HL DT - Topic 4 (part 2)

Forms of Composites

• sheet

• particle

• fiber

• matrix

Matrix

the material that surrounds and binds together the reinforcement materials in a composite

Pultrusion

a manufacturing process where reinforcing fibers are saturated with resin and pulled through a heated die

Lamination

the process of manufacturing materials in multiple layers (eg. applying thin layers of plywood in a mould to create a desired shape)

Engineered Wood

composite materials made from strands, particles, or veneers of wood (eg. MDF, particle/chipboard, plywood, laminated veneer timber/LVL)

MDF (Medium Density Fiberboard)

a type of engineered wood made from wood fibers and resin

Kevlar

a composite that can be woven into fabric or combined with resin, and it has a high-strength to weight ratio

Fiberglass

a composite material made from glass fibers encased in resin, good strength to weight ratio

Batch Production

manufacturing set quantities of products at one time, allowing for some customer choice

Mass Production

the manufacturing of large quantities of standardized products on the production line

Mass Customization

manufacturing products to individual consumer orders but on a large scale

Additive Techniques

manufacturing processes that add material to create a product (eg. laminated object manufacturing, stereolithography, 3D printing/fused deposition modelling)

Subtractive Techniques

manufacturing that removes material to create a product (laser cutting, sawing, drilling, boring, planing, CNC router, CNC milling machine, metal/wood lathe, sanding, filling)

CNC (Computer Numerical Control)

manufacturing using computer controlled machine tools (moves in XYZ movements)

Design for Manufacture

designing products to optimize the manufacturing process and capabilities

Moulding/Spray-Up

an open mould where both resin and reinforcements are sprayed directly onto the mould

Particle Board

wood chips or sawdust encased in resin (used for cheap flatpack furniture)

LVL vs Plywood

plywood has gain at 90 degrees, LVL does not

Composite Advantages

• high strength to weight ratio

• high tensile strength

• stronger than initial components

• corrosion and chemical resistant

Composite Disadvantages

• expensive

• special manufacturing required

• weak in compression

• air bubbles in matrix can cause weak spots

• cannot be recycled

One-Off Production

only one individual specialized product is produced

One-Off Production Advantages

• unique

• high quality

• workers are motivated

One-Off Production Disadvantages

• labor intensive

• prices are higher

• production take sa long time

• no EOS

Batch Production Advantages

• unit costs are lower

• some consumer choice

• can achieve EOS

• easy to adjust to market demand

• good for small companies

Batch Production Disadvantages

• goods have to be stored

• down time in production when retooling

Mass Production Advantages

• minimal labor costs

• can achiever EOS

• huge quantity produces

• production line is running 24/7

Batch Production Disadvantages

• machinery is expensive

• production stops for repairs

Mass Customization Advantages

• minimal labor costs

• customer can choose colors/style/appearance

• high quality products

• efficient production

Mass Customization Disadvantages

• machinery is expensive

• not as quick as mass production

• production stops when repairs are made

Shaping Techniques (moulding)

injection, extrusion

Shaping Techniques (thermoforming)

vacuum forming, stripheater, line bending, convection oven

Shaping Techniques (casting)

sand, die

Shaping Techniques (yarn)

knitting, weaving, felting, lacemaking

Joining Techniques (permanent)

welding, fusing, brazing, soldering, pop riveting, cold rivets

Joining Techniques (temporary)

screws, rivets, bolts, pins, clips, nails, gluing

Strip Heater

heats only a narrow strip of acrylic to allow local bending

Oven Heating

complex acrylic shaping requires an oven for heating to at least 150ºC

Pop Riveting

a pop rivet pin is pulled through the rivet and is deformed slightly, joining the pieces

Cold Rivet

the rivet is placed through the holes and hammered to create a joint

Craft Production

small scale production focused on manual skills

Craft Production Advantages

• locally based

• high valued products

• customizable products

• flexible

• higher status

Craft Production Disadvantages

• high costs

• no EOS

• lots of time/effort

• slow production

Mechanized Production

process involving machines controlled by humans

Mechanized Production Advantages

• achieve EOS

• fewer human errors

• repetitive tasks are done by machines

• less time to produce goods

Mechanized Production Disdvantages

• work conditions are poor

• repetitive strain injuries

• high cost of machinery and training

• minimal consumer choice

• low job satisfaction

• pollution

Automated Production Advantages

• eliminates human error

• build in quality control

• minimizes waste

• consistent output

• reduction of labor costs

• EOS

• adaptable systems

• machines work 24/7

Automated Production

process involving machines controlled by computers

Automated Production Disadvantages

• high capital cost

• training costs

• machines take human jobs, causing unemployment

Assembly Line Production

products are moved continuously along a conveyor and components are added at each work station

4 Types of Design for Manufacture

• design for materials

• design for process

• design for assembly

• design for disassembly

Ways to Design for Manufacture

• reduce number of parts

• develop modular design (reduces number of different manufacturing activities)

• use standardized components

• design parts for multi-use (used in different products)

• design parts to be multi-functionsl (need fewer parts)

• design for ease of fabrication

• avoid separate fasteners

• assemble in one direction (eg. add parts from above)

• minimize handling

Single Task Robot

a robot who performs one task within a work envelope

First Generation Robot

simple mechanical arm with the ability to make precise motion at high speed (requires human supervision)

Second Generation Robot

robots equipped with sensors that provide information about surroundings (does not require total human supervision)

Machine to Machine Robot (M2M)

a team of robots that communicate between each other

Third Generation Robots

autonomous robots that can operate without any human supervision

Robot Advantages

• improve health and safety

• high accuracy

• reduced waste and errors

• perform repetitive and dangerous tasks

• work 24/7

• programmable and flexible

Robot Disadvantages

• experts needed to operate robots

• high capital cost

• training required for operation and maintenance