midterm Flashcards
1
Q
What is NOT TRUE of plastics?
A
they are non-synthetic
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 apparently
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 (moderate strength)
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
- Carbon’s free radical serve as place for new chain growth
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 breath (aka 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 style?
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
- true or false?
I am ready for this midterm.
TRUE RAAAAHHHHHHHHHHH
