01 December 2009
01 December 2009
YSA Yacht Design & Building has followed up its YSA 10, launched in 2006, with a Catamaran, YSA Competition Cat 30.
This new craft was developed with vacuum infusion resins supplied by ebalta. Using GL (German Lloyd) infusion material, along with ebalta epoxy resin BIV 800, the designers were able to lower the weight of the craft and reduce unnecessary odour during manufacture.
When using vacuum infusion, a lower volume of resin gets drawn into the fibre material, which usually results in a higher fibre percentage versus that achieved with hand lamination; this often results in a higher strength to weight ratio for the part.
The following case study examines the stages of the build:
Step by step to the part
The epoxy mould was produced from ebalta´s AH 140 resin with hardener TC 90, and was also fabricated by the vacuum infusion process.
For production of the CFRP parts, the carbon fibre fabric is placed in the mould in a dry condition. The peel ply layer is then inserted followed by the perforated release film. Flow medium and hoses can easily be removed through the perforated release film after curing of the resin. The flow medium is then placed in position and fixed. The resin feed and vacuum hoses are attached and secured using an adhesive tape.
After applying vacuum-film in position, the structure is tested for leaks and the ebalta epoxy resin BIV 800 is drawn in through the resin feed and is distributed over the entire component. The procedure of infusion takes no more than 60 minutes for each part.
Advantages of the process
The vacuum-infusion method also brings further advantages says Stefan Koppmair, expert for Composites at ebalta “Because it provides a better and unchanging quality for each parts which means you can achieve uniform impregnation without bubbles.” According to ebalta, the percentage of the infused resin content varies by less than 0.5% across the component which means there is virtually no difference in thickness. The carbon fabrics can be placed in without any time pressure, and there are no restrictions relating to the pot life. Moreover, through the use of resins with a short pot life, a faster demoulding time is possible. Such time savings are most notable for larger parts with core material.
“The fact the carbon fibre is dry loaded means clean working conditions and consequently a significant reduction of emissions is possible” emphasises Stefan Koppmair. Further potential advantages using vacuum bagging as opposed to hand lamination is a reduced resin content in the parts and a lower resin volume requirement for larger parts.
According to ebalta, vacuum infusion also has advantages over prepreg/autoclave processes as well, such as no costs for the purchase of the autoclave and the fact that thick laminates are made in one working step so no debulking is necessary. Compared to Resin Transfer Moulding (RTM), ebalta´s specialist Koppmair states the advantages come from lower tool costs and in addition, there is no need for an expensive injection system. For lot sizes under 100 pieces, the vacuum infusion process proves to be far more economical.
The success of the YSA Competition Cat 30 demonstrates the wide expert knowledge of the ebalta specialists for vacuum infusion.
Stefan Koppmair says “We are happy to oversee whole projects and stay at our customer´s disposal for specific questions about the products or the manufacturing processes, as well as providing intensive training if required. With a complete integrated portfolio of materials for composites, we are prepared to face almost any project.”