Extrusion and Drawing

1
Extrusion and Drawing

• Manufacturing Processes

2
Outline

• Extrusion
• Extrusion of Metals
• Extrusion Defects
• Extrusion Equipment
• Extrusion of Nonmetals
• Drawing
• Drawing Process
• Drawing Equipment

3
Extrusion

• A compression process in which the material is
  forced to flow through an opening to produce a
  shape with a specific cross-section

input
die
product
pump
4
Examples of Extruded Parts
5
Extrusion

• Metals
• Nonmetals

6
Metal Extrusion

• Direct Extrusion
• A ram compresses the material, forcing it
  through the die
• Indirect Extrusion
• The die is mounted on the ram the material is
  forced out in the opposite direction of the ram
  movement

7
Direct Extrusion
8
Indirect Extrusion
9
Extrusion
10
Extrusion
11
Metal Flow
12
Example of an Extrusion Machine
13
Extrusion
14
Extrusion

• Hot Extrusion
• Involves pre-heating the material above the
  recrystallization temperature to increase
  ductility
• Cold Extrusion
• Does not pre-heat material used to produce
  parts in finished or near-finished form

15
Extrusion

• Cold extrusion advantages
• Improved mechanical properties from
  work-hardening
• Good control of dimensional tolerances
• Improved surface finish (no oxide film)
• No heating required
• Competitive production rates and costs

16
Extruded Metals

• Typical extruded metals (hot or cold)
• Aluminum, copper, magnesium, zinc, tin and
  alloys of these
• Steel alloys are usually extruded hot softer
  steels may be extruded cold
• Others such as titanium and refractory metals may
  be extruded, but with difficulty

17
Extruded Metals

• Extrusion Temperature Ranges
• Lead 200-250 C
• Aluminum and its alloys 375-475 C
• Copper and its alloys 650-975 C
• Steels 875-1300 C
• Refractory alloys 975-2200 C

18
Extrusion Defects
19
Extrusion Dies
20
Extrusion Dies
21
Example of an Extrusion Die
22
Extrusion of Nonmetals

• Materials
• rubber
• plastic
• solvents
• candy
• glass
• Products
• window seals
• door seals
• hose and tubing
• wire insulation
• candy canes

23
Hot Feed and Cold Feed Extrusion
Ribbon
Pellets
Cold Feed Extrusion
Heating/melting
Hot Feed Extrusion
Temperature zones
24
Extrusion of Nonmetals
Candy Canes
cone rollers
candy
25
Extrusion of Nonmetals
Window Seals Cold Feed Extrusion
input
windup
die
extruder
takeaway belt
die
26
Extrusion of Nonmetals
Plastic Bags
extruder
die
air
cutting and sealing
27
Example of a Dual Extruded Product
28
Dual Extrusion
Opposed Head
extruder
extruder
die
Piggy Back
die
extruder
extruder
29
Dual Extrusion White Side Wall
White rubber die
Black rubber die
Exit die
30
Wire, Tube, Bar, Rod Drawing

• Extrusion pushes the material through the die
  drawing pulls the material through the die

31
Drawing

• Products
• electrical wire
• cable
• wire stock for fences, hangers, shopping carts
  etc.
• rod stock for nails, screws, rivets, springs
  etc.
• metal bars

32
Drawing Process

• Advantages
• Close dimensional control
• Good surface finish
• Improved strength and hardness
• Adaptability to mass production

33
Drawing of a Wire
34
Drawing
35
Drawing

• Preparation of the work material
• Annealing
• Cleaning
• Pointing

36
Single and Multi Stage Drawing
37
Gold

• Gold is the most ductile metal that exists.
• 4 pounds of gold can be drawn into a wire that
  stretches across the country.

38
Tube and Bar Drawing
39
Draw Bench Production Process
40
Summary

• Extrusion and drawing provide ways to form shapes
  with uniform cross sections at high production
  rates

41
(No Transcript)