18 - Adhesives and fixings Flashcards
1
Q
Name 5 adhesives
A
- Polyvinyl acetate (PVA)
- Contact adhesive
- UV hardening adhesive
- Solvent cement
- Epoxy resin
2
Q
Polyvinyl acetate (PVA)
A
- Water-based adhesive used to bond woods and wood-based materials
- Not usually waterproof
- Often used to further bond wood joints together
3
Q
Contact adhesive
A
- Used for bonding large areas, such as sheet metal
- Can be used to join materials to the same or a different material. E.G wood sheet to wood sheet, metal sheet to wood sheet, metal sheet to polymer sheet
- Two surfaces are coated in contact ashesive and left for 10 mins until the adhesive feels ‘tacky’
- They are then joined together, and adhesion occurs instantly on contact
4
Q
UV hardening adhesive
A
- Clear liquid which quicky cures when exposed to UV light
- Can be used to join metal, glass and polymers
- Excessive adhesive can be wiped away before it is exposed to UV light, allowing a clean joint to be made
5
Q
Solvent cement
A
- Clear liquid used to join polymers
- Softens the surface of the polymers to be joined, allowing them to fuse together
- Often used by plumbers to bond pipes
6
Q
Epoxy resin
A
- Used to join different materials together (e.g timber to metal)
- Comes in two parts; resin and hardener
- Equal amounts of resin and hardener are mixed to form the adhesive
- Starts to set immediately, but can take up to 24hrs to fully set
7
Q
What is a Jig?
A
- A device that can control the motion of a tool relative to the workpiece
- It will hold the piece, and guide the tool, removing the need to mark out
8
Q
What is a fixture?
A
- Something that holds the work in a given position while manufacturing takes place
- E.G a clamping frame during welding
9
Q
What is the general point of fixtures and jigs?
A
- Ensures components can be made repeatedly, accurately and efficiently
- Mainly used in larger production scales
