Abstract: Disclosed herein is a method comprising deforming an organic polymer composition at a temperature below a glass transition temperature of an organic polymer in the organic polymer composition; the deforming being conducted by an application of a shear force, an elongational force, a compressive force, or a combination comprising at least one of the foregoing forces; the forces being applied to the organic polymer composition as it is disposed between a first roll that comprises a rubber surface and a second roll that comprises a textured metal surface; the deforming producing a textured film having a ratio of texturing of about 0.5 to about 3; the textured film having a thickness of about 5 to about 75 micrometers and an average roughness of about 0.3 to about 6 micrometers on opposing surfaces of the film.

Abstract: (EN) The invent on relates to polymethylmethacrylate with a nacreous effect. (DE) Die Erfindung betrifft Polymethylmethacrylat mit Perlglanzeffekt.

Abstract: A thermoplastic composition is disclosed, comprising a polymer component comprising a polysiloxane-polycarbonate copolymer comprising siloxane units of the formula wherein each occurrence of R is the same or different and is independently a C1-13 monovalent organic group; the average value of E is 4 to 60; and carbonate units of the formula wherein at least about 60 percent of the total number of R1 groups are a divalent C6-36 aromatic organic group, and the balance thereof are C1-36 aliphatic, C5-36 alicyclic, or C6-36 aromatic organic groups; and 0.03 to 5 weight percent, based on the total weight of the polymer component, of a polymeric compound comprising at least two epoxy groups, wherein the polymeric compound has a weight average molecular weight of 1,500 to 18,000 Daltons.

Abstract: A cellulose ester film comprising a cellulose ester and a compound containing an acrylate group or a methacrylate group; and a phenolic hydroxyl group, in the molecule.

Abstract: A battery separator comprises a co-extruded, microporous membrane having at least two layers made of extrudable polymers and having: a uniform thickness defined by a standard deviation of <0.80 microns (?m); or an interply adhesion as defined by a peel strength >60 grams.

Abstract: An optical film includes a multi-layer sheet including: a plurality of polyethylene terephthalate polymer layers, the polymer layers having a first refraction index in a first direction parallel to a plane of the polymer layers and a second refraction index in a second direction parallel to the plane of the polymer layers, and a plurality of polyethylene terephthalate copolymer layers, the copolymer layers having a third refraction index in the first and second directions, a protection sheet on at least one side of the multi-layer sheet, and an adhesive member between the multi-layer sheet and the protection sheet.

Abstract: A manufacturing method of an artificial strip for imitated rattan furniture is completed by steps of: inputting polyester plastic material with one color or two colors into at least one plastic extruder; thermal-melting the polyester plastic material to pour into a shaping molds, extruding the melted polyester plastic material in form of a continuous geometry strip so that the strip has at least one color on its surface; cooling the strip; twisting the strip to perform spiral wavy surface to enhance vivid appearance. Lastly, the strip is reeled up to achieve an annular bundle. Thereby, the artificial strip has a verisimilitude texture approximately like the natural willow or rattan strips to make the manufactured imitated rattan/willow furniture have excellent appearance. A device system carries out the manufacturing method is also disclosed in this invention.

Abstract: A method of manufacturing an ink stick for use in a phase change ink jet imaging device comprises heating phase change ink material to an extrusion temperature at which the phase change ink material is in a malleable state. The heated ink material is then extruded through an extrusion orifice to form an extruded element. A forging element is then pressed against the extruded element to form an ink stick.

Abstract: In a molded surface fastener (10) having engaging elements (2) of minute dimension of thermoplastic resin molded together with a base member (1) by continuous molding, each engaging element (2) comprises first and second engaging portions (22a, 22b) each having a different configuration extending in parallel to a surface of the base member from a top end of a pillar portion (21) rising from the base member (1) such that they intersect at right angle. The second engaging head (22b) has an ordinary hook shape structure while the first engaging head (22a) has a wing-like thin plate structure as seen in a plan view. The engaging elements having such a structure in which each engaging element has appropriate engagement force, shearing force and separation force so as to keep an excellent tactile feeling of a surface of the surface fastener, prevents itself from falling down against a pressing force, secures a high engagement ratio with mating pile pieces and satisfies a durability.

Abstract: The invention provides a tape film backing including a mixing layer comprising 40-60 parts by weight of PE and 60-40 parts by weight of EPDM rubber and a PE layer. The invention also provides a tape with an adhesive layer coated on the mixing layer or the PE layer of the tape film backing. The tape and the film backing is a halogen-free eco-material possessing superior physical properties as well as fine electrical insulating properties.

Abstract: A biodegradable laminate sheet having as its object to provide a formed body superior in heat resistance, shock resistance, transparency and formability, and having non-stretched polylactic acid-family resin layer of which the crystallinity is 20% or less, and a layer comprising a biodegradable resin other than a polylactic acid-family resin.

Abstract: A thermoplastic film having a first surface defining pockets, each pocket having a depth and breadth and a bottom, the bottom is preferably textured and is thinner than the thickness of the first surface. Devices made from the film include one or more of a variety of materials contained within the pockets and a second layer overlying the first surface to cover the openings of the pockets. A process of making the film is also disclosed.

Abstract: The present invention relates to a thermo-shrinkable polyester film with a superior thermal shrinkage, which has an orientation angle of a molecular chain in a range of from 0° to about ±10° relative to a main shrinkage direction, and a molecular orientation ratio (MOR) in a range of from 1.29 to about 2.5, thereby preventing a label made from the film from curling or waving.

Abstract: Invention relates to a process for producing a single-layer or multilayer film by extrusion or coextrusion, biaxial orientation, and heat setting based on crystallizable thermoplastics whose principal constituent is a crystallizable thermoplastic having a standard viscosity SV (DCA) of from 600 to 1000. The thermoplastic is mixed prior to extrusion or coextrusion with 50% by weight (based on the total weight of all thermoplastics) of a secondary thermoplastic having a standard viscosity SV (DCA) of more than 900 to 1500, the standard viscosity SV (DCA) of the two thermoplastics differing by at least 100 units. The secondary thermoplastic is a byproduct or waste product from the production of PET plastic bottles or originates from recycled PET bottles.

Abstract: A process for produces an adhesive closing element including a plurality of hook elements connected to a backing (10) forming a single piece with the hook elements and being disposed symmetrically thereon. The hook elements are provided in the form of a stem component (17) having a head piece (16). A deformable material is introduced into a forming zone in between a production master (3) and a forming tool (5). The opposite-lying defining walls, at least when seen in a longitudinal section of the respective forming cavity (12), are provided with a continuous convex trajectory. A continuous transition between the cross-sectional forms of the stem component (17) and the head piece (16) is provided for a hooking of the backing (10) resulting in seamless removal.

Abstract: A polytrimethylene terephthalate resin comprising: 90 to 100 mole % of trimethylene terephthalate recurring units, and 0 to 10 mole % of at least one monomer unit obtained from a comonomer other than the monomers used for forming the recurring units and copolymerizable with at least one of the monomers used for forming the recurring units, which resin has the following characteristics: (A) an intrinsic viscosity [?] of from 0.8 to 4.0 dl/g; (B) an Mw/Mn of from 2.0 to 2.7; (C) a psychometric lightness L-value (L-1) of from 70 to 100 and a psychometric chroma b*-value (b*-1) of from ?5 to 25; and (D) a psychometric lightness L-value (L-2) of from 70 to 100 and a psychometric chroma b*-value (b*-2) of from ?5 to 25 as measured after heating the resin at 180° C. for 24 hours in air.

Abstract: A method for forming fibers/composite material having an anisotropic structure, comprising the steps of mixing an effective amount of fibers with a matrix material to form a deformable mixture containing less than about 96 weight percent of the fibers to about parts per billion of the fibers and wherein the fibers are randomly oriented in the deformable mixture. The deformable mixture can be extruded, stretched or otherwise deformed to form an extrudate. Pressure is applied about the extrudate to substantially compress the fibers in the extrudate to provide the fibers/composite material having an anisotropic structure.

Abstract: The present invention relates to a multi-component composite separate membrane and a method for preparing the same, and to a multi-component composite membrane comprising a support layer and active layers, wherein the support layer is located between the active layers.

Abstract: A method for plugging a subset of cells of a honeycomb structure having a plurality of open-end cells extending therethrough including providing at least one cylindrically-shaped first roller including an engagement surface having a plurality of outwardly-extending teeth spaced along a length and about a circumference of the at least one first roller, wherein the teeth are spaced so as to engage a first subset of a total number of cells exposed on a first end of the honeycomb structure. The method also includes rolling the engagement surface of the at least one first roller across the first end of the honeycomb structure with the teeth extending into the first subset of cells, thereby deforming the first end of the honeycomb structure and plugging a second subset of the total number of cells substantially different from the first subset of cells.

Abstract: A method for producing a polyolefin stretched sheet which comprises extruding a polyolefin having a weight average molecular weight of 100,000 to 500,000 into a primary sheet, rolling the primary sheet at a rolling magnification of 5 or more, and stretching the rolled sheet into a polyolefin sheet which is totally stretched at a stretching magnification of 15 or more. The method can be employed for producing a polyolefin stretched sheet excellent in creep resistance, tensile strength and modulus in tension, with no use of a ultra-high molecular weight polyethylene and with excellent productivity.

Abstract: Volatile organic compound or other materials are produced in the thermoplastic manufacture of thermoplastic polyester beverage containers. Such materials can be eluted into beverages such as carbonated beverages, sparkling or still water from the polyester. Such thermoplastic polyester resins can be manufactured with a material that can prevent the formation of, or react with, and absorb volatile by-products during the formation of thermoplastic preforms or containers from the thermoplastic pellet or chip. Further, as the preform is blown into a polyester container, the active materials of the invention prevent the generation of additional undesirable volatile materials. Lastly, the scavenger material can act as a barrier that prevents transport of materials from the exterior of the container into the container contents.

Abstract: An automotive trim product is made as follows. A single or multiple layer sheet is extruded so as to include at least one color pigmented and/or metallized layer therein. The sheet is then thermoformed into a three-dimensionally shaped preform via vacuum forming or the like. The preform is placed into a cavity of an injection molding apparatus and heated semi-molten material is injected thereinto. The semi-molten material bonds to the preform in the cavity. After cycling, the molding apparatus ejects a final automotive trim part. Optionally, some processing (e.g. trimming) may be performed following ejection.

Abstract: There is provided a particulate filter for trapping particulates contained in an exhaust gas discharged from a combustion chamber of an engine, comprising a plurality of exhaust gas flow passages each formed by three porous partitions extending substantially parallel with each other, each of the exhaust gas flow passages having a triangular cross section, wherein the partitions defining one of the adjacent exhaust gas flow passages are deformed at one end area of the filter so that the partitions at one end area of the filter approach each other toward one of the ends of the filter, the deformed portions of the partitions are connected to each other at their ends, thereby an opening of one of the adjacent exhaust gas flow passages is at least partially closed, the partitions defining the other exhaust gas flow passage are deformed at the other end area of the filter so that the partitions at the other end area of the filter approach each other toward the other end of the filter, and the deformed portions of t

Abstract: A method and a device for production of a web with good breathing properties, for example having a nonwoven web based on plastic filaments and/or plastic fibers and a plastic film, applied on one side of the nonwoven web and containing at least one mineral filler. For the production of the good breathing properties, the web is stretched in the longitudinal direction of the same, in two successive steps, and an embossing is carried out, at least in certain sectors of the surface, between the two steps which effect the stretching in the longitudinal direction.

Abstract: A method of fabricating a substrate used for purifying an exhaust gas is provided. This method comprises the step of transforming a pre-mold having a first end, a second end, a plurality of partition walls extending between the first end and the second end, the first transforming step for transforming the end portions of the partition walls at the first end in such a manner that the ends of the partition walls defining one of two adjacent passages at the first end of the pre-mold are collected toward the center of a corresponding passage and connected to each other, and the second transforming step for transforming the ends of the partition walls at the first end in such a manner that the end surfaces of the partition walls at the first end are depressed toward the center of each of the end surfaces.

Abstract: A method of producing contoured vehicle floor mats having integrally formed nibs. The sheet is formed by a nib forming roll in an extrusion roll stack having a plurality of indentions. The nibbed sheet is placed onto the thermoform mold with the nibs directed away from the mold. The sheet is heated to a plastic state and stretched over the mold to form a contoured mat shaped to vehicle within a vehicle compartment, trunk or cargo area. The nibs on the underside of the mat contacts the floor covering and prevents the mats from sliding on the interior surface of the vehicle.

Abstract: A polyolefin microporous breathable film having improved tear and impact strength as well as a soft feel is provided by a film including a polypropylene precursor film and a filler. Other embodiments include a second polymer component.

Abstract: A low crystallizability polypropylene sheet which has an average spherulite radius between 0.1 ?m and 4 ?m, an average number of spherulites of 600/mm2 or less in a sheet cross section, a solid density of 0.895 g/cm3 or less, a fusion enthalpy H of less than 90 J/g at the highest endothermic peak of the differential scanning calorimetry (DSC) curve, a degree of gloss of 90% or higher on at least one side and shows an exothermic peak of 1 J/g or higher at the low temperature side of said highest endothermic peak and a thickness of 50 ?m or more.

Abstract: A non-woven fabric which consists of a blend 75% to 95% by weight of polypropylene based fibers and 5 to 25% by weight of polyester based fibers. The polypropylene fibers are extruded from a melt mixture of about 80 to 99% by weight polypropylene and about 1 to 20% by weight of a suitable heat stabilizer. The polyester based fibers are extruded from a melt mixture of 80% to 100% by weight polyester and 0 to 20% by weight of other stabilizers and/or fire retardants. The flame retardant compounds are added to and blended with the polyester melt prior to the extrusion of the polyester based fibers. Most preferably, the extruded polypropylene and polyester based fibers are staple fibers of between about 2 and 12 denier.

Abstract: A running length of fastener product is formed of longitudinally pre-oriented synthetic resin. The product is characterized by a base web and an array of discrete fastener elements protruding from at least one side of the web, the web being in a laterally stretched molecular oriented condition. After forming a preform having discrete fastener elements integral with a base web in a stretchable state, the preform is stretched in a manner that substantially increases the fastener element spacing and reduces the thickness of the base web. A machine is shown that is capable of lengthwise orienting before forming and widthwise stretching after forming, which employs controlled heating to render the product widthwise stretchable while preserving or achieving a desired shape of the fastener elements.

Abstract: A method includes the steps of co-extruding a first component and a second component. The first component has a recovery percentage R1 and the second component has a recovery percentage R2, wherein R1 is higher than R2. The first and second components are directed through a spin pack to form a plurality of continuous, molten fibers. The plurality of molten fibers is then routed through a quenching chamber to form a plurality of continuous cooled fibers. The plurality of continuous cooled fibers is then routed through a drawing unit to form a plurality of continuous, solid linear fibers. The linear fibers are then deposited onto a moving support, such ass a forming wire, to form an accumulation or fibers. The accumulation of fibers are stabilized and bonded to form a web. The web is then stretched by at least 50 percent in at least one direction before being allowed to relax.

Abstract: Process for preparing an industrial polyester multifilament yarn with high modulus and low shrinkage, in which polyethylene terephthalate polyester is wound at 2000 m/min or more to produce undrawn yarns with an intrinsic viscosity of 0.88 or higher and a density of 1.338 to 1.365 g/cm3, an oiling agent is provided to undrawn yarns, the resulting undrawn yarns are wound, drawn through three stages, heat set, relaxed, and wound again. The polyethylene terephthalate polyester yarn is produced by drawing undrawn yarns at a glass transition temperature (Tg, about 80° C.) or lower through three stages under conditions that a draw ratio of the 1st stage is greater than a draw ratio of the 2nd stage or a draw ratio of the 3rd stage and the draw ratio of the 3rd stage is greater than the draw ratio of the 2nd stage.

Abstract: A ceramic material containing organic binder is formed by extrusion, dried and cut off so as to make the honeycomb body 100 having the bulkheads 11 and a plurality of cells 12 partitioned by the bulkheads 11 and penetrating between both end faces of the honeycomb body 100. The tapered jig 3 having a tapered forward end portion 31 is inserted into the opening 13 of the cell 12 of the honeycomb body 100. Then, the bulkheads 11 are heated and softened and deformed by a pushing force given by the tapered jig 3 so that the opening 13 of the cell 12 is expanded to form the large opening 131, and the opening 13 of the adjoining cell 12 is reduced at the same time so as to form the small opening 132. After that, the honeycomb body 100 is fired. In this way, the exhaust gas purifying filter for collecting particulates is manufactured.

Abstract: A drawn film production method including steps of drawing a crystalline thermoplastic resin film in the TD direction is characterized in that the orientation coefficient of the c-axis of the crystal of the thermoplastic resin in the film to the MD direction of the film is 0.8 or higher.

Abstract: A control panel assembly having a plurality of buttons located in a bezel and supported by a switch mat. A bezel and/or button is formed using a vacuum forming technique and has a transparent inner surface layer and a middle translucent color layer and an opaque outer surface layer. A portion of the opaque outer surface layer is removed to define a desired indicia on an outer surface of the bezel or button. In addition, the bezel or button can be backlit to allow visibility in low light conditions. A method of making a control panel component, such as a bezel or button, is also disclosed.

Abstract: A film made of a vinylidene-trifluoroethylene or tetrafluoroethylene copolymer is uniaxially drawn to fabricate a uniaxially drawn film. Then, the uniaxially drawn film is thermally treated at a temperature within a temperature range of the Curie temperature through the melting point of the vinylidene-trifluoroethylene or tetrafluoroethylene copolymer for five hours or over, to diffuse the molecular chains of the uniaxially drawn film along the orientation direction and thus, to remove the intertwining between the molecular chains.

Abstract: A unitary fastener of a thermoplastic resin comprising a base film layer having generally parallel upper and lower major surfaces, arranged in a first direction the base film layer being oriented at least in the first direction. The backing layer having on at least one surface separated surface elements extending at an angle to said first direction. The invention is also related to a method of forming a unitary fastener. The method includes the steps of extruding a thermoplastic resin in a machine direction through a die plate having a continuous base portion cavity and one or more rib cavities extending from the base portion cavity, forming a strip having a base layer and continuous rib. This scoring or cutting the ribs and at least a surface layer of the film structure forms predetermined separable elements. This inelastically stretching the strip to separated projections and the separated separable surface elements across the strip.

Abstract: A method of making a polyolefin film in accordance with this invention includes the steps of: blending a propylene block copolymer with a beta nucleating agent; extruding a film layer from the blend and providing a total area draw ratio in excess of 20, where at least one part of the stretching occurs at <120° C., for forming the film with a density no greater than 0.40 g/cm3 and a thickness greater than 160 gauge.

Abstract: Disclosed is a light directing polymeric film bearing on a surface thereof a three-dimensional features having an Ra of at least 3, the features containing a polymer dispersion comprising a continuous phase thermoplastic first polymeric material and a discontinuous phase thermoplastic second polymeric material that is immiscible with the first polymeric material and is dispersed in elongated micro-regions.

Abstract: A continuous process for making a thermoplastic article comprises extruding a sheet of thermoplastic and contacting the sheet with a mold surface while the sheet is in a substantially non-oriented state. The mold surface is selectively heated and/or cooled during thermoforming to maintain the sheet in a molten or thermoformable state. A stripper plate adjacent to the mold surface is maintained at different temperature for inducing a predetermined degree of crystallinity to the sheet, for increasing web stiffness and improving web alignment, and optionally for assisting in the separation of the articles from the mold. A continuous apparatus for making thermoformed articles has co-extruders for extruding at least two distinct layers, which can have dissimilar properties (e.g., polar and non-polar), and a temperature controlled molding surface. Preferred thermoplastic compositions of the present invention have improved toughness and retained intrinsic viscosity.

Abstract: A sizer assembly for providing a shaped polymeric article in an extrusion process comprises a sizer body having a product profile channel corresponding to the shaped polymeric article formed therethrough. The sizer body comprises a plurality of cooling liquid inlet slots forming an opening substantially around the product profile channel and a plurality of vacuum slots forming an opening substantially around the product profile channel for removing cooling liquid expelled from said cooling liquid inlet slots.

Abstract: Soft and elastic polymer products arc obtained by stretching a composition comprising a biodegradable polyhydroxyalkanrate copolymer comprising at least two randomly repeating monomer units. The first randomly repeating monomer unit has the structure (I), wherein R1 is H, or C1 or C2 alkyl, and n is 1 or 2. The second randomly repeating monomer unit has the structure (II), wherein R2 is a C3-C19 alkyl or C3-C19 alkenyl. At least about 70 mole % of the copolymer comprises randomly repeating monomer units having the structure of the first randomly repeating monomer unit (I). The products exhibit advantageous combinations of softness and elasticity while maintaining strength.

Abstract: A process for forming a rod of bioabsorbable polymeric material includes extruding the material at a temperature above its melting point at a controlled rate of between 0.4 to 20 feet per minute to form a continuous rod. The continuous rod is then cooled by passing the rod through a cooling bath to cause nucleation. The continuous rod is passed through a first puller running at least at the same speed as the extruder. A second puller is provided which is moving faster than the first puller so that the continuous rod is elongated at a ratio of between 2 and 12 times. During this elongation, the rod is heated to a temperature of between 55° C. and 140° C. in an oven located between the first and second pullers. The rod is annealed at a temperature of between 70° C. and 110° C. after being elongated but prior to exiting the second puller. Upon exiting the second puller, the tension in the rod is released and the continuous rod is then allowed to cool.

Abstract: Polypropylene resin compositions are provided that are useful in the production of biaxially oriented polypropylene films (BOPPs). The resins of the present invention are blends of high crystalline (low solubles) polypropylene homopolymer and an ethylene/propylene random copolymer (RCP). These blends can be used to replace standard high solubles BOPP grade polypropylene homopolymers. In addition, the use of high crystalline polypropylene homopolymers in the blends imparts improved stiffness to the finished films while maintaining good processability of the blends.

Abstract: A production line for the manufacture of strips of vinyl siding comprises an extruder extruding a strip of hot plastic material, such as vinyl. Next, an embosser supplies a decorative pattern to the heated strip. A cooling apparatus receives the heated strip and immerses the strip in a water bath to lower the temperature to a selected temperature range. The material, now reduced in temperature, is then passed to a former having dies creating joining runs in the cooled, embossed siding strip. Finally the strip runs through a final cooling tank which chills the strip to harden the joining runs created by the former. The cooling apparatus consists of a water bath tank with entry and exit guides for the strip, which are mounted above the level of the water in the water bath tank.

Abstract: A film includes a core layer including a polyamide; two intermediate layers, disposed on opposite surfaces of the core layer, including an adhesive; and two outer layers, each disposed on a surface of the respective intermediate layer, comprising an ethylene/alpha olefin copolymer; wherein the two outer layers each constitute at least 27% of the total thickness of the film. The core layer can include either a single polyamide layer, or three layers wherein two layers of polyamide have therebetween a layer comprising a polymeric adhesive. The film is made preferably by a hot blown process at a blow up ratio of between 2.0:1 and 3.0:1. A process and package are also described.

Abstract: A method including forming a pseudo-gel of a semi-crystalline polymer material and a solvent. The pseudo-gel is shaped into a first form and stretched. A portion of the solvent is removed to create a second form. The second form is stretched into a microstructure including nodes interconnected by fibrils. A method including forming a first form of a pseudo-gel including an ultra-high molecular weight polyethylene material and a solvent; stretching the first form; removing the solvent to form a second form; stretching the second form into a microstructure including nodes interconnected by fibrils; and annealing the stretched second form. An apparatus including a body portion formed of a dimension suitable for a medical device application and including a polyolefin polymer including a node and a fibril microstructure. An apparatus including a body portion including an ultra-high molecular weight polyolefin material including a node and a fibril microstructure.

Abstract: A die apparatus, a method of using the die apparatus to produce co-extruded polymeric articles, and co-extruded polymeric articles produced using the die apparatus and method are disclosed. The die apparatus includes a hollow vane configured to extrude a material into a chamber within the die, thereby producing a co-extruded web. The co-extruded web has a plurality of distinct, discontinuous phases in the cross-web direction, the phases having a uniform width as shown by a coefficient of variation of less than 8 percent for any three consecutive phases. The phases are substantially continuous down-web and are surrounded by a matrix having two or more layers.

Abstract: The present invention relates to a process for making polymer tapes utilizing metallocene catalysts. An isotactic propylene polymer is prepared by polymerizing propylene in the presence of an isospecific metallocene catalyst. The resulting polypropylene is heated, extruded and withdrawn as a sheet. The sheet is then slit longitudinally into tape segments and drawn in the longitudinal direction to a draw ratio of at least about 4.5:1 to produce an oriented tape. It has been found that these polypropylene tapes have different characteristics than those polypropylene tapes produced using Ziegler-Natta catalyst drawn at the same draw ratios.

Abstract: A process for preparing a blow molding preform comprises melting plastic flakes in a plasticizing screw extruder to prepare a homogeneous stream of hot polymer melt at the discharge of the extruder, cooling the polymer melt stream to a temperature at least 20 degrees Centigrade below the extruder discharge temperature by heat exchange with a liquid heat transfer medium, and forming the cooled polymer melt into a blow molding preform.