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ETM 2080 > final > Flashcards

final Flashcards

1
Q

are plastics non-synthetic?

A

yes

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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

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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

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79
Q

What is Covalent?

A

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

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80
Q

What does ‘poly’ mean in Greek?

A

many

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81
Q

What does ‘meros’ mean in Greek?

A

part or unit

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82
Q

What does ‘mono’ mean in Greek?

A

one

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83
Q

What does polymer mean?

A

many units

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84
Q

What does monomer mean?

A

one unit

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85
Q

What is polymerization?

A

combining monomers into polymers

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86
Q

What are thermoplastics?

A

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

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87
Q

What are thermosets?

A

materials that become may be heated and formed one time

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88
Q

Heat reactions for thermoplastics?

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

Heat reactions for thermosets?

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

What does transparent mean?

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

What does translucent mean?

A

light passes thru but is not clear

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92
Q

What does opaque mean?

A

no light passes thru

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93
Q

crystalline vs amorphous…
Which one do chemicals attack?

A

amorphous

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94
Q

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

A

crystalline

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95
Q

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

A

high
low

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96
Q

crystalline vs amorphous…
Which one has good lubricity?

A

crystalline

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97
Q

What kind of order does amorphous have?

A

no order

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98
Q

What kind of order does crystalline have?

A

crystal-like orderly regions

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99
Q

Is Linear thermoplastic or thermoset?

A

thermoplastic

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100
Q

Is Cross-linked thermoplastic or thermoset?

A

thermoset

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101
Q

Is Branched thermoplastic or thermoset?

A

thermoplastic

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102
Q

Any branching with HDPE?

A

no

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103
Q

Any branching with MPDE/LLDPE?

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 ________.

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

no. 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?

112
Q

About how many landfills in 2007?

113
Q

What percentage of waste management is discarded?

114
Q

What percentage of waste management is combustion with energy recovery?

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?

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?

124
Q

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

125
Q

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

126
Q

______% of U.S. MSW is incinerated

127
Q

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

128
Q

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

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

134
Q

no. 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.
137
Q

What is branching?

A
  • polymerization at high temp and pressure
  • carbon-hydrogen bond breaks, and hydrogen leaves
138
Q

What is the no. 1 usage of LDPE?

139
Q

What is the no. 1 usage of HDPE?

A

blow molding

140
Q

What was the no. 1 usage of polypropylene?

A

extrusion sheet/fiber

141
Q

What is the second most used plastic?

142
Q
  • true or false?
    Polyvinyl can breathe (aka, it’s porous to oxygen).
143
Q

What is the no. 1 usage of PVC?

144
Q
  • true or false?
    Polyester has great solvent resistance.
A

false. it has poor solvent resistance.

145
Q

What is the no. 1 usage of PET?

A

blow molding

146
Q

What is the no. 1 usage of polystyrene?

147
Q

ABS is about ______% higher than the cost of polystyrene

148
Q

What is the no. 1 usage of phenolics?

A

bond plywood

149
Q
  • true or false?
    A common usage of phenolic is pool billiard balls.
A

true. balls hehe

150
Q

What is the hardest plastic?

151
Q

What is the no. 1 usage of polyurethane?

A

flexible foam

152
Q

What is the four-step process of rotational molding?

A

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

153
Q

Biaxial rotation has rotations from _____ to
_____ rpm

154
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
155
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
156
Q

How many arms do individual-arm styles have?

A

1-arm to 4-arms

157
Q

What is the lowest usage of rotationally molded plastics?

A

playground equipment (2.3%)

158
Q

What is the lowest typical plastic material used?

A

Fluorocarbons (0.1%)

159
Q

Name the five examples of molding/casting materials.

A
  • Cast Aluminum
  • Fabricated Aluminum
  • Machined Aluminum
  • Fabricated Mild Steel
  • Fabricated Stainless Steel
160
Q

What is fabricated aluminium fabricated from?

A

sheet stock

161
Q

What is cast aluminum produced from?

A

pattern (idk what this means.)

162
Q

What are monomers?

A

liquid resin thermosets

163
Q

What are modified monomers?

A

partially polymerized sort chain polymers, TP or TS

164
Q

What are powders?

A

fully polymerized thermoplastics

165
Q

What are plastisols?

A

solvent solutions of plastics

166
Q

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

A

1) Heat dip
2) Cool (cure)
3) Strip/remove

167
Q

What plastic are drill bodies commonly made out of?

168
Q

What plastic are integral hinges commonly made out of?

A

polypropylene (PP)

169
Q

What plastic are trashbags commonly made out of?

A

polyethylene (PE)

170
Q

What plastic would Boeing787s be commonly made out of?

A

carbon fiber epoxy

171
Q

What plastic are fishing lines commonly made out of?

172
Q

What % of the market does packaging take up?

173
Q

What are some advantages of thermoforming?

A

Low Machine Costs
Low Temperature
Low Mold Cost
Low Pressure
Large Parts
Fairly Fast Cycles

174
Q

What are some disadvantages of thermoforming?

A

High Raw Material $
High Scrap (trim)
Limits Part Geometry
Only One “Good” Side
Wall Thickness Variation
Internal Stresses

175
Q

What is the top material used for thermoforming?

A

polystyrene

176
Q

When thermoforming, the sheets must be thermoplastic or thermoset?

A

thermoplastic

177
Q

What are the two major issues with thermoforming?

A
  • sheet thickness
  • size limits
178
Q

What are the four forming forces in thermoforming?

A
  • mechanical (matched die forming)
  • air (pressure forming)
  • vacuum (straight vacuum forming)
  • any combination (drape, plug assist, etc.)
179
Q

What is the #1 tool in thermoforming?

180
Q

What is a straight vacuum (cavity) in thermoforming?

A

limited force, one “good side,” heat comes from the top and there are vent holes in the mold (idk man just look at the pics on the presentations)

181
Q

What is a drape (plug) in thermoforming?

A

mechanical stretch before vacuum, plastic is pressed down onto mold

182
Q

What is straight pressure in thermoforming?

A

uses high force air pressure from the top and forces the plastic down into the mold

183
Q

What is straight mechanical in thermoforming?

A

high mold cost and high force, the male mold presses the plastic into the female mold

184
Q

What is plug assist in thermoforming?

A

a plug pushes a hot sheet in a clamp frame into the mold and vacuum secures it

185
Q

Compression produces ________ molded parts.

186
Q

For a high pressure process, how much PSI of a projected area does it take?

187
Q

For compression molding, what is a positive type mold?

A

the core side presses down into the part against the cavity (no flash)

188
Q

For compression molding, what is a flash type mold?

A

the core side presses the part down into the cavity side, and excess material (or “flash”) squeezes out

189
Q

For compression molding, what are the five most common materials?

A
  • phenolic
  • melamine
  • polyester
  • epoxy
  • silicone
190
Q
  • true or false?
    Compression molding has good heat and chemical resistance.
191
Q

Extrusion is a ________ process for forming ________ materials into three products.

A

continuous
thermoplastic

192
Q

What are the three products that extrusion forming forms?

A
  • profile shapes
  • films / sheets
  • wire / cable coverings
193
Q

For extrusion, what is a die swell?

A

the flow of polymer goes into the die, it’s extrudated in the gap, and then goes between a sizing plate and a cooling tank

194
Q

A common dye to produce sheets is referred to as the __________.

A

coat hanger die

195
Q

What is blow molding?

A

plastic formation process-manufacture of bottles and hollow-shaped parts

196
Q

What is a parison?

A

a cylinder or tube

197
Q

What is parison programming?

A

the changing of parison thickness during the blow molding process

198
Q

What is machine sizing when injection molding?

A
  • 2-10 tons per square inch
  • this varies w amount of material used
199
Q

What is sprue?

A

sprue gets molded with the part and then must be trimmed off with the gate and runner afterwards

200
Q

For injection molding, what is “shot”?

A

the amount of plastic it takes to make the part and any material that is anywhere else

201
Q

For injection molding, what is a gate?

A

an opening that allows the plastic to enter the mold cavity

202
Q

For injection molding, what is a runner?

A

a channel cut into the mold that allows plastic material to flow from the nozzle to the cavity

203
Q

For injection molding, what is the feeder system?

A

directs molten plastic from the injection machine’s nozzle into the mold cavity

204
Q

For injection molding, what does the toggle clamp do?

A

opens and closes the mold

205
Q

For injection molding, what does the hydraulic clamp do?

A

uses hydraulic pressure to forcefully close the mold together

206
Q

What are flouroplastics?

A
  • polytetraflouroethylene (PTFE or TFE)
  • highly crystalline
  • low friction and low strength
  • no known solvent
207
Q

What are some examples of flouroplastics?

A
  • anti-stick coatings
  • tape
  • lubricants
  • gasket Material
  • plates, pads, bushings
208
Q

What is pultrusion?

A

manufacturing process that converts fibre reinforcements and resin matrices into finished composite parts

209
Q

What is blown film?

A

to extrude thin film, air is forced into an extruded sheet and then either pinched or cut

210
Q

For co-extrusion, how many extruders are required?

211
Q

What is potting?

A

the ‘filling in’ or encapsulating of a space with an adhesive

212
Q

What are cast acrylic sheets?

A

acrylic sheets made when acrylic liquid is pumped in between a mold of two pieces of glass and submerged in warm water

213
Q

What is dip casting?

A

the mold is heated, dipped into plastic, and then heated to fuse

214
Q

What is slush casting?

A

the hot mold is filled, the mold sets up with the material around the wall of the mold, and then excess is poured out

215
Q

What is solid casting?

A

material poured into mold (open or closed) forms to the mold (like the coasters we made in lab)

216
Q

What is rotational cast molding?

A

material poured into mold and then cooked while spinning in an oven

217
Q

What is ultrasonic welding?

A

a process that uses high-frequency sound waves to join materials together

218
Q

What is hot gas welding?

A

uses a stream of heated gas, usually air, to heat and melt both the thermoplastic substrate material and the thermoplastic welding rod

219
Q

What are adhesives?

A

substances specifically designed to bond different plastic materials together

220
Q

What are cohesives?

A

it sticks to itself readily, essentially creating a self-adhering quality without the need for additional adhesives to bond to another surface

221
Q

What are cellulosics?

A
  • acetate (CA)
  • acetate butyrate (CAB)
222
Q

Charcateristics of cellulosics?

A
  • non-petrochemical
  • very tough
  • poor solvent resistance
  • clear
223
Q

A plastic material, often formed by casting, which has better optical qualities than glass

A

Polymethyl Methacrylate (PMMA)

224
Q

Bathroom faucets plated to look like “chrome” are most likely made from…

A

polyacetal

225
Q

Coke bottles are made from what?

A

polyethylene terephthalate (PET)

226
Q

thermoplastic or thermoset?
- epoxy

227
Q

thermoplastic or thermoset?
- cellulosics

A

thermoplastic

228
Q

thermoplastic or thermoset?
- ABS

A

thermoplastic

229
Q

thermoplastic or thermoset?
- acrylic

A

thermoplastic

230
Q

thermoplastic or thermoset?
- PVC

A

thermoplastic

231
Q

thermoplastic or thermoset?
- phenolic

232
Q

thermoplastic or thermoset?
- polystyrene

A

thermoplastic

233
Q

thermoplastic or thermoset?
- PET

A

thermoplasic

234
Q

thermoplastic or thermoset?
- polyethelyene

A

thermoplastic

235
Q

thermoplastic or thermoset?
- melamine

236
Q

What material might be used in manufacturing clear police shields?

A

polycarbonate

237
Q
  • true or false?
    Mixing virgin plastic with recycled plastic could affect physical properties such as optical clarity
238
Q

While thermoforming, the plastic material is heated to its….

A

softening temperature

239
Q

The plastic materials selected for thermoforming is because of their what?

A

wide softening range

240
Q
  • true or false?
    Straight vacuum thermoforming can use either a cavity or a plug type tool.
241
Q
  • true or false?
    Straight pressure forming uses air pressure to force the sheet into the mold to help get more detail.
242
Q
  • true or false?
    Thermoforming using straight mechanical methods with a matched die uses higher force compared to a vacuum forming and has higher mold costs
243
Q

What thermoplastic would process best for thermoforming?

244
Q
  • true or false?
    Polyurethane can be foamed to be rigid or flexible and it could also have open or closed cells
245
Q
  • true or false?
    Injection molds have small vent holes so excess plastic could escape.
246
Q

Material enters the mold through the…

A

spruce bushing

247
Q
  • true or false?
    A non-returning valve is located in the front of the screw on a reciprocating screw type injection molder to prevent hydraulic oil from flowing backward in the system
248
Q
  • true or false?
    In injection molding, thermoplastic granules are plasticized by heat generated from the barrel, and frictional heat and compression of materials as the screw turns
249
Q

An injection molder commonly will utilize one of two clamping designs. Which of the following better describes the toggle type when compared to the hydraulic?

A

faster speed of motion

250
Q

What 3 things are most likely to increase flash in the injection molding process?

A
  • increase material temperature
  • increase injection pressure
  • reduce clamping pressure
251
Q

The junction between the runner system and the cavity in an injection mold is normally bridged by a ____ which increases material velocity as well as facilitates part removal from the runner system.

252
Q
  • true or false?
    In a reciprocating screw injection molding machine, the screw arguers the material into the mold using the flutes on the screw.
253
Q

Plastics are referred “Green” if they exhibit one or more of the what properties?

A
  • renewability
  • biodegradability
  • environmentally friendly processing
254
Q

Advantages of green plastics?

A
  • reduction in petroleum dependency
  • biodegradability / compostability
  • reduced use of toxic chemicals in plastics manufacturing
255
Q

Disadvantages of green plastics?

A
  • costs
  • biodegradation = green house gasses
  • contamination of recycling system
  • use of agricultural land
  • potential shelf life issue for packaging

ETM 2080 (2 decks)

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