18 Adhesives & Fixings

Question 1

PVA
What is it based on
What does it join
DIS

Answer 1

Water based, bonds woods
Not waterproof
Can do wood joints

Question 2

Contact adhesive
What does it join
What type of surface does it do
Method of application

Answer 2

Bond large areas
Join same or different materials (but sheet stock form only ok)
Method: must be coated separately for 10 min then stuck together. Adhesion is instant

Question 3

UV hardening adhesive
What is it and how does it stick and why
What does it join
ADV of how clean it is to use

Answer 3

Is clear liquid, quickly cures to form bond when exposed to UV (as it contains a photo initiator)
Joins metals, glass and polymers
Excess can be wiped away with cloth before UV applied to give a clear, solid joint

Question 4

Solvent cement
What does it look like
What does it join and how
What industry can it be used in

Answer 4

Its a clear liquid called dichloromethane
Joins polymers eg acrylic ABS add PVC
Softens polymers to be joined allowing them to joined
Can be used in plumbing to bond non pressure pipes made of ABS or PVC

Question 5

Epoxy resin

What’s special about it

Answer 5

Comes it 2 parts - resin and hardener, joins different materials together
Equal amounts of resin and hardener are mixed to form adhesive, takes time to fully set

Question 6

Jigs and fixtures
Why are they used + 2 ADV
Jig Def
Fixture def

Answer 6

Used to allow parts to be made repeatedly, with more speed and accuracy

Jig - HOLDS work AND GUIDES tool, eliminates need to repeatedly mark out

Fixture - HOLDS work in place while MANUFACTURING PROCESSES takes place