Breckin Foster Flashcards
Briefly Describe a thermo -softening
A thermo softening polymer is** a polymer that can be repeatedly melted and solidified without changing its properties**
Describe the stucture of a thermo softening polymer
have a linear strcuture (long, straight chains of repeating units connected end-to-end) or branch structure (a main chain with various side chains or branches extending from it)
Describe engineering Textiles,
Provide examples and properites
Engineering textiles are specialised fabrics designed for specific technical applications,
Propeties:
* high strength,
* durability,
* heat resistance, or
* chemical resistance,
** usally woven or knitten threads of fabrics.**
examples:
* kelvar -
* gore tex
* Geotextiles (used in roads)
Explain the process of Blow moulding and injection moulding.
Blow Moulding - Produces hollow parts. material is melted and formed into a parison, which is clamped into a mould. Air is blown , expanding the material to the mould’s shape. .
**Injection Moulding: **Produces solid parts with complex shapes, The material is melted and injected under high pressure into a mould, shaping the plastic. High pressure ensures the mould is completely filled.
Desribe the process of Extrusion of polymers
Extrusion is used to create objects with a fixed cross-sectional profile, like:
* pipes
* containers/ straws
* window and door frames
* Construction - like decking, and fencing.
Plastic granules are fed into an extruder, where they are heated and melted. A screw then pushes the molten plastic through a die to form the desired shape.
What is a thermo setting polymer?
type of polymer that irreversibly hardens when heated or cured.
they cannot be remelted or reshaped once set.
Describe the structure of a thermo setting polymer.
have a** cross linked ** structure which feaures many links betwteen each molecule.
This structure creates a network of bonds that are difficult to break. Explaining why they cannot be reshaped with heat.
Explain the process of lay up.
(hand layup and vaccum)
The lay-up process is layering reinforcement fibres and resin in a mould, then curing
Hand Lay-up: Layers reinforcement fibres to the desired thickness, applies resin, and uses a hand roller to integrate the resin
Vacuum Lay-up (Vacuum Bagging): Layers reinforcement fibres, applies resin, and uses a vacuum bag to remove air and bind the resin to the fibres,
How are thermo setting polymers modified for use on Aricraft?
Materials are modified to withstand aerospace conditions like: extreme heats, exposure to chemicals and extra mehanical stresses.
done by:
* adding re-enforcement fibres (like carbon
* adding high perfomance fillers - like Resins with Fire Retardant Additives
* Resins with Toughening Agents
Explain the Porcess of compression moulding and what materials are amde by it?
involves pre-heating the mould, placing the material in the bottom half, closing the mould, and applying high pressure and holding at high temps to shape.
Things made:
* automotive parts
* plants and bowls
* Sports helmets and pads
Why are composites materials often used in aerospace?
thye have high strength-to-weight ratio compared to other materials and usally have **better corrosion resistance. **
contribute to better performance, reduced maintenance, and overall cost savings.
What is reinforced glass fibre (fibre glass) ?and what are its applications in aircraft?
is a composite material made of glass fibres in a resin matrix. The glass fibres provide strength and rigidity, while the resin binds them,
**Applications: **
* combined with alluminuim to be used in fuselage, wings and tail
* cabin interiors (panels & seats)
* fairings and engine cowlings
What is Fibre metal laminate (FML) ?and what are its applications in aircraft?
(FML) is a composite material made of **alternating layers of metal sheets and fibre-reinforced polymers. ** This combo enhances strength, durability, and resistance to fatigue
Applications:
*Fuselage Panels
* wings and tail compoents
* cargo doors
What is kevlar? and what are its applications in aircaft?
Kevlar is a, synthetic aramid fibre is 5x stronger than steel by weight, lightweight, flexible, tough, good heat resistance as well.
**Appilcations: **
* fuel tanks - inner walls coated in kelvar
* can be intregated into wings and fuselage
* inside the engine cowl
What is Carbon fibre?and what are its applications in aircraft?
is a high-strength, lightweight material made from thin strands of carbon atoms bonded in a crystalline structure, excellent strength-to-weight ratio and rigidity.
** Applications: **
* Tail: vertical and horizontal stabilisers
* wing and Fuselage
* Interior Components - cabin linings & seats
