Extrusion and

Drawing

Manufacturing

Processes

Outline

Extrusion

Extrusion of Metals

Extrusion Defects

Extrusion Equipment

Extrusion of Nonmetals

Drawing

Drawing Process

Drawing Equipment

Extrusion

A compression process in which

the material is forced to flow

through an opening to produce

a shape with a specific cross-

section

pump

input

dieproduct

Examples of Extruded

Parts

Extrusion

Metals

Nonmetals

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

Direct Extrusion

Indirect Extrusion

Extrusion

Extrusion

Metal Flow

Example of an

Extrusion Machine

Extrusion

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

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

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

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

Extrusion Defects

Extrusion Dies

Extrusion Dies

Example of an

Extrusion Die

Extrusion of Nonmetals

Materialsrubber

plastic

solvents

candy

glass

Productswindow seals

door seals

hose and tubing

wire insulation

candy canes

Hot Feed and Cold

Feed Extrusion

Heating/melting

Ribbon Pellets

Cold Feed Extrusion

Hot Feed Extrusion

Temperature zones

Extrusion of Nonmetals

candy

cone rollers

Candy Canes

Extrusion of Nonmetals

Window Seals

Cold Feed Extrusion

takeaway belt

windupdie

extruder

input

die

Extrusion of Nonmetals

die

cutting

and

sealing

air

extruder

Plastic

Bags

Example of a Dual

Extruded Product

Dual Extrusion

Opposed Head

die

extruder extruder

extruder

extruder

Piggy Back

die

Dual Extrusion – White

Side Wall

White rubber dieBlack rubber die

Exit die

Wire, Tube, Bar, Rod

Drawing

Extrusion pushes the material

through the die; drawing pulls

the material through the die

Drawing

Products

electrical wire

cable

wire stock for fences, hangers,

shopping carts etc.

rod stock for nails, screws,

rivets, springs etc.

metal bars

Drawing Process

Advantages:

- Close dimensional control

- Good surface finish

- Improved strength and hardness

- Adaptability to mass production

Drawing of a Wire

Drawing

Drawing

Preparation of the work material:

1. Annealing

2. Cleaning

3. Pointing

Single and Multi Stage

Drawing

Gold

Gold is the most ductile metal

that exists.

4 pounds of gold can be drawn

into a wire that stretches

across the country.

Tube and Bar Drawing

Draw Bench Production

Process

Summary

Extrusion and drawing provide

ways to form shapes with

uniform cross sections at high

production rates