The present invention provides a synthetic resin microporous film which has excellent permeability of lithium ions, can constitute high performance power storage devices, and is less likely to cause a short circuit between a positive electrode and a negative electrode as well as rapid decrease in discharge capacity due to a dendrite even when used in high power applications. The synthetic resin microporous film of the present invention is a synthetic resin microporous film comprising a synthetic resin, the synthetic resin microporous film being stretched, the synthetic resin microporous film having, in a cross section along a thickness direction and a stretching direction of the synthetic resin microporous film: a plurality of support portions extending in the thickness direction of the synthetic resin microporous film; a plurality of fibrils formed between the support portions; and the support portions having the number of branch structures of 150 or less per 100 m.sup.2; and the synthetic resin microporous film being configured such that micropore portions are formed in areas surrounded by the support portions and the fibrils.

A method for testing a stretch film includes unwinding a roll of stretch film in an unwinding station, successively throughfeeding through a first stretching station and a second stretching station for controlling respectively a first stretch and a second stretch according to a predetermined first and second stretch pattern until a predetermined result is achieved, measuring impurities in the stretch film, and correlating the measured impurities to the predetermined result.

The present invention relates to a process for producing a fluoropolymer article having a high surface roughness and high coarseness which comprises the following steps: a) forming a paste comprising a fluoropolymer into a paste-formed fluoropolymer product at a temperature lower than 50 C., b) densifying the paste-formed product, and c) stretching the densified paste-formed fluoropolymer product in at least one direction.

The present invention further relates to a fluoropolymer article obtainable by a process according to the invention.

The present invention furthermore relates to a fiber comprising, or consisting of, a fluoropolymer having a surface roughness expressed as a peak to valley distance (Rt) greater than 10 micrometer and/or an average surface roughness (Ra) greater than 1.5 micrometer.

The present invention furthermore relates to a membrane comprising, or consisting of, a fluoropolymer having a coarseness index /EBP of at least 0.3, an air permeability of 15 ft.sup.3/ft.sup.2/min or higher and a node aspect ratio of below 25.

Provided is a film for packaging chemicals which does not change in appearance (e.g. yellowing), or does not generate odor, even after long-term storage; which is prevented from being scratched or contaminating rolls when the film is drawn from a roll thereof; and which expresses excellent chemical resistance. Also provided is a film for packaging chemicals which is easily detachable from a heat seal plate when contents are packed and sealed therein. The film for packaging chemicals includes polyvinyl alcohol; and a surfactant, the amount of the surfactant being 0.9% to 5% by mass based on 100% by mass of the polyvinyl alcohol, the surfactant having a polyoxyethylene structure, the number of moles of oxyethylene groups in the surfactant being 5 to 13 mol, the surfactant having a HLB of 9 to 14.5.

A black film containing a thermoplastic resin (A) that contains two or more types of dyes other than black, where a thickness T is 45 to 550 m, a total concentration C of the dyes other than black is 0.4 to 5 mass % with respect to the thermoplastic resin (A), the total concentration C of the dyes and the thickness T satisfy the following expression (1):

CT210(1) where in a L*a*b* color system measurement compliant with HS Z 8781-4, L* (lightness) is no more than 10, an absolute value of a* is no more than 2.0, and an absolute value of b* is no more than 2.0, and a total light transmittance obtained after the black film is stretched twofold in one axial direction at a temperature higher than a glass transition temperature by 20 C. is no more than 3.0%.

A system for controlling the temperature of a film before and/or during application, the system including: a heat source for heating a film; and stretch rollers; wherein the heat source heats the film from an ambient temperature to a temperature from about 2 C. to about 40 C. above the ambient temperature, wherein the film is heated prior to or simultaneous to being stretched by the stretch rollers, and wherein the ambient temperature is below 15 C. The preheating system may be used to enhance binding and sealing properties of stretch films used for wrapping palletized products in a reduced temperature environment. Other embodiments of the preheating film system, and methods for its use, are described herein.

A system for controlling the temperature of a film before and/or during application, the system including: a heat source for heating a film; and stretch rollers; wherein the heat source heats the film from an ambient temperature to a temperature from about 2 C. to about 40 C. above the ambient temperature, wherein the film is heated prior to or simultaneous to being stretched by the stretch rollers, and wherein the ambient temperature is below 15 C. A system for improving the application of film by transfer of electrostatic charge is also described. The preheating system and/or electrostatic charge system may be used to enhance binding and sealing properties of stretch films used for wrapping palletized products in a reduced temperature environment. Other embodiments of the preheating film system and electrostatic charge system, and methods for their use, are described herein.

High tenacity, high elongation multi-filament polymeric tapes as well as ballistic resistant fabrics, composites and articles made therefrom. The tapes are fabricated from multi-filament fibers/yarns that are twisted together, bonded together, compressed and flattened.

The present disclosure relates to a process for preparing of high thermal conductivity and high heat capacity oriented ultrahigh molecular weight polyethylene (UHMWPE) product. The process includes feeding UHMWPE through rollers to obtain a pre-laminate which is further hot stretched to obtain the oriented UHMWPE product having high thermal conductivity and high heat capacity. The temperature of stretching is maintained below the melt temperature of the UHMWPE throughout the entire process. There is also provided a high thermal conductivity and high heat capacity oriented UHMWPE product prepared by the process of the present disclosure. The oriented UHMWPE product is characterized in the axial thermal conductivity in the range of 70 to 200 W/mK, transverse direction thermal conductivity in the range of 0.022 to 0.045 W/mK and heat capacity in the range of 6 to 25 MJ/m.sup.3K.