Polykemi�s antistatic materials - breaking through at automotive manufacturers!

For this specific reason - one of the leading automotive producers in Europe have been using Polykemi´s anstistatic treated material in their premium models-actually already for some years in growing volumes. The material is used for especially sensitive & dust obvious parts – placed directly in the field of eye sight. Example of such parts are storage boxes for sun-glasses in the center roof console and make up mirrors in the sun visors.

Substantial growth for Polykemi!

Sometimes the anti-static property has been obtained by using additives regretfully disappearing over time, but now the dominant technology is to establish a permanent network of semi-conductive polymer that dissipate electrical charge. The advantage of such materials has become so obvious, that nowadays it is not only exclusive cars that are equipped with them. Also models intended for a wider market use these materials for especially sensitive parts.

SCANBLEND PC/ASA from Polykemi is a material being especially successful on this growing market in recent years. The growth can be explained partly by increased customer demands from car buyers driving in more dusty traffic environments than we are used to in Europe. This fact has created a market for permanently antistatic PC/ASA also in China, where it is produced by a wholly owned subsidiary of Polykemi, located close to Shanghai.

A unique material welcomes its less unique sibling!

Another reason for the success of the material is that it is unique. This is from the perspective of the automotive standard defining the properties for blends of PC and ASA. It is unique in the sense that it places itself in the category with the highest requirements for dimensional stability at elevated temperatures.

fig. 1: Example of application.

Historically parts have been assigned materials belonging to this category, but since they were not found on the market, drawings were made with statements specifying how certain property requirements were exempted. For the first time with SCANBLEND PC/ASA it was possible to fulfill the designers original demands on technical performance.

For some constructions within certain car models this PC/ASA is considered as being over engineered. For such instances, Polykemi offers a version with lower dimensional stability at elevated temperatures. Instead of PC/ASA - this version is designated ASA/PC, indicating that the composition is slightly altered. One of the main advantages with a higher part of ASA is a wider processing window for the injection moulder. Both materials comes with a powerful UV stabilization, more than sufficient for the typical applications – not being exposed to direct sun light.

The production of injection moulded parts made of materials with permanent anti statics function is challenging – both for the compounder as well as the part producer. The material has to consist of a robust interpenetrating  net work of dissipative polymer, stable enough for the shear intensive processing conditions often present when complex and thin walled parts are produced. Additionally, this has to be accomplished without having the dissipative component placing a too big footprint in the compound - neither with respect to technical performance or with respect to cost.

The Polykemi laboratory adds rare equipment

In order to offer help to sub suppliers by being able to validate the anti-static properties in parts produced, Polykemi has invested in a new instrument. This characterizes the parts ability to lead away electrical charges, exactly in the way car manufacturers do in their own laboratories. Thanks to this investment the part approval can be done quicker, simpler and finally cheaper, since expensive tests so far conducted at external labs can be avoided.

fig. 2: Polykemi´s new lab equipment for measuring antistatic properties in accordance with PV 3977 & development manager Mr Henrik Eriksson.

One critical challenge for the injection moulder is to apply the correct graining to achieve the proper surface structrure of the mould. Once selected, the process has to be fine-tuned to replicate the delicate microstructure of the overall pattern, which is what gives the matte appearance associated with state of the art car interiors. From the compounder side the color, the perception of which is also influenced by the gloss of the molding one beholds, has to be reproduced perfectly from batch to batch. The combined result must be in accordance with the very narrow tolerances set by the brand owners. With this in mind the co-operation between the materials producer and injection moulder is a vital factor of success. This is since the impression of a color is not only a result the material, but the combination of  material and the moulding - both being equally critical to be able to produce parts complying with set demands.

More anti static materials coming up...

SCANBLEND PC/ASA is in successful service in multiple car models, being the first choice for many variations of both for boxes for sun glasses as well as make up mirrors. The hope is that further car producers will realize how highly appreciated dust free car interiors are by the consumers, and thus the market for this category of materials will expand further.

PC/ASA & ASA/PC are not the only materials with permanent anti-static properties offered by Polykemi.

Since also parts of the B-pillar trims sometimes are required to have antistatic properties, especially where the seat belts are rolled in, also solutions for those applications are available. In such cases PP-based materials are used.

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