woodflour compound launched

MATERIALS

DuPont

introduces multi-purpose engineering thermoplustics DuPont Packaging and Industrial Polymers has introduced a new range of Elvaloy@ AC ethylene acrylic copolymers. The company says that the new resins are different from other acrylic copolymers and from ethylene-vinyl acetates (EVAs), offering better thermal and processing stability, greater melt strength and higher filler acceptance. DuPont believes that they will present plastics compounders and processors with profitable options in polymer modification and masterbatch production. The new resins, including ethylene methyl (EMA, ethyl (EEA) and butyl (EBA) acrylates, are produced in a free radical polymerization process carried out in a tubular reactor. According to the company,

this process leads’ to a more heterogeneous molecular architecture than that from the conventional autoclave process. Another characteristic of the tubular process, says DuPont, is that the resulting polymer shows a higher level of long chain branching, leading to better processability and higher melt strength. The materials are claimed to remain stable up to 350°C in air, or 400°C in nitrogen, and have higher crystalline melt temperatures than conventionally made polymers or EVAs (lo-15% higher at the same comonomer level). A higher thermal tolerance improves overall processing stability and allows their use in combination with high temperature engineering polymers. Halogen-free Elvaloy AC

New PVClwoodfJour

modifier

ethylene acrylates are also said to help lower injection moulding costs. The materials are non-reactive, therefore they tend to reduce the specific weight and volume-price of the finished injection-moulding compound, while their higher melt flow index creates shorter cycle times. The company adds that that their high polarity makes them compatible with a broad range of commodity and engineering thermoplastics, including PA, PP, PBT, PET, ABS, PC and LCPs. They can also be used to enhance the compatibility in blends such as PC and PBT, or PC and ABS. The polarity means that they have high filler acceptance - up to 80% by weight - and can also be used as pigment binders. There are further processing

compound

for

advantages resulting from the fact that the resins have low adhesion to metal. In combination with their high melt point, this helps to prevent stickiness and bridging in the feed zone of compounding extruders. DuPont maintains that these non-corrosive, low-odour ethylene acrylate modifiers should be considered’for improving impact resistance and increasing flexibility in engineering polymers where a moderate to intermediate level of toughness is required at a reasonable cost. They are claimed to be highly suitable for use in universal masterbatches. Contact: DuPont Packaging and Industrial PoPolymers TeL. +44 1442 218541 Fax: +44 1442 218663

launched

DoeflexNitapol, the PVC division of Vita Thermoplastic

company. Applications include building and construction

Compounds Limited, has developed Timbercel - a PVC compound with a 30-50% woodflour content. The company says that the new product offers a number of advantages, including that it is foamed during extrusion and can produce lengths of PVC that exhibit many of the attributes of machined wooden strips. Timbercel is said not

uses, such as window frames, decking and cornicing. According to Doeflex Vitapol’s managing director David

to degrade because the organic cellular structure of the wood is bound up in a matrix of PVC. It can be drilled,

opportunities. Contact: Doeflex/Vitapol Tel: t 44 I793 442442

Plastics Additives

Outen, the development of Timbercel is part of the company’s programme to find new and improved uses for PVC. He adds that he does not see PVC as being a mature product, but one that is still open to exciting development

screwed or nailed and it is recyclable. The material

& Compounding&wary

2002

will also exhibit a certain level of fire retardance, says the