MANUFACTURING OF PVC PRODUCTS
The polyvinyl chloride (PVC) is the polymer of vinyl chloride, having formula (C2H3Cl)n and molecular weight between 60,000 and 150,000 units. It is the most important polymer of the series obtained from vinyl monomers and is one of the highest consumption of plastics in the world. The main criteria to distinguish the vinyl polymers are given both by the various polymerization processes (PVC-E emulsion, PVC-S suspension, PVC-M by mass) is the characteristics of the materials (PVC-U unplasticized , PVC-P is plasticized). There are also some variants, such as for example PVC-C (chlorinated).
CHARACTERISTICS AND APPLICATION FIELDS
The PVC can be processed and treated in various ways: extrusion, compression molding, injection molding, calendering, blow molding, welding, gluing, thermoforming and machining by chip removal. PVC-C is more difficult to work with than standard PVC.
The PVC-U is presented as a rigid material, while the PVC-P presents greater elasticity and less brittle due to the addition of plasticizers (plasticizers phthalate, esters of aliphatic dicarboxylic acids, esters of phosphoric acid, esters of citric acid, trimellitates, polyester plasticizers). The PVC-U presents abrasion resistance, impact strength at low temperatures and resistance to fatigue is not high; also the use temperatures are relatively low (65 ° C – 75 ° C). It has excellent electrical properties, air permeability of less than polyolefins and very good vapor permeability. It has a good stability to crack formation under stress. Up to 60 ° C PVC-U is stable to most dilute acids or concentrated, lactic acid and concentrated nitric acid, alkaline and saline solutions diluted or concentrated. And ‘stable to lower alcohols, petrol and mineral oils. Esters, ketones, aromatic and chlorinated hydrocarbons him swell and can dissolve. PVC-U is considered inert and this makes it suitable for applications in the food industry. With the addition of special additives (fine-grained chalk, silicates, aluminum hydroxide, barium ferrite) can improve properties such as wear resistance, resistance to mechanical stress, the flame resistance and the volume resistivity. The PVC-P behaves in a manner similar to rubber and its maximum use temperature is about 80 ° C. At elevated temperatures the PVC-P tends to become brittle due to the migration of the plasticizers contained in it, which can also damage the materials in which they migrate, creating cracks and fissures. The S-PVC and PVC-M are extremely pure materials, bear strong mechanical and electrical stress and have a good behavior as regards the stability to corrosion so as to aging.
The PVC is used for the realization of many products: it goes from components (suction cups, protective covers, knobs, plugs, couplings, dampers) to the sealing rings, the gaskets from the pipes, coatings for cables from the power supplies to the tapes.
Shown below are the most common PVC trade names available at LIMA.
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PVC: TRADE NAMES
Shown below are the most common trade names for the PVC material.
Please remember that LIMA can provide both generic materials and materials covered by trademark (ie that show the TM or ® endorsements), based on the requirements of the customer. If the customer wishes to details made of plastic material covered by trademark, LIMA will stock up directly by the holding company of the said trademark.