Bridgewood have developed a unique manufacturing option for large engine hood applications for medium volume vehicles in the off-road construction and agricultural vehicle markets.
Engine compartment hoods and components to meet Tier 4 final requirements. The progression of engine emission upgrade programmes results in increased localised engine compartment temperatures. Medium volume vehicles require engine bonnet / exterior panels with higher temperature resistant materials whilst retaining the low cost tooling route that vacuum forming offers and an attractive high gloss exterior finish.
The demands of this application are:
- Aesthetically pleasing formed shape / design
- Localised Engine compartment temperature approaching 140 degrees centigrade
- Rigid solid engine panels
- Decorative custom coloured high gloss exterior finish
- High level of impact resistance
- High levels of chemical resistance- engine compartment
- Cost effective tooling
- UV protection
- Scratch resistance
A twin skin sandwich construction has been created that gives the required combination of properties / benefits:
- A high gloss outer material with a tough impact & scratch resistant surface. The material incorporates a UV resisting coextruded outer layer.
- The inner is moulded from a thermoformable composite sheet of short strand fibre reinforced Polyolefin with a specific range of properties to suit the demands of engine compartment applications – toughness, chemical resistance, high impact and good flexural strength and a heat distortion temperature 60 °C in excess of the traditional ABS type materials.
- The use of a bonded twin skin structure allows for increased rigidity and strength.
The finished design allows for a gloss exterior colour matched outer panel that gives the sleek design and specific branded machine look. The interior panel has a ribbed structure that reinforces the whole panel and allows for the insertion of bracketry, noise insulation and other components. The inner panel material selection has the required heat distortion characteristics for this demanding application. The vacuum forming process affords an economic tooling solution.