PVC Formulations changing with new regulations and chemical safety testing

Compounding PVC is an art and it takes a high level of skill to develop new recipes. Formulations are changing with new regulations and chemical safety testing driving development. The second AMI international conference, PVC Formulation 2010, brings together top industry experts to debate cost-effective changes from 16–18 March 2010. Sustainability is the current buzz word and additive companies have responded to this with new product offerings. Stabilisation is a hot topic for PVC users and compounders; companies like Chemtura have studied both regulatory and commercial viewpoints. PVC resin suppliers have been conducting their own research – Shin-Etsu PVC has looked at the effects of changing stabilisers in pipe and profile. Lead is being phased out and alternatives are being brought in, for example, Baerlocher has investigated calcium stabilisers in profiles. There is renewed interest in Europe in tin stabilisers according to the European Stabilisers Producers Association, and Arkema has developed a mono octyl tin. Süd-Chemie is marketing hydrotalcite as a co-stabiliser for calcium/zinc systems. Catena Additives has heavy metal-free stabilisers for transparent injection moulded and extruded PVC. After the controversy over the use of phthalates, many companies have moved towards new plasticisers. Roquette Freres has a diester isosorbide from vegetables – the company specialises in chemicals from crops such as maize and potatoes. Lanxess has a polymeric plasticiser, and Eastman Chemical has a new high solvating alternative. Processing PVC can be improved with additives such as lubricating waxes from Clariant Produkte Deutschland. Dr Michael Schiller has taken up the post of Managing Director of Akeniz Kimya Austria and will be talking about computer-aided rheology control for window profile extrusion. An oscillating screw kneader, such as that from Buss, can aid compounding of highly filled PVC. Nabaltec has modified mineral hydrates to give multifunctional effects in PVC: stabilisation, fire retardancy and smoke suppression. Impurities in minerals can cause problems in compounds: Chemson Polymer-Additives is investigating the effects as applied to calcium carbonate. Many PVC compounds are coloured and the titanium dioxide content can affect a formulation, according to DuPont de Nemours. External exposure, as in profiles and pipe, can cause heat build up particularly in darker colours. The Shepherd Color Company has reflective pigments that can help to reduce the problem. Colour control systems have been developed by ROC Optical Control to improve consistency.