Diamond tools cut GRP to close tolerances

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PROCES~&~

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Filament winding

gives stronger parts

A UNIQUE filament winding technique is allowing French firm Composites des Pays de Loire (CPL) to produce medical and industrial products that are much stronger than those made using other filament winding methods. CPL’s proprietary technology is combined with its manufacturing process to produce composite carbon or glass fibres which it says are more resistant to bending, twisting or compression than conventional products. Instead of cutting the hbres, they are used intact, regardless of the complexity of the shape. A high percentage of fibre is another key point of the process, typically 60-85X is used. CPL has produced a composite spring, using glass fibres, for a 1300 kg axletree. The spring is small, with dimensions of

Diamond

Class fibre

spring fitted

to an axlewheel.

0.8 x 180 mm. It has a rigidity of 70 N/mm and a wheel clearance of 130 mm. A displacement of the spring on a lever when the axletree is loaded

will give a progressive rigidity of 100-400 N/mm. A road test confirmed that the suspension is more secure, providing greater comfort. Applications for the

composite spring are numerous, says CPL, and inelude caravans, trailers and electric cars. cyrille Bex, CYL; tel:

fax;

+ 33-41-50+ 33-41-50

74-20; 75-86.

tools cut GRP to close tolerances

DIAMOND tooling supplied by Cranden Diamond Products Ltd of Cranbrook, UK, is being used to cut and trim precisely glass reinforced plastic (GRP) moulds for producing racing boats. Colvic Craft plc is producing ten Clipper 96 boats at its site in Colchester, UK. Each boat needs approximately 168 kg of gel-coat, 3180 kg of resin and 1700 kg of glass fibre, to produce 35 separate moulded parts. These parts are then trimmed and trepanned using diamond cutting discs and holesaws in 44/60 dia-

mond grit size, to ensure a precise fit, they are then joined together to form the complete vessel bodywork. Three hulls are fitted out at a time. The boats are scheduled to be completed in time for the start of a one year race around the world in October 1996. Each boat is expected to have a short workout period, followed by intensive inspection before being used in competition.

Stuart Cleary, Cranden Diamond Products tel: + 44- 1580Ltd; 241252; fax: + 441.580-241838.

Colvic Craft’s Clipper, Cranden Diamond.

produced

using diamond

Reinforced

tooling from

Plastics July/August

1996