A micro-voided film comprising high density polyethylene having a molecular weight of at least about 200,000, and low aspect ratio filler having a mean particle size from about 1 to about 25 microns. The film has a thickness of from about 10 to about 75 microns and a void fraction of from about 0.60 to about 0.75. The micro-voided film is made by a process comprising extruding the composition into a film having a thickness of from about 50 to about 300 microns, and orienting the extruded film using a high stalk, blown film process. The process produces a stabilized high stalk for increasing the production rate of blown, high molecular weight polyethylene, while increasing the film's physical and mechanical properties. The high stalk can be stabilized by application of high velocity, low volume flow rate of air over the interior and exterior surfaces of the extruded film.

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.

Methods of coating a base tube are disclosed. Various methods include passing a hollow base tube into a coating die while maintaining a chamber pressure outside the hollow base tube that is lower than a pressure within an inner lumen of the hollow base tube. Such methods can include extruding coating material onto the hollow base tube to form a coated hollow tube by delivering coating material into the coating die. Vacuum may be formed within the coating die proximate a point of impingement where the coating material is applied to the hollow base tube.

An object of the present invention is to provide a heat shrink tube excellent in peelability and transparency, and a method for producing the heat shrink tube. The present invention provides a peelable heat shrink tube comprising a composition containing a melt-processable fluororesin and PTFE, the PTFE lacking a heat history of its melting point or higher after polymerization and having a specific gravity, as measured according to ASTM D4894, of 2.20 or less. The content of the PTFE is 0.05 to 3.0 wt % based on the total weight of the melt-processable fluororesin and the PTFE. The present invention also provides a method for producing the tube which comprises melt-extruding the composition at a temperature lower than the melting point of the PTFE.

A micro-voided film comprising high density polyethylene having a molecular weight of at least about 200,000, and low aspect ratio filler having a mean particle size from about 1 to about 25 microns. The film has a thickness of from about 10 to about 75 microns and a void fraction of from about 0.60 to about 0.75. The micro-voided film is made by a process comprising extruding the composition into a film having a thickness of from about 50 to about 300 microns, and orienting the extruded film using a high stalk, blown film process. The process produces a stabilized high stalk for increasing the production rate of blown, high molecular weight polyethylene, while increasing the film's physical and mechanical properties. The high stalk can be stabilized by application of high velocity, low volume flow rate of air over the interior and exterior surfaces of the extruded film.

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.

Provided is a sizing die corresponding to a member installable between an extruder and a take-up machine, including a side surface in contact with an inner or outer surface of a tubular molten resin extruded toward the take-up machine through an annular die by the extruder, and causing the molten resin to flow along the side surface such that a shape of the molten resin matches a shape of the side surface, wherein the side surface includes a first region and a second region in an order of being close to the annular die in a flow direction of the molten resin, and surface roughness of the first region is smaller than surface roughness of the second region.

An apparatus produces plastic tubes by extrusion with an extruder, a pipehead being attached to the extruder in production direction, having a base material with at least one mandrel and a sleeve, a melt channel between the mandrel and the sleeve, the melt channel shaped to aid flow in production direction at least at the mandrel's end and at the sleeve's end, the mandrel and sleeve being adjustable backwards and forward relatively to one another, the outer surface of the mandrel and/or the inner surface of the sleeve at least partially has a material that allows for a higher sliding quality than the base material. The outer and/or the inner surface (i) has a coating either unvaried, or whose sliding quality constantly improves, or whose sliding quality alternately improves and worsens, in the production direction, or (ii) is partially coated, or (iii) the mandrel and/or sleeve fronts are coated.

A method of making an optical fiber with multiple openings comprising the steps of fabricating an extrusion die using additive manufacturing such that the extrusion die has a plurality of channels that combine inside the die into another set of channels, extruding a glass, forming a fiber optic preform having a plurality of longitudinal openings that run the entire length, attaching a barrier layer for pressure application, and stretching the preform into an optical fiber with multiple openings. An extrusion die comprising an additive manufactured material, having a proximal side having openings and having a distal side having openings, wherein the openings of the proximal side are of feed channels, wherein the openings of the distal side are of forming channels, and wherein in side the body of the die, two of the feed channels combine the forming channels.

Described is a plastic bag having a top portion with a top thickness, a center portion with a center thickness and a bottom portion with a bottom thickness. The top portion has an opening and a drawstring running therethrough. The top thickness is approximately equal to the bottom thickness. The center thickness is less than the top thickness and the bottom thickness.