Resin Transfer Moulding (RTM)

Resin Transfer Moulding (RTM) is a low pressure, “closed mould” process, which offers high-quality dimensional and surface finish composite mouldings. In the RTM process a male and female mould is required and RTM parts are made by injecting liquid resin and catalyst into a closed mould cavity, containing dry fibre reinforcements. Both RTM (high pressure) and RTM light (low pressure vacuum assisted) are available. In the latter, a lighter duty mould and counter mould are used reducing initial capital costs. The cycle time is slower and resin to glass ration higher which has a bearing on both cost and lower part strength. The primary surface of the moulding may be gel-coated, which is applied directly to the mould surface before installing the fibre. If a gel-coat is not required, the exterior finish is the same from the front to the back of the moulded part. The preformed or cut glass matt is then placed in the mould.

Resin is injected at pressure (low pressure vacuum assisted in the case of RTM light) through a suitable point or points in the mould. Curing takes place at room temperature. Vacuum assistance is also employed on High pressure RTM in relevant cases. RTM is particularly suited to the production of medium volume parts (100-500 per month) that require faster cycle times and produces parts very close to tolerances.

There are numerous benefits of RTM, including:
• Parts can be produced with the same finish on both sides (rough or smooth)
• Durable and dimensionally stable parts
• Uniform thickness of parts produced
• Tooling cost affordable compared to the size of the component
• Composite or metal moulds can be used
• Parts will not corrode or rust
• Parts are impact resistant
• Parts can be chemical resistant
• Parts can be fire retardant
• Ability to customise input materials to suit customers’ requirements
• Custom tooling assures the accuracy of a customer’s design and parts
• Best suited for larger surface area components
With the benefits RTM offers, some of the most common uses of RTM composites include automotive and public transportation parts, machine covers and housings, wind deflectors and spill containment

Profibre has wide experience in the production of RTM
composite products for the following industries and categories:
• Automotive and trucking industry
• Aircraft and aeronautics industry
• Public transportation
• Agricultural and farm products/applications
• Industrial and manufacturing
• Building and construction
• Alternate energy products

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