Current vacuum cleaners have several problems to acknowledge. From the point of view  of materials and technology, and the importance of these for the consumer, the dust  collector- and the filter system are most appealing. Possible solutions have been  evaluated on the basis of criteria: hygiene, user comfort, environmentally friendly and  cost reduction. The most favourable results will be booked when filters, which make use  of the electret-principle, will replace existing filters. Eventually, this has led to a  cassette that filters air by using rest material from the production process of electrets.