Abstract: The invention relates to a process for manufacturing a hose including a layer of ultra-high molecular weight polyethylene on at least the inside or the outside, which layer is directly bonded to an elastomeric layer, the layer of polyethylene being provided by folding an oblong polyethylene film to form an oblong tube with an overlapping seam in its longitudinal direction, resulting in a hose fit for uses, even at low temperatures, in which the inside and/or the outside of the hose are/is exposed to the action of chemical substances and/or of substances having a strongly abrasive action.

Abstract: An ultrastretchable polymer material is prepared starting from polyolefine particles with a low entanglement density and a weight average molecular weight (M.sub.w) higher than 400,000, the particles being densified to a coherent material together with a process auxiliary material at an elevated temperature, but below the melting point of the pure polyolefine.From this ultrastretchable material, objects with a high tensile strength and a high modulus can be produced by stretching it, for instance, at a temperature which is at most 70.degree. C. below the temperature at which the polyolefine melts under the prevailing conditions, if desired after removal of the process auxiliary agent present in it.

Abstract: The invention relates to a process for the preparation of a caprolactam that is not appreciably subject to re-equilibration during melt spinning of textile fibres. In the process such an amount of chain length regulating agent is used that the relative viscosity of the polyamide increases by not more than 0.5 units after 20 hour heat treatment in the solid phase in an inert gas atmosphere at between 110.degree. C. and 190.degree. C., after extraction.

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.