Before you start any project where you may need composite materials, there are a number of things you need to consider.
What material will you use?
Carbon fibre is a material consisting of very thin filaments of carbon atoms bound together with plastic polymer resin through heat, pressure or in a vacuum to form a reinforced polymer.
There are a number of advantages to using carbon fibre for your project including:
- High strength to weight ratio
Also referred to as specific strength, Carbon fibre is extremely lightweight while being very strong, with a specific strength score of 2457kN.m/kg compared to steel alloy (254kN.m/kg) and aluminium alloy (222kN.m/kg)
- Very rigid
Carbon fibre reinforced plastics are over 4 times stiffer than glass reinforced plastics
- Good tensile strength
Tensile strength is the maximum stress that a material can withstand while being stretched or pulled, carbon fibre has very good tensile strength
- Fire resistant
Because of carbon fibres non flammable properties, it is frequently integrated into protective clothing
There are however a number of disadvantages to using carbon fibre:
- Very expensive
Because carbon fibre offers so many advantages, it is very expensive. It would only be advisable to use if the high strength to weight ratio is imperative
The sheet-like aggregations allow the spread of cracks. Carbon fibre will not bend much before it fails
- Electrically conductive
Carbon fibre is electrically conductive and can facilitate galvanic corrosion in fittings
The only viable reason that you would utilise carbon fibre for your project would be if the weight of your components needed to be as light and strong as possible. The ultimate question you need to ask yourself is, is it commercially viable and does the project need the qualities of carbon fibre? If not other composite materials are more commercially viable, however if your project does need a carbon fibre composite, contact us today and we could put you in touch with a manufacturer.
Resin transfer moulding
RTM is a cleaner and a more efficient and effective way of producing a composite part, using resin injection and vacuum. RTM is typically used to mould components with large surface areas, complex shapes and smooth finishes. There are a number of advantages to using RTM:
- Good surface quality
On both faces
Flexibility to create complex shapes and forms, including compound curves
- Strong and lightweight
RTM has a high fibre content (25%-50%) by volume, creating a strong and lightweight product
- Lower costs
High material recovery and labour efficiencies decrease production costs
- Reduced waste
- Low environmental impact
Environmentally friendly RTM process lessens styrene emissions
- Short mould cycle
The short mould cycle times increase production volumes
- Consistent product weight and finish
Mould cavity is set to produce same laminate thickness each time
There are also disadvantages to using RTM for your project:
- Higher Tooling cost
For low volume when compared to hand or spray lay-up.
- Limitation on reinforcing materials
Due to the flow and resin saturation of fibres.
Resin transfer moulding is ideal for projects where the surface finish is critical, typically in the automotive industry. RTM ensures composite parts are consistent in thickness, weight and strength and it is ideal for high volume orders and the production of engineered parts that have a high gloss finish both front and back. For more information on RTM contact us today.
GRP (Glass Reinforced Plastic) hand and spray lamination
GRP lamination is a method of producing a composite part utilising glass fibre and resin, this is accomplished through the use of either hand lamination (utilising rollers and brushes to wet the fibres with resin) or spray lamination (utilising a spray to combine the resin and fibreglass). GRP lamination is typically used in lower volumes of products.
There are a number of advantages to using GRP lamination for your project including:
- Short lead times
For component production
The shape of the part, size and laminate configuration are very flexible, typically used for bath panels, undercut parts and parts with large cores
- Design changes can be easily made
- Low cost
Low equipment & tooling cost and inexpensive materials
For a wide range of physical and mechanical properties in the laminate
- Corrosion resistant components
There are also disadvantages to using GRP for your project including:
- Operator error
Without controls there is more chance of operator error, which may result in parts with variable thickness and weight
- Back surface finish
Is of poorer quality than the front
GRP hand and spray lamination is ideal for parts that need to be flexible in shape, size and laminate configuration; and GRP lamination is often the most commercially viable for parts which can be ordered in higher or lower volumes (MPM have done one offs and production runs of over 40,000). For more information on GRP lamination contact us today.