An ion exchange resin membrane or an ion exchange precursor resin membrane having a thickness of 25 microns or less and having an orientation ratio of 1.5 or less; which may be produced by co-extruding an ion exchange precursor resin with an incompatible polymer to form a multilayer film having a layer of the ion exchange precursor resin supported on a layer of the incompatible polymer. The layer of incompatible polymer is then removed from the layer of ion exchange precursor resin to provide the ion exchange precursor resin membrane. The ion exchange precursor resin membrane may be converted to an ion exchange resin membrane by hydrolysis, and subsequent acidification if desired.

Provided is a lightweight mesh nonwoven fabric having excellent adhesiveness between uniaxially oriented bodies, excellent low-temperature heat sealability, and high strength. A mesh structure 1 includes two or more uniaxially oriented bodies 2, 3; which include a thermoplastic resin layer and a linear low-density polyethylene layer laminated on at least one side of the thermoplastic resin layer; the mesh structure is produced by laminating or weaving the uniaxially oriented bodies through the linear low-density polyethylene layer in such a way that orientation axes L, T of the uniaxially oriented bodies cross; and the mesh structure has properties of: (1) a fiber weight per unit area of 5 to 70 g/m.sup.2, (2) a thickness of the linear low-density polyethylene layer of 2 to 10 m, (3) an adhesive force between the uniaxially oriented bodies of 10 to 60 N, and (4) a tensile strength of 20 to 600 N/50mm.

A device and method for blowing and stretching a plastic film are provided. A first blow-expanding mechanism subjects a primitive plastic film made of PVC, PLA, or PET to extrusion at a temperature of 140 C.-180 C. and primary blow-expansion to form a volume in which the primitive plastic film has a lateral opening ratio of 1:1. Front-stage press rollers and middle-stage press rollers then subject the primitive plastic film to primary longitudinal press-flattening and pull-stretching, followed by heating and blow-expanding by the second blow-expansion mechanism at a temperature of 160 C.-220 C. and a pressure of 1.1-1.6 atm to achieve a volume in which the primitive plastic film has lateral opening ratio of at least 2:1, further followed by reduction of temperature to a temperature of 10 C.-20 C. for shape fixing to form a shaped plastic film. Finally, rear-stage press rollers subject the shaped plastic film to secondary longitudinal press-flattening and pull-stretching.

The present invention is directed to a method of incrementally stretching polymeric film formed from a blown film extrusion process. The present invention is further directed to a polymeric bag formed from an incrementally stretched polymeric film. The incremental stretching is performed on a collapsed polymeric bubble via a pair of intermeshing rollers. The incrementally stretched polymeric film may be stretched only along a portion of its width. The polymeric bag may be a drawstring trash bag with an extended hem where only the extended hem of the bag or the body of the bag comprises incrementally stretched polymeric film.

A polyetheretherketone pipe of length greater than 250 meters and a residual stress of less than 5 MPa may be made using a calibrator device 2 which includes a cone shaped opening 6 arranged to receive a molten extruded pipe shaped polymer. Attached to the front member 4 is a vacuum plate 14a and successive vacuum plates 14b-14h are attached to one another to define an array of vacuum plates, the vacuum plates being arranged to allow a vacuum to be applied to a pipe precursor passing through opening 16. The vacuum plates 14 also include temperature control means for heating or cooling the plates and therefore heating or cooling a pipe precursor passing through the openings. With a vacuum applied to opening 6, 16 and heating/cooling the plates, an extruded hot plastics pipe is inserted into calibrator 2 via opening 6 and conveyed through opening 16 in plates 14, whereupon it is urged by the vacuum against the cylindrical surface defined by plates 14 to maintain its shape and the temperature of each plate is controlled to control the rate of cooling of the pipe precursor passing through. The pipe may be cooled at a relatively slow rate so that a pipe made from a relatively fast crystallising polymer crystalises and the crystallinity of the pipe along its extent and throughout its thickness is substantially constant.

A polyetheretherketone pipe of length greater than 250 meters and a residual stress of less than 5 MPa may be made using a calibrator device (2) which includes a cone shaped opening (6) arranged to receive a molten extruded pipe shaped polymer. Attached to the front member (4) is a vacuum plate (14a) and successive vacuum plates (14b-14h) are attached to one another to define an array of vacuum plates, the vacuum plates being arranged to allow a vacuum to be applied to a pipe precursor passing through opening (16). The vacuum plates (14) also include (10) temperature control means for heating or cooling the plates and therefore heating or cooling a pipe precursor passing through the openings. With a vacuum applied to opening (6, 16) and heating/cooling the plates, an extruded hot plastics pipe is inserted into calibrator (2) via opening (6) and conveyed through opening (16) in plates (14), whereupon it is urged by the vacuum against the cylindrical surface defined by plates (14) to maintain its shape and the (15) temperature of each plate is controlled to control the rate of cooling of the pipe precursor passing through. The pipe may be cooled at a relatively slow rate so that a pipe made from a relatively fast crystallizing polymer crystallizes and the crystallinity of the pipe along its extent and throughout its thickness is substantially constant.

A process for producing an ion exchange precursor resin membrane involves co-extruding an ion exchange precursor resin with an incompatible polymer to form a multilayer film having a layer of the ion exchange precursor resin supported on a layer of the incompatible polymer. The layer of incompatible polymer is then removed from the layer of ion exchange precursor resin to provide the ion exchange precursor resin membrane. The ion exchange precursor resin membrane may be converted to an ion exchange resin membrane by hydrolysis, and subsequent acidification if desired. Ion exchange resin membranes and ion exchange precursor resin membranes having a uniform thickness of 25 microns or less may be formed by the process.

The present invention is directed to a method of incrementally stretching polymeric film formed from a blown film extrusion process. The present invention is further directed to a polymeric bag formed from an incrementally stretched polymeric film. The incremental stretching is performed on a collapsed polymeric bubble via a pair of intermeshing rollers. The incrementally stretched polymeric film may be stretched only along a portion of its width. The polymeric bag may be a drawstring trash bag with an extended hem where only the extended hem of the bag or the body of the bag comprises incrementally stretched polymeric film.

An extrusion device for producing an object having a cavity, in particular a tube or a container, includes a material feed that opens into an extrusion nozzle, and a support gas feed that opens into a blow-in opening for introducing support gas into the interior of the resulting object, wherein the support gas feed has at least one valve for regulating the support gas, characterized in that at least one valve for regulating the support gas is a proportional valve which can be regulated by a controller.

The present invention is directed to a method of incrementally stretching polymeric film formed from a blown film extrusion process. The present invention is further directed to a polymeric bag formed from an incrementally stretched polymeric film. The incremental stretching is performed on a collapsed polymeric bubble via a pair of intermeshing rollers. The incrementally stretched polymeric film may be stretched only along a portion of its width. The polymeric bag may be a drawstring trash bag with an extended hem where only the extended hem of the polymeric bag comprises incrementally stretched polymeric film.