Abstract: An absorbent, microporous foam comprising a crosslinked polymer having interconnected fluid cells distributed throughout its mass, wherein the fluid cells have a diameter of between about 0.1 and about 100 .mu.m, and wherein the foam can rapidly absorb at least about twice its dry weight in fluid, is disclosed.A method for producing a microporous, absorbent foam is also disclosed. This method comprises the steps of:(a) mixing a cross-linkable polymer and a first solvent to form a stable solution, wherein the stable solution can be induced to phase separate;(b) inducing the stable solution to phase separate into a polymer-concentrated phase and a polymer-dilute phase after a predetermined period of time;(c) inducing crosslinking of said polymer, so that the polymer will crosslink in said concentrated phase for a predetermined period of time during phase separation to thereby form a microporous material; and(d) drying the microporous material to produce the absorbent foam.

Abstract: There are provided a method and an apparatus for continuously manufacturing a cross-linked thermoplastic resin foam arranged as follows. A resin composition, which contains at least a thermoplastic resin, a foaming agent, and a cross-linking agent, is extruded into a closed die, which includes at least a molding region, a heating region, and a cooling region, continuously arranged in the order named. The resin composition is molded into a desired shape in the molding region of the die, and is then heated in the heating region to decompose the cross-linking agent and also to decompose at least part of the foaming agent so that cell nuclei are produced, thereby forming a partially foamed product. In the cooling region of the die, the partially foamed product is cooled to a temperature lower than the softening point thereof to be increased in rigidity, and is extruded to the outside of the die while being subjected to a damping force as it moves in the cooling region.

Abstract: The cross-linkable, foamable polyolefin resin composition capable of forming foams with excellent mechanical properties and heat resistance is made of (a) 30-80 weight % of a propylene-ethylene random copolymer having an ethylene content of 1.5-6 weight %; (b) 10-60 weight % of a propylene-ethylene random copolymer having an ethylene content of 0.2-1.0 weight %; (c) 10-60 weight % of a linear low-density polyethylene; and (d) 1-30 parts by weight, per 100 parts by weight of the above resin components, of a foaming agent.

Abstract: A heat-shrinkable, tubular foam can be produced from a composition which comprises 100 parts by weight of an ethylene-.alpha.-olefin-nonconjugated diene copolymer, 1 to 20 parts by weight of a foaming agent, 5 to 100 parts by weight of a thermoplastic resin having a Vicat softening point of 50.degree. to 200.degree. C., and up to 10 parts by weight of a crosslinking agent, by shaping the composition into a tube, crosslinking and foaming the tube and pressurizing the tube in the interior to inflate it. This heat-shrinkable, tubular foam is best suited for jacketing pipes, hoses, and the like.

Abstract: Disclosed is an extruded, low density, non-outgassing ethylenic polymer foam containing 30-85% open cells and the remainder closed cells and having an essentially integral surface. The foam possesses superior compression recovery and lower compression resistance when compared with similarly comprised ethylenic closed cell foams and superior moisture resistance and handling characteristics when compared to open cell foams.

Abstract: An expanded polyolefin foam with uniform fine closed cells is produced by placing a pre-form of a heat-expandable polyolefin resin composition in a mold cavity of generally uniform depth and closed by a platen, heating the mold to a temperature above the blow activation temperature of the pre-form while constraining the pre-form against any expansion under heavy controlled pressure, and then after cooling of the thus treated pre-form, removing the same from the mold and heating to effect expansion thereof. The pre-form is in a solid form with a volume exceeding the volume of the mold by a controlled amount in the range of 0.1-1 percent. The area of the pre-form is such as to fit readily within the mold cavity and its thickness exceeds the mold depth so that as the mold is closed by the platen the excess volume of the pre-form extrudes out around the peripheral edge of the mold before activation of the blowing and cross-linking agents.

Abstract: A method of making a solid core locatable between a wheel rim and a tire fitted to the rim, includes introducing a foamable composition into a mould cavity having a substantially inflexible mould surface. The cavity is suitably shaped so that a core locatable between a wheel rim and a tire fitted to the rim can be moulded therein. The composition is allowed to foam, thereby to fill the mould cavity. Air and excess composition is allowed to vent from the cavity via an elongate vent slit extending along a major portion of the cavity. The foamed core thus moulded in the cavity is removed from the cavity on the composition having set at least partially.

Abstract: A foam material, particularly suitable for use as a midsole material for an athletic shoe, comprises polyethylene modified by an elastomer modifier and cross-linked, preferably using a peroxide cross-linking agent, to form a closed cell foam material which has superior strength properties, improved energy return and reduced sensitivity to temperature change.

Abstract: A method of producing a crosslinked, uniformly foamed article of a polypropylene resin is provided. The polypropylene resin containing a crosslinking agent and a foaming agent is extruded through a long-land die which is provided with a choking die at an intermediate portion thereof; a lubricant is provided on the inner surface of the long-land die; the crosslinking agent is decomposed in the front stage of the long-land die; and the foaming agent is decomposed in the rear stage of the long-land die.An ethylene-propylene random copolymer resin which contains 2 to 10 wt. % of ethylene and has a melt flow rate of 5 g/10 minutes or more at 230.degree. C. and a melt expansion ratio of 1.4 of less at 190.degree. C. is used as the polypropylene resin.

Abstract: This disclosure relates to a method for producing polyethylene open-cell foam materials, comprising a process step of pressurized heating at a temperature of 110.degree. to 135.degree. C. of a base compound consisting of polyethylene or a copolymer of polyethylene which has been compounded with an azodicarbonamide foaming agent and a bridging agent, in order to obtain a primary intermediate product with a cubical expansion coefficient of 1.0 to 2.0 times; a process step of heating the primary intermediate product under normal atmospheric pressure at a temperature of 150.degree..about.190.degree. C.

Abstract: The invention relates to a hyperfiltration membrane containing a supporting layer and a separation layer. The membrane is characterized in that the separation layer consists of a crosslinked monomolecular film of molecules, the molecules of the separation layer in the uncrosslinked state being surfactants or surfactant-like lipoids containing at least one hydrophobic chain and at least one hydrophilic group, the hydrophobic chains of these molecules being oriented mainly perpendicularly to the plane of the membrane and parallel to the diffusion direction after crosslinking and the molecules of the separation layer being crosslinked with one another through functional groups in at least one of their hydrophobic chains and/or through functional groups in at least one of their hydrophilic groups.

Abstract: Process of producing a foamed product by forming a shaped article from a composition comprising a thermoplastic olefin polymer, a hydrolyzable, unsaturated silane, a gas generating compound and an organic peroxide in an amount of about 0.5 to about 2 percent by weight, and thereafter subjecting the shaped article to elevated temperatures to activate the gas generating compound and organic peroxide.

Abstract: Thin film membranes of polyurea, polyureapolyurethane alloy, polyurea-polyurea/urethane alloy or polyurea/urethane are prepared by deposition of a thin film of suspension of the selected polymer on a thick permeable support layer by the technique of preparing a suspension of the selected polymer in a solvent which does not dissolve the thick permeable support layer and permitting the solvent to evaporate and/or permeate through the thick-permeable layer.

Abstract: A foam of a polyolefin/polystyrene resin mixture obtained by mixing a polyolefin resin and a polystyrene resin in the presence of a hydrogenated styrene/butadiene block copolyer, and subjecting the resultant mixed resinous composition to extrusion foaming, wherein;(1) said hydrogenated styrene/butadiene block copolymer comprises, as components before hydrogenation, 10 to 38% by weight of styrene and butadiene with a content of 1,2-bond type butadiene of 20 to 50% by weight based on butadiene, and;(2) said foam comprises a thin surface skin portion showing a value of 0.65 or more of the surface structural index S represented by the following formula:S=t/T.gtoreq.0.65wherein t and T each represent a total light-transmission evaluated according to the method of ASTM D1003 with respect to a surface skin layer and an inner layer of the foam,is found to have the cushioning properties (or the foam properties) that enables elastic cushioning of a large load.

Abstract: A process for the manufacture of molded parts from fibrous material, particularly cellulose-containing fibers. A particulate binder is incorporated into a fiber filling after which the mixture is precompacted into a fiber mat which is subjected to a hot steam treatment and is finally molded into the finished part under pressure and heat. The binder consists of thermoplastic particles into which a blowing agent is incorporated by forming an alloy-like state which is activated prior to final molding of the part, preferably by means of hot steam treatment, and a binder which cross-links when exposed to heat applied to the surface of the particles.

Abstract: A method of molding pre-foamed synthetic resin particles is described, which comprises increasing the pressure in a mold cavity with a pressurized gas, charging the mold cavity with pre-foamed synthetic resin particles as they are compressed with a gas pressurized to a pressure higher than the pressure in the mold cavity and heating the charged pre-foamed synthetic resin particles with steam so that they are fused together or expanded and fused together to form a foamed molded article, wherein a pressure detector is provided in a conduit for conveying the pre-foamed synthetic resin particles into the mold cavity as they are carried by the pressurized gas or at an inlet portion of a charging port leading to the mold cavity, and the supply of pre-foamed synthetic resin particles into the mold cavity is stopped when the pressure detected by the detector exceeds the pressure in the mold cavity by a predetermined amount.

Abstract: Closed-cell foam particles are pressurized to produce particles useful in a process using secondary foaming to achieve a lower density foam. Closed-cell foam particles are initially compressed in a first stage compression tank and then transferred to a main gas pressurization tank. The main gas pressurization tank comprises multi-level shelves, each with a set of compartments. Charges of foam particles pass sequentially through the shelves while becoming fully pressurized. The multi-level shelves with means to move charges of foam particles from shelf to shelf are responsible for the closed cell foam particles becoming pressurized in an efficient manner.

Abstract: An electrically conductive polyethylene foam which is in the form of a profile, e.g. a sheet, having a closed cell foam structure and exhibiting a surface resistivity of not more than 10.sup.5 ohms/square. The sheet is prepared by a continuous method wherein an extruded, foamable, non-crosslinked preform containing a mixture of polyethylene, ethylene copolymer, chemical blowing agent, crosslinking agent and conductive carbon black is heated to produce the foam.

Abstract: A non-crosslinked foam of a composition comprising:(A) 72 to 98% by weight of a 1-butene polymer; and(B) 28 to 2% by weight of a propylene polymer, the percentages being based on the total weight of the 1-butene polymer and the propylene polymer.

Abstract: Foams are prepared from a linear low density polyethylene and, optionally, other olefinic polymers, such as a low density polyethylene using a chemical cross-linking agent. The resulting cross-linked polyethylene foams exhibit an excellent balance of properties at generally lower densities than foams prepared from low density polyethylene only.

Abstract: A process for the preparation of a fiberboard, including the steps of:providing a fiber layer or mat;forming at least one layer of expandable phenol resin particles over and/or under the surfaces of the fiber layer; andhot pressing the resulting superimposed layers to allow the expandable phenol resin particles to expand and to fill the void space within the fiber layer and to consolidate the fiber layer.

Abstract: A foam of cross-linked polyethylene having microcell structure is prepared using a chemical cross-linking initiator having a 10 hours half life temperature of from 80.degree. to 110.degree. C. In a preferred embodiment, the chemical cross-linking agent is employed in combination with co-cross-linking agent such as triallyl cyanurate.

Abstract: An electrically conductive polyethylene foam which is in the form of a profile, e.g. a sheet, having a closed cell foam structure and exhibiting a surface resistivity of not more than 10.sup.5 ohms/square. The sheet is prepared by a continuous method wherein an extruded, foamable, non-crosslinked preform containing a mixture of polyethylene, ethylene copolymer, chemical blowing agent, crosslinking agent and conductive carbon black is heated to produce the foam.

Abstract: Moldable foam beads comprising a silane-crosslinked polyolefin foam are produced by mixing a composition comprising a silane-modified polyolefin (such as a silane-grafted polyethylene) and a silanol condensation catalyst in an extruder to produce a melt, then injecting a blowing agent into the melt at a rate effective to produce a desired foam density in the extrudate; extruding and cutting the melt to form foam beads; and exposing the foam beads to moisture to produce silane crosslinking of the polyolefin foam.

Abstract: Expandible synthetic resinous particles are molded by injecting heated air generally centrally into the mold cavity by means of a probe, withdrawing the probe and heating the surface of the mold. Low densities and rapid cycle times are obtained.

Abstract: A steam expandable alkenyl aromatic polymer composition and methods of preparation are provided. The composition is mixed with a volatile blowing agent containing, as a primary blowing agent, dichlorodifluoromethane and as a secondary blowing agent, a halogenated hydrocarbon, a hydrocarbon, or an aliphatic alcohol containing from 1 to 4 carbon atoms, the secondary blowing agent having a normal atmospherpic boiling point of from about 0.degree. to about 100.degree. C. The composition may be expanded by steam immediately after extrusion foaming or may be expanded after aging of the composition which has been impregnated with volatile blowing agent.

Abstract: A process for the production of expanded particles, which comprises providing an aqueous dispersion containing expandable particles which are formed of a polypropylene resin and which contain a blowing agent and an expansion aid and maintained at a temperature higher than the softening point of the resin and under a pressurized condition, and subjecting the dispersion to a lower pressure so that the expandable particles are expanded. The expansion aid is organic or inorganic solids having a particle size of 0.1 to 150 .mu.m and a melting point higher than the temperature at which the expansion of the expandable particles is performed and serves to improve the expansion ratio.

Abstract: Closed-cell foam molded parts or articles of crosslinked polyolefin are manufactured according to a process comprising the steps of filling a foamable and crosslinkable polyolefin composition containing a blowing agent and a crosslinking agent into a closed mold and molding a correspondingly shaped, foamable product under pressure, the crosslinking reaction progressing without decomposition of the blowing agent; subsequent heating of the resultant foamable, crosslinked product to a blowing temperature between a pair of metal plates, wherein the product can expand biaxially within the region left between the metal plates; and then heating of the thus-obtained intermediate product under low pressure of about 1 bar so that it can expand into all directions with complete decomposition of the residual blowing agent to result in the completely foamed molded part.

Abstract: Useful resilient extruded closed cell foam compositions are produced by the present invention by forming an extrudable blend comprising a heat activatible chemical blowing agent and a polymer component consisting essentially of chlorinated polyethylene and at least one other thermoplastic polymer. The amount of chlorinated polyethylene is from 0.025 to 0.5 parts per part of the thermoplastic polymer. The blend is extruded at a temperature below the activation temperature of the blowing agent to form an unfoamed thermoplastic sheet, and the sheet is thereafter heated to a temperature sufficient to activate the blowing agent and expand the sheet and produce a non-crosslinked closed cell thermoplastic foam.

Abstract: A method for aging an expansion-molded body of polyolefin prepared by heating pre-expanded polyolefin particles within a mold involves cooling the molded body within the mold so that the molded body is not substantially smaller than the volume of the mold cavity and is temporarily expandable after being removed from the mold to not more than 110% relative to the volume in the mold cavity, removing the molded body from the mold, placing the molded body in an atmosphere substantially under atmospheric pressure and having a temperature of 25.degree. to 55.degree. C. lower than the melting point of the polyolefin while the volume of the molded body is 70 to 110% relative to the volume of the mold cavity and holding the molded body in this atmosphere until the temperature of the molded body is at least equal to the temperature of the atmosphere.

Abstract: Polymer compositions and methods of making them are provided. Selected surface layers of the polymers, integral with the polymer body, possess pressure sensitive adhesive properties. The polymers are cured with the selected surfaces in contact with a cross-linking inhibition agent which controls the amount of cross-linking of the polymer taking place at the surface. The polymers are useful as, or in conjunction with, prosthetic appliances which are adhered to skin or other substrates.

Abstract: A method for manufacturing a low density rubber foamed body is provided which comprises the steps of forming a sheet from a mixture of 100 parts by weight of natural rubber or a synthetic rubber, 10 to 80 parts by weight of a foaming agent, and 0.5 to 15% by weight of a crosslinking agent; enclosing said sheet within a mold and heating said mold under pressure from the exterior to thereby foam said sheet; forcibly cooling said mold; and releasing a foamed body from said mold. When 10 to 60 parts by weight of a thermoplastic synthetic resin are further added to the mixture, a rubber foamed body of still lower density and lower shrinking property is obtained.

Abstract: The present invention relates to superior wear layer-coated embossed surface coverings which are prepared by depositing a cross-linking inhibitor on at least a portion of the surface of a cross-linkable foam formed on a backing and containing a cross-linking initiator. Preferably a wear layer is applied at this point and cross-linking of the affected areas is accomplished by heating the sheet. The sheet of material is either uniformly or differentially heated and then uniformly compressed to a desired embossing depth using a non-patterned press or roll. The noncross-linked regions remain depressed upon removal of the compressing force whereas the cross-linked regions return essentially to their original height. The wear layer remains in contact with all of the foam regions so that the resulting sheet of material has a wear layer which is uniformly adhered to the contour of the foam layer. The surface of the sheet has an embossed or textured finish.

Abstract: An improved process for the production of cross-linked polyolefin foams by mixing polyolefins with conventional foaming agents and cross-linking agents known for polyolefin foam production, shaping the mixture into a plate or into a continuous sheet, substantially without cross-linking and foaming, the improvement comprises mixing said mixture with up to 50% by weight of an .alpha.,.beta.-unsaturated polyester, heating the plate or sheet optionally by IR radiation, and cross-linking the foaming by dielectric heating at a temperature above the decomposition temperature of the cross-linking and foaming agents.

Abstract: Process for the preparation of bodies of expanded cross-linked polyethylene, with closed cells, comprising the steps of:melting a polymer of ethylene selected among ethylene homopolymers, copolymers of ethylene with alpha-olefins, copolymers of ethylene with conjugated diolefins and relevant mixtures;homogenizing the polymer of ethylene in the molten state with a quantity of from 0.1 to 2.5% by weight of a cross-linking agent and with a quantity of from 2 to 25% by weight of an expanding agent, the cross-linking agent and expanding agent having a decomposition temperature higher than the melting point of the polymer of ethylene, the homogenizing step operating at temperatures of from 130.degree. to 150.degree. C., and for times of from 5 to 10 minutes;forming the homogeneous mixture in a solid parallelepiped shape by means of extrusion and subsequent cooling, or by means of moulding wherein the extrusion or moulding step is operated at temperatures within the range of from 130.degree. to 150.degree. C.

Abstract: A method for producing a crosslinked, uniformly expanded article of thermoplastic resin is provided.Thermoplastic resin containing a crosslinking agent and a foaming agent is extruded through a long-land die which is provided with a choking orifice at an end and/or an intermediate portion thereof; a lubricant is provided on the inner surface of the long-land die; the crosslinking agent is decomposed in the long-land die to lower the flow rate of the resin and the foaming agent is decomposed or heated to its boiling point in the long-land die to provide an expandable resin and the crosslinked, expandable resin is then released into an atmospheric or controlled pressure zone to produce the uniform, finely expanded article.

Abstract: An electroconductive cross-linked polyolefin foam having electric resistance of not more than 100 M.OMEGA. and comprising uniform minute cells and proving useful for the production of IC cases, etc. is provided by a method which comprises kneading 100 parts by weight of a polyolefin, 10 to 30 parts by weight of carbon particles, and suitable amounts of a foaming agent and a cross-linking agent and heating the resultant cross-linkable and foamable composition under atmospheric pressure thereby allowing the composition to be cross-linked and foamed without being abruptly foamed or expanded or by a method which comprises heating the aforementioned cross-linkable and foamable composition in a metal mold under pressure to a temperature at which the foaming agent is not substantially decomposed thereby cross-linking the composition and then heating the resultant cross-linked foamable composition under atmospheric pressure thereby allowing the composition to be foamed without being abruptly foamed or expanded.

Abstract: The invention provides a method for producing permeable polymeric membranes comprising decomposing, in a polymeric matrix, molecular moieties, bound to the polymer or contained in compounds dispersed therein, into smaller, discrete, molecular units, whereby the smaller, discrete molecular units, which are formed, spontaneously leave the polymeric matrix and a membrane of defined permeation characteristics is obtained.

Abstract: A core material for automobile bumpers which is composed of a molded article of foamed particles of a polypropylene-type resin. The molded article has a density of 0.015 to 0.045 g/cm.sup.3 and a compression stress at 50% compression of at least 1 kg/cm.sup.2. The core material simultaneously has excellent energy absorbing property and dimensional recovery and a low density.

Abstract: Process and composition for single step production of foam by utilizing a blowing agent, organic peroxide cross linking agent and a silicone block copolymer.

Abstract: A microwave energy treated cross-linked styrenic polymer shaped article and method of forming the same.

Abstract: The present invention relates to a process for preparing a polyolefin foam by heat-molding pre-expanded beads of an expandable polyolefin resin containing a foaming agent in a mold, said process being improved in preparing beads having a peak expansion rate at pre-expansion equal to 1.3 to 3 times the expansion rate of beads to be packed into the mold, adjusting the beads to a pre-expansion rate depending on an expansion rate of the desired foam, and packing and molding the pre-expanded beads in a mold without any further addition of expandability thereto. The polyolefin foam prepared by the process of the present invention is evenly fused to the interior and is less liable to shrink or deform.

Abstract: A shrink-fit article is made by extruding a silane-grafted polymer which foams, at least at its surface, and cross-links. Upon completion of foaming and cross-linking, the article is expanded while (still) warm and cooled in the expanded state.

Abstract: Process for obtaining cellular materials, based on unsaturated polyester in optionally containing reinforcing and/or inert fillers, having a density between 0.2 and 1.0 kg/l by moulding under pressure a liquid foam of said resins, characterized by the fact that the liquid foam based on unsaturated polyester resins containing conventional additives, optionally containing an inert and/or reinforcing charge of mineral or organic fibers having a length which is less than 5 mm, preferably less than 3 mm and more preferably less than 1.5 mm, obtained by mechanical introduction of a gas and/or by means of a chemical and/or physical foaming agent, is firstly introduced into an open half-mould optionally containing a further fiber reinforcement, by casting an amount higher than the free volume of the mould, and subsequently said foam is cross-linked.

Abstract: The invention relates to an earplug, produced with the use of a polysiloxane which is made foamable and cross-linkable by the use of expanding and cross-linking agents. The method for producing such an earplug comprises preshaping the polysiloxane together with the additives, then finally shaping the earplug in the foaming process and then tempering the finally shaped product.

Abstract: High quality plastic foam and the like expanded products and articles are made by incorporating a blowing agent in an acid-containing alkenyl aromatic polymer, such as a copolymer of styrene and acrylic acid; extruding while cross-linking the polymer with a polyfunctional cross-linking agent.

Abstract: An open-cell foamed article of a cross-linked polyolefin having a high open-cell ratio and a high degree of expansion is produced by a method which comprises the steps of preparing a foamable and cross-linkable polyolefin composition, forming the composition into a desired shape maintaining its gel percent at zero, decomposing the cross-linking agent and blowing agent concurrently by heating the composition under atmospheric pressure in such conditions that the peak of the ratio of the degree of cross-linking to the degree of decomposition of the blowing agent is not more than 20 and exerting a mechanical deformation to the resulting polyolefin foam to rupture the cell membranes.

Abstract: This invention provides a method of continuously manufacturing a cross-linked polyvinyl chloride resin foam sheet which has a low density, uniformly fine cell, excellent thermal moldability and high heat resistance and is neither deformed nor deteriorated even by long storage characterized by uniformly kneading the polyvinyl chloride resin with a blowing agent, stabilizer, plasticizer and cross-linking promoter without causing the blowing agent to decompose itself, thereby providing an unfoamed kneaded composition in which the polyvinyl chloride resin is gelled and forming said composition into a continuing sheet, irradiating said sheet with ionizing radiation to cross-link the resin; and thermally foaming the cross-linked sheet.

Abstract: A composition suitable for open-cell polyolefin foam which comprises 100 parts by weight of olefin resin, 1 to 20 parts by weight of blowing agent, 0.3 to 10 parts by weight of organic peroxide crosslinking agent, 0.1 to 10 parts by weight of trifunctional monomer, and 1 to 5 parts by weight of silicone oil or a derivative thereof.

Abstract: The cross-linkable, foamable polyolefin resin composition capable of forming foams with excellent mechanical properties and heat resistance is made of (a) .[.30-80.]. .Iadd.14-80 .Iaddend.weight % of a propylene-ethylene random copolymer having an ethylene content of 1.5-6 weight %; (b) 10-60 weight % of a propylene-ethylene random copolymer having an ethylene content of 0.2-1.0 weight %; (c) 10-60 weight % of a linear low-density polyethylene; and (d) 1-30 parts by weight, per 100 parts by weight of the above resin components, of a foaming agent.