less than 25%, an average cell diameter of 10 to 200 μm, and a maximum cell diameter of not more than 300 μm, wherein the thickness recovery ratio at high temperatures is defined as follows: a resin foam in a sheet form is compressed, in an atmosphere of 80° C., for 22 hours in a thickness direction so as to have a thickness of 20% of the initial thickness; then, the compression state is released in an atmosphere of 23° C.; and a ratio of a thickness 24 hours after the release of the compression state to the initial thickness is defined as the thickness recovery ratio at high temperatures.
Abstract:
A method for infusing gas into a thermoplastic material includes positioning a sheet of a thermoplastic material into a vertical or substantially vertical position; positioning a sheet of a gas-permeable material into a vertical or substantially vertical position; and winding together the positioned sheet of thermoplastic material sheet and the positioned sheet of gas-permeable material to form a roll of the thermoplastic material interleaved with the gas-permeable material, the interleaved roll having a longitudinal axis oriented in a vertical or substantially vertical position. The method also includes exposing the interleaved roll to an atmosphere of a gas pressurized to infuse the thermoplastic material with the gas, while the longitudinal axis of the interleaved roll is oriented in a vertical or substantially vertical position; and then unwinding the gas-infused interleaved roll, while the longitudinal axis of the interleaved roll remains in a vertical or substantially vertical position.
Abstract:
A thermoplastic material having a thickness includes a polymer having a microstructure that includes a plurality of closed cells disposed in an inner region of the material's thickness. Each of the plurality of closed cells contains a void and each of the cells has a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 500 micrometers long. The thermoplastic material also includes a substantially solid skin disposed in an outer region of the material's thickness. The skin includes a surface having a surface energy and a texture that increases the surface energy to more than 38 dynes per square centimeter.
Abstract:
A first polymer (preferably in granular form) is exposed to a gas at a pressure higher than atmospheric pressure to introduce the gas into the polymer. This occurs at a temperature from the glass transition temperature to the melting temperature when the first polymer is crystalline or semi-crystalline in nature, or at a temperature below the glass transition temperature when the first polymer is amorphous in nature. Optionally, the gas-laden polymer may then be mixed with a second polymer. The polymer is then melted to produce a foamed article.
Abstract:
Disclosed is a method for producing a microcellular foam polypropylene thick board, by foaming a polypropylene motherboard by a flat foaming equipment, wherein the polypropylene motherboard bears a core structure and a pore canal structure in the core of the foam polypropylene motherboard, shortening a diffusion path of supercritical carbon dioxide into a polypropylene matrix, thus reducing the saturation time required for diffusion equilibrium and significantly increasing the production efficiency. Also provided is a method for preparing the foam polypropylene motherboard bearing the pore canal structure in the core, by extrusion molding, from general polypropylene as the raw material. The method described in the present invention may be used to produce the microcellular foam board with small cell size, high cell density and high thickness.