1
Q
are plastics non-synthetic?
A
yes
2
Q
Small molecules from which plastics are made are called _____.
A
monomers
3
Q
The process by which the above molecules are combined is called _____.
A
polymerization
4
Q
- true or false?
A crystalline polymer structure has crystal like (orderly) regions that when heated become amorphous.
A
true
5
Q
- true or false?
Van der Waals forces are more electrical in nature and weaker than chemical (atomic) covalent bonds.
A
true
6
Q
What molecular structure best describes a thermoset?
A
cross linked
7
Q
Formation of side chains of the basic polymer backbone is ____________.
A
branching
8
Q
- true or false?
Amorphous polymer structure materials have a sharp melting point.
A
false
9
Q
In typical plastic product costs, about 75% of cost is attributed to…
A
material
10
Q
What are the advantages of using plastic?
A
- relatively less energy to process
- good strength to weight ratio
- electrical insulation
11
Q
- true or false?
Generally plastic grocery bags are heavier than paper for a given capacity
A
false
12
Q
The EPA suggests four methods to deal with solid waste. Which is the least desirable?
A
landfill
13
Q
______ is the most used method of disposing of municipal solid waste in America today.
A
landfilling
14
Q
Which of the following has the highest BTU content (potential heat energy)?
A
High Density Polyethylene (HDPE)
15
Q
- true or false?
Properly designed landfills act as a compost pit allowing biodegradable materials to return to their natural state.
A
false
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
17
Q
- true or false?
Thermoset plastics can easily be heated and reformed into a new shape.
A
false
18
Q
- true or false?
Epoxy adhesives are an example of a thermoset material.
A
true
19
Q
Which plastics ARE considered to be in the polyfin family?
A
Polyethylene
Polypropylene
20
Q
This high impact polymer is often used for appliance housings and helmets.
A
Acrylonitrile Butadiene Styrene (ABS)
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
22
Q
This is by far the most used plastic material.
A
polyethylene
23
Q
This polyolefin material is often used in applications of “living” or integral hinges.
A
Polypropylene
24
Q
Often “foamed” for insulation and packaging, this material is also transparent.
A
polystyrene
25
Siding, gutters, wire coating, and hoses are common uses of this material.
Polyvinyl Chloride (PVC)
26
A plastic surgeon may select this material to reshape your nose.
silicone
27
The billiard balls and the handle on your fry pan are likely to be made of this material.
phenolic
28
A unique thermoplastic, having extremely high heat resistance and a low coefficient of friction, originally used to coat frying pans is…
Polytetrafluoroethylene (PTFE)
29
- true or false?
Casting processes produce parts with little to no built in stress.
true
30
- true or false?
Casting is a good process to make varying shapes such as Sheets, Tubes, Rods, Tooling, Foams and other objects.
true
31
- 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.
true
32
Casting is considered a low cost method to produce low volume parts because...
- molds can be very inexpensive
- low volume production economy
- thermosets can be cast
33
In rotational molding, thermoplastic powder material joins together because it is...
self-fusing
34
Even distribution of the material to the mold surface in rotational casting is accomplished by using a...
biaxial rotation
35
- true or false?
Cast acrylic sheet can be produced by casting between panes of glass.
true
36
Which of the following casting processes would be used to produce a hollow coin bank with a detailed exterior surface?
slush casting
37
What is an advantage of rotational molding?
size range of parts
38
Which state has the highest rotomolding plants?
!! OHIO !!
39
Rotational Molding can use which of the following form of materials?
powder
liquids
pellets
40
The most used material in rotational molding is...
polyethylene
41
What mold material is often used for rotational molding?
aluminum
42
The Industrial breakdown of Rotational Molding shows that the largest percentage of products are...
toys
43
- true or false?
The PVC Welding we did in the lab creates a cohesive bond of the material
true
44
- true or false?
The PVC welding process we performed in the lab utilized a filler rod of PVC
true
45
- true or false?
You should wear safety glasses while in the plastics lab
true
46
Wear what gloves when fiber glassing?
latex
47
The plastics is industry the _______ largest manufacturing industry in the United States, providing significantly to the nation's economy.
third
48
The U.S. plastics industry employs more than ______ million workers.
1.1
49
The U.S. plastics industry creates $______ in annual shipments.
$279 billion
50
There are nearly ______ plastics facilities in the United States.
18,500
51
Since 1980, U.S. plastics industry shipments have grown _______ percent per year.
3.4%
52
Over the past _____ years, productivity in plastics manufacturing has grown _____ percent per year, which is faster than productivity growth for manufacturuing as a whole.
26
2.3%
53
No.1 state for plastics employment?
California
54
No.2 state for plastics employment?
Ohio
55
LOWEST typical plastics product costs?
space (1%)
56
What are the FOUR main characteristics or plastics?
- typically organic
- typically hydrocarbon
- synthetic (manmade)
- capable of being formed by heat and/or pressure
57
Who invented the first thermoplastic and when?
John Hyatt in 1868
58
What was the first thermoplastic?
Cellulose Nitrate (Celluloid)
59
Today, most paint & glues are _______.
plastics
60
What is stress?
amount of effort/force applied per unit area
61
What is strain?
deformation (change in length) to original length
62
What is tensile strength?
ability to withstand stress in tension
63
What is elasticity?
ability to return to original length
64
What is plastic?
pliable/deformed
65
What is the yield point?
stress at which deformation starts plastically
66
What is the modulus of elasticity?
(also called Young's Modulus)
ratio of stress to strain
67
What is compressive strength?
ability to withstand squeezing/pressing
68
What is fatigue strength?
ability to withstand cyclic loading
69
What is impact resistance or toughness?
ability to absorb impact/shocks
70
What is flow/creep?
deformation upon prolonged load
71
What is shear strength?
separating by tearing
72
What is ductility?
ability to bend stretch or distort without failure
73
What is hardness?
ability to resist scratch or dent
74
All ______ compounds are covalent bonded.
organic
75
Oxygen needs ______ electrons.
two
76
Van der Waals have the ______ bond strength.
weakest
77
What is Metallic?
delocalized sharing of free electrons between a lattice of metal atoms
78
What is Ionic?
opposite charged ions attract
79
What is Covalent?
gain or share electrons non metals and common in plastics (strong strength)
80
What does 'poly' mean in Greek?
many
81
What does 'meros' mean in Greek?
part or unit
82
What does 'mono' mean in Greek?
one
83
What does polymer mean?
many units
84
What does monomer mean?
one unit
85
What is polymerization?
combining monomers into polymers
86
What are thermoplastics?
materials that become soft when heated and solid when cooled to room temperature (can be repeated many times)
87
What are thermosets?
materials that become may be heated and formed one time
88
Heat reactions for thermoplastics?
- similar to candle wax
- can be heated and softened many times
89
Heat reactions for thermosets?
- similar to concrete
- cannot be re-softened
- chemically cures once
90
What does transparent mean?
- light passes thru clearly
- may be colored
91
What does translucent mean?
light passes thru but is not clear
92
What does opaque mean?
no light passes thru
93
crystalline vs amorphous...
Which one do chemicals attack?
amorphous
94
crystalline vs amorphous...
Which one has a sharp melting point?
crystalline
95
Crystalline has a ______ shrink rate, while amorphous has a ______ shrink rate.
high
low
96
crystalline vs amorphous...
Which one has good lubricity?
crystalline
97
What kind of order does amorphous have?
no order
98
What kind of order does crystalline have?
crystal-like orderly regions
99
Is Linear thermoplastic or thermoset?
thermoplastic
100
Is Cross-linked thermoplastic or thermoset?
thermoset
101
Is Branched thermoplastic or thermoset?
thermoplastic
102
Any branching with HDPE?
no
103
Any branching with MPDE/LLDPE?
slight
104
Any branching with LDPE?
long branches
105
As density increases, so does ________, ________, & ________.
melt temperature
viscosity
strength
106
Heating/melting does not break covalent bonds, but ________.
weakens
107
When heat is removed, molecules
________.
remain in place
108
What is MSW?
municipal solid waste
(trash or garbage)
109
no. 1 material in MSW?
paper and paperboard (32.7%)
110
Lowest waste management in America?
(landfill vs incinerate vs recycle)
recycle (13%)
111
About how many landfills in 1988?
8000
112
About how many landfills in 2007?
1700
113
What percentage of waste management is discarded?
54%
114
What percentage of waste management is combustion with energy recovery?
12.6%
115
What is the EPA Hierarchy for integrated solid waste management?
1) Source Reduction
2) Recycling
3) W-T-E Incineration
4) Landfilling
116
Three focuses of Source Reduction?
- Material Replacement Creating Less Waste
- Materials Engineering Using Less material
- Recycling At The Source
117
!! For the Plastics Coding System, what is 1?
polyethylene terephthalate (PET/PETE)
118
!! For the Plastics Coding System, what is 2?
high density polyethylene (HDPE)
119
For the Plastics Coding System, what is 3?
vinyl
120
For the Plastics Coding System, what is 4?
low density polyethylene (LDPE)
121
!! For the Plastics Coding System, what is 5?
polypropylene (PP)
122
!! For the Plastics Coding System, what is 6?
polystyrene (PS)
123
For the Plastics Coding System, what is 7?
other
124
For recycled Coke bottles, what is the highest RPET Product Category?
fiber
125
W-T-E Incineration reduces MSW volume by ______%
80-90
126
______% of U.S. MSW is incinerated
15
127
High energy content in plastics allow "______" to be burned.
wet waste
128
Heat can produce steam to produce electricity. This can save over ______ million barrels of oil per year.
30
129
What has the lowest BTU content (potential heat energy)?
food waste (2600 btu/lb.)
130
What is the average BTU content for MSW?
4500 btu/lb.
131
What is the #1 item in landfills?
paper (35%)
132
What item has the lowest volume in landfills?
glass (2%)
133
Plastics account for ______% of Natural Gas and ______% of Petroleum Consumption per year
7
2
134
no. 1 Natural Gas and Petroleum Consumer?
transportation (62%)
135
What is the the myth regarding
biodegradability?
Properly designed landfills block out sunlight, moisture, and air which are necessary for biodegradation.
136
- true or false?
The Plastics Packaging Industry voluntarily stopped using fully-halogenated CFCs in 1988.
true
137
What is branching?
- polymerization at high temp and pressure
- carbon-hydrogen bond breaks, and hydrogen leaves
138
What is the no. 1 usage of LDPE?
film
139
What is the no. 1 usage of HDPE?
blow molding
140
What was the no. 1 usage of polypropylene?
extrusion sheet/fiber
141
What is the second most used plastic?
polyvinyl
142
- true or false?
Polyvinyl can breathe (aka, it’s porous to oxygen).
true
143
What is the no. 1 usage of PVC?
extrusion
144
- true or false?
Polyester has great solvent resistance.
false. it has poor solvent resistance.
145
What is the no. 1 usage of PET?
blow molding
146
What is the no. 1 usage of polystyrene?
extrusion
147
ABS is about ______% higher than the cost of polystyrene
20%
148
What is the no. 1 usage of phenolics?
bond plywood
149
- true or false?
A common usage of phenolic is pool billiard balls.
true. balls hehe
150
What is the hardest plastic?
melamine
151
What is the no. 1 usage of polyurethane?
flexible foam
152
What is the four-step process of rotational molding?
1) Load Material
2) Heating Phase
3) Cooling Phase
4) Unload Product
153
Biaxial rotation has rotations from _____ to
_____ rpm
7 to 20
154
Name some advantages of rotational molding.
- 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
Name some disadvantages of rotational molding.
- 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
How many arms do individual-arm styles have?
1-arm to 4-arms
157
What is the lowest usage of rotationally molded plastics?
playground equipment (2.3%)
158
What is the lowest typical plastic material used?
Fluorocarbons (0.1%)
159
Name the five examples of molding/casting materials.
- Cast Aluminum
- Fabricated Aluminum
- Machined Aluminum
- Fabricated Mild Steel
- Fabricated Stainless Steel
160
What is fabricated aluminium fabricated from?
sheet stock
161
What is cast aluminum produced from?
pattern (idk what this means.)
162
What are monomers?
liquid resin thermosets
163
What are modified monomers?
partially polymerized sort chain polymers, TP or TS
164
What are powders?
fully polymerized thermoplastics
165
What are plastisols?
solvent solutions of plastics
166
What are ways to dip-cast? (i actually dont totally know what im asking here)
1) Heat dip
2) Cool (cure)
3) Strip/remove
167
What plastic are drill bodies commonly made out of?
ABS
168
What plastic are integral hinges commonly made out of?
polypropylene (PP)
169
What plastic are trashbags commonly made out of?
polyethylene (PE)
170
What plastic would Boeing787s be commonly made out of?
carbon fiber epoxy
171
What plastic are fishing lines commonly made out of?
nylon
172
What % of the market does packaging take up?
75%
173
What are some advantages of thermoforming?
Low Machine Costs
Low Temperature
Low Mold Cost
Low Pressure
Large Parts
Fairly Fast Cycles
174
What are some disadvantages of thermoforming?
High Raw Material $
High Scrap (trim)
Limits Part Geometry
Only One “Good” Side
Wall Thickness Variation
Internal Stresses
175
What is the top material used for thermoforming?
polystyrene
176
When thermoforming, the sheets must be thermoplastic or thermoset?
thermoplastic
177
What are the two major issues with thermoforming?
- sheet thickness
- size limits
178
What are the four forming forces in thermoforming?
- mechanical (matched die forming)
- air (pressure forming)
- vacuum (straight vacuum forming)
- any combination (drape, plug assist, etc.)
179
What is the #1 tool in thermoforming?
aluminum
180
What is a straight vacuum (cavity) in thermoforming?
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
What is a drape (plug) in thermoforming?
mechanical stretch before vacuum, plastic is pressed down onto mold
182
What is straight pressure in thermoforming?
uses high force air pressure from the top and forces the plastic down into the mold
183
What is straight mechanical in thermoforming?
high mold cost and high force, the male mold presses the plastic into the female mold
184
What is plug assist in thermoforming?
a plug pushes a hot sheet in a clamp frame into the mold and vacuum secures it
185
Compression produces ________ molded parts.
thermoset
186
For a high pressure process, how much PSI of a projected area does it take?
1-3 tons
187
For compression molding, what is a positive type mold?
the core side presses down into the part against the cavity (no flash)
188
For compression molding, what is a flash type mold?
the core side presses the part down into the cavity side, and excess material (or "flash") squeezes out
189
For compression molding, what are the five most common materials?
- phenolic
- melamine
- polyester
- epoxy
- silicone
190
- true or false?
Compression molding has good heat and chemical resistance.
true
191
Extrusion is a ________ process for forming ________ materials into three products.
continuous
thermoplastic
192
What are the three products that extrusion forming forms?
- profile shapes
- films / sheets
- wire / cable coverings
193
For extrusion, what is a die swell?
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
A common dye to produce sheets is referred to as the __________.
coat hanger die
195
What is blow molding?
plastic formation process-manufacture of bottles and hollow-shaped parts
196
What is a parison?
a cylinder or tube
197
What is parison programming?
the changing of parison thickness during the blow molding process
198
What is machine sizing when injection molding?
- 2-10 tons per square inch
- this varies w amount of material used
199
What is sprue?
sprue gets molded with the part and then must be trimmed off with the gate and runner afterwards
200
For injection molding, what is "shot"?
the amount of plastic it takes to make the part and any material that is anywhere else
201
For injection molding, what is a gate?
an opening that allows the plastic to enter the mold cavity
202
For injection molding, what is a runner?
a channel cut into the mold that allows plastic material to flow from the nozzle to the cavity
203
For injection molding, what is the feeder system?
directs molten plastic from the injection machine's nozzle into the mold cavity
204
For injection molding, what does the toggle clamp do?
opens and closes the mold
205
For injection molding, what does the hydraulic clamp do?
uses hydraulic pressure to forcefully close the mold together
206
What are flouroplastics?
- polytetraflouroethylene (PTFE or TFE)
- highly crystalline
- low friction and low strength
- no known solvent
207
What are some examples of flouroplastics?
- anti-stick coatings
- tape
- lubricants
- gasket Material
- plates, pads, bushings
208
What is pultrusion?
manufacturing process that converts fibre reinforcements and resin matrices into finished composite parts
209
What is blown film?
to extrude thin film, air is forced into an extruded sheet and then either pinched or cut
210
For co-extrusion, how many extruders are required?
3
211
What is potting?
the 'filling in' or encapsulating of a space with an adhesive
212
What are cast acrylic sheets?
acrylic sheets made when acrylic liquid is pumped in between a mold of two pieces of glass and submerged in warm water
213
What is dip casting?
the mold is heated, dipped into plastic, and then heated to fuse
214
What is slush casting?
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
What is solid casting?
material poured into mold (open or closed) forms to the mold (like the coasters we made in lab)
216
What is rotational cast molding?
material poured into mold and then cooked while spinning in an oven
217
What is ultrasonic welding?
a process that uses high-frequency sound waves to join materials together
218
What is hot gas welding?
uses a stream of heated gas, usually air, to heat and melt both the thermoplastic substrate material and the thermoplastic welding rod
219
What are adhesives?
substances specifically designed to bond different plastic materials together
220
What are cohesives?
it sticks to itself readily, essentially creating a self-adhering quality without the need for additional adhesives to bond to another surface
221
What are cellulosics?
- acetate (CA)
- acetate butyrate (CAB)
222
Charcateristics of cellulosics?
- non-petrochemical
- very tough
- poor solvent resistance
- clear
223
A plastic material, often formed by casting, which has better optical qualities than glass
Polymethyl Methacrylate (PMMA)
224
Bathroom faucets plated to look like "chrome" are most likely made from...
polyacetal
225
Coke bottles are made from what?
polyethylene terephthalate (PET)
226
thermoplastic or thermoset?
- epoxy
thermoset
227
thermoplastic or thermoset?
- cellulosics
thermoplastic
228
thermoplastic or thermoset?
- ABS
thermoplastic
229
thermoplastic or thermoset?
- acrylic
thermoplastic
230
thermoplastic or thermoset?
- PVC
thermoplastic
231
thermoplastic or thermoset?
- phenolic
thermoset
232
thermoplastic or thermoset?
- polystyrene
thermoplastic
233
thermoplastic or thermoset?
- PET
thermoplasic
234
thermoplastic or thermoset?
- polyethelyene
thermoplastic
235
thermoplastic or thermoset?
- melamine
thermoset
236
What material might be used in manufacturing clear police shields?
polycarbonate
237
- true or false?
Mixing virgin plastic with recycled plastic could affect physical properties such as optical clarity
true
238
While thermoforming, the plastic material is heated to its....
softening temperature
239
The plastic materials selected for thermoforming is because of their what?
wide softening range
240
- true or false?
Straight vacuum thermoforming can use either a cavity or a plug type tool.
true
241
- true or false?
Straight pressure forming uses air pressure to force the sheet into the mold to help get more detail.
true
242
- 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
true
243
What thermoplastic would process best for thermoforming?
acrylic
244
- true or false?
Polyurethane can be foamed to be rigid or flexible and it could also have open or closed cells
true
245
- true or false?
Injection molds have small vent holes so excess plastic could escape.
false
246
Material enters the mold through the...
spruce bushing
247
- 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
false
248
- 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
true
249
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?
faster speed of motion
250
What 3 things are most likely to increase flash in the injection molding process?
- increase material temperature
- increase injection pressure
- reduce clamping pressure
251
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.
gate
252
- true or false?
In a reciprocating screw injection molding machine, the screw arguers the material into the mold using the flutes on the screw.
false
253
Plastics are referred “Green” if they exhibit one or more of the what properties?
- renewability
- biodegradability
- environmentally friendly processing
254
Advantages of green plastics?
- reduction in petroleum dependency
- biodegradability / compostability
- reduced use of toxic chemicals in plastics manufacturing
255
Disadvantages of green plastics?
- costs
- biodegradation = green house gasses
- contamination of recycling system
- use of agricultural land
- potential shelf life issue for packaging
ETM 2080
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