The Plastic pipe extrusion line and the extrusion process

The extrusion process have been extensively applied in the manufacture of different products. An important product is the plastic pipe.

Here, we take a look at the general plastic pipe extrusion process.

Process

In the plastic pipe extrusion process, the molten material, in this case a polymer, is forced to pass through a die, this forms a continuous profile of constant section that is cooled and solidified. Typically this process is profitable for simple profiles to high production volumes.

The main advantage of this process is the possibility of creating long pieces.

On the other hand, say that plastic does not dissipate heat as efficiently as metals, thus requiring water baths or cooling rollers to obtain a correct cooling speed.

The most widely used plastic extrusion processes are:

Blown film extrusion: Also called "tubular film". In the plastic pipe extrusion line, the blowing and the extrusion process work together to produce a thin film. It begins with the extrusion of the tube film, which is stretched towards rollers and at the same time expanded by air to a mandrel. The film to make the bags and the sheets / plates are made by this method.

Sheet and Film Extrusion: Used for extruding plastic sheets and film films that are too thick to be manufactured by the above method. The molten material is extruded through a flat die. It is then stretched through a set of chill rollers that are used to determine the thickness and texture of the surface.

Tubular extrusion: The molten material is extruded through a die with a mandrel, forming a hollow section.

Coating extrusion: This process allows the application of an outer layer of plastic over a wire or cable that exits through the center of the die.

Coextrusion: Through this method it is possible to manufacture multiple layers simultaneously. It is used to apply one or more layers on top of a base material in order to obtain a series of specific properties.

Extrusion coating: Used to make an additional layer on paper, foil or film.

Production

Borun Machinery has extensive experience in the design, development and manufacture of plastic profile extrusion lines.

With our many years of experience, we are sure to provide you with the right machinery you need for your production needs.

We offer our clients a quality product at very competitive prices.

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Materials and products required in the extrusion process

There are various plastics that can be formed by extrusion. These are some examples:

· Nylon

· Polymethylmethacrylate (PMMA)

· High impact polystyrene (HIPS)

· Polystyrene (PS)

· Polypropylene (PP)

· Polyethylene (PE)

· ABS

· PVC

There is a wide variety of plastic parts manufactured by extrusion such as pipes, fences, window frames and profiles, adhesive tapes, cables, car interiors, bags, plates. These parts are widely used in packaging, construction, decoration, automotive, electricity, and textile.

TOLERANCES

Tolerances for extruded plastics differ considerably from metal extrusions. This is because metals harden quickly, thus allowing smaller tolerances to be obtained than for polymeric materials. Getting tight tolerances on extruded plastic parts is quite difficult in general, this depends largely on the raw materials used, the complexity of the part, and the tool that was made to produce it.

In the manufacture of the plastic pipes using the PVC, the material has to be cooled more efficiently. Here, the plastic pipe extrusion line is very important.