© Goodheart-Willcox Co., Inc. Chapter 16 Manufacturing Products.

© Goodheart-Willcox Co., Inc.

Chapter 16

Manufacturing Products


Learning Objectives

• List the basic steps involved with casting and molding.

• Identify methods used in casting and molding processes.

• Name safety rules involved with casting processes.

• Identify the basic concepts of forming actions.• Name the types of separating processes.• Identify methods used in separating processes.


Learning Objectives

• Name safety rules involved with using machine tools.

• List the three types of conditioning processes.• Identify methods used in conditioning

processes.• Identify methods used in assembling

processes.• Identify methods used in finishing processes.• Name safety rules involved in finishing

processes.


Secondary Manufacturing Processes

• Six groups: – casting and molding– forming– Separating– conditioning– assembling– finishing.


Casting and Molding


Producing a Mold

• Two types of molds:– Expendable molds are made in two steps: a

pattern slightly larger than the product is made and then, is surrounded with an inexpensive material and dried.

– Permanent molds are often made from steel, aluminum, or plaster and are used for die casting, injection molding, and slip casting.


Preparing the Material

• Three types of liquids are used in casting processes:– Solutions– Suspensions are mixtures in which the

particles will settle out, like slip.– Molten materials are solids in hot, liquid

states.


Introducing the Material

• expendable molding processes use gravity to fill the mold.

• Permanent molds, use force to fill the mold.

• Die casting with metals and injection molding (shown to the right) are very similar processes.


Solidifying the Material

• Once the liquid material is introduced into the mold cavity, it must become a solid through one of three ways:– Cooling: sending cool water through the

mold or actually freezing the product.– Drying is used in slip casting.– Chemical action, like polymerization,

allows liquid plastic to change into a solid.


Extracting the Product

• Expendable molds are destroyed to remove the product.

• Permanent molds are designed to easily eject the product after it is solidified.(Stahl)


Forming Processes

• Forming processes.• All materials have an

elastic range, which, includes a yield point.

• A material’s plastic range goes to the fracture point of the object.


Forming Devices

• Two forming devices are used to ensure a consistent shape is attained during forming:– Dies.– Rolls.

• Smooth and shaped rolls are used to make curved shapes from sheets, shapes of metal, piping, tubing, and corrugated metal.


Dies

• Dies can be used to form anything that is softer than they are.

• Dies depend on pressure to actually shape the material.


Material Temperature

• All materials have a temperature at which their properties change.

• The internal structure of any material changes when heated.


Separating Processes- remove excess

material by machining or shearing.

• machining methods:– Chip removal.– Flame cutting.– Nontraditional machining.


Chip Removal Machines

• Chip removal machines are based on their cutting motion and feed motion:– Milling machines like table saws and routers.– Drilling machines like the drill press.– Turning machines like wood and metal lathes.– Shaping machines like metal-working shapers

and hacksaws.– Planing machines like metal shapers and

planers.


Flame Cutting

• Flame cutting is used to melt away excess metal on workpieces.

• The fuel gas is either acetylene or natural gas.


Nontraditional Machining

• Three common nontraditional processes:– Electrical discharge machining (EDM) is used

to create cavities on metals.– Laser machining uses intense light to melt

material.– Chemical machining uses chemical reactions to

remove excess.


Shearing- The second group of separating processes

• Shearing can be used to:– cut material to length – produce an external shape – generate an internal feature


Conditioning Processes• The three types: mechanical, chemical, and thermal

conditioning.• Mechanical conditioning works on the principle that most

metals become harder when squeezed, stretched, pounded, or bent.

• Chemical conditioning can be used to make glass more shatterproof or even change fiberglass resins.

• Thermal Conditioning– most common conditioning processes– Include heat treating, firing, and drying.

• Hardening, annealing, and tempering is used on metals

• Firing: is used on ceramics.• Drying: is used for both ceramics and wood materials.


Assembling Processes• Brings parts together through:

– Bonding-uses cohesive or adhesive forces to hold parts together.

• Cohesive forces hold molecules of one material together• Adhesive forces occur between different kinds of molecules.

Bonding Agents:• The same material—steel melted together or steel welding rod used to strengthen

the bond.• Similar material—metal (solder) bonds metallic parts.• Different material—white glue holds wood together.

– Mechanical fastening - uses friction and seams to join parts.

Mechanical Fasteners:• Permanent fasteners - nails, rivets, wood screws.• Semi-permanent fasteners- Bolts, nuts• Temporary fastener - wing nut


Types of Joints

• Joints can occur at the ends, sides, and faces.

• They are used to add length, width, or thickness and to make corners.


Finishing Processes - Finishing

processes involve cleaning the surface, selecting the finish, and applying the finish.

• Two types: – A group to change the surface of the product.

• A converted surface finish is applied to some metals to prevent rapid corrosion.

– A group that applies a coating.• Films are applied to products to protect the surface and

add color, as well.


Selecting the Finish

• Either inorganic or organic.

• Metal and ceramic coatings are mostly inorganic.

• Paints, varnish, enamels, and lacquers are organic finishes.


Applying the Finish

• Metallic coatings are often applied through dipping or plating.

• Organic materials can be applied through brushing, rolling, spraying, flow coating, and dip coating.


Automating and Controlling Processes

• New machines can load materials, adjust tool feeds and speeds, and do many other tasks humans once did.

• These machines make up systems called automation.

• Automation includes robots, programmable logic controllers (PLCs), computer-controlled machines, and artificial intelligence (AI) systems.


Automation Parts• Industrial robots are

commonly used for welding, painting, assembling, moving materials and parts, and inspecting products.

• Programmable logic controllers (PLCs) have three basic functions: input, control, and output, all programmed by a technician.


Automation Parts

• Computer-controlled machining uses computer numerical control (CNC) to produce automatic, precise motion of a machine’s tools or the material being processed.

• Artificial intelligence (AI) uses digital cameras or sensors for automatically controlling various tasks.


Review

What are the five basic steps followed when casting and molding?

Producing a mold, preparing the material, introducing the material to the mold, solidifying the material, and extracting the product from the mold.


Review

What two general kinds of molds are made?

Expendable and permanent molds.


Review

What four things are to be considered when forming a product?

The yield point, elastic range, plastic range, and fracture point of the material being formed.


Review

What are the two major separating processes?

Machining and shearing.


Review

Name three safety rules to be obeyed when using machine tools.

Wear eye protection, wear hearing protection when loud or high-pitched noises are present, and do not talk to anyone while running a machine.


Review

What are some types of machining used in the separation processes?

Chip removal, flame cutting, and non-traditional machining.


Review

What are the three types of conditioning processes?

Mechanical, chemical, and thermal conditioning.


Review

What do some thermal conditioning processes include?

Hardening, annealing, and tempering.


Review

What are the two assembling processes?Bonding and mechanical fastening.


Review

What two groups can finishing processes be separated into?

Changing the surface of the product and applying a coating.


Review

List three safety rules considered during finishing processes.

Wear eye and face protection and protective clothing, use a spray booth to

remove toxic fumes, and never apply a finish near an open flame.

© Goodheart-Willcox Co., Inc. Chapter 16 Manufacturing Products.

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Transcript of © Goodheart-Willcox Co., Inc. Chapter 16 Manufacturing Products.