Manufacturing processes

Introduction to Manufacturing
Processes

Products and Manufacturing
Product Creation Cycle
Design → Material Selection → Process
Selection → Manufacture → Inspection →
Feedback
Typical product
cost breakdown

Manufacturing Process
A sequence of operations and processes
designed to create a specific product
The process of turning materials into a
product

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Engineers in Manufacturing
Manufacturing Engineer
Select and coordinate specific processes
and equipment
Industrial Engineer
Responsible for the manufacturing system
design
Materials Engineer
Develop and select materials based on
desired material properties and
manufacturing processes

Manufacturing System Designs
Job Shop
Small quantities of products
Large variety of products
Products move through the shop to
various machines
General-purpose machines

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Flow Shop
Larger quantities of products
Production line
Special purpose machines



Linked-Cell Shop
Manufacturing and subassembly cells
connected to final assembly
Lean production system
One piece flow system

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©iStockphoto.com

Project Shop
Product being manufactured cannot be
easily moved during production
Production processes are brought to the
product
Examples: Bridges, ships, large airplanes,
locomotives, large machinery



Continuous Process
Large plants
Utilized in the manufacture of liquids, oils,
gases, and powders


Lean Manufacturing
100% “good” units flow from process
to process
Integrated quality control (IQC)
All employees are inspectors


Basic Manufacturing Processes
Casting and Foundry
Forming or Metalworking
Machining
Joining and Assembly
Rapid Prototyping
Other

Casting and Foundry Processes
In one step raw materials are transformed
into a desirable shape
Parts require finishing processes
Excess material is recyclable

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Basic Casting Process
A mold is created – A cavity that holds the molten
material in a desired shape until it is solidified
Multiple-use mold
Single-use molds
Material is heated to a specified temperature
Molten material is poured into a mold cavity
Molten material solidifies into the shape of the cavity
Casting or mold is removed
Casting is cleaned, finished, and inspected

Forming and Metalworking Processes
Utilizes material that has been cast
Modify the shape, size, and physical
properties of the material
Hot and cold forming


Rolling – Material passes through a series of
rollers, reducing its thickness with each pass

Forging – Material is shaped by the controlled
application of force (blacksmith)

Extrusion – Material is compressed and forced
through a die to produce a uniformed cross section

Wire, rod, and tube drawing – Material is pulled
through a die to produce a uniformed cross section

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Cold forming and forging – Slugs of material
are squeezed into dies

Machining Processes
Controlled removal of material from a part to
create a specific shape or surface finish
Cutting element is used
Movement must exist between the part and
cutting element

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Machining Processes
Turning Processes
Operations that create cylindrical parts
Work piece rotates as cutting tool is fed into
the work

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©iStockphoto.com

Machining Processes
Turning Processes
Lathes and turning centers
Processes include: Straight, taper, contour
turning, facing, forming, necking, parting,
boring, threading, and knurling


Machining Processes
Milling Processes
Operations that create flat or curved
surfaces by progressively removing
material
Cutting tools rotate as the work piece is
secured and fed into the tool

Machining Processes
Milling Processes
Mills – Vertical and horizontal
Processes include: Surfacing, shaping,
forming, slotting, T-slotting, angle,
straddle, dovetailing, and slab milling

Machining Processes
Drilling Processes
Operations that create holes
Cutting tools rotate and are fed into
nonmoving secured work pieces

Machining Processes
Drilling Processes
Drilling and boring machines
Processes include: Drilling, counter drilling,
step drilling, boring, counter boring,
countersinking, reaming, spot facing, and
tapping

Machining Processes
Shearing Processes
Operations that break unwanted material away
from the part
A material is placed between a stationary and
movable surface. The movable surface (blade,
die, or punch) applies a force to the part that
shears away the unwanted material.

Machining Processes
Shearing Processes
Automated hole punch, squaring shear, and
rotary cutter
Processes include: Shearing, blanking, cutoff,
and parting; punching, perforating, and slotting;
notching, lacing, and trimming

Machining Processes
Abrasive Machining Processes
Operations in which small particles of materials
(abrasives) remove small chips of material upon
contact
Drum, disc, and belt sanders; surface, vertical
and horizontal spindle; disc grinders; media
blaster; tumblers

Machining Processes
Thermal and Chemical Processes
Operations that cut and shape materials
through chemical means
No mechanical force is used
Electrical discharge, electrochemical,
chemical, laser, electron beam, flame
cutting, and plasma-arc cutting
Processes include: Grinding, sawing,
cutting, machining, milling, blanking, and
etching

Heat Treating Processes
Controlled heating and cooling of a material to
alter its properties while maintaining its shape
Properties include: Strength, toughness,
machinability, wear resistance, and corrosion
resistance
90% of heat treating is preformed on steel
and other ferrous metals

Heat Treating Processes
To aid in the manufacturing process,
materials can be treated to be weak and
ductile and then can be re-treated to provide
high strength.
Can also occur incidentally during the
manufacturing process

Joining and Assembly Processes
Can you think of a product with only one
part?
Most products consist of multiple parts that
are assembled to form a finished product.
Typical assembly processes include:
Mechanical fastening; soldering and
brazing, welding; adhesive bonding

Mechanical Fastening
Use physical force to hold parts together
Mechanical fasteners or part design
Screws, bolts, nails, rivets, cotter pins,
retaining clips, and edge design


Welding
Operations that use heat, pressure, or
both to permanently join parts
Gas, arc, stud, spot, forge, roll laminating,
resistance, and induction welding


Adhesive bonding
Bonding of adjoining surfaces by filling the
gap between each surface with a bonding
material
Glue, cement, thermoplastic, thermosetting,
and elastomers


Soldering and Brazing
Operation in which metal surfaces are
bonded together by an alloy
Heated molten alloy flows between the
adjoining surfaces
When the heat is removed, the molten
metal solidifies and the metal surfaces are
bonded

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Rapid Prototyping
Additive process
Parts are produced directly from software
applications
Common rapid prototyping systems include:
stereolithography (SLA), selective laser
sintering (SLS), fused deposition modeling
(FDM), laminated object manufacturing
(LOM), digital light processing (DLP)

Rapid Prototyping
Finished parts can be field tested depending
upon building material
Created parts can be used to create a mold
Modifications to design can be implemented
quickly

Plastics Manufacturing Processes
Extrusion
A rotating screw forces plastic through a
heating chamber and then through a
heated die
Produces long plastic parts with uniform
cross sections

Injection Molding
Heated plastic is forced by a movable plunger
through a nozzle and then into a mold. The material
fills the mold and then is cooled.
Most widely used high-volume production process

Casting
Plastic is melted and poured into a mold –
No pressure or fillers are required.
Rotational Molding
A closed mold is filled with a
predetermined amount of plastic. The
mold is heated, rotated, and then cooled
to create a hollow plastic object with
uniform wall thickness.

Blow Molding
A solid bottom hollow tube is placed
between two mold halves and heated.
The heated tube is then expanded into
the sides of the mold with compressed
air.

Thermoforming
Plastic sheets are heated over an open
mold to a working temperature. Once
workable, a vacuum is applied to the mold,
forcing the plastic sheet to take the shape
of the mold.
Reaction Molding
Liquid reactants are mixed and then
pressurized into a mold.
No heat is needed. Curing time is typically
less than 1 minute.

Ceramic Manufacturing Processes
Two distinct classes of materials and
processes exist.
Glass is heated to a molten state, shaped
by viscous flow, and then cooled to
produce a solid.

Crystalline Ceramics
Material is shaped and then heated
to produce a permanent solid.

Manufacturing Importance

Typical product
cost breakdown

Manufacturing processes

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