A method is for producing a coextruded and biaxially stretched composite film using a novel combination of stretching and relaxation steps. A corresponding composite film has little or no shrinkage.

According to an example aspect of the present invention, there is provided A process for making a cellulose fibre or film comprising the steps of dissolving pulp in an ionic liquid containing a cationic 1,5,7-triazabicyclo[4.4.0]dec-5-enium [TBDH]+ moiety and an anion selected from the group according to Formula a), Formula b) and Formula c), wherein each of R, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9 and R.sup.10 is H or an organyl radical and X.sup.− is selected from the group consisting of halides, pseudohalides, carboxylates, alkyl sulphite, alkyl sulphate, dialkylphosphite, dialkyl phosphate, dialkyl phosphonites and dialkyl phosphonates, to provide a spinning dope, extruding the spinning dope through a spinneret to form one or more filaments, and a step selected from the group consisting of spinning cellulose fibres from the solution, and extruding a cellulose film from the solution.

Provided is a biaxially oriented polypropylene film that has high stiffness, has excellent heat resistance at a high temperature of 150° C., easily maintains a bag shape when being made into a packaging bag, and has less pitch shift during printing or fewer wrinkles in a sealed portion when being heat-sealed. A biaxially oriented polypropylene film, wherein a stress at 5% elongation (F5) at 23° C. of the biaxially oriented polypropylene film is not lower than 40 MPa in a longitudinal direction and not lower than 160 MPa in a width direction, and a heat shrinkage rate at 150° C. of the biaxially oriented polypropylene film is not higher than 7% in the longitudinal direction and not higher than 16% in the width direction.

A lithium-ion battery separator with high-temperature resistance, a preparation method thereof and a lithium-ion battery prepared therefrom fall within the field of lithium-ion battery separators. The separator has a thickness of 3.5-30 μm, a porosity of 30-80%, an adjustable pore size of 20-2000 nm, a biaxial tensile strength of ≥50 MPa, an air permeability of ≤400 s/100 cc, and a breaking temperature of ≥160° C. The preparation method comprises the following steps: mixing, melting, and plasticizing 20%-60% of a polypropylene main material, 2%-10% of a solubilizer, 30%-80% of a solvent. 0.1%-5% of a nucleating aid and/or 0.1%-1% of an antioxidant, carrying out twin-screw extrusion, carrying out thermally induced phase separation to obtain a cast sheet, and carrying out cast sheet stretching, extraction, and post-treatment or directly carrying out extraction and post-treatment. The separator has the characteristics of high-temperature resistance, biaxial high strength, uniform pore size, high specific resistance.

A lithium-ion battery separator with high-temperature resistance, a preparation method thereof and a lithium-ion battery prepared therefrom fall within the field of lithium-ion battery separators. The separator has a thickness of 3.5-30 μm, a porosity of 30-80%, an adjustable pore size of 20-2000 nm, a biaxial tensile strength of ≥50 MPa, an air permeability of ≤400 s/100 cc, and a breaking temperature of ≥160° C. The preparation method comprises the following steps: mixing, melting, and plasticizing 20%-60% of a polypropylene main material, 2%-10% of a solubilizer, 30%-80% of a solvent. 0.1%-5% of a nucleating aid and/or 0.1%-1% of an antioxidant, carrying out twin-screw extrusion, carrying out thermally induced phase separation to obtain a cast sheet, and carrying out cast sheet stretching, extraction, and post-treatment or directly carrying out extraction and post-treatment. The separator has the characteristics of high-temperature resistance, biaxial high strength, uniform pore size, high specific resistance.

The invention relates to a multi-layer, preferably co-extruded, plastic film with improved modulus properties, which is suitable, in particular, for producing three-dimensionally shaped articles.

The invention relates to a multi-layer, preferably co-extruded, plastic film with improved modulus properties, which is suitable, in particular, for producing three-dimensionally shaped articles.

A method for forming a multilayer plastic sheet material (1) for floor and/or wall panels, wherein a first polymer mass comprising a rigid PVC is melted under pressure and is passed through an extruder head at a specified discharge rate in the form of a plastic strand in sheet form that is provided with one or more layers so that a multilayer plastic strand is formed, which is passed to two or more rolls of a finishing stand, which processes the multilayer plastic strand into a sheet of defined thickness, which is then led away via a transport device to a sawing device to be cut to the desired length, wherein, after the plastic strand in sheet form leaves the extruder head, it is first passed between a top roll and a bottom roll of a roughing stand, wherein the speed of the rolls of the finishing stand and the rolls of the roughing stand is synchronized with the discharge rate of the plastic strand in sheet form from the extruder head, so that said plastic strand is processed without stress.

A method for forming a multilayer plastic sheet material (1) for floor and/or wall panels, wherein a first polymer mass comprising a rigid PVC is melted under pressure and is passed through an extruder head at a specified discharge rate in the form of a plastic strand in sheet form that is provided with one or more layers so that a multilayer plastic strand is formed, which is passed to two or more rolls of a finishing stand, which processes the multilayer plastic strand into a sheet of defined thickness, which is then led away via a transport device to a sawing device to be cut to the desired length, wherein, after the plastic strand in sheet form leaves the extruder head, it is first passed between a top roll and a bottom roll of a roughing stand, wherein the speed of the rolls of the finishing stand and the rolls of the roughing stand is synchronized with the discharge rate of the plastic strand in sheet form from the extruder head, so that said plastic strand is processed without stress.

A composite thermoplastic film and the manufacturing method are provided in the present invention. The method includes: providing a first structural layer and a second structural layer; performing a co-extrusion step to form a composite layer, in which to use a first extruding machine to perform the co-extrusion step, so the first structural layer is divided into a first thermal fuse film and a third thermal fuse film, and use a second extruding machine to perform the co-extrusion step, so the second structural layer is formed as a second thermal fuse film and disposed between the first thermal fuse film and the third thermal fuse film to form a composite layer; and performing a film-forming step, the composite layer is cooled to form a film through a forming wheel, and a rotating speed of the forming wheel can be controlled to acquire a desired thickness of the composite thermoplastic film.