27947 Design Guide Cover - Quality Plastic Injection Molding

292 Pages·1999·1.79 MB·English

Design
Guide
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GE Plastics
GE Engineering Thermoplastics
DESIGN GUIDE
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GE Plastics
We bring good things to life.
General Electric Company
One Plastics Avenue
Pittsfield, MA 01201
800.845.0600
PBG-130 (6/99) CA http: / / www.geplastics.com
GE Engineering Thermoplastics DESIGN GUIDE
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Introduction
About GE
The General Electric Company has its roots in the ‘age of
invention’ when, more that 100 years ago, it was founded by
pioneering inventor Thomas Edison.
Closely following its founder’s philosophy of innovation and the
creative application of technology, GE has grown to become one
of the world’s largest and most diversified companies in the world.
Today, GE products and services make a positive contribution to
virtually every sector of commerce and industry. From jet engines
to financial services, from lighting and medical systems to factory
automation, power generation, transportation and construction.
About GE Plastics
Of all GE businesses, one of the fastest growing is GE Plastics. In
a short 25 years, GE Plastics has emerged as the leading producer
of engineering thermoplastics. Through Application Development
Centers around the world, customers can access assistance from
GE designers, engineers, tooling, processing and finishing experts,
utilizing the most sophisticated equipment and systems available.
Working closely with customers on a “share to gain” basis is at
the core of the GE Plastics’ business culture. It provides the
technologies, ideas and improvements that will get the job
done better, more cost-effectively and within tighter schedules.
Having a concentration of molding equipment, testing labora-
tories and product specialists close to the action enables easy
access to unmatched expertise and permits a cross flow of
information that leads to important breakthroughs and exciting
new product developments.
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At the nucleus of this unmatched global technical network are
the world-class facilities at GE Plastics’ headquarters in Pittsfield,
Massachusetts. Realizing that speed is the key to profitability
today, these support services are backed-up by production
plants in several locations in the U.S., Europe, Australia, Japan
and Mexico.
The ultimate value of materials technology is its practical appli-
cation in the marketplace. That is why GE Plastics offers its
engineering thermoplastic resources and technologies to help
design engineers and processors develop better products. There
are no barriers or boundaries, No limit to the resources that
can be brought together for your benefit.
Engineering Thermoplastics
The advantages of high performance engineering thermoplastics
have grown dramatically both from new material developments
and through a new generation of design engineers.
Today, designers have learned to “think” in plastics and take
full advantage of their inherent benefits, rather than just simply
translate metal components into plastic. Some of the unique
design benefits offered by GE Plastics discussed in this Design
Guide include:
• Consolidation of parts
• Integrated system assembly
• Molded-in assembly features
• Unprecedented strength to weight ratios
• Elimination of painting and other operations
• Outstanding impact resistance
• Excellent chemical resistance
Through re-thinking and re-design, traditional metal assemblies
can be produced in dimensionally stable plastics: with 50% fewer
parts, engineered for automated assembly and offering a full
range of impact, heat, electrical and chemical properties. This
Design Guide is one example of how designers can benefit from
the knowledge and experience available from GE Plastics.
GE Plastics Design Guide • ii
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Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .i – iii
Product Development . . . . . . . . . . . . . . . . . . . . . . . . . .1-1 – 1-51
Thermoplastic Material Properties . . . . . . . . . . . . . . .2-1 – 2-63
Part Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1 – 3-46
Product Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1 – 4-35
Product Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1 – 5-83
Industry Specific Design Considerations . . . . . . . . . .6-1 – 6-32
Guidelines for Injection Molded Design . . . . . . . . . . .7-1 – 7-15
Prototyping and Testing . . . . . . . . . . . . . . . . . . . . . . . . . .8-1 – 8-9
Quality Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1 – 9-15
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1 – 10-16
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-17 – 10-21
DISCLAIMER: THE MATERIALS AND PRODUCTS OF THE BUSINESSES MAKING UP THE GE PLASTICS UNIT OF GENERAL ELECTRIC COMPANY, ITS
SUBSIDIARIES AND AFFILIATES (”GEP“), ARE SOLD SUBJECT TO GEP‘S STANDARD CONDITIONS OF SALE, WHICH ARE INCLUDED IN THE
APPLICABLE DISTRIBUTOR OR OTHER SALES AGREEMENT, PRINTED ON THE BACK OF ORDER ACKNOWLEDGMENTS AND INVOICES, AND
AVAILABLE UPON REQUEST. ALTHOUGH ANY INFORMATION, RECOMMENDATIONS, OR ADVICE CONTAINED HEREIN IS GIVEN IN GOOD FAITH,
GEP MAKES NO WARRANTY OR GUARANTEE, EXPRESS OR IMPLIED, (I) THAT THE RESULTS DESCRIBED HEREIN WILL BE OBTAINED UNDER END-USE
CONDITIONS, OR (II) AS TO THE EFFECTIVENESS OR SAFETY OF ANY DESIGN INCORPORATING GEP MATERIALS, PRODUCTS, RECOMMENDATIONS
OR ADVICE. EXCEPT AS PROVIDED IN GEP‘S STANDARD CONDITIONS OF SALE, GEP AND ITS REPRESENTATIVES SHALL IN NO EVENT BE
RESPONSIBLE FOR ANY LOSS RESULTING FROM ANY USE OF ITS MATERIALS OR PRODUCTS DESCRIBED HEREIN. Each user bears full responsibility
for making its own determination as to the suitability of GEP‘s materials, products, recommendations, or advice for its own particular use. Each user
must identify and perform all tests and analyses necessary to assure that its finished parts incorporating GEP materials or products will be safe and
suitable for use under end-use conditions. Nothing in this or any other document, nor any oral recommendation or advice, shall be deemed to alter,
vary, supersede, or waive any provision of GEP's Standard Conditions of Sale or this Disclaimer, unless any such modification is specifically agreed
to in a writing signed by GEP. No statement contained herein concerning a possible or suggested use of any material, product or design is intended,
or should be construed, to grant any license under any patent or other intellectual property right of General Electric Company or any of its
subsidiaries or affiliates covering such use or design, or as a recommendation for the use of such material, product or design in the infringement
of any patent or other intellectual property right.
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GE Plastics
GE Engineering Thermoplastics
DESIGN GUIDE
Product
Development
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Product Development
Early in design development, parts are identified as potential
plastic applications and applicable manufacturing processes
are considered. Designers must decide which should come
first: selection of a material or a process for manufacturing a
part? Normally, the configuration requirements of the plastic
part will direct the design toward a process. In most cases, the
process must be determined before a specific resin grade can
be selected. During this review, designers also need to consider
if the process is capable of meeting the design requirements
such as size, shape, detail and tolerances.
1-2 • Product Development
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Contents
The Design Development Process . . . . . .1-4 Processing Considerations . . . . . . . . . . .1-36
New Product Development . . . . . . . . . . . . . . . . . . . . . .1-4 Plastic Manufacturing Process . . . . . . . . . . . . . . . . .1-36
The Plastics Development Cycle . . . . . . . . . . . . . . . . .1-4 Volume Considerations . . . . . . . . . . . . . . . . . . . . . . . . .1-38
Basic Design Guidelines . . . . . . . . . . . . . . . . . . . . . . . .1-6 Application Matrix . . . . . . . . . . . . . . . . . .1-42
Application Requirements . . . . . . . . . . . . . . . . . . . . . . .1-8
Identifying Special Needs . . . . . . . . . . . . . . . . . . . . . .1-13 Successful Applications . . . . . . . . . . . . . . . . . . . . . . . .1-42
Polymer Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . .1-20 Material Selection . . . . . . . . . . . . . . . . . .1-48
Product Line Creation . . . . . . . . . . . . . . . . . . . . . . . . . .1-21
Design-Based Material Selection . . . . . . . . . . . . . . . .1-48
Product Line Structure . . . . . . . . . . . . . . . . . . . . . . . . .1-21
Polymer Technologies . . . . . . . . . . . . . . . . . . . . . . . . .1-23
Resin Families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-23
Product Offerings . . . . . . . . . . . . . . . . . . .1-25
Resin Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-25
Computer-Based Information Resources . . . . . . . . .1-32
Design Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-32
Materials Selection Database . . . . . . . . . . . . . . . . . . .1-33
Product Development • 1-3
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Product Development
The Design Development Process
New Product Development
New products are frequently vital parts of a business strategy.
Bringing the right product to the market at the right time and
at the right price is an enviable goal. Knowing the process for
new product development and executing the steps flawlessly
can provide a substantial edge. Manufacturing with engineering
thermoplastics continues to enable new product developers to
propose innovative solutions.
The Plastics Development Cycle
While the development process is open to variations, offering
a systematic approach can be valuable by highlighting key ele-
ments of the process. By-passing steps or ignoring issues raised
Design Development Process
can increase the risk facing the project. Figure 1-1 presents an
Three “D’s” overview of the natural progression and groupings at the three
• Discover phases of the design development process, which includes:
• Develop
• Deliver Discover: Identify an opportunity for a product, consider
the market and visualize a competitive edge you feel is
obtainable.
Develop: Embracing the conceptual strategy to achieve the
stated product goals/requirements, create parts, assemblies
and components needed to make the product. Support
proposal with engineering analysis or tests.
Deliver: With confidence the design will function and can
be produced at acceptable cost, the manufacturing capability
is ordered, supplies selected, tooling and facilities identified
or built. After checking initial parts, pilots are assembled,
debugged, and procedures recorded. If all goes well, the
product is released for production.
Delivery of the product alone does not ensure success.
Distribution, promotion and ability to support customer
needs in the use of the product can impact greatly on
a commercial endeavor.
1-4 • Product Development
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The Design Development Process
Figure 1-1. An overview of the
process can be seen by looking
at the natural progression and
grouping the steps into three
phases – discover, develop
and deliver.
Present The Challenge
The Starting Point
Research
Conceptualize
The
a Strategy
Opportunity
PRODUCT GOALS / REQUIREMENTS
Analyze
Propose Integrate Prototype
Potential
A Design Manufacturing and Test
Problems
PRODUCT DESIGNS
Select Sample Inspect Test vs
Refine &
Vendors Tools Parts Pilot Requirements.
Finalize
Design First Make Production Check Reliability
Design
Tools Parts Corrections Submit to Agencies
PRODUCT RELEASE – MANUFACTURING IN PLACE
ACTIONS DURING DESIGN PROCESS ACTIONS TO INITIATE DURING DESIGN PROCESS
• Search Literature – Identify Barriers • Design for Assembly – Consolidate Parts
• Test Existing Products – New Technology • Select Process – Analyze Structure
• Benchmark • Select Material – Process Simulation
• Observe Relationships • Estimate Costs – Prototype & Validate Design
• Consider Alternative Solutions • FMEA – Failure Mode
• Set Requirements
• Application Needs (Quality, Function,
Deployment)
Product Development • 1-5
DELIVER DEVELOP DISCOVER
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Product Development
Basic Design Guidelines
A successful application of an engineering thermoplastic
requires more than identifying a specific product or grade. Of
equal importance are following application design guidelines
and making sure that the product is properly converted in the
molding process. Three areas, product, process and design, are
Inter-Relationships all interrelated and the appropriate guidelines in each area
must be used for a successful application.
Product
Design
The design of parts using GE Plastics’ products is a very specific
Design expertise. Achieving optimal performance in a component
Process made from an engineering thermoplastic requires the use of
appropriate design practices. Two principles of design are:
• Minimum Stress – Stress (Load) should be minimized to
prevent high localized stresses (stress concentration).
• Uniform Stress – Stress should be distributed uniformly.
To achieve these two design objectives, a designer will strive for
uniform and consistent wall thicknesses and gradual transitions
when uniformity cannot be maintained. Also, to reduce stress
concentration, all sharp inside corners (notches) must have as
large a radius as possible.
Processing
GE Plastics’ engineering thermoplastic resins are converted
into final parts by a melt process. Generally this is the injection
molding process where a plastic melt is injected at high pressures
into a precision mold. In addition to this being a high pressure
process, it is also a high temperature process. GE materials are
converted (processed) at temperatures ranging from <400˚F
(<205°C) (CYCOLAC® ABS resin) to 800˚F (427°C) (ULTEM®
PEI resin). Proper molding practices for GE materials must be
employed to prevent excessive product degradation.
1-6 • Product Development