midterm Flashcards

1
Q

What is NOT TRUE of plastics?

A

they are non-synthetic

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2
Q

Small molecules from which plastics are made are called _____.

A

monomers

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3
Q

The process by which the above molecules are combined is called _____.

A

polymerization

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4
Q
  • true or false?
    A crystalline polymer structure has crystal like (orderly) regions that when heated become amorphous.
A

true

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5
Q
  • true or false?
    Van der Waals forces are more electrical in nature and weaker than chemical (atomic) covalent bonds.
A

true

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6
Q

What molecular structure best describes a thermoset?

A

cross linked

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7
Q

Formation of side chains of the basic polymer backbone is ____________.

A

branching

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8
Q
  • true or false?
    Amorphous polymer structure materials have a sharp melting point.
A

false

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9
Q

In typical plastic product costs, about 75% of cost is attributed to…

A

material

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10
Q

What are the advantages of using plastic?

A
  • relatively less energy to process
  • good strength to weight ratio
  • electrical insulation
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11
Q
  • true or false?
    Generally plastic grocery bags are heavier than paper for a given capacity
A

false

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12
Q

The EPA suggests four methods to deal with solid waste. Which is the least desirable?

A

landfill

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13
Q

______ is the most used method of disposing of municipal solid waste in America today.

A

landfilling

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14
Q

Which of the following has the highest BTU content (potential heat energy)?

A

High Density Polyethylene (HDPE)

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15
Q
  • true or false?
    Properly designed landfills act as a compost pit allowing biodegradable materials to return to their natural state.
A

false

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16
Q
  • true or false?
    According to the EPA, plastics account for the biggest portion of Municipal Solid Waste by weight in the landfill
A

false

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17
Q
  • true or false?
    Thermoset plastics can easily be heated and reformed into a new shape.
A

false

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18
Q
  • true or false?
    Epoxy adhesives are an example of a thermoset material.
A

true

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19
Q

Which plastics ARE considered to be in the polyfin family?

A

Polyethylene
Polypropylene

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20
Q

This high impact polymer is often used for appliance housings and helmets.

A

Acrylonitrile Butadiene Styrene (ABS)

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21
Q

This “slippery” material (low coefficient of friction) is often used for gears and fibers, but one drawback of this material is its high water absorption rate.

A

nylon

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22
Q

This is by far the most used plastic material.

A

polyethylene

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23
Q

This polyolefin material is often used in applications of “living” or integral hinges.

A

Polypropylene

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24
Q

Often “foamed” for insulation and packaging, this material is also transparent.

A

polystyrene

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25
Q

Siding, gutters, wire coating, and hoses are common uses of this material.

A

Polyvinyl Chloride (PVC)

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26
Q

A plastic surgeon may select this material to reshape your nose.

A

silicone

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27
Q

The billiard balls and the handle on your fry pan are likely to be made of this material.

A

phenolic

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28
Q

A unique thermoplastic, having extremely high heat resistance and a low coefficient of friction, originally used to coat frying pans is:

A

Polytetrafluoroethylene (PTFE)

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29
Q
  • true or false?
    Casting processes produce parts with little to no built in stress.
A

true

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30
Q
  • true or false?
    Casting is a good process to make varying shapes such as Sheets, Tubes, Rods, Tooling, Foams and other objects.
A

true

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31
Q
  • true or false?
    One difference between a casting process and a molding process could be the amount of force that is applied to the material.
A

true

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32
Q

Casting is considered a low cost method to produce low volume parts because…

A
  • molds can be very inexpensive
  • low volume production economy
  • thermosets can be cast
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33
Q

In rotational molding, thermoplastic powder material joins together because it is…

A

self-fusing

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34
Q

Even distribution of the material to the mold surface in rotational casting is accomplished by using a…

A

biaxial rotation

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35
Q
  • true or false?
    Cast acrylic sheet can be produced by casting between panes of glass.
A

true

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36
Q

Which of the following casting processes would be used to produce a hollow coin bank with a detailed exterior surface?

A

slush casting

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37
Q

What is an advantage of rotational molding?

A

size range of parts

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38
Q

Which state has the highest rotomolding plants?

A

!! OHIO !!

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39
Q

Rotational Molding can use which of the following form of materials?

A

powder
liquids
pellets

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40
Q

The most used material in rotational molding is…

A

polyethylene

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41
Q

What mold material is often used for rotational molding?

A

aluminum

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42
Q

The Industrial breakdown of Rotational Molding shows that the largest percentage of products are…

A

toys

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43
Q
  • true or false?
    The PVC Welding we did in the lab creates a cohesive bond of the material
A

true apparently

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44
Q
  • true or false?
    The PVC welding process we performed in the lab utilized a filler rod of PVC
A

true

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45
Q
  • true or false?
    You should wear safety glasses while in the plastics lab
A

true

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46
Q

Wear what gloves when fiber glassing?

A

latex

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47
Q

The plastics is industry the _______ largest manufacturing industry in the United States, providing significantly to the nation’s economy.

A

third

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48
Q

The U.S. plastics industry employs more than ______ million workers.

A

1.1

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49
Q

The U.S. plastics industry creates $______ in annual shipments.

A

$279 billion

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50
Q

There are nearly ______ plastics facilities in the United States.

A

18,500

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51
Q

Since 1980, U.S. plastics industry shipments have grown _______ percent per year.

A

3.4

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52
Q

Over the past _____ years, productivity in plastics
manufacturing has grown _____ percent per year, which is faster than productivity growth for manufacturuing as a whole.

A

26
2.3

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53
Q

No.1 state for plastics employment?

A

California

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54
Q

No.2 state for plastics employment?

A

Ohio

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55
Q

LOWEST typical plastics product costs?

A

space (1%)

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56
Q

What are the FOUR main characteristics or plastics?

A
  • typically organic
  • typically hydrocarbon
  • synthetic (manmade)
  • capable of being formed by heat and/or pressure
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57
Q

Who invented the first thermoplastic and when?

A

John Hyatt in 1868

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58
Q

What was the first thermoplastic?

A

Cellulose Nitrate (Celluloid)

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59
Q

Today, most paint & glues are _______.

A

plastics

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60
Q

What is stress?

A

amount of effort/force applied per unit area

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61
Q

What is strain?

A

deformation (change in length) to original length

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62
Q

What is tensile strength?

A

ability to withstand stress in tension

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63
Q

What is elasticity?

A

ability to return to original length

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64
Q

What is plastic?

A

pliable/deformed

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65
Q

What is the yield point?

A

stress at which deformation starts plastically

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66
Q

What is the modulus of elasticity?
(also called Young’s Modulus)

A

ratio of stress to strain

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67
Q

What is compressive strength?

A

ability to withstand squeezing/pressing

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68
Q

What is fatigue strength?

A

ability to withstand cyclic loading

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69
Q

What is impact resistance or toughness?

A

ability to absorb impact/shocks

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70
Q

What is flow/creep?

A

deformation upon prolonged load

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71
Q

What is shear strength?

A

separating by tearing

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72
Q

What is ductility?

A

ability to bend stretch or distort without failure

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73
Q

What is hardness?

A

ability to resist scratch or dent

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74
Q

All ______ compounds are covalent bonded.

A

organic

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75
Q

Oxygen needs ______ electrons.

A

two

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76
Q

Van der Waals have the ______ bond strength.

A

weakest

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77
Q

What is Metallic?

A

delocalized sharing of free electrons between a lattice of metal atoms

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78
Q

What is Ionic?

A

opposite charged ions attract
(moderate strength)

79
Q

What is Covalent?

A

gain or share electrons non metals and common in plastics
(strong strength)

80
Q

What does ‘poly’ mean in Greek?

A

many

81
Q

What does ‘meros’ mean in Greek?

A

part or unit

82
Q

What does ‘mono’ mean in Greek?

A

one

83
Q

What does polymer mean?

A

many units

84
Q

What does monomer mean?

A

one unit

85
Q

What is polymerization?

A

combining monomers into polymers

86
Q

What are thermoplastics?

A

materials that become soft when heated and
solid when cooled to room temperature (can be repeated many times)

87
Q

What are thermosets?

A

materials that become may be heated and formed one time

88
Q

Heat reactions for thermoplastics?

A
  • similar to candle wax
  • can be heated and softened many times
89
Q

Heat reactions for thermosets?

A
  • similar to concrete
  • cannot be re-softened
  • chemically cures once
90
Q

What does transparent mean?

A
  • light passes thru clearly
  • may be colored
91
Q

What does translucent mean?

A

light passes thru but is not clear

92
Q

What does opaque mean?

A

no light passes thru

93
Q

crystalline vs amorphous…
Which one do chemicals attack?

A

amorphous

94
Q

crystalline vs amorphous…
Which one has a sharp melting point?

A

crystalline

95
Q

Crystalline has a ______ shrink rate, while amorphous has a ______ shrink rate.

A

high
low

96
Q

crystalline vs amorphous…
Which one has good lubricity?

A

crystalline

97
Q

What kind of order does amorphous have?

A

no order

98
Q

What kind of order does crystalline have?

A

crystal-like orderly regions

99
Q

Is Linear thermoplastic or thermoset?

A

thermoplastic

100
Q

Is Cross-linked thermoplastic or thermoset?

A

thermoset

101
Q

Is Branched thermoplastic or thermoset?

A

thermoplastic

102
Q

Any branching with HDPE?

A

no

103
Q

Any branching with MPDE/LLDPE?

A

slight

104
Q

Any branching with LDPE?

A

long branches

105
Q

As density increases, so does ________, ________, & ________.

A

melt temperature
viscosity
strength

106
Q

Heating/melting does not break covalent bonds, but ________.

A

weakens

107
Q

When heat is removed, molecules
________.

A

remain in place

108
Q

What is MSW?

A

municipal solid waste
(trash or garbage)

109
Q

1 material in MSW?

A

paper and paperboard (32.7%)

110
Q

Lowest waste management in America?
(landfill vs incinerate vs recycle)

A

recycle (13%)

111
Q

About how many landfills in 1988?

A

8000

112
Q

About how many landfills in 2007?

A

1700

113
Q

What percentage of waste management is discarded?

A

54%

114
Q

What percentage of waste management is combustion with energy recovery?

A

12.6%

115
Q

What is the EPA Hierarchy for integrated solid waste management?

A

1) Source Reduction
2) Recycling
3) W-T-E Incineration
4) Landfilling

116
Q

Three focuses of Source Reduction?

A
  • Material Replacement Creating Less Waste
  • Materials Engineering Using Less material
  • Recycling At The Source
117
Q

For the Plastics Coding System, what is 1?

A

polyethylene terephthalate (PET/PETE)

118
Q

For the Plastics Coding System, what is 2?

A

high density polyethylene (HDPE)

119
Q

For the Plastics Coding System, what is 3?

A

vinyl

120
Q

For the Plastics Coding System, what is 4?

A

low density polyethylene (LDPE)

121
Q

For the Plastics Coding System, what is 5?

A

polypropylene (PP)

122
Q

For the Plastics Coding System, what is 6?

A

polystyrene (PS)

123
Q

For the Plastics Coding System, what is 7?

A

other

124
Q

For recycled Coke bottles, what is the highest RPET Product Category?

A

fiber

125
Q

W-T-E Incineration reduces MSW volume by ______%

A

80-90

126
Q

______% of U.S. MSW is incinerated

A

15

127
Q

High energy content in plastics allow “______” to be burned.

A

wet waste

128
Q

Heat can produce steam to produce electricity. This can save over ______ million barrels of
oil per year.

A

30

129
Q

What has the lowest BTU content (potential heat energy)?

A

food waste (2600 btu/lb.)

130
Q

What is the average BTU content for MSW?

A

4500 btu/lb.

131
Q

What is the #1 item in landfills?

A

paper (35%)

132
Q

What item has the lowest volume in landfills?

A

glass (2%)

133
Q

Plastics account for ______% of Natural Gas and
______% of Petroleum Consumption per year

A

7
2

134
Q

1 Natural Gas and Petroleum Consumer?

A

transportation (62%)

135
Q

What is the the myth regarding
biodegradability?

A

Properly designed landfills block out sunlight, moisture, and air which are necessary for biodegradation.

136
Q
  • true or false?
    The Plastics Packaging Industry voluntarily stopped using fully-halogenated CFCs in 1988.
A

true

137
Q

What is branching?

A
  • Polymerization at high temp and pressure.
  • Carbon-Hydrogen bond breaks, and hydrogen
    leaves
  • Carbon’s free radical serve as place for new
    chain growth
138
Q

What is the no. 1 usage of LDPE?

A

film

139
Q

What is the lowest usage of LDPE?

A

rotomold

140
Q

What is the no. 1 usage of HDPE?

A

blow molding

141
Q

What is the lowest usage of HDPE?

A

export

142
Q

What was the no. 1 usage of polypropylene?

A

extrusion sheet/fiber

143
Q

What is the lowest usage of polypropylene?

A

blow molding

144
Q

What is the second most used plastic?

A

polyvinyl

145
Q
  • true or false?
    Polyvinyl can breath (aka porous to oxygen)
A

true

146
Q

What is the no. 1 usage of PVC?

A

extrusion

147
Q

What is the lowest usage of PVC?

A

injection

148
Q
  • true or false?
    Polyester has great solvent resistance.
A

false. it has poor solvent resistance.

149
Q

What is the no. 1 usage of PET?

A

blow molding

150
Q

What is the lowest usage of PET?

A

sheeting

151
Q

What is the no. 1 usage of polystyrene?

A

extrusion

152
Q

What is the lowest usage of polystyrene?

A

export

153
Q

ABS is about ______% higher than the cost of polystyrene

A

20%

154
Q

What are some key properties of polyamides (nylon)?

A

Crystalline
High Impact Strength
Chemical Resistance
Low Friction Coefficient
Abrasion Resistance
Hygroscopic
High Shrinkage

155
Q

What are some key properties of ABS?

A
  • Opaque
  • Impact Resistant
  • Chemical Resistant
  • Heat Resistant
  • Easy To Fabricate
  • Poor Solvent Resist
  • Platable
156
Q

What are some key properties of polystyrene?

A
  • Inexpensive
  • Hard / Rigid – Low
  • Impact Strength
  • Transparent
  • Easily Molded
  • Easily Fabricated
  • Easily Foamed
  • Poor Chemical Resist.
157
Q

What are some key properties of polyester?

A
  • Low Gas Permeability
  • Toughness
  • Rigidity
  • Poor Solvent Resistance
  • Crystalline but can be clear through Orientation & Co-Polymerization
158
Q

What are some key properties of polyvinyls?

A
  • Easily Fabricated
  • Transparent
  • Good Weatherabilty
  • Easy To Process
  • Easy To Foam
  • Some Solvent Attack
  • Self Extinguishing
159
Q

What are some key properties of polypropylene?

A
  • Crystalline
  • Higher Service Range
  • Harder, More Rigid
  • More Resistant To Stress Cracking
  • High Melting Point than PE (except UHMWPE)
160
Q

What are some key properties of acrylics (PMMA)?

A
  • Optical Clarity
  • U. V. Resistant
  • Easy Fabrication
  • High Gloss
  • Poor Solvent Resist.
  • Rigid / Inflexible
  • Super Glue- Ethyl Cyano acrylite
161
Q

What are some key properties of polycarbonates (PC)?

A
  • High Impact Strength
  • Transparent
  • Service: -275 to +270
  • High Processing Temps: 550+
  • Self Extinguishing
  • Solvent Sensitive/UV sensitive
  • Moisture / Process Problem
162
Q

What are some key properties of acetal?

A
  • Crystalline
  • Stiff and Tough
  • Chemical Resistance
  • Low Coeff. Of Friction
  • Platable
163
Q

What are some key properties of fluroplastics (PTFE or TFE)?

A
  • Antistick Coatings
  • Tape
  • Lubricants
  • Gasket Material
  • Plates, Pads. Bushings
164
Q

What are some key properties of cellulosics (CA and CAB)?

A
  • Easily Fabricated
  • Non-petrochemical
  • Permeable to oxygen-fruits packaging
  • Very tough
  • Good Weatherability
  • Poor Solvent Resist
  • Clear
165
Q

What are thermosetting plastics and their properties?

A
  • Phenolics
  • Urea / Melamine
  • Polyurethane
  • Polyesters
  • Epoxies
  • Silicones
166
Q

What are some key properties of phenolics?

A
  • Service to 400 F
  • Rigidity
  • Chemical Resistance
  • High Compression Strength
  • Too Dark In Color
167
Q

What is the no. 1 usage of phenolics?

A

bond plywood

168
Q

What is the lowest usage of phenolics?

A

moldings

169
Q
  • true or false?
    A common usage of phenolic is pool billiard balls.
A

true. balls hehe

170
Q

What are some key properties of urea/melamine?

A
  • Service to 400 F
  • Rigidity
  • Chemical Resistance
  • Stain Resistant
  • High Compression Strength
171
Q

What is the hardest plastic?

A

melamine

172
Q

What are some key properties of polyurethane?

A
  • Flexible – Elastomer
  • Puncture Resistant
  • Abrasion Resistant
  • Ozone Resistant
  • Oil Resistant
  • Toxic (isocyanate)
  • Foam
173
Q

What is the no. 1 usage of polyurethane?

A

flexible foam

174
Q

What is the lowest usage of polyurethane?

A

RIM

175
Q

What are some key characteristics of unsaturated polyesters?

A
  • Very Strong with Reinforcement
  • Water Extendable
  • Processing Variety
  • Can Be Used As Own Tooling
176
Q

What are some key properties of epoxy?

A
  • Strength with Reinforcement
  • Low Shrinkage
  • Service To 600 F.
  • Excellent Adhesion
  • Toxic (isocyanate)
  • Sensitizer
177
Q

What are key properties of silicones?

A
  • Flexibility
  • Service -100 to +600 F
  • Chemical Resistant
  • Low Water Absorption
178
Q

What are key properties of kevlar?

A
  • Extreme Tensile Strength
  • Light Weight 50% of Glass
  • Flexibility
  • Difficult to Cut
179
Q

What is the four-step process of rotational molding?

A

1) Load Material
2) Heating Phase
3) Cooling Phase
4) Unload Product

180
Q

Biaxial rotation has rotations from _____ to
_____ rpm

A

7 to 20

181
Q

Name some advantages of rotational molding.

A
  • Seamless hollow parts
  • Size Range of parts
  • Multiple & varied parts
  • Nearly stress-free parts
  • Complexity of shapes
  • Inexpensive tooling
  • Consolidation of parts
  • Decorating possibilities
  • Time to market
182
Q

Name some DISadvantages of rotational molding.

A
  • Single sided surface detail
  • Wall thickness variation
  • Long heat cycles
  • Mold & material must be cooled
  • Limited materials
  • self fusing
  • Material prep cost (pulverizing)
  • Shrinkage = warp, twist, dimensional problems
183
Q

How many arms do individual-arm style?

A

1-arm to 4-arms

184
Q

What is the lowest usage of rotationally molded plastics?

A

playground equipment (2.3%)

185
Q

What is the lowest typical plastic material used?

A

Fluorocarbons (0.1%)

186
Q

Name the five examples of

A
  • Cast Aluminum
  • Fabricated Aluminum
  • Machined Aluminum
  • Fabricated Mild Steel
  • Fabricated Stainless Steel
187
Q

What is fabricated aluminium fabricated from?

A

sheet stock

188
Q

What is cast aluminum produced from?

A

pattern (idk what this means.)

189
Q

What are monomers?

A

liquid resin thermosets

190
Q

What are modified monomers?

A

partially polymerized sort chain polymers, TP or TS

191
Q

What are powders?

A

fully polymerized thermoplastics

192
Q

What are plastisols?

A

solvent solutions of plastics

193
Q

What are ways to dip-cast? (i actually dont totally know what im asking here)

A

Heat Dip / Cool (cure) / Strip

194
Q
  • true or false?
    I am ready for this midterm.
A

false