25th IKV Colloquium: Focus PU-Technology

Sixty years of the IKV and 25 Colloquia: the IKV is holding its Jubilee Colloquium on 3-4 March 2010 in the Eurogress, Aachen. Under the motto "Plastics Technology - Looking Ahead" the IKV will be giving an overview of the latest research results in the fields of plastics and rubber technology.

The research topics covered at the IKV take in the fields of injection moulding, extrusion, rubber technology, moulded part design and materials technology, fibre-reinforced plastics and PU. The PU processing topics at IKV are treated in an inter-disciplinary way.

The session "Polyurethane - optimised processes for versatile products" will be focussing on the development of a permanent plasma-induced release coating as substitution for release agents, on the systematic process optimisation for the processing of flexible foams and on PU as alternative for conventional matrix systems in pultrusion. The session will be moderated by Dipl.-Ing. Albrecht Manderscheid of Cannon Germany.

The IKV research topics in the field of polyurethanes

Due to their varied appearance and the possibility to adapt the material properties to the respective application, polyurethanes are highly significant in the plastic industry.

A considerable disadvantage of polyurethane is its tendency to adhere to the cast or spray mould after hardening, which currently makes the use of release agents unavoidable. A joint project by the Institute of Plastics Processing Aachen (IKV), Aachen, and the Fraunhofer Institute for Manufacturing Technology and Applied Materials Research (IFAM), Bremen, is hoping to develop a permanent release coating for PU moulds. The test object for this project is a plasma polymer coating, which has already demonstrated excellent anti-adhesive properties in preliminary tests. The service life must still be improved considerably. The primary aim of the tests conduced during this research is to understand the reason for the premature failure of the coating and based on these findings to develop an optimised coating that meets the high demands of everyday industry.

An important part of PU processing is the manufacture of flexible moulded foam. As part of a research project, basic findings were established concerning the formation of mould marks in the PU flexible moulded foam parts. The tests show that selected process parameters, such as component temperature, mixing pressure and output rate, but also process variables such as shot weight, index and mould temperature, can significantly influence the mechanical properties of the PU flexible moulded foam. Compliance with the aforementioned process parameters and setting variables results in an adjustable, predictable and constant component quality. Thanks to the results of statistical tests as part of this presentation, the processor is able to judge the influence of various process parameters on the formation process for moulded part.

During the highly automated production of large-volume components made from continuous fibre-reinforced plastics, the polyurethanes harbour significant potential due to their rapid reaction times and good viscosity-dependent fibre impregnation. Particularly during pultrusion, PU offers a real alternative to conventional matrix systems such as epoxy resin. Measurements of component rigidness and strength in 3-point bending tests prove that components manufactured with single- or double-component polyurethane systems achieve comparable and in some cases even better mechanical strengths than pultrudata with epoxy matrices. Moreover, pultrusion with double-component PU can achieve process speeds far in excess of the processing speeds achieved with conventional matrix systems.

The lectures, discussions and workshops will be simultaneously translated into English. For further information please visit www.ikv-kolloquium.de.

 
BU: Pultrusion profiles with PU as matrix system (photo: IKV)