Abstract: A method of making phosphorescent fiber having phosphorescent particles composed, by weight, of 55-62.5% of strontium oxide, 35-42.5% of aluminum oxide, 1-9% of dysprosium oxide and 0.5-1.5% of europium oxide encapsulated with a wall material. The encapsulated particles are mixed and pelletized at a weight ratio of 15-25:85-75 with polymer capable of fiber formation to give a master batch, which is then compounded at a weight ratio of 30-70:70-30 with a polymer mixture, in combination with a softener and a dispersing agent. Polymer mixture consists of two polymers. One is the same polymer used to produce a master batch, the other is a polymer in the same chemical structure but different in physical properties such as melt index and tenacity. The compounded chip is melt-spun at 190-290° C. through a melt extruder. The fibers with the encapsulated phosphorescent particles exhibit such excellent physical properties as to be applicable to various textile products and show a high degree of luminescence.

Abstract: Toughened biaxially oriented polyamide films prepared by dry blending i) a polyamide homopolymer, copolymer, or blends thereof; and ii) a functionalized polyolefin terpolymer comprising maleic anhydride, ethyl acrylate, and an olefin, to thereby form a dry mixture. The dry mixture is melted to form a polymer blend, which is then formed into a polymer film. The edges of the film are pinned to a casting roll, and the film is plasticized in at least one water bath. The polymer film is subsequently biaxially oriented. The result is a toughened biaxially oriented film which is resistant to pinholes, cracks, and other structural defects. Such films are particularly suited for making packaging materials for various food products.

Abstract: Improvements in increasing the amount of available silver in thermoplastic articles comprising certain silver-containing antimicrobial agents are provided. Such an invention requires the incorporation of a sufficient amount of a carboxylic acid salt within the thermoplastic article simultaneously with the necessary silver-containing antimicrobial agent. Certain carboxylic acid salts are standard acid scavengers for thermoplastic applications; however, the amounts required within this inventive thermoplastic article is well in excess of that commonly added within such articles. Surprisingly, such an excess amount of such standard salts, as well as other non-standard salts, present within the target thermoplastic causes the release of greater amounts of silver to the target article's surface, thereby permitting a greater degree of antimicrobial activity, among other potential benefits for such an increase in surface-available silver.

Abstract: A process for preparing poly(trimethylene terephthalate) fibers comprising (a) providing a poly(trimethylene terephthalate) composition comprising about 0.05 to about 5 mole % tetramethylene terephthalate repeat units and (b) spinning the polymer composition to form fibers. Poly(trimethylene terephthalate) fiber comprising poly(trimethylene terephthalate) composition comprising about 0.05 to about 5 mole % tetramethylene terephthalate repeat units, as well as yarns, fabrics (e.g., woven, knitted, and nonwoven fabrics) and carpets. A poly(trimethylene terephthalate) composition comprising about 0.05 to about 5 mole % tetramethylene terephthalate repeat units.

Abstract: A production process for a long fiber-filled thermoplastic resin composition using an apparatus having an extruder with at least two raw material feeding ports and a resin impregnating bath at the tip of the extruder, comprising the steps of feeding a resin mixture to a first feeding port provided at an upstream position of the extruder, feeding alkaline earth metals to a second feeding port provided at a downstream position of the extruder, melt-kneading to a mixture, allowing the obtained molten resin mixture to flow into the resin impregnating bath, passing a continuous fiber bundle through the molten resin mixture in the resin impregnating bath to impregnate the continuous fiber bundle with the resin mixture.

Abstract: A method of forming a composite door is disclosed. The method comprises: mixing together a thermoplastic polymer with an organic fibrous material in a ratio such that the organic fibrous material constitutes 40 to 60 percent by weight of the mixture; extruding the mixture under heat and pressure to create a thin sheet form; cutting the sheet to a predetermined size; removing material from at least one surface of the sheet to create a homogeneous appearance devoid of obvious fibrous particles; thermoforming the sheet to impart to the at least one surface an exterior three dimensional door surface to create a thin door facing; and assembling two of the thermoformed thin door facings, a peripheral frame and a core material into a door.

Abstract: A method of producing fiber having functional mineral powders includes the steps of a first pulverizing functional mineral which crystal form of is pinacoid, a second closely pulverizing the first pulverized functional mineral powders to be less than ⅓ granularity of desired fineness, mixing and synthesizing 0.1-10 weight % of the second pulverized functional mineral powders and 90-99.9 weight % of a chemical resin, and spinning the mixture of functional mineral powders and the chemical resin.

Abstract: Process of making polypropylene fibers obtained from an isotactic polypropylene homopolymer with an isotactic index of 90-99%, through melt-spinning or through drawing after melt-spinning, and shows two differential scanning calorimeter (DSC) endothermic peaks between 155 and 170 ° C. When being thermally bonded with each other, the fibers are made into non-woven fabrics which have excellent strength in addition to being soft. A high quality of the non-woven fabrics can be produced in a high speed carding machine with high yields.

Abstract: The present invention provides a process for manufacturing an molded article that involves the occurrence of reduced number of gels and less corrosion of the molding equipment in high-temperature molding, particularly extrusion molding onto such substrate as paper; an extruded article; and an olefin polymer composition suitable therefor. The olefin polymer composition comprises an olefin polymer containing 5 to 200 ppm of aluminum, as aluminum atom, 0 to not more than 1,000 ppm of a phenolic stabilizer and 50 to 2,000 ppm of a phosphoric stabilizer.

Abstract: The present invention relates to a process for the production and for the spooling of preoriented polyester filaments comprising at least 90 weight %, relative to the total weight of the polyester filament, of polybutylene terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT), preferably of PTMT, characterized in that: a) the spinline extension ratio is set in the range of 70 to 500; b) the filaments, immediately after exiting from the spinning nozzles, pass through a cooling delay zone from 30 mm to 200 mm in length; c) the filaments are cooled off to below the solidification temperature; d) the filaments are bundled at a distance of between 500 mm and 2500 mm from the lower side of the spinneret plate; e) the tension of the thread in front of and between the draw-off galettes is set to between 0.05 cN/dtex to 0.20 cN/dtex; f) the thread is spooled with a tension of the thread of between 0.025 cN/dtex to 0.15 cN/dtex; g) the spooling speed is adjusted to between 2200 m/min. and 3500 m/min.

Abstract: Fluoropolymer materials containing tetrafluoroethylene monomers, such as PTFE, are significantly swollen by supercritical carbon dioxide at high temperatures and pressures. The swollen fluoropolymer is processable by molding, extrusion, and other techniques. In addition, the fluoropolymer may be sintered at significantly lower temperatures compared to a nonswollen fluoropolymer material. The melting temperature of fluorinated polymers containing tetrafluoroethylene and triflouroethylene monomers which are swollen with supercritical carbon dioxide is significantly reduced, thereby permitting manufacturing operations such as extruding and molding to be performed at lower temperatures and with reduced risk of decomposition.

Abstract: A process for manufacturing an article using a predetermined amount of crumb rubber comprising the steps of selecting an article to be manufactured, determining a maximum amount of recycled rubber which can be used in manufacturing the article selected. A particle size for recycled rubber to be used is determined and a binder for binding the recycled rubber is selected. The amount of binder required to be added is determined. Curing agents to be used in the process are selected and their weight determined. The components are mixed in a mixer and heated to a predetermined temperature. The mixture is removed and a mold is filled with the mixture. The mixture is then molded at a predetermined temperature and a predetermined pressure being at least sufficient to cure the mixture so as to form the article previously selected and then the molded product is removed from the mold.

Abstract: The present invention relates to a method of producing a plank product and related components having a controllable and realistic wood-grain appearance, the planks and related components having at least one accent color, the method including the steps of: a) introducing into an extruder a powdered or pelletized base material and accent color pellets, the base material containing less than about 75% by weight wood flour, and having a vicat softening temperature, the accent color pellets (i) having a higher vicat softening temperature than said base material, and (ii) including a styrene polymer having a high vicat softening temperature and a melt flow index of greater than or equal to 1.

Abstract: A process and resulting thermoplastic article is provided suitable for use in constructing furniture. The thermoplastic article contains hardened particulates such as powders of alumina oxide which brings about an improved cut and scratch resistance to the surface of the articles. The hardened particulates may be integrally mixed with the extruded product or applied post-molding to a surface of the shaped article.

Abstract: A process for extruding a thin positive electrode sheet having at least 40% /wt of solid content for a lithium polymer battery through a single or twin screw extruder is disclosed as well as a positive electrode sheet produced therefrom. A mixture of active cathodic intercalation material, lithium salt and electronic conductive material is mixed with a polymer of the polyether family in a ratio of at least 40% of total weight into the mixing chamber of an extrusion machine and extruded through a classical sheet die into a thin cathode sheet or film onto a substrate in sheet form.

Abstract: A process for making a multiphase polymeric film having a lamellar structure with controlled permeability and/or controlled mechanical properties, comprising the steps of: preparing a molten blend made of a first polymer phase dispersed in a second polymer phase which is a matrix polymer phase incompatible with the said first phase and of a compatibilizer selected from the group consisting of DEM, MAH, DEM-g-SEBS, MAH-g-SEBS, DEM-g-PP and MAH-g-PP; extruding the molten blend through a flat die provided with an exit and stretching the so extruded blend downwards said exit at a preselected stretching ratio to produce the said multiphase polymeric film, and solidifying the extruded film sufficiently rapidly to preserve the lamellar structure and the multiphase polymeric films thereby obtained. Granules with a lamellar structure are obtained by grinding the so obtained multiphase polymeric film and are useful for preparing shaped articles with improved physical properties.

Abstract: A shoe outsole (1) is formed of a polymer, e.g. rubber, composition including a short fiber. The amount of the short fiber to be blended is 2 to 40 parts by weight for 100 parts by weight of a base polymer, e.g. rubber. The short fiber has an orientation in an almost horizontal direction. An orientation angle to the horizontal direction of the short fiber is 30 degrees or less. The short fiber may have an orientation in almost horizontal and lateral directions. Moreover, the short fiber may have an orientation in almost horizontal and longitudinal directions. The outsole (1) is excellent in a strength.

Abstract: The invention provides a compounded polymer feedstock formed by cold-pressing of the ingredients into tablets or pellets. This avoids the need for heating associated with conventional pellet-forming processes, and is particularly suitable for compounding of heat-sensitive materials such as PVA. The invention also provides a novel tablet-forming apparatus, suitable for forming large volumes of pressed compounded polymer feedstock, together with tablets of the feedstock, and methods of manufacturing plastics products using the tablets.

Abstract: A method of molding a rubber product from a rubber compound by a molding apparatus having a kneading region. A full amount of carbon black (CB) and a full amount of process oil, together with other auxiliary materials except vulcanizing chemicals, are compounded with raw rubber to thereby knead and prepare a granular master batch (granular MB) . The rubber product is extrusion-molded and vulcanized after vulcanizing chemicals (a vulcanizing agent and a vulcanization accelerator) are quantitatively supplied into the kneading region of the molding apparatus through a material supply port while the vulcanizing chemicals are mixed with the granular MB.

Abstract: A modified polymer material is discloses, including a polymer base and boehmite particles provided in the polymer base. the boehmite particles are made up of mainly anisotropically shaped particles.

Abstract: In one embodiment, a method of forming an absorbent material from clay fines, which includes treating the clay fines with an additive, wetting the clay fines so as to have a moisture content of the clay fines of about 22% to 50% of the weight of the clay fines plus the weight of the additive, and extruding the treated and wetted clay fines so as to produce the absorbent material is disclosed. In a particular embodiment, at least a portion of the clay fines is a clay selected from sepiolite, saponite, hectorite, attapulgite clay, and mixtures thereof.

Abstract: The present invention provides a method for making an odor adsorbent tampon or related catamenial device. The method of the present invention includes the steps of forming a plurality of fibers, preferably by extrusion, and impregnating or urging into or inserting into the interstices of the fibers with one or more odor adsorbent materials while the process of forming the fibers is being performed. Thereafter, the plurality of fibers so formed are suitably and conventionally brought together to produce the finished device. Preferably, the one or more odor adsorbent materials is in liquid form and/or is naturally sourced.

Abstract: An article of manufacture comprises an ultrahigh molecular weight polyethylene (UHMWPE) mixed with a processing oil and a lubricant selected from the group consisting of fatty acid esters, ethoxylated fatty acid esters, glycol esters, PEG esters, glycerol esters, ethoxylated esters, sorbitol esters, ethoxylated sorbitol esters, aromatic ethoxylates, alcohol ethoxylates, mercaptan ethoxylates, modified ethoxylates, amide surfactants, phosphate esters, phosphonate esters, phosphite esters, alkyl sulfates, fatty acid ethers, alkyl ether sulfates, alkylaryl ether sulfates, sulfonates, naphthalene sulfonates, sulfosuccinates, sulfonated esters, sulfonated amides, alkyl ether carboxylates, alkylaryl ether carboxylates, quaternary amines, amino quaternary amines, ethoxylated amines, imidazoline derivatives, betaines, sultaines, aminopropionate, catechol derivatives, saturated fatty acids, unsaturated fatty acids, and combinations thereof. The method for making those articles is also disclosed.

Abstract: A cellulose/polyolefin pellet comprising polyolefin material and cellulosic material. The pellet may be concentrated such that it contains less than about 20% by weight of the polyolefin material and at least about 55% by weight of the cellulosic material. The pellet may be shipped to a remote manufacturing location where it may be blended with additional polyolefin material to make a synthetic wood component.

Abstract: A process for producing a honeycomb structure, which comprises adding, to a particulate ceramic raw material, a fatty acid salt-containing dispersing agent and at least water, kneading the mixture to obtain a puddle, and extruding the puddle, wherein the fatty acid salt constituting the dispersing agent comprises:

Abstract: The present invention is directed to ion-sensitive, hard water dispersible polymers. The present invention is also directed to a method of making ion-sensitive, hard water dispersible polymers and their applicability as binder compositions. The present invention is further directed to fiber-containing fabrics and webs comprising ion-sensitive, hard water dispersible binder compositions and their applicability in water dispersible personal care products.

Abstract: The present invention relates to industrial high relative viscosity (RV) filaments, such as, for use in papermaking machine felts and other staple fiber applications. The invention is further directed to apparatus and processes for solid phase polymerization (SPP) of polyamide flake suitable for use, such as, in remelting and then spinning the industrial high RV filaments. The invention is also directed to processes for melt phase polymerization (MPP) of molten polymer for making the filaments.

Abstract: A method for manufacturing sheet-like elements made of plastics, particularly nets and the like, comprising the step of: extruding mixtures based on fully biodegradable thermoplastic material at a temperature between 70 and 100° C. at the beginning of the extrusion process and between 120 and 140° C. at the end of the extrusion process; maintaining an extrusion pressure between 20 and 50 bar; and performing at least one stretching in a preset direction at a temperature between 35 and 60° C.

Abstract: This invention provides processes for preparing fiber or film comprising a polyurethane and layers delaminated from a lamellar clay, said layers being dispersed in said Polyurethane. Fiber and film produced by the processes of the present invention exhibit reduced tack and an increased ability to affix at least one dye.

Abstract: A process for making load limiting yarn comprising making block copolymer and then spinning the block copolymer into yarn. The process employs a twin screw extruder and comprises (A) forwarding aromatic polyester melt to an injection position in a twin screw extruder, (B) injecting lactone monomer into the molten aromatic polyester, (C) dispersing the monomer into the aromatic polyester melt so that a uniform mixture forms in less than about thirty seconds, and (D) reacting the uniform mixture resulting from step (C) at a temperature from about 250° C. to from a block copolymer. Steps (A) through (D) occur in less than about four minutes residence time in the twin screw extruder. The process is advantageous because high IV starting aromatic polyester can be used and the short reaction time at high temperature results in block copolymer with minimum transesterification, a high melting point, and a high melt viscosity.

Abstract: Injection-molding materials comprised of polycarbonate can be processed into optically isotropic films in a chill roll extrusion method. The optically isotropic films are used as covering films for protecting data carriers (CD-ROMS) from becoming scratched, or they are used as supporting materials for the information layer.

Abstract: The invention relates to a process for melt-shaping a polymer composition wherein the constituent components for the polymer composition are supplied directly to the shaping device in the form of a mixture of granules on or in which the constituent components are present. The granule mixture contains at least 3 granule-fractions containing the matrix polymer that differ in composition.

Abstract: The method for manufacturing a thermoplastic elastomer composition of the present invention comprises continuously feeding a mixture comprising pelletized olefinic resin (A), a pulverized product (B) obtained by pulverizing bulk olefinic rubber, and a crosslinking agent (C) into a continuous kneading machine, and performing a dynamic heat treatment to yield the thermoplastic elastomer composition. An olefinic thermoplastic elastomer composition having excellent tensile characteristics and molded appearance can be manufactured with high productivity by the method of the present invention.

Abstract: A discontinuous lignocellulose fiber is described for use as a reinforcing filler for thermoplastic composite compositions. The fiber filler includes a significant percentage by weight of long, “hair-like” fibers. Specifically, at least about 20 percent by weight of the fiber filler is discontinuous lignocellulose fiber with a fiber length greater than about 15 millimeters and a fiber diameter less than about 0.5 millimeters. A moldable thermoplastic composite composition including the discontinuous lignocellulose fiber comprises about 20 to about 50 percent by weight of the fiber filler and about 50 to about 80 percent by weight thermoplastic. The discontinuous lignocellulose fiber filler yields thermoplastic composite compositions having improved physical properties over basic thermoplastic. The improved physical properties can be achieved without the use of coupling agents, although coupling agents may be used to further enhance the composite properties.

Abstract: A method of making a polypropylene product for use in making films and preferably biaxially oriented films and more preferably biaxially oriented films wherein a tenter-frame processing line is employed. The method includes the addition of low concentrations of a nucleating system in a mini-random polypropylene that allows for better processability and improved tensile properties. In one embodiment the nucleating system comprises a blend of a monocarboxylic acid nucleating agent and dicarboxylic acid nucleating agent. The nucleating system is combined with the polypropylene material and the resultant hot melt blend is further processed into biaxially oriented film. Alternately, the hot melt blend is formed into a convenient raw material for later use in a biaxial oriented film production facility. The resulting films possess superior processing and material characteristics.

Abstract: This invention generally relates to the formulation of thermoplastic pellets from a combination of raw sludge material from a paper mill with thermoplastic material from post industrial or consumer sources. Initially, waste raw sludge material is transported via a conveyor to a dryer for removal of excess water. The waste thermoplastic material is preferably shredded into a desired size and transported to a densifier. The dried sludge is added to the densifier where the shredded thermoplastic material and dried sludge is suitably mixed with additive agents. The mixed sludge and shredded thermoplastic material is then transported to a grinder for grinding. The ground material is then transported to a hopper for introduction into an extruder. The ground combined material is then subjected to an extrusion process for the formulation of thermoplastic pellets having supplemental fibers to enhance the properties for use as starting material in an injection molding process.

Abstract: The present invention includes a composition having a co-continuous interconnecting channel morphology. These co-continuous interconnecting channels are predominately occupied with a polymer and particles that control the surface properties of the composition. The polymer composition may be used to form a desired shaped article such as plug type inserts and liners for closed containers, or it may be formed into a film, sheet, bead or pellet.

Abstract: A ceramic paste composition containing a liquid carrier, ceramic particles, a binder and a dispersant additionally contains a cushioning agent so that it may be extruded at a low extrusion pressure, i.e. below about 0.04 MPa. The cushioning agent is in the form of particles which have a bulk modulus of elasticity of from about 0.1 MPa to about 4 MPa.

Abstract: The present invention relates to high dielectric non-woven fabrics and their synthetic process and more particularly, relates to a process for preparing high dielectric non-woven fabrics including the steps of (a) mix-spinning polyvinylidene fluoride (PVDF) and polypropylene (PP) to prepare a fiber, (b) polarizing the fiber prepared in the step (a) to improve the dielectric constant of the fiber, and (c) manufacturing non-woven fabrics from the fiber having improved dielectric constant, prepared in the step (b), and non-woven fabrics prepared according to the mentioned process.

Abstract: The combination of fluoropolymer processing aid with foam cell nucleating agent gives a combined processing aid that is far superior to either individually when used in the extrusion of melt processible polymers.

Abstract: A process for fabricating biaxially oriented polypropylene to modify the properties of polypropylene through treatment of flame is disclosed. The surface tension and the planarity of the polypropylene films is improved after adjusting the composition of the polypropylene and treating the polypropylene films with flame. The polypropylene products through the treatment process have good lamination strength for water-based inks and good adherence with aluminum foils. The requirements of the process for fabricating the polypropylene is illustrated following: 1. The surface for future printing and electroplating is heated by flame. 2. The flame comes from the combustion of a liquid natural gas which contains more than 85% of methane. 3. The flame has following properties: (1) polrization voltage: 0.1-0.8 KV, optimal voltage: 0.2 KV. (2) The temperature of cooling cylinders : 20-50° C., optimal temperature 25° C. (3) The temperature of flame : 700-900° C., optimal temperature 760° C.

Abstract: The present invention is directed to the combined use of a dispersant as an internal melt additive and a surfactant as an outer topical additive to impart or improve the wettability of extruded thermoplastic constructs. A dispersant is provided to, and blended with, a thermoplastic polymer which is then formed into a thermoplastic construct. A surfactant is then applied to the thermoplastic construct to impart or improve the wettability of the thermoplastic construct.

Abstract: Provided is a flexible resin boot of which the noise-preventing effect lasts long and which ensures improved sealability and durability. The boot is formed from a base resin of a thermoplastic elastomer resin, and has a large port and a small port that are connected with each other via a bellows therebetween. For this, mineral oil or vegetable oil is added to the thermoplastic elastomer resin. Preferably, the thermoplastic elastomer resin is a thermoplastic polyester elastomer, and the mineral oil is process oil having an aromatic content of at most 13%. The boot is used for covering the constant velocity joint in an automobile.

Abstract: This invention describes the use of organoclays as additives to plasticizers to provide a plasticizer composition, to allow the mixing of the plasticizers with thermoplastic resins in the same process used to convert the resin formulation to finished product. The use of this invention eliminates the need for a preliminary compounding step to incorporate plasticizers into thermoplastics prior to extrusion or molding.

Abstract: A novel adhesion adjusting additive for semiconductive dielectric shields for electric power cables is disclosed. The additive comprises a compound with a carbon-oxygen dipole, and a molecular weight less than 20,000 daltons. The additive is blended with a base polymer and conductive carbon black to form the material for the semiconductive shield.

Abstract: The use of a sulfonated salt polyester ionomer resin in a colored, drawn polyamide or polyester fiber results in improved color strength and appearance. Sodium sulfo isophthalate polybutylene terephthalate copolymers when melt blended with colorants and subsequently used to make melt spun synthetic polyamides or polyesters fibers are shown to enhance color strength in drawn fibers.

Abstract: A process for producing mono-axially oriented polyethylene terephthalate film having increased mechanical strength in the machine direction which comprises the steps of drying substantially homopolymer or copolymer polyethvlene terephthalate resin having an intrinsic viscosity in the range of about 0.65 to about 0.85 dg/cc and then blending the dried resin with from about 0.5 to about 4.0% by weight of anti-block additive; extruding the resin blend to re-melt the resin and make it homogeneous: casting a film web with the resin blend; orienting the film immediately after casting it to produce a film of uniform thickness, by drawing the film at a ratio of from about 3.5 to about 4.

Abstract: A paper-feeding roller (1) formed by cylindrically molding a thermoplastic elastomer composition containing a thermoplastic resin or a thermoplastic elastomer in which a rubber or a thermoplastic elastomer that can be crosslinked is dispersed by dynamic crosslinking. A surface layer of the paper-feeding roller (1) contains titanium oxide at not less than 1.5% nor more than 50% in a volume fraction.

Abstract: A woody formed article, characterized as being produced by admixing a woody material W and, as a binding agent, a fibrous and/or ribbon shaped thermoplastic resin R which is easy to be intertwined with the woody material W, and molding the resultant mixture. The thermoplastic resin R is preferably admixed in a state of being heated and melted. A method for producing a woody formed material, characterized in that it comprises providing a mat M of a raw material mixture Mx of a woody material W and a fibrous and/or ribbon-shaped thermoplastic resin R and subjecting the mat M to heat pressing, or comprises, in admixing the woody material W with the above fibrous thermoplastic resin R, stretching and thinning the resin R by means of a hot wind and/or a cold wind pressure, and admixing homogeneously it with the woody material W by utilizing a negative pressure zone due to the hot wind and/or the cold wind, to prepare a mat M of a raw material mixture Mx, and then subjecting the mat M to pressing.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.