Composite Design Consultancy
Carbon fibre shouldn’t just be treated as black metal, the wonderful thing about designing with composites is that you can design the material as well as the product.
This opens up many possibilities that wouldn’t be possible with any other materials.
Although Carbon fibre does have many good properties, there are many other materials that offer different properties. If you want a part to flex during use it may not be the best material for you to use.
Our strength is in listening to you, and finding out what you actually want. We will then identify the pros and cons of different paths available to you.
A little guidance at the start can save you a lot of pain later on.
By applying good composite design and process principles throughout out the development process, we can help you target specific solutions at an early stage in order to provide substantial cost savings beyond the cost of our services.
We have experience working with a whole range of thermoplastic composites and thermosets each have there pro’s and cons
- 3D CAD Engineering
- Tooling Design
- Laminate Design
- Bespoke fabric design
- Design Detail
- Design for composite Manufacture
- Product Design
Wet / Hand layup
Resins are impregnated by hand into fibres which are in the form of woven, knitted, stitched or bonded fabrics. This is achieved with rollers or brushes, Laminates are left to cure under standard atmospheric conditions
Resins: Any, e.g. epoxy, polyester, vinylester, phenolic.
Fibres: Any, although heavy fabrics can be hard to wet-out by hand.
- Widely used for many years.
- Simple principles to teach.
- Low cost tooling, if room-temperature cure resins are used.
- Wide choice of suppliers and material types.
- Higher fibre contents, and longer fibres than with spray lay-up.
- Resin mixing, laminate resin contents, and laminate quality are very dependent on the skills of laminators.
- High void content
- Low fibre volume fraction,
- Limiting airborne styrene concentrations to legislated levels from polyesters and vinylesters is becoming increasingly hard without expensive extraction systems.
- Resins need to be low in viscosity to be workable by hand. This generally compromises their mechanical/thermal properties due to the need for high diluent/styrene levels
The vacuum infusion process is becoming more widespread within the composites industry. It is already commonly used in the marine sector and wind energy.
In marine, hulls are regularly manufactured from 6 m to 40 m as well as decks, floors, trays and other large components where strength and weight are important. However, the process is not limited to marine and can be used in all other market sectors, in particular construction and land transport for the manufacture of most large structures.
Vacuum infusion can be used for both one off mouldings and regular production but due to the preparation time required it would not normally be used for more than one moulding per day per mould. Larger mouldings such as boat hulls would have a much longer cycle time.
One specialist area for vacuum infusion is to manufacture low smoke fire retardant mouldings for building and train applications using speciality filled resins (such as Scott Bader’s Crestapol range) that are difficult to process by other methods.
RTM - Resin Transfer moulding
Resin transfer moulding (RTM) is an increasingly common form of moulding
It is primarily used to mold components with large surface areas, complex shapes and smooth finishes.
The resins used in RTM are thermally activated from the fibre mat or preform and mold wall.
Final RTM products will be light in weight and high in strength. However, RTM uses heavy structured tooling to withstand the hydraulic pressure, and hence it has high tooling cost.
Resin Transfer Moulding Process
RTM is a closed-mold, vacuum-assisted process that employs a flexible membrane for the B-side surface compression. This process yields excellent strength-to-weight characteristics, high glass-to-resin ratio and increased laminate compression.
In this process, fibre preform or dry fibre reinforcement is packed into a mold cavity that has the shape of the desired part. The mold is then closed and clamped.
A vacuum is then pulled on the mold and Catalysed resin is then pumped into the mold under pressure until the mold is filled.
After the fill cycle, the cure cycle starts during which the mold is heated, and the resin polymerizes to become rigid plastic. Gel coats may be used to provide a high-quality, durable finished product.
This process is well-suited for mass production of 100 to 10,000 units/year of high-quality composite fiberglass or fiber-reinforced plastic parts. It is recommended for products that require high strength-to-weight requirements. Tooling used in this process can be made from various materials including aluminum, nickel shell, mild steel and polyester.
Need a hand with your RTM processing or RTM product design , Don't hesitate to Contact us
With the development of multi-axial weaving, small batches of fabric with bespoke properties can be manufactured.
This can have many advantages over your more traditional fabrics
Pultrusion and Pull winding
Images from pultrex and excel composites