24 Questions
What is an advantage of the pultrusion process in terms of economy?
Fast impregnation and curing of materials
What type of resin is typically not used in Resin Transfer Moulding (RTM)?
Bismaleimides at ambient temperature
What type of fibre works well in Resin Transfer Moulding (RTM)?
Stitched materials
What is an advantage of the Resin Transfer Moulding (RTM) process?
High fibre volume laminates with very low void contents
What is a limitation of the pultrusion process?
Limited to constant or near constant cross-section components
What is not a suitable core material in Resin Transfer Moulding (RTM)?
Honeycombs
What type of application is Resin Transfer Moulding (RTM) typically used for?
Small complex aircraft and automotive components
What is an advantage of the Resin Transfer Moulding (RTM) process in terms of design?
Can produce complex shapes and geometries
What is a common limitation of using polyesters and vinylesters in resin selection?
They have problems with excessive styrene extraction
What is a benefit of using vacuum bagging in manufacturing?
It achieves higher fibre content laminates
What is a characteristic of fibres used in filament winding?
They are used straight from a creel
What is a typical application of vacuum bagging?
Large, one-off cruising boats
What is a disadvantage of the vacuum bagging process?
The extra process adds cost
What is a type of fibre that can be used in filament winding?
Any type of fibre
What is a benefit of using filament winding in manufacturing?
It is suitable for hollow, circular sectioned components
What is a consideration when selecting a resin for filament winding?
Any type of resin can be used
What is the purpose of the heated die in the pultrusion process?
To complete the impregnation of the fibre and cure the material
Which of the following resin types is commonly used in the pultrusion process?
Epoxy
What is the advantage of using the pultrusion process over other manufacturing methods?
It is a fast and economic method of laying material down
What is the main limitation of the pultrusion process?
It is limited to convex shaped components
What is the purpose of the creel in the pultrusion process?
To pull the fibres through the resin bath
What is pulforming, and how does it differ from pultrusion?
Pulforming is a variant of pultrusion that allows for some variation in cross-section, and is a non-continuous process
What is the typical application of pultruded materials?
Beams and girders used in roof structures, bridges, ladders, and frameworks
What is the main advantage of using the pultrusion process for fibre-reinforced materials?
It minimizes fibre cost and produces good structural properties
Study Notes
Pultrusion
- Fibers are pulled from a creel through a resin bath and then on through a heated die, which completes the impregnation of the fiber, controls the resin content, and cures the material into its final shape.
- The process pulls the materials through the die for impregnation, and then clamps them in a mold for curing.
- Materials options: resins (epoxy, polyester, vinylester, and phenolic), fibers (any), and cores (not generally used).
- Typical applications: beams and girders used in roof structures, bridges, ladders, and frameworks.
Resin Transfer Moulding (RTM)
- Fabrics are laid up as a dry stack of materials, sometimes pre-pressed to the mould shape, and held together by a binder.
- Resin is injected into the cavity, and vacuum can be applied to assist resin flow into the fabrics.
- Materials options: resins (epoxy, polyester, vinylester, and phenolic), fibers (any), and cores (not honeycombs).
- Typical applications: small complex aircraft and automotive components, train seats.
Vacuum Bagging
- The process uses a vacuum bag to reduce void contents and achieve higher fiber content laminates.
- Advantages: higher fiber content laminates, lower void contents, better fiber wet-out, and reduced volatiles emission.
- Disadvantages: adds cost, requires higher operator skill, and mixing and control of resin content is still operator-dependent.
Filament Winding
- Fibre tows are passed through a resin bath before being wound onto a mandrel in a variety of orientations.
- Materials options: resins (any), fibers (any), and cores (any).
- Typical applications: chemical storage tanks and pipelines, gas cylinders, fire-fighters breathing tanks.
Learn about the pultrusion process, a manufacturing method that combines fibers and resins to create strong, composite materials. Discover the steps involved, material options, and common applications.
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