Plastic Product Material and Process Selection Handbook Part 1 ppsx

Plastic Product Material and
Process Selection Handbook
by Dominick V. Rosato, Donald V. Rosato, Matthew V. Rosato


• ISBN: 185617431X
• Pub. Date: September 2004
• Publisher: Elsevier Science & Technology Books
List of fig u res
1.1
1.2
1.3
1.4
1.5
1.6
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.1
Overview of the plastic industries from source to
products that includes plastics and fabrication
processes (courtesy of Plastics FALLO)
Highlighting load-time/viscoelasticity of plastics:
(1) stress-strain-time in creep and (2) strain-
stress-time in stress relaxation

Examples of plastics subjected to temperatures
Guide on strength to temperature of plastics & steel
(courtesy of Plastics FALLO)
Temperature-time guides retaining 50% plastic
properties (courtesy of Plastics FALLO)
FALLO approach includes going from material to
fabricated product (courtesy of Plastics FALLO)
Example how melt index and density influence PE
performances; properties increase in the direction of
arrows
Examples of plasticized flexible PVC
Examples of rigid PVC
Guide to fluoroplastic properties
Basic compounding of natural rubber
With modifications each of these plastics can be
moved into literally any position in the pie section
meeting different requirements
Examples of plastic contraction at low temperatures
Guide to clear and opaque plastics
Examples of the weatherability of plastics
Non-plastic (Newtonian) and plastic (non-Newtonian)
melt flow behavior (courtesy of Plastics FALLO)
13
16
16
25
38
50
58
59

74
111
120
124
127
127
145
xx List of figures
3.2
3.3
3.4
3.5
3.6
3.7
3.8
Relationship of viscosity to time at constant
temperature
Molecular weight distribution influence on melt flow
Examples of reinforced plastic directional properties
Nomenclature of an injection screw (top) and
extrusion screw (courtesy of Spirex Corp.)
Nomenclature of an injection barrel (top) and
extrusion barrel (courtesy of Spirex Corp.)
Assembled screw-barrel plasticator for injection
molding (top) and extruding (courtesy of Plastics
FALLO)
Action of plastic in a screw channel during its rotation
in a fixed barrel: (1) highlights the channel where the
plastic travels; (2) basic plastic drag action; and
(3) example of melting action as the plastic travels

through the barrel where areas A and B has the melt
occurring from the barrel surface to the forward screw
surface, area C has the melt developing from the solid
plastic, and area D is solid plastic; and (4) melt model
of a single screw (courtesy of Spirex Corp.)
146
147
153
157
157
158
159
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
Schematic of an IM machine
Three basic parts of an injection molding machine
(courtesy of Plastics FALLO)
Schematics of single and two-stage plasticators
Simplified plastic flow through a single-stage IMM

Example of mold operation controls
Plastic residence time
Molding area diagram processing window concept
Molding volume diagram processing window concept
Quality surface as a function of process variables
Example of a 3-layer coinjection system (courtesy of
Battenfeld of America)
Example of mold action during injection-compression
(courtesy of Plastic FALLO)
Schematic of a ram (plunger) injection molding
machine
Metal injection molding cycle (courtesy of Phillips
Plastics)
192
194
196
196
198
203
205
205
207
209
213
224
225
5.1
5.2
Simplifies example of a single-screw extruder
Schematic identifies the different components in an

extruder (courtesy of Welex Inc.)
227
232
List of figures xxi
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
5.12
5.13
5.14
5.15
5.16
5.17
5.18
5.19
5.20
5.21
5.22
5.23
Blown film control
Sheet line control
Assembled blown film line (courtesy of Battcnfelt
Gloucester)
Blown film line schematic with more details

Schematic of flat film chilled roll-processing line
Example neck-in and beading that occurs between
die orifice and chill roll
Simplified water quenched film line
Schematic of sheet line processing plastic
Coextruded (two-layer) sheet line
Schematic of a three-roll sheet cooling stack
Introduction to downstream pipe/tube line
equipment
(a) Example of an inexpensive plate die. (b) Examples
of precision dies to produce close tolerance profiles
Coating extruder line highlights the hot melt
contacting the substrate just prior to entry into the
nip of the pressure-chill rolls
Example of a wire coating extrusion line
Example in using a gear pump to produce fibers (left)
and example in using an extruder and gear pump to
produce fibers
Schematic of a basic three layered cocxtrusion sheet
or film system
Example of upward extruded blown film process for
b i axi ally o ri e n tin g film
Example of two-step tenter process
Few examples of many different postformed shapes
and cuts with some showing dies
Examples and performances of compounding
equipment
Schematic of compounding PVC
235
236

245
246
248
249
250
250
251
251
253
256
259
261
265
268
272
273
276
280
280
6.1
6.2
6.3
6.4
Examples of extrusion, injection, and stretch blow
molding techniques
Example of a 3-layer coextrusion parison blow mold
head with die profiling (left) and example of a 5-layer
coextrusion parison blow mold head with die
profiling (courtesy of Graham Machinery Group)
Schematic of extrusion blow molding a single parison

Simplified view of a heart shaped parison die head
(left) and grooved core parison die head
283
285
289
291
xxii List of figures
6.5 Examples ofparison wall thickness control by axial
movement of the mandrel
6.6 Example of rectangular parison shapes where (1) dic
opening had a uniform thickness resulting in weak
corners and (2) die opening designed to meet the
thickness requirements required
6.7 Introduction to a continuous extruded blow
molding system with its accumulator dic head
6.8 Schematics of vertical wheel machine in a production
line (courtesy of Graham Machinery Group)
6.9 Three station injection blow molding system
6.10 Schematic of injection blow mold with a solid handle
(left) and simple handles (ring, strap, etc.) can be
molded with blow molded bottles
6.11 Example of stretched injection blow molding using a
rod (left) and example of stretched injection blow
molding by gripping and stretching the preform
6.12 Examples of different shaped sequential extrusion
blow molding products
6.13 Example of a suction extrusion blow molding process
fabricating 3-D products (courtesy of SIG Plastics
International)
6.14 Examples of 3-D extrusion blow molded products in

their mold cavities (courtesy of SIG Plastics
International)
6.15 Example of a 3-part mold to fabricate a complex
threaded lid 305
6.16 Examples of water flood cooling blow molding molds 307
292
293
294
295
296
297
299
301
303
304
7.1 Examples of thermoforming methods 309
7.2 (1) In-line high-speed sheet extruder feeding a rotary
thcrmoformer and (2) view of the thermoforming
drum (courtesy ofWelex/Irwin)
Schematic of roll-fed thermoforming line
Schematic example of a rotating clockwise three-stage
machine
View of a rotating clockwise five-stage machine
(courtesy of Wilmington Machinery)
7.3
7.4
7.5
313
316
316

316
8.1
8.2
Example of tandem extruder foam sheet line (courtesy
of Battcnfeld Gloucester
Expandable polystyrene process line starts with
precxpanding the PS beads
353
357
List of figures xxiii
8.3 View of PS beads in a perforated mold cavity that are
expanding when subjected to steam heat
8.4 Schematic of foam reciprocating injection molding
machine for low pressure
8.5 (a) Schematic of gas counterpressure foam injection
molding (Cashiers Structural Foam patent). (b) Example
of an IMM modified nozzle that handles simultaneously
the melt and gas. (c) Microcellular foaming system
directing the melt-gas through its shutoff nozzle
into the mold cavity
8.6 Liquid (left), froth (center), and spray polyurethane
foaming processes 366
8.7 Example of flexible foam density profile 367
358
361
363
9.1
9.2
9.3
9.4

Example of the sheet or film passing through nip rolls
to decrease thickness 370
Calender line starting with mixer 371
Examples of the arrangements of rolls in calender lines 372
Example of roll covering 380
10.1
10.2
10.3
10.4
Simplified examples of basic roll coating processes
Example of knife spread coating
Examples of transfer paper coating line
Example of an extrusion coating line
388
388
389
389
11.1
11.2
Example of a liquid injection molding casting process
Example of a more accurate mixing of components
for liquid injection casting
399
400
12.1
12.2
12.3
12.4
12.5
Example of typical polyurethane RIM processes

(courtesy of Bayer)
RIM machine with mold in the open position
(courtesy of Milacron)
Gating and runner systems demonstrating laminar
melt flow and uniform flow front (courtesy of Bayer)
Example of a dam gate and runner system (courtesy
of Bayer)
Example of melt flow around obstructions near the
vent (courtesy of Bayer)
407
411
413
414
414
13.1
Rotational molding's four basic stations (courtesy of
The Queen's University, Belfast)
430
xxiv List of figures
13.2 Rotational rate of the two axes is at 7" 1 for this
product (courtesy of Plastics FALLO ) 432
13.3 Example of large tank that is RM 433
14.1 Schematics of compression molding plastic materials. 439
14.2 Examples of flash in a mold: (a) horizontal,
(b) vertical, and (c) modified vertical
Example of mold types: (a) positive compression mold,
(b) flash compression mold, and (c) semipositive
compression mold
Example of land locations in a split-wedge mold
Schematic of transfer molding

14.3
14.4
14.5
442
445
446
454
15.1
15.2
15.3
15.4
15.5
15.6
15.7
15.8
15.9
15.10
Effect of matrix content on strength (F) or elastic
moduli (E) of reinforced plastics
Properties vs. amount of reinforcement
Modulus of different materials can be related to their
specific gravities with RPs providing an interesting
graph
Short to long fibers influence properties of RPs
Reinforced plastics, steel, and aluminum tensile
properties compared (courtesy of Plastics FALLO)
Fiber arrangements and property behavior (courtesy
of Plastics FALLO)
Layout of reinforcement is designed to meet structural
requirements

Views of fiber filament wound isotensoid pattern of
the reinforcing fibers without plastic (left) and
with plastic cured
Use is made of vacuum, pressure, or pressure-vacuum
in the Marco process
Cut away example of a mold used for resin transfer
molding
455
455
457
461
467
467
479
483
486
488
17.1
17.2
17.3
17.4
17.5
17.6
Examples of mold layouts, configurations, and
actions
Sequence of mold operations
Examples to simplify mold design and action
Example of 3-plate mold
Examples of stacked molds
Examples of melt flow patterns in a coathanger and

T-type die
520
521
522
523
524
530
List of figures xxv
17.7 Examples of melt flow patterns behavior 531
17.8 Flow coefficients calculated at different aspect
ratios for various shapes using the same equation
Example of the land in an extrusion blow molding die
that can have a ratio of 10 to 1 and film or sheet rigid
(R) and flexible (F) die lip land
Examples of a flat die with its controls
Examples of single layer blown film dies include side
fed type (left), bottom fed with spiders type (center)
and spiral fed type
Examples of different pipe die inline and crosshead
designs
(a) Schematic for determining wire coated draw ratio
balance in dies. (b) Schematic for determining wire
coated draw down ratio in dies
Examples of layer plastics based on four modes of
die rotation
17.9
17.I0
17.11
17.12
17.13

17.14
533
535
539
540
541
543
546
18.1 Examples of plant layout with extrusion and injection
molding primary and auxiliary equipment
18.2 Example of an extrusion laminator with auxiliary
equipment
18.3 Examples of tension control rollers in a film, sheet,
or coating line
18.4 Example of roll-change sequence winder (courtesy
of Black Clawson) 559
18.5 Guide to slitting extruded film or coating 567
551
551
558
List of ta b les
1.1
1.2
1.3
1.4
1.5
1.6
1.7
2.1
2.2

2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
2.14
Examples of major plastic families
Thermoplastic thermal properties are compared to
aluminum and steel
General properties of thermoplastic
General properties of thermoset plastic
General properties of reinforced thermoplastic
General properties of reinforced thermoset plastic
Examples of drying different plastics (courtesy of
Spirex Corp.)
General properties of plastics
Example of plastic shrinkage without and with glass
fiber
Density, melt index, and molecular weight influence
PEs performances
Examples of polyethylene film properties
Property guide for thermoset plastics
Elastomer names
Elastomers cost to performance guide

Guide to elastomer performances where E = Excellent,
G - Good, F = Fair, and P = Poor)
Example for comparing cost and performance of
nylon and die-cast alloys
Examples of processes for plastic materials
Examples of processes and plastic materials to
properties
Chemical resistance of plastics (courtesy of Plastics
FALLO)
Examples of permeability for plastics
Examples of transparent plastics
14
18
20
22
24
32
41
43
46
47
102
106
116
117
122
122
123
125
128

129
List of tables xxvii
3.1
3.2
3.3
3.4
3.5
Examples of names of plastic fabricating processes 133
Flow chart in fabricating plastic products (courtesy
of Adaptive Instruments Corp.) 138
Examples of thermoplastic processing temperatures
for extrusion and injection molding (courtesy of
Spirex Corp.) 143
Purging: preheat/soak time (courtesy of Spirex Corp.) 165
Guide to performance of different sensors 171
4.1 Processing window analysis
207
5.1
5.2
5.3
5.4
Example of thermoplastics that are extruded
(courtesy of Spirex)
Selection guide for barrel heater bands (courtesy of
Spirex)
Examples of film yields
Guide on different information pertaining to different
coating methods
229
234

246
258
7.1 Comparison of thermoformer heaters
314
8.1 Examples of rigid plastic foam properties 334
8.2 Examples of physical blowing agent performances 339
8.3 Examples of chemical blowing agents 339
8.4 Properties of 1/4" thick thermoplastic structural foam
(20% weight reduction)
344
9.1
Example of comparing calendering and extrusion
processes
380
10.1 Examples of coating processes
387
12.1 Comparing processes to mold large, complex products 420
13.1 Comparison of different processes 429
13.2 Examples of RM products 432
14.1
14.2
Example of applications for compression molded
thermoset plastics
Comparing compression molded properties with
other processes
440
441
15.1 Review of a few processes to fabricate RP products
457
xxviii List

of
tables
15.2 Examples of reinforced thermoplastic properties 458
15.3 Examples of properties and processes of reinforced
thermoset plastics
Properties of fiber reinforcements
Examples of different carbon fibers
General properties of thermoset RPs per ASTM
testing procedures
Reinforcement orientation layup patterns
Examples of interrelating product-RP material-process
performances
Guide to product design vs. processing methods
15.4
15.5
15.6
15.7
15.8
15.9
459
460
461
466
469
493
506
16.1 Example of a PVC blend formulation
506
17.1
17.2

17.3
17.4
Examples of the properties of different tool materials
SPI Moldmakers Division quotations guide
Examples of extrusion dies (courtesy of Extrusion
Dies, Inc.)
Rapid prototyping processes
514
527
537
549
18.1
18.2
Examples of different rolls used in different extrusion
processes
Examples of machining
562
565
19.1
Comparison of theoretically possible and actual
experimental values for properties of various
materials
572
Preface,
acknowledgement
This book is for people involved or to bc involved in worldng with
plastic matcrial and plastic fabricating proccsscs that include thosc
concerned or in dcpartmcnts of material, processing, design, quality
control, management, and buyers. Thc information and data in this
book arc provided as a comparative guidc to hclp in undcrstanding thc

performance of plastics and in making thc decisions that must be made
when devcloping a logical approach to fabricating plastic products to
mcct performance rcquircmcnts at the lowest costs. Information and
data can also bc uscd whcn compromises have to be made in evaluating
plastics and proccsses. Thc book is formatted to allow for easy rcadcr
acccss and this carc has bccn translated into the individual chaptcr
constructions and indcx.
This book has been prepared with the awarcncss that its uscfulncss will
depend on its simplicity and its ability to provide essential information.
Thc information and data prcscntcd in this book arc not intcndcd to bc
used as a substitute for more up-to-datc and accurate information on
the specific plastics and proccsscs. Such specific details can be obtained
from in-house sources, testing laboratorics, computer databases,
matcrial suppliers, data/information sources, consultants, and various
institutions. Rcfercnccs in this book represent cxamplcs for additional
sources of plastics and processcs.
This book was written to scrvc as a useful rcfcrcncc source for people
new to plastics as well as providing an update for those with cxpcricncc.
It highlights basic plastic matcrials and proccsscs that can bc uscd in
dcsigning and fabricating plastic products. As with dcsigning any
matcrial and/or using any process for plastic, stccl, aluminum, wood,
ceramic, and so on, it is important to lmow their behaviors in ordcr to
maximize product performance-to-cost efficiency. This book provides
xxx Preface. acknowledgement
information on the behaviors and proccssing of the different plastics
and primary fabricating equipment including upstream and down-
stream auxiliary equipment. The information is interrelated between
chapters so it is best to review more than one chapter to maximize you
understanding the behavior of plastic materials and processes.
Designing to meet product performance and cost depends on being

able to analyze the many diverse plastics and processes already existing.
One important reason for this approach is that it provides a means to
enhance the users' skills. It calls for the ability to recognize situations in
which certain plastics and processing techniques may be used and
eliminate potential problems.
Problems that are reviewed in this book should not occur. As explained
they can be eliminated so that they do not effect the product per-
formance when qualified people understand that the problems can
exist. They are presented to reduce or eliminate costly pitfalls resulting
in poor product performances or failures. With the potential problems
or failures reviewed there are solutions presented. These failure/
solution reviews will enhance the intuitive sldlls of those people who are
already worldng in plastics. Cross-referencing of many pertinent
behavior patterns is included so one will better understand the
advantages and limitations that can develop with improper approaches.
Products reviewed range from toys to medical devices to cars to boats
to underwater devices to containers to springs to pipes to buildings to
aircraft to spacecraft and so on. The reader's product to be designed
and/or fabricated can directly or indirectly be related to plastic
materials, fabricating processes, and/or product design reviews in the
book.
This book makes very clear the behavior of the 38,000 different plastics
with the different behaviors of the hundreds of processes. It con-
centrates on the important plastics and processes used to fabricate
products. The result is a complete logical approach to designing that
involves the proper use of materials and fabricating processes.
Information contained and condensed in this book has been collected
from many sources. Included is the extensive information assembled
from worldwide personal experience, industrial, and teaching experiences
of the two authors totaling over a century. Use was also made of

worldwide information from industry (personal contacts, material and
equipment suppliers, conferences, books, articles, etc.) and major trade
associations. For someone to collect this information would require the
person having familiarity in the many facets involved in the plastic
industry worldwide.
Preface, acknowledgement xxxi
The information contained in this book is not available on the Internet.
The Internet contains an extensive amount of useful and important
information that can be used but it is reviewed under many different
subjects. However it does not contain all the information in this book.
Patents or trademarks may cover information presented. No authoriza-
tion to utilize these patents or trademarks is given or implied; they are
discussed for information purposes only. The use of general descriptive
names, proprietary names, trade names, commercial designations, or
the like does not in any way imply that they may be used freely.
While information presented represents useful information that can be
studied or analyzed and is believed to be true and accurate, neither the
authors nor the publisher can accept any legal responsibility for any
errors, omissions, inaccuracies, or other factors. The authors and
contributors have taken their best effort to represent the contents of
this book correctly.
The Rosatos
2004
ACKNOWLEDGEMENT
Special and useful contributions in preparing practically all the figures
and tables in this book were provided by David P. DiMattia. David is an
experienced graphics art director specializing in marketing, product
promotion, advertising, and public relations.
About the authors
Dominiek V. Rosato

Since 1939 has been involved worldwide principally with plastics from
designing-through-fabricating-through-marketing products from toys-
through-commercial electronic devices-to-aerospace and space products
worldwide. Experience includes Air Force Materials Laboratory (Head
Plastics R&D), Raymark (Chief Engineer), Ingersoll-Rand (International
Marketing Manager), and worldwide lecturing. Past director of
seminars and in-plant programs and adjunct professor at University
Massachusetts Lowell, Rhode Island School of Design, and the Open
University (UK). Has received various prestigious awards from USA
and international associations, societies (SPE Fellows, etc.), publi-
cations, companies, and National Academy of Science (materials
advisory board). He is a member of the Plastics Hall of Fame. Received
American Society of Mechanical Engineers recognition for advanced
engineering design with plastics. Senior member of the Institute of
Electrical and Electronics Engineers. Licensed professional engineer of
Massachusetts. Involved in the first all plastics airplane (1944/RP sand-
wich structure). Worked with thousands of plastics plants worldwide,
prepared over 2,000 technical and marketing papers, articles, and
presentations and has published 25 books with major contributions in
over 45 other books. Received BS in Mechanical Engineering from
Drexel University with continuing education at Yale, Ohio State, and
University of Pennsylvania.
Donald V. Rosato
Has extensive technical and marketing plastic industry business
experience from laboratory, testing, through production to marketing,
having worked for Northrop Grumman, Owens-Illinois, DuPont/
~xxiv About the authors
Conoco, Hoechst Celanese, and Borg Warner/G.E. Plastics. He has
written extensively, developed numerous patents within the polymer
related industries, is a participating member of many trade and industry

groups, and currently is involved in these areas with PlastiSource, Inc.,
and Plastics FALLO. Received BS in Chemistry from Boston College,
MBA at Northeastern University, M.S. Plastics Engineering from
University of Massachusetts Lowell (Lowell Technological Institute),
and Ph.D. Business Administration at University of California, Berkeley.
Matthew V. Rosato
Has a strong, Marine Corps influenced, skill set in information
technology and software application areas, which has been helpful in
constantly updating and keeping current the numerous plastic material
and process selection reviews in this book. He is presently a bachelors
candidate at Ohio State University, and is involved in technical marketing
projects with Plastics Fallo.
Table of Contents

Ch. 1 Introduction 1

Ch. 2 Plastic property 40

Ch. 3 Fabricating product 130

Ch. 4 Injection molding 192

Ch. 5 Extrusion 227

Ch. 6 Blow molding 282

Ch. 7 Thermoforming 308

Ch. 8 Foaming 333

Ch. 9 Calendering 369

Ch. 10 Coating 382

Ch. 11 Casting 394

Ch. 12 Reaction injection molding 406

Ch. 13 Rotational molding 428

Ch. 14 Compression molding 439

Ch. 15 Reinforced plastics 455

Ch. 16 Other process 497

Ch. 17 Mold and die tooling 512

Ch. 18 Auxiliary equipment 550

Ch. 19 Summary 570


INTRODUCTION
Overview
The growth of the plastic industry for over a century has been spectacular
evolving into today's routine to sophisticated high performance products.
Examples of these products include packaging, building and con-
struction, electrical and electronic, appliance, automotive, aircraft, and
practically all markets worldwide. The plastic industry is the fourth

largest industry in USA providing 1.5 million jobs. Because of the wide
range of products meeting different performance/cost requirements
and the large number of materials (35,000) used with different
processes, material and process selection can become quite complex if
not properly approached as reviewed in this book.
Plastic selection ultimately depends upon the performance criteria of
the product that usually includes aesthetics and cost effectiveness.
Analyzing how a material is expected to perform with respect to require-
ments such as mechanical space, electrical, and chemical requirements
combined with time and temperature can be essential to the selection
process. The design engineer translates product requirements into
material properties. Characteristics and properties of materials that
correlate with lmown performances are referred to as engineering
properties. They include such properties as tensile strength and modulus
of elasticity, impact, hardness, chemical resistance, flammability, stress
crack resistance, and temperature tolerance. Other important con-
siderations encompass such factors as optical clarity, gloss, UV stability,
and weatherability. 1,248,482
It would be difficult to imagine the modern world without plastics.
Today they are an integral part of everyone's life-style, with products
varying from commonplace domestic to sophisticated scientific
products. 4s~ As a matter of fact, many of the technical wonders we take
2 Plastic Product Material and Process Selection Handbook
~ .: :. : : :: :
for granted would be impossible without versatile, economical plastics.
The information in this book reviews the World of Plastics from plastic
materials-to-processes that influence product designs that continue to
generate the growth of plastics worldwide (Figure 1.1).
Figure 1.1 Overview of the plastic industries from source to products that includes plastics and
fabrication processes (courtesy of Plastics FALLO)

There have been a number of paradigm shifts in the plastic business
model due to market changes. Gone are the days of just buying plastic
and fabricating. Now industries want these associated with design collab-
oration, numerical analysis and virtual prototyping, global specifications,
shorter technology life-cycle factors, quick market introduction windows,
and product stewardship such as dematerialization and multiple life
cycles. Expectations are higher for plastic materials and processes as
well. Metals-to-plastic conversions, micro-molded parts, reinforced
structural parts, shielded housings, thermoplastic elastomer applica-
tions, and parts for harsh environments are malting use of a variety of
developed plastics and filler systems.
Plastics are a worldwide, multibillion-dollar industry in which a steady
flow of new plastic materials, new fabrication processes, new design
concepts, and new market demands have caused rapid and tremendous
1 9 Introduction 3
growth. The profound impact of plastics to people worldwide and in all
industries worldwide includes the plastics' industry intelligent practical
application that range from chemistry to engineering principles
established in the past centuries. 1, 482 These materials utilize the
versatility and vast array of inherent plastic properties as well as high-
speed/low-energy processing techniques. The result has been the
development of cost-effective products used worldwide that in turn
continue to have exceptional benefits for people and industries
worldwide.
Plastics arc now among the nations and world's most widely used
materials, having surpassed steel on a volume basis in 1983. With the
start of this century, plastics surpassed steel even on a weight basis. 1
These figures do not include the two major and important materials
consumed, namely wood and construction or nonmetallic earthen
(stone, clay, concrete, glass, etc.). Volume-wise wood and construction

materials each arc possibly about 70 billion ft 3 (2 billion m3). Each
represents about 45% of the total consumption of all materials. The
remaining 10% include other materials with plastics being the largest.
Plastic materials and products cover the entire spectrum of the world's
economy, so that their fortunes are not tied to any particular business
segment. Designers are in a good position to benefit in a wide variety of
markets: packaging, ~2 building and construction, electronics and
electrical, furniture, apparel, appliances, agriculture, housewares, luggage,
transportation, medicine and health care, recreation, and so on.
Classifying plastic
Plastics arc a family of materials such as ceramics and metals. The family
of plastics is classified several ways. The two major classifications are
thermoplastics (TPs) and thermosets (TSs). Over 90wt% of all plastics
used are TPs. The TPs and TSs in turn arc classified as commodity or
engineering plastics (CP and EP). Commodities such as PEs, PVCs,
PPs, and PSs account for over two-thirds of plastic sales. Engineering
plastics arc characterized with meeting higher and/or improved
performances such as heat resistance, impact strength, and the ability to
be molded to high-precision standards. Examples are polycarbonatc
(PC representing at least 50wt% of all EPs), nylon, acctal, etc. Most of
the thermosct plastics, as well as reinforced thermoplastics and
thermosct plastics, are of the engineering type. Historically, as more
competition and/or production occur for certain engineering plastics,
their costs go down and they become commodity plastics. Half a
4 Plastic Product Material and Process Selection Handbook
century ago the dividing line costwisc was about $0.15/lb; now it is
above $1.00/lb.
There arc different types of plastics that arc usually identified by their
composition and/or performance. As an example there arc virgin plastics.
They are plastic materials that have not been subjected to any fabricating

process. NEAT polymers identify plastics with Nothing Else Added To.
They are true virgin polymers since they do not contain additives, fillers,
etc. They arc very rarely used. Plastic materials to be processed are in the
form of pellets, granules, flakes, powders, flocks, liquids, etc. Of the
35,000 types available worldwide there are about 200 basic types or
families that arc commercially recognized with less than 20 that arc
popularly used. Examples of these plastics are shown in Table 1.1.
Within these 20 popular plastics there arc five major families of thermo-
plastics that consume about two-thirds of all thermoplastics. They are
the low density polyethylenes (LDPEs), high density polyethylenes
(HDPEs), polypropylenes (PPs), polystyrenes (PSs), and polyvinyl
chlorides (PVCs),
Thermoplastic" Crystalline or Amorphous
There are crystalline and amorphous thermoplastics (TPs). During
processing they soften and upon cooling harden into products that are
capable of being repeatedly softened by reheating with their
morphology (molecular structure) being crystalline or amorphous.
Their softening temperatures vary. An analogy would be a block of ice
that can be softened (turned back to a liquid), poured into any shape
mold or die, then cooled to become a solid again. This cycle repeats.
During the heating cycle care must be taken to avoid degrading or
decomposition. With some TPs no change or practically no significant
property changes occur. However some may have significant changes.
The crystalline plastics (basic polymers) tend to have their molecules
arranged in a relatively regular repeating structure such as polyethylene
(PE) and polypropylene (PP). This behavior identifies its morphology;
that is the study of the physical form or structure of a material. They are
usually translucent or opaque and generally have higher softening
points than the amorphous plastics. They can be made transparent with
chemical modification. Since commercially perfect crystalline polymers

are not produced, they are identified technically as semicrystalline TPs.
The crystalline TPs normally has up to 80% crystalline structure and the
rest is amorphous.
The amorphous plastic is the term used that means formless describing
a TP having no crystalline plastic structure. They form no pattern
1 9 Introduction 5
Table 1~1 Examples of major plastic families
Acetal (POM)
Acrylics
Polyacrylonitrile (PAN)
Polymethylmethacrylate (PMMA)
Acrylonitrile butadiene styrene (ABS)
Alkyd
Allyh
Diallyl isophthalate
(DAIP)
Diattyt phthalate (DAP)
Aminos
Melamine formaldehyde (MF)
Urea formaldehyde (UF)
Cellulosics
Cellulose acetate (CA)
Cellulose acetate butyrate (CAB)
Cellulose acetate propionate (CAP)
Cellulose nitrate
Ethyl cellulose (EC)
Chlorinated polyether
Epoxy (EP)
Ethylene vinyl acetate (EVA)
Ethylene vinyl alcohol (EVOH)

Fluorocarbons
Fluorinated ethylene propylene (FEP)
Polytetrafluoroethylene (FTFE)
Polyvinyl fluoride (PVF)
Polyvinylidene fluoride (PVDF)
Ionomer
Ketone
Liquid crystal polymer (LCP)
Aromatic copolyester (TP polyester)
Melamine formaldehyde (MF)
Nylon (Polyamide) (PA)
Parytene
Phenolic
Phenol formaldehyde (PF)
Polyamide (nylon) (PA)
Polyamide-imide (PAl)
Polyarylethers
Polyaryletherketone (PAEK)
Polyaryl sulfone (PAS)
Polyarylate (PAR)
Polycarbonate (PC)
Polyesters
Saturated polyester (TS polyester)
Thermoplastic polyesters
Potybutylene terephthalate (PBT)
Polyethylene terephthalate (PET)
Uns,turated polyester (TS polyester)
Polyetherketone (PEK)
Polyetheretherketone (PEEK)
Polyetherimide (PEI)

Polyimide (PI)
Thermoplastic P[
Thermoset Pl
Polymethylmethacrylate (acrylic) (PMMA)
Polyolefins
(PO)
Chlorinated
PE (CPE)
Cross-linked PE (XLPE)
High-density PE (HDPE)
Ionomer
Linear LDPE (LLDPE)
Low-density PE (LDPE)
Polyallomer
Polybutylene (PB)
Polyethylene (PE)
Polypropylene (PP)
Ultra-high-molecular weight PE (UHMWPE)
Polyurethane (PUR)
Silicone (SI)
Styrenes
Acrylic styrene acrylonitrile (ASA)
Acrylonitrile butadiene styrene (ABS
General-purpose PS (GPPS)
High.impact PS (HIPS)
Polystyrene (PS)
Styrene acrytonitrile (SAN)
Styrene butadiene (SB)
Sulfones
Polyether sutfone (PES)

Polyphenyl sutfone (PPS)
Polysulfone (PSU)
Urea formaldehyde (UF)
Vinyls
Chlorinated PVC (CPVC)
Potyvinyt acetate (PVAc)
Polyvinyl alcohol (PVA)
Polyvinyl butyrate (PVB)
Potyvinyl chloride (PVC)
Polyvinylidene chloride (PVDC)
Polyvinylidene fluoride (PVF)
6 Plastic Product Material and Process Selection Handbook
whereby their structure tends to form like spaghetti with their molecules
going in all different directions These TPs have no sharp melting point
and are usually glassy and transparent such as PS and PMMA.
Amorphous plastics soften gradually as they are heated. If they are rigid
they may be brittle unless modified with certain additives.
Plastics during processing are normally in the amorphous state with no
definite order of molecular chains. If TPs that normally crystallize are
not be properly quenched (when hot melt is cooled to solidify the
plastic) the result is an amorphous or partially amorphous solid state
usually resulting in inferior properties. Compared to crystalline types,
amorphous polymers undergo only small volumetric changes when
melting or solidifying during processing. This action influences the
degree of dimensional tolerance that can be met after the heating/
cooling process.
As symmetrical molecules approach within a critical distance during
melt processing, crystals begin to form in the areas where they are the
most densely packed. A crystallized arca is stiffer and stronger, a non-
crystallized (amorphous) area is tougher and more flexible. With increased

crystallinity, other effects occur. As an example, with polyethylene
(crystalline) there is increased resistance to creep.
In general, crystalline types of plastics arc more difficult (but control-
lable) to process, requiring more precise control during fabrication,
have higher melting temperatures, and tend to shrink and warp more
than amorphous types. They have a relatively sharp melting point. That
is, they do not soften gradually with increasing temperature but remain
hard until a givcn quantity of heat has been absorbed, then change
rapidly into a low-viscosity liquid. If the correct amount of heat is not
applied properly during processing, product performance can be
drastically reduced and/or an increase in processing cost occurs.
Different processing conditions influence the performance of plastics.
For example, the effects of time are similar to those of temperature in
the sense that any given plastic has a preferred or equilibrium structure
in which it would prefer to arrange itself timewise. However, it is
prevented from doing so instantaneously or at least on short notice. If
given cnough time, the molecules will rearrange themselves into their
preferred pattern. Proper heating time causes this action to occur
sooncr. Othcrwise with a fast action severe shrinkage property changes
could occur in all directions in the processed plastic products. This
characteristic morphology of plastics can be idcntified by tests. It
provides excellent control as soon as material is received in the plant,
during processing, and after fabrication.
1 9 Introduction 7
Liquid Crystalline Polymer
These are self-reinforcing TP liquid crystal polymers (LCPs) with
molecules that are rodlike structures in parallel arrays. 3~ LCP's densely
packed fibrous polymer chains result in high performance plastics.
Unlike many high-temperature TPs, LCPs have a low melt viscosity and
arc thus more easily processed resulting in faster cycle times than those

with a high melt viscosity thus reducing processing costs. They have the
lowest warpagc and shrinkage of all the TPs. When they are injection
molded or extruded, their molecules align into long, rigid chains that in
turn align in the direction of flow and thus act like reinforcing fibers
giving LCPs both very high strength and stiffness. Result is high
strength at extreme temperatures, excellent mechanical property retention
after exposure to weathering and radiation, good dielectric strength as
well as arc resistance and dimensional stability, low coefficient of
thermal expansion, excellent flame resistance, and easy processability.
Their high strength-to-weight ratios are particularly useful for weight-
sensitive products. Hydrolytic stability in boiling water is excellent.
They are exceptionally inert and resist stress cracldng in the presence of
most chemicals at elevated temperatures, including the aromatic and
halogenated hydrocarbons as well as strong acids, bases, ketones, and
other aggressive industrial products. High-temperature steam, con-
centrated sulfuric acid, and boiling caustic materials will deteriorate
LCPs. In regard to flammability, LCPs have an oxygen index ranging
from 35 to 50%. When exposed to open flame they form an intumes-
cent char that prevents dripping.
Their UL continuous-use rating for electrical properties is as high as
240C (464F). High heat deflection value permits LCP molded
products to be exposed to intermittent temperatures as high as 315C
(600F) without affecting their properties. Their resistance to high-
temperature flexural creep is excellent, as are their fracture-toughness
characteristics. This family of different LCPs resists most chemicals and
weathers oxidation and flame, making them excellent replacements for
metals, ceramics, and other plastics in many product designs.
Thermoset
When processing thermosets (TSs) heat is applied malting them
flowablc. At a higher temperature they solidify and become infusible

and insoluble. Cured TSs can not be resoftcned with heat. Its curing
cycle is like boiling an egg that has turned from a liquid to a solid and
cannot be converted back to a liquid. They undergo a crosslinldng
chemical reaction of its molecules by the action of heat and pressure
8 Plastic Product Material and Process Selection Handbook
(cxothermic reaction), oxidation, radiation, and/or other means often in
the presence of curing agents and catalysts. Their scrap can be granulated
and used as filler in TSs as well as TPs. In general, with their tightly
crosslinked structure there are TSs that resist higher temperatures and
provide greater dimensional stability and strength than most TPs.
Cure A-B-C stages identify their cure cycle where A-stage is uncured,
B-stage is partially cured, and C-stage is fully cured. Typical B-stage is
TS molding compounds and prepregs, which in turn are processed to
produce C-stage fully cured plastic material products (Chapters 14 and
15).
Crosslinked Plastic
Certain TPs can readily be converted to TSs providing improved
and/or different properties. Crosslinking is an irreversible change that
goes through a chemical reaction. Cure is usually accomplished by the
addition of curing (crosslinldng) agents with or without heat and
pressure. Crosslinking improves resistance to thermal degradation of
physical properties and improves resistance to cracldng effects by liquids
and other harsh environments, as well as resistance to creep and cold
flow, among other effects. Prime interest has been with aliphatic
polymers such as the olefins that include the polyethylenes and
polypropylenes; also popular are polyvinyl chloride. The crosslinked PE,
identified as XLPE or PEX, is recognized as a standard within the
industry. Use includes electrical cable coverings, cellular materials
(foams), rotationally molded articles, and piping. 68, 69
High-intensity radiation from electron beams or UV (ultraviolet)

sources has been used to initiate polymerization in TS systems of
oligomers capped with reactive methacrylate (acrylic) groups or
isocyanates. Using this crosslinking polymerization technique, films
with low shrinkage and high adhesion properties have been used in
such applications as pressure-sensitive adhesives, glass coatings, and
dental enamels.
Property and behavior
When designing and/or fabricating a product a specific plastic is used.
A type from a plastic producer and/or requirements for a plastic
identifies it. The same named, such as low density polyethylene, from
two different companies usually has slightly different properties and
processing characteristics. Data throughout this book which identifies a