Engineering Thermoplastics: families, properties, applications and selection

In the second presentation at the SPRA meeting on ‘Materials and Design’, Peter Burke, Ticona UK Account Manager for Scotland and the North of England, started with an overview of Ticona and its portfolio of engineering thermoplastics, all partially crystalline materials, outlining their properties and typical applications. The portfolio includes polyacetals (POM) [trade name Hostaform], thermoplastic polyesters (PET, PBT) [trade names Impet and Celanex], polyphenylenesulphide (PPS) [trade name Fortron], liquid crystalline polymers (LCP) [trade name Vectra] and ultrahigh molecular weight polyethylene (UHMWPE) [trade name GUR].

In a link to the first presentation on solar thermal collectors, Peter then described development work from Ticona on components for photovoltaic (PV) collectors and the huge USA market for solar tiles, predicted to be $100 billion by 2014 and a major potential application for polymeric materials. The essential properties for plastics in the solar energy market are fire performance, thermal resistance, humidity resistance and low temperature impact resistance.

Turning to the more general topic of material selection in design projects, Peter provided a check list of material property requirements, which included defining the mechanical load stresses to which the component will be subjected, identifying a range of other mechanical properties (stiffness, impact, fatigue), quantifying thermal exposure (time and temperature), chemical and environmental exposure and electrical properties.

Requirements of transparency, colour and surface finish are also established at an early stage. Overall cost (material cost, tooling and manufacture) has also to be considered. When the property portfolio has been defined it is then compared to property values in the data sheets of candidate materials to find the most suitable material. To select families of thermoplastics or individual grades within a family, Ticona frequently use spider graphs to identify the most appropriate material.

Ticona UK www.ticona.co.uk

Report by C Geddes, SPRA Hon Secretary May 2011