Rigid PVC UPVC

This is used most often in process plants. It is a tough, low-cost material with probably the widest range of chemical resistance of any of the low-cost plastics. On a volume basis, PVC is more favorable than polypropylene because the modulus of PVC is considerably higher than that of polypropylene, so it will form more rigid structures when used at the same thickness. On a weight basis it is not as favorable as PVC because it has a specific gravity of 1.4 compared with 0.92 for polypropylene. 

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Successful processing of unplasticized or rigid PVC (UPVC) requires lubricants, such as lead or calcium stearates, stearic acid or hydrocarbon waxes. UPVC is frequently extruded, and so lubricants melting at 100-120°C are most effective for extrusion at 165°C. UPVC is also widely used in sheet form, obtained by compression moulding multiple plies of calendered foil. 

Trade names and synonyms Excelon , Tedlar , Trovicel , Tygon , Verilon , polychloroethene (lUPAC name), uPVC, PPVC, rigid PVC, vinyl... 

The paper deals with the investigation by differential scanning calorimetry of extended rigid PVC formulations. The DSC traces of processed UPVC depend on the thermal history of the melt. The DSC tests can be used to estimate extrusion conditions e.g. of failed products. 16 refs. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. 

Polyvinyl chloride is processed into a number of forms by including additives. Additives are used to vary the properties of PVC so that it can be made soft and flexible or hard and rigid. Additives are also used to inhibit decomposition as a result of exposure to sunlight, ozone, and chemicals. Plasticizers are the primary additive included in PVC materials. Di(2-ethylhexyl) phthalate (DEHP) and a host of other phthalates are the most common plasticizers. Plasticizers impart flexibility, thermal stability, strength, and resilience to PVC compounds. PVCs without plasticizers are classified as UPVC the letters stand for unplasticized polyvinyl chloride. UPVC is rigid and used for conduit, containers, gutters, and floor tiles. Other common PVC additives are biocides, lubricants, and pigments. 

UPVC (unplasticized PVC)—may contain a low level of modifier (vinyl acetate). Has a low permeability to oxygen but is moderately permeable to moisture. The material is fairly rigid and is not heat sealable. 

A rigid polymer may be internally plasticised by chemically modifying the polymer chains with structural groups incorporated through a plasticising comonomer, which is a common way of plasticisation or it can be externally plasticised, simply by blending it with the resin. The latter being the most common because of the costs involved. UPVC (PVC-U) can be externally plasticised by use of certain phthalates. 

Milled below 10 pm uncoated/coated with stearic acid high gloss, toughne ss/rigidity in thermoplastics for uPVC extrusions, plasticized PVC cables and extrusions, polypropylene mouldings, masterbatch, and silicone sealants. 

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