Abstract: Novel gel-spun, irradiated and drawn ultra high strength high molecular weight and at least partially cross-linked and/or branched polyethylene filaments, tapes and films, exhibiting a combination of substantially lower creep rates, very high heat shrink characteristics and high abrasion resistance properties than corresponding but non-irradiated articles, and with a process for making the same.

Abstract: A process is described for the preparation of highly stretchable high-molecular weight polyolefin gel articles and polyolefin gel articles prepared therefrom having combined high tensile strength and high modulus, wherein an initial shaped article of the polyolefin is exposed to or contacted with a swelling agent to form an intermediate swollen article, which is then converted to the gel state and then subsequently subjected to stretching at up to relatively high draw ratios.

Abstract: Polyacrylonitrile articles, such as filaments, tapes and films, having high tensile strength and modulus, and prepared by adding to a solution of polyacrilonitrile with a molecular weight above 3.times.10.sup.5, preferably above 5.times.10.sup.5, a minor amount of a bivalent metal compound, converting the solution into a solvent containing article, cooling this article to form a gel article, removing from this gel the solvent and metal compound, and stretching the resulting article at increased temperature. With this process filaments with a tensile strength above 1.2 GPa and a modulus above 16 GPa can be obtained.

Abstract: The adhesive strength of highly oriented, highmolecular polyolefin filaments for polar polymeric matrices is improved by subjecting the filaments to a corona treatment with a total irradiation dosage of ##EQU1## effected intermittently in several smaller dosages. The process is particularly suited for treating superstrong polyethylene fibers, and making reinforced materials while applying as matrix a polyester, polyamide or epoxy resin.

Abstract: High strength and modulus articles, such as filaments, fibers, tapes, films, tubes, bars or profiles, are prepared by irradiating a solid, particular, lamellar, disentangled polyethylene with a Mw>4.times.10.sup.5, transforming this polyethylene above the melt temperature into an article, cooling said article to below the melting point and stretching it in several steps at rising temperature but below the melting point of the article.Advantages are i.a. the lower costs compared with the known processes, such as solid state extrusion or thermoreversible gelation.

Abstract: High modulus and high strength articles of polyvinylalcohol are obtained by thermoreversible gelation of a 5-50 wt. % solution of a polyvinylalcohol with an M.sub.W of 2.5.times.10.sup.4 to 5.times.10.sup.5 in water, followed by solvent removal and high stretching.Pref. gelation is obtained by cooling to a temperature of at least 40.degree. C. below the gelation temperature.With this process low costs of solvent removal and regeneration are obtained.

Abstract: A continuous process is described wherein suspensions of high molecular weight polymers are readily transformed into solutions thereof for extrusion, to make gel filaments, tapes, tubes and films, by use of an extruder having alternate mixing and transporting sections and operating at mechanical shear rates of from 30 to 2,000 sec..sup.-1, and with relatively short residence times therein.

Abstract: The invention accords to a laminate at least consisting of a first layer from a mixture of at least a propylene polymer and an ethylene-vinylalcohol copolymer and a second layer from at least one propylene polymer, the first layer at least consisting of a mixture of 60-99 parts by weight of a substantially crystalline propylene polymer and 1-40 parts by weight of an ethylene-vinylalcohol copolymer, the second layer at least consisting of a substantially crystalline propylene polymer, the said ethylene-vinylalcohol copolymer having a melting temperature at atmospheric pressure which is at most equal to and not more than 30K lower than the melting temperature at atmospheric pressure of the one of the substantially crystalline propylene polymers used having the highest melting temperature, and the laminate having been subjected to multi-axial stretching to a degree of at least twice in at least 2 directions at a temperature which at most equals the melting temperature of the one of the substantially crystalline

Abstract: An improved process for the preparation of polymer filaments having a high tensile strength and modulus by spinning a solution of high-molecular weight polymer and thereafter stretching the filament thus formed. A solution of an ethylene polymer or copolymer, containing at least 80 percent by weight solvent, is spun at a temperature above the gel point of the solution. The ethylene polymer or copolymer contains at most about 5 percent by weight of an alkene having 3 to 8 carbon atoms, has a weight-average molecular weight Mw higher than 4.times.10.sup.5 kg/kmole, and has a weight/number average molecular weight ratio Mw/Mn lower than 5. The spun polymer solution is thereafter cooled to a temperature below its gel point to form a gel filament, which gel filament is thereafter stretched to form a polymer filament having a tensile strength of at least about 1.5 GPa at room temperature.

Abstract: New rigid polyvinyl chloride foam having a density of less than 200 kg/m.sup.3 and having a uniform, fine-celled cell-structure consisting of a rigid vinyl chloride homopolymer containing per 100 parts by weight of polyvinyl chloride 0.1-15 parts by weight of a homo- or copolymer of an alkyl methacrylate having an alkylgroup of 1-10 carbon atoms having a viscosity of the solution .eta..sub.0.1 of between 1.times.10.sup.-6 and 4.times.10.sup.-6 m.sup.2 /s measured at 293 K in 1,2 dichloro ethylene and a method for the preparation of such a new rigid polyvinyl chloride foam.

Abstract: The invention relates to the preparation of filaments with a high tensile strength and a high modulus and to the filaments thus prepared. A solution of a linear polyethylene with a weight-average molecular weight of at least 4.times.10.sup.5 is spun and the filaments, from which the solvent may have been removed in whole or in part, are drawn using a draw ratio of at least (12.times.10.sup.6 /M.sub.w)+1. The filaments are drawn at a temperature such that the modulus is at least 20 GPa.The invention allows filaments to be prepared at high drawing rates, of 0.5 sec.sup.-1 or more, with a modulus of at least 20 GPa and a tensile strength of at least 1 GPa.

Abstract: New rigid polyvinyl chloride foam having a density of between 10 and 50 kg/m.sup.3 and having a uniform, fine-celled cell-structure consisting of a rigid vinyl chloride homopolymer containing per 100 parts by weight of polyvinyl chloride 0.1-15 parts by weight of a homo- or copolymer of an alkyl methacrylate having an alkyl group of 1-10 carbon atoms and a method for the preparation of such a rigid polyvinyl chloride foam.

Abstract: The invention relates to the preparation of filaments with a high tensile strength and a high modulus and to the filaments thus prepared. A solution of a linear polyethylene with a weight-average molecular weight of at least 4.times.10.sup.5 is spun and the filaments, from which the solvent may have been removed in whole or in part, are drawn using a draw ratio of at least (12.times.10.sup.6 /M.sub.w)+1. The filaments are drawn at a temperature such that the modulus is at least 20 GPa.The invention allows filaments to be prepared at high drawing rates, of 0.5 sec.sup.-1 or more, with a modulus of at least 20 GPa and a tensile strength of at least 1 GPa.

Abstract: Method for the preparation of rigid polyvinyl chloride foams with a density of below 200 kg/m.sup.3, in which method rigid polyvinyl chloride which is provided with a melt-flow improver is foamed with a physical blowing agent via an extruder, in which method in a first step, rigid polyvinyl chloride, together with and preferably mixed with 0.1-15 parts by weight per 100 parts by weight of polyvinyl chloride of a melt-flow improver is fed to an extruder and extruded therewith to form a granulate, this granulate is subsequently impregnated, in a second step, with a physical blowing agent and finally, in a third step, the impregnated granulate is fed, to a foaming extruder in which the granulate is extruded while it passes through a temperature profile in which process the rigid polyvinyl is foamed.

Abstract: The invention relates to polypropylene-based plastic products, biaxially stretched below the melting point, wherein the plastic consists substantially of a mixture of 60-95 % by weight of a substantially crystalline propylene polymer and 5-40 % by weight of an ethylene-vinylalcohol copolymer, and to a process for making such products.According to the invention an ethylene-vinylalcohol copolymer is used having a melting point which is at most equal to that of the propylene polymer, preferably 0-20 K below the melting point of the propylene polymer.The invention provides biaxially stretched polypropylene products having an outstandingly good gas impermeability while retaining their good properties in respect of optical clarity, mechanical properties and simplicity of production.

Abstract: A process for making polymer filaments which have a high tensile strength and a high modulus by stretching a polymer filament which contains an appreciable amount of polymer solvent at a temperature between the swelling point and the melting point of the polymer.