Material Selection

High Density Polyethylene - HDPE

As the name suggests, High Density Polyethylene has a higher density to that of LLDPE. Although this increase in density is not great, HDPE has a significantly better strength to density ratio, the difference in strength being larger than the difference in density. HDPE is also more opaque than LLDPE and is harder, feeling slightly waxy to the touch. It is generally easy to process, and colour, although the opacity can take the edge of bright colours.

Significant quantities of HDPE are used in the manufacture of piping and related fixings and joints, as well as in the Packaging field, where it is used for blow moulded bottles.

Ethylene Vinyl Acetate- EVA

Ethylene Vinyl Acetate is a co-polymer of Ethylene and Vinyl Acetate, where the percentage of Vinyl Acetate can be varied to achieve distinctive characteristics. The lower the level of Vinyl Acetate, the more like Ethylene the material becomes, where higher levels of Vinyl Acetate make the material more like a rubber. The rubber-like characteristics of softness and flexibility make it very good for low temperature toughness, and where stress cracking (ESCR) would be a consideration.

EVA is often used in twin-shot moulding applications where the EVA is the softer more tactile material in the application. Its flexibility makes it a good substitute for rubber or flexible PVC, and it is used quite extensively in electrical applications. EVA has a distinctive vinegar-like smell when it is processed. 

Acrylonitrile Butadiene Styrene - ABS

As the name suggests, Acrylonitrile Butadiene Styrene is a mix of three different materials. The characteristics of the finished article can be changed by changing the ratios of the three materials, but generally ABS is regarded as having good impact resistance and toughness even at low temperatures - down to -20 degrees Celsius for some applications.

ABS is readily injection moulded, but care must be given when manufacturing the tooling to allow gaseous elements given off by the material to escape from the tool. If the gas cannot escape, then moulded-in defects are to be expected, with the attendant failure of the product. Injection moulded ABS has good gloss characteristics.

ABS is used significantly in the electrical closures market and for Automotive and Construction applications. Its high gloss and good colourability have made it a hit with manufacturers of children's toys.

Plasmotec has significant experience in successfully running products in a wide variety of materials. We are also adept at colouring these materials to customer specification via the use of Masterbatch colourant. Over the years that Plasmotec has been in business, we have also enhanced materials to customer specification by the use of such agents as, slip additive, bio-degradable additives, laser marking enhancement additives, flame retardancy additives, and anti-static agents to name but a few.

Linear Low Density Polyethylene - LLDPE

We manufacture many millions of products annually from this material type. It offers good colourability , relative ease of processing, and comes in food contact approved grades. It shows good resistance to environmental stress cracking (ESCR), and good general chemical resistance. The material is generally recyclable via kerbside collection facilities.

LLDPE is used in the manufacture of stretch film, toys, packaging products such as lids and containers, piping, buckets, and automotive parts. Storage of parts manufactured from LLDPE should be dry, dust free and the ambient temperature should not exceed 50 degrees Celsius or be below 10 degrees Celsius.

Co-Polymer Polypropylene - CoPo

As with LLDPE we have a good proven history of the manufacture of mouldings in this material and its sister Homo Polypropylene. It offers good colourability , relative ease of processing, and comes in food contact approved grades. Random Co-Polymer grades offer good visual clarity compared to the more opaque CoPo and Homo PP grades.

Polypropylene is used in the manufacture of caps and closures, Co-Polymer Polypropylene is excellent for the manufacture of "live hinges", moulded in hinges such as those used in shampoo and washing-up liquid bottle closures. Other applications are in the automotive and engineering industries. Storage of parts manufactured from Polypropylene should be dry, dust free and the ambient temperature should not exceed 50 degrees Celsius or be below 10 degrees Celsius.

Homo Polymer Polypropylene - Homo PP

Homo Polypropylene is similar in many ways to its sister material Co-Polymer Polypropylene, but it tends to be much stiffer. Where CoPo generally has very good impact resistance, Homo Polypropylene can be more likely to shatter when impacted. The greater stiffness of Homo PP lends itself to applications where tamper evidence is required.

Applications are again in the Packaging, Automotive and Engineering sectors. The impact resistance of Homo PP is decreased as the ambient temperature reduces, so care must be exercised in the selection of this material where a low temperature environment is likely.