Helical extrusion

Last updated

Helical extrusion technology is applied in the plastic pipe industry. Basically the production process is a direct extrusion. During the pipe production several different materials - depending on the desired final pipe - are mixed in the extrusion unit according to a special formula depending. The production machine is fed with granule material (PE or PP for structured wall gravity pipes and PE, glass fiber and bonding agent for pressure pipes). During the complex extrusion and mixing process a homogeneous profile is helically extruded on a preheated rotating mandrel. In the case that a gravity pipe is being produced the profile is a structured wall and in the case of pressure pipe the profile is a solid wall. The production is a discontinuous procedure.

Related Research Articles

<span class="mw-page-title-main">Plumbing</span> Systems for conveying fluids

Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.

<span class="mw-page-title-main">Drainage</span> Removal of water from an area of land

Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess water. The internal drainage of most agricultural soils can prevent severe waterlogging, but many soils need artificial drainage to improve production or to manage water supplies.

<span class="mw-page-title-main">Sewerage</span> Infrastructure that conveys sewage or surface runoff using sewers

Sewerage is the infrastructure that conveys sewage or surface runoff using sewers. It encompasses components such as receiving drains, manholes, pumping stations, storm overflows, and screening chambers of the combined sewer or sanitary sewer. Sewerage ends at the entry to a sewage treatment plant or at the point of discharge into the environment. It is the system of pipes, chambers, manholes or inspection chamber, etc. that conveys the sewage or storm water.

<span class="mw-page-title-main">Heat pipe</span> Heat-transfer device that employs phase transition

A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces.

<span class="mw-page-title-main">Pressure vessel</span> Vessel for pressurised gases or liquids

A pressure vessel is a container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.

<span class="mw-page-title-main">Extrusion</span> Process of pushing material through a die to create long symmetrical-shaped objects

Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex cross-sections; and to work materials that are brittle, because the material encounters only compressive and shear stresses. It also creates excellent surface finish and gives considerable freedom of form in the design process.

<span class="mw-page-title-main">High-density polyethylene</span> Class of polyethylenes

High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber. HDPE is commonly recycled, and has the number "2" as its resin identification code.

<span class="mw-page-title-main">Blow molding</span> Manufacturing process for forming and joining together hollow plastic parts

Blow molding is a manufacturing process for forming hollow plastic parts. It is also used for forming glass bottles or other hollow shapes.

Cross-linked polyethylene, commonly abbreviated PEX, XPE or XLPE, is a form of polyethylene with cross-links. It is used predominantly in building services pipework systems, hydronic radiant heating and cooling systems, domestic water piping, insulation for high tension electrical cables, and baby play mats. It is also used for natural gas and offshore oil applications, chemical transportation, and transportation of sewage and slurries. PEX is an alternative to polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC) or copper tubing for use as residential water pipes.

Filament winding is a fabrication technique mainly used for manufacturing open (cylinders) or closed end structures. This process involves winding filaments under tension over a rotating mandrel. The mandrel rotates around the spindle while a delivery eye on a carriage traverses horizontally in line with the axis of the rotating mandrel, laying down fibers in the desired pattern or angle to the rotational axis. The most common filaments are glass or carbon and are impregnated with resin by passing through a bath as they are wound onto the mandrel. Once the mandrel is completely covered to the desired thickness, the resin is cured. Depending on the resin system and its cure characteristics, often the mandrel is autoclaved or heated in an oven or rotated under radiant heaters until the part is cured. Once the resin has cured, the mandrel is removed or extracted, leaving the hollow final product. For some products such as gas bottles, the 'mandrel' is a permanent part of the finished product forming a liner to prevent gas leakage or as a barrier to protect the composite from the fluid to be stored.

<span class="mw-page-title-main">Pipe (fluid conveyance)</span> Tubular section or hollow cylinder

A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members.

<span class="mw-page-title-main">Plastic extrusion</span> Melted plastic manufacturing process

Plastics extrusion is a high-volume manufacturing process in which raw plastic is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weatherstripping, fencing, deck railings, window frames, plastic films and sheeting, thermoplastic coatings, and wire insulation.

<span class="mw-page-title-main">Plastic pipework</span> Tubular section or hollow cylinder made of plastic

Plastic pipe is a tubular section, or hollow cylinder, made of plastic. It is usually, but not necessarily, of circular cross-section, used mainly to convey substances which can flow—liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipes are far stiffer per unit weight than solid members.

<span class="mw-page-title-main">Tube bending</span>

Tube bending is any metal forming processes used to permanently form pipes or tubing. Tube bending may be form-bound or use freeform-bending procedures, and it may use heat supported or cold forming procedures.

Hot plate welding, also called heated tool welding, is a thermal welding technique for joining thermoplastics. A heated tool is placed against or near the two surfaces to be joined in order to melt them. Then, the heat source is removed, and the surfaces are brought together under pressure. Hot plate welding has relatively long cycle times, ranging from 10 seconds to minutes, compared to vibration or ultrasonic welding. However, its simplicity and ability to produce strong joints in almost all thermoplastics make it widely used in mass production and for large structures, like large-diameter plastic pipes. Different inspection techniques are implemented in order to identify various discontinuities or cracks.

A pipe support or pipe hanger is a designed element that transfer the load from a pipe to the supporting structures. The load includes the weight of the pipe proper, the content that the pipe carries, all the pipe fittings attached to pipe, and the pipe covering such as insulation. The four main functions of a pipe support are to anchor, guide, absorb shock, and support a specified load. Pipe supports used in high or low temperature applications may contain insulation materials. The overall design configuration of a pipe support assembly is dependent on the loading and operating conditions.

<span class="mw-page-title-main">Metal hose</span>

A metal hose is a flexible metal line element. There are two basic types of metal hose that differ in their design and application: stripwound hoses and corrugated hoses.

A die in polymer processing is a metal restrictor or channel capable of providing a constant cross sectional profile to a stream of liquid polymer. This allows for continuous processing of shapes such as sheets, films, pipes, rods, and other more complex profiles. This is a continuous process, allowing for constant production, as opposed to a sequential (non-constant) process such as injection molding.

Electrofusion welding is a form of resistive implant welding used to join pipes. A fitting with implanted metal coils is placed around two ends of pipes to be joined, and current is passed through the coils. Resistive heating of the coils melts small amounts of the pipe and fitting, and upon solidification, a joint is formed. It is most commonly used to join polyethylene (PE) and polypropylene (PP) pipes. Electrofusion welding is the most common welding technique for joining PE pipes. Because of the consistency of the electrofusion welding process in creating strong joints, it is commonly employed for the construction and repair of gas-carrying pipelines. The development of the joint strength is affected by several process parameters, and a consistent joining procedure is necessary for the creation of strong joints.

HDPE pipe is a type of flexible plastic pipe used to transfer fluids and gases. It is often employed for replacing aging concrete or steel main pipelines. Constructed from the thermoplastic HDPE, it has low permeability and robust molecular bonding, making it suitable for high-pressure pipelines. HDPE pipe is often used for water mains, gas mains, sewer mains, slurry transfer lines, rural irrigation, fire-suppression system supply lines, electrical and communication conduits, and stormwater and drainage pipes.

References