Conventional PVCs are sheets that have a porous structure with a rough surface and matte sheen. If you foam PVC, you can get tear-resistant and hard-to-touch material with a smooth glossy surface, having a structure of the type of "sandwich". Its inner layer will be porous, but the texture will remain uniform.
PVC foam production
In order to foam PVC and format the product from it, use production lines consisting of equipment such as an extruder, dies of the required calibrators, a cooler, a receiving device and a device that prepares the product for storage. Despite the fact that this production is complex in terms of physico-chemical parameters, the entire technological process takes place in a small, clean and tidy workshop.
The main raw materials in the form of a granular mixture and granules are delivered in plastic bags. Stainless steel tanks with mixers are installed on a small raw material site, into which it is poured, water is added. So the process begins, as a result of which foamed PVC will be obtained . Its production at first glance is very simple. The polymer component aged in the vats during the day interacts with each other, matures, reaches the consistency of the molten mass and is fed into the receiving compartment of the extruder, which should foam PVC qualitatively.
Depending on the productivity of the enterprise, the extruder can be with one working screw or with two. Specialists prefer installations with two screws. In them, the molten mass flows in parallel flows, so the temperature remains unchanged for longer, which allows foaming PVC evenly and effortlessly to achieve the required density in the product.
Screws transfer the plastic mass to extrusion. Here (due to overpressure), it is possible to foam the PVC, and then squeeze it out of the extruder through holes that give the product volume and shape. The formed profiles, pipes, sheets, films enter the receiving table, from where they are fed to the moving conveyor belt and are simultaneously cooled.
Cutting and decorating
For cutting PVC products, circular saws are used, equipped with a vacuum cleaner and a collection for fragments. Cutting products is carried out at high speed. Then, a decorative pattern can be applied to the surface. To do this, the machine chain includes grain machines that print images and markings directly on the PVC product. A decorative coating can imitate marble chips, plaster, and have other types of decoration.
What is valued and where is it used?
Such qualities as strength, lightness and a fine-meshed structure, which have foamed PVC, are very valuable. The photo attached to this article clearly demonstrates them with the example of a pipe. The porosity is clearly visible in the section, and this despite the fact that the surface of the product is shiny and smooth.
Resistance to external weather and climatic factors, chemical and physical interactions and to corrosion has widely opened the door to this material for use in construction, advertising, agriculture, thermal power, oil and gas and chemical industries, in everyday life.