A method for producing a high-pressure tank that can, when forming a reinforcement layer following a previous reinforcement layer using fiber bundles, ensure the strength of the tank by reducing disturbance of the orientation of the fiber bundles. The method is adapted to form each reinforcement layer by winding fiber bundles while holding a preset tension for each layer, and includes a winding start step of stopping rotation of the tank liner upon completion of formation of at least one of the reinforcement layers, and, at the start of forming a following reinforcement layer, winding the fiber bundles at a tension smaller than a preset tension for the following reinforcement layer while alternately repeating rotation of the tank liner in the forward direction and the reverse direction, thereby forming a winding start portion of the following reinforcement layer; and a main winding step of winding the fiber bundles at the preset tension after the winding start step, so as to complete the formation of the following reinforcement layer.

A method of making a paint roller cover includes feeding a single strip of polypropylene, by a core material strip feeder, onto a mandrel; heating the single strip of polypropylene, by a heater, before the single strip of polypropylene is wound about the mandrel; and overlapping edges of the single strip of polypropylene as the single strip of polypropylene is wound about the mandrel so that the overlapped edges fuse together. The method also includes applying an adhesive, by an adhesive applicator, to an outer surface of the single strip of polypropylene; and feeding a strip of fabric cover material, by a fabric cover strip feeder, about the mandrel and onto the outer surface of the single strip of polypropylene.

A high-pressure gas storage container includes a liner and a reinforcing layer. The liner houses a high-pressure gas. The reinforcing layer is formed by winding a plurality of strip-shaped reinforcing members around an outer perimeter surface of the liner. The reinforcing members are made of a plurality of reinforcing fibers that are impregnated with a resin. At least a portion of the reinforcing fibers is irradiated with plasma.

An apparatus to move plastic tube lengthwise in its production process, includes a support organ and move apparatus The counterpart of the support organ rotates with the feeding perimeter speed of the material fed upon it into the same direction with it. The support organ and the move apparatus fit concentrically one after the other. A center axis has bearings to keep it in its place concentrically with the support organ and the move organ. Three essentially lengthwise adapted move organs upon the perimeter the size of the counterpart continuation perimeter or greater perimeter with equal distribution installed move organs are supported with support organs from the center axis and rotate with the center axis. The out part of the mover of every move organ press against the inner surface of the plastic tube to move itself and the plastic tube into its production direction with the speed.

An apparatus to move plastic tube lengthwise in its production process, includes a support organ and move apparatus The counterpart of the support organ rotates with the feeding perimeter speed of the material fed upon it into the same direction with it. The support organ and the move apparatus fit concentrically one after the other. A center axis has bearings to keep it in its place concentrically with the support organ and the move organ. Three essentially lengthwise adapted move organs upon the perimeter the size of the counterpart continuation perimeter or greater perimeter with equal distribution installed move organs are supported with support organs from the center axis and rotate with the center axis. The out part of the mover of every move organ press against the inner surface of the plastic tube to move itself and the plastic tube into its production direction with the speed.

The method for forming from a round shaped cylinder to a square shaped cylinder which can be inserted in a square or rectangular shape metal container (shipping container and frac tanks) includes initiating turning of a heated mandrel, extruding heated polymer, wrapping while compressing a first layer of heated polymer, disposing a mesh layer over the cylinder encapsulating the cylinder on the turning mandrel while simultaneously laying a second layer of heated polymer over the turning mandrel and compressing the layer of heated polymer into the mesh layer and the mesh layer into the first layer of heated polymer simultaneously, and repeating the layering of the heated polymer and mesh layer until a desired wall is reached. The method forms a hybrid polymer square or oval tank or a hybrid polymer round, which achieves over 95 percent of the total volume of the metal container.

The method for forming from a round shaped cylinder to a square shaped cylinder which can be inserted in a square or rectangular shape metal container (shipping container and frac tanks) includes initiating turning of a heated mandrel, extruding heated polymer, wrapping while compressing a first layer of heated polymer, disposing a mesh layer over the cylinder encapsulating the cylinder on the turning mandrel while simultaneously laying a second layer of heated polymer over the turning mandrel and compressing the layer of heated polymer into the mesh layer and the mesh layer into the first layer of heated polymer simultaneously, and repeating the layering of the heated polymer and mesh layer until a desired wall is reached. The method forms a hybrid polymer square or oval tank or a hybrid polymer round, which achieves over 95 percent of the total volume of the metal container.

The method for forming from a round shaped cylinder to a square shaped cylinder which can be inserted in a square or rectangular shape metal container (shipping container and frac tanks) includes initiating turning of a heated mandrel, extruding heated polymer, wrapping while compressing a first layer of heated polymer, disposing a mesh layer over the cylinder encapsulating the cylinder on the turning mandrel while simultaneously laying a second layer of heated polymer over the turning mandrel and compressing the layer of heated polymer into the mesh layer and the mesh layer into the first layer of heated polymer simultaneously, and repeating the layering of the heated polymer and mesh layer until a desired wall is reached. The method forms a hybrid polymer square or oval tank or a hybrid polymer round, which achieves over 95 percent of the total volume of the metal container.

Helically winding an extruded web to form a wall of a heated hose about a central axis, extruding a bead of plastics material around a heating wire such that the extruded bead comprises the heating wire at a first location within a cross-section of the extruded bead, helically winding the extruded bead onto the wall of the hose to provide a support helix, and exerting tension on the heating wire to draw down the heating wire toward the central axis such that the heating wire migrates radially inward from the first location to a second location within the cross-section of the extruded bead.

Unwinding a portion of a support helix that comprises a heating wire from a wall of a hose at an end of the hose; sleeving a length of heatshrink tubing at least partly onto the unwound portion of the support helix; heating the heatshrink tubing to shrink onto at least part of the unwound portion of the support helix; and at an end of the unwound portion, directly connecting the heating wire to an electrical contact of an electrical connector.