Protected against the weather and curious eyes

Car trailers are very popular in Scandinavia. They are also useful for homeowners as well as for owners of cabins and weekend cottages or small businessmen. Trailers with covering offer a practical possibility to transport bulky and unwieldy material dry and clean by car, in winter, for example, the popular snow scooter.

In Denmark, Norway, Sweden and Finland, there are some 50,000 vehicle trailers a year that are produced by around 100 manufacturers. Each fourth trailer is provided with a sturdy covering hood.

Earlier, these hoods were mainly made of glass-fiber-reinforced plastics, but in the last few years the thermoforming process has become the most important manufacturing method; some coverings also being produced in the rotational molding process.

The thermoforming process is used predominantly in coverings made of PE and ABS, both fitted with UV protection. Röchling Rimito Plast with its headquarters in Finnish Rusko supplies sheets made of PE-HD for the leading manufacturer of trailer coverings in Sweden. The biggest sheet size that can be processed by the customer is 2 x 5 meters. These sheets can be thermoformed to one meter. The large moulding machine can thus satisfy all customer wishes regarding covering size in demand on the market.

The connection of the large PE-HD hoods with the aluminum trailers, however, demands specialist know-how: The shrinkage process of the PE-HD sheet must be taken into precise consideration in order to be able to compensate for the enormous differences in the thermal expansion of the two materials. The difference in temperature - depending on the period of the year - can be as much as 100 degrees Centigrade. What's more, the demands made on the extruded PE-HD sheets are extraordinarily high, if it is a question of constant shrinkage and thermoforming properties.