20-08-2012, 11:38 AM
MOULDING SHOP
MOULDING.pptx (Size: 880.38 KB / Downloads: 49)
ABOUT THE INDUSTRIES
THIS IS AN ANCILARY INDUSTREIS OF HERO MOTAR CORP.
UM Group is a USD 250 million technology driven
Unitech Machines Limited is one of the fastest growing Public Limited Companies
Unitech Machines Limited 8th km mileston from saharanpur
INJECTION MOULDING PROCESS
Injection Moulding is a manufacturing technique for making parts from plastic material.
Molten plastic is injected at high pressure into a mould, which is the inverse of the desired shape.
The mould is made by a mouldmaker (or toolmaker) from metal.
In Unitech,this plastic injection molding machine is used for making winkers,utility box,head light,tail light etc.
Process
1. Granules of plastic powder are poured or fed into a hopper which stores it until it is needed.
2. A heater heats up the tube and when it reaches a high temperature a screw thread starts turning.
3. A motor turns a thread which pushes the granules along the heater section which melts then into a liquid.
4. The liquid is forced into a mould where it cools into the shape.
5. The mould then opens and the unit is removed.
PART DESIGN RULE
Simple shapes to reduce tooling cost
No undercuts, etc.
Draft angle to remove part
In some cases, small angles (1/4) will do
Problem for gears
Even wall thickness
Minimum wall thickness ~ 0.025 in
Avoid sharp corners
Hide weld lines
Holes may be molded 2/3 of the way through the wall only, with final drilling to eliminate weld lines