The Complete Part Design Handbook

Dedication

Preface

Contents

1 Polymeric Materials

1.1 Introduction to Plastic Materials

1.1.1 Beginning of Plastics

1.1.2 Polymer Families

1.2 Thermoplastic Polymers

1.2.1 Classification of Polymers by Performance

1.2.2 Molecular Structure of Plastic Materials

1.2.3 Acrylonitrile-Butadiene-Styrene (ABS)

1.2.4 Acetal (POM, Polyacetal)

1.2.5 Polymethyl Metacrylate (Acrylic, PMMA)

1.2.6 High Temperature Nylon (HTN)

1.2.7 Ionomer Polymers

1.2.8 Liquid Crystal Polymer (LCP)

1.2.9 Polyamide (PA, Nylon)

1.2.10 Polyetherimide (PEI)

1.2.11 Polyarylate (PAR)

1.2.12 Polyetherether Ketone (PEEK)

1.2.13 Polycarbonate (PC)

1.2.14 Modified Polyphenylene Oxide (PPO)

1.2.15 Polybutylene Terephthalate (PBT)

1.2.16 Polyethylene Terephthalate (PET)

1.2.17 Polyethylene (PE)

1.2.18 Polytetrafluoroethylene (PTFE)

1.2.19 Polyphenylene Sulfi de (PPS)

1.2.20 Polypropylene (PP)

1.2.21 Polystyrene (PS)

1.2.22 Polysulfone (PSU)

1.2.23 Polyvinyl Chloride (PVC)

1.2.24 Styrene Acrylonitrile (SAN)

1.3 Thermoplastic Elastomers (TPE)

1.3.1 Thermoplastic Elastomer Families

1.3.2 Thermoplastic Polyurethane Elastomer (TPU)

1.3.3 Styrenic Block Copolymer (SBS)

1.3.4 Polyolefin Thermoplastic Elastomer (TPO)

1.3.5 Elastomeric Alloy Thermoplastic Vulcanized (TPV).

1.3.6 Melt Processible Rubber (MPR)

1.3.7 Copolyester Thermoplastic Elastomer

1.3.8 Polyamide Thermoplastic Elastomer

1.4 Liquid Injection Molding Silicone (LIM®)

1.4.1 LIM® Silicone Processing

1.5 Thermoset Polymers

1.5.1 Polyester Alkyd (PAK)

1.5.2 Diallyl Phthalate/Isophthalate (DAP, DAIP)

1.5.3 Melamine Formaldehyde (MF)

1.5.4 Cellulosic Ester

1.5.5 Cyanate

1.5.6 Epoxy (EP)

1.5.7 Phenol Formaldehyde (Phenolic, PF)

1.5.8 Polybutadiene (PB)

1.5.9 Bismaleimide (BMI)

1.5.10 Unsaturated Polyester (UP)

1.5.11 Polyimide (PI)

1.5.12 Polyxylene

1.5.13 Polyurethane (PUR)

1.5.14 Silicone (SI)

1.5.15 Urethane Hybrid

1.5.16 Vinyl Ester (BPA)

2 Engineering Product Design

2.1 Understanding the Properties of Materials

2.1.1 Plastics Selection Guidelines

2.2 Structural Design of Thermoplastic Components

2.2.1 Stress-Strain Behavior

2.2.2 Tensile Testing of Viscoelastic Materials

2.3 Mechanical Properties of Materials

2.4 Tension and Compression Curves

2.5 Modulus of Elasticity (E)

2.6 Stress and Strain Analysis

2.7 Thermoplastics Elastic Design Method

2.7.1 Working Stress

2.7.2 Compressive Stress

2.7.3 Flexural Stress

2.7.4 Coefficient of Linear Thermal Expansion (?)

2.7.5 Poisson’s Ratio (?)

2.7.6 Moisture Effects on Nylon

2.7.7 Effects of Temperature on the Behavior of Thermoplastics

2.8 Stress-Strain Recovery (Hysteresis)

2.8.1 Creep Behavior of Thermoplastics

2.8.2 Creep and Rupture Under Long-Term Load

2.8.3 Creep and Relaxation of Thermoplastics

2.9 Flexural Beam Stress Distribution

2.10 Viscoelastic Modulus Design Method

2.11 Centroid, Section Area, and Moment of Inertia

2.12 Radius of Gyration

2.13 Stress Analysis of Beams

2.13.1 Types of Loads

2.13.2 Normal Stresses in Beams

2.13.3 Shearing Force

2.14 Beam Deflection Analysis

2.14.1 Beam Deflection by Double Integration Method

2.14.2 Beam Deflection Moment Area Method

2.14.3 Applications of Moment Area and Double Integration Methods

2.14.4 Beam Deflection Superposition Method

2.15 Column Structural Analysis

2.15.1 Long Slender Column Critical Load (PCr)

2.15.2 Column Slenderness Ratio (L / r)

2.15.3 Eccentrically Loaded Columns

2.16 Flat Circular Plates

2.16.1 Classification

2.16.2 Stress Analysis Methods

2.16.3 Flat Circular Plate Equations

2.16.4 Flat Circular Plate Stresses

2.16.5 Theory of Flexure Comparison

2.16.6 Circular Plates Simply Supported, Concentrated center Load

2.16.7 Flat Circular Plate under Concentrated Center Load

2.16.8 Flat Circular Plate with Fixed Edge

2.16.9 Flat Circular Plate Compensation Factor for Deflection

2.16.10 Flat Circular Plate Bending under Edge Boundaries

2.17 Torsion Structural Analysis

3 Structural Designs for Thermoplastics

3.1 Uniform and Symmetrical Wall Thickness

3.1.1 Part Geometries Difficult to Mold

3.1.2 Wall Draft Angle per Side

3.2 Structural Rib Design

3.2.1 Rib Strength Analysis Method

3.3 Internal Sharp Corners and Notches

3.4 Injection Molded Thermoplastic Bosses

3.5 Injection Molded Thermoplastic Threads

3.6 Collapsible Core for Molding Internal Threads

3.7 Preferred Standard Thread Forms for Thermoplastics

3.7.1 Thermoplastic Threads Creep Effects

3.8 Injection Molded Products with Undercuts

3.9 Injection Molded Integral Life Hinges

3.9.1 Injection Molded Integral Life Hinge Design

3.9.2 Mold Design Considerations for Hinges

3.9.3 Proper Gate Design for Life Hinges

3.10 Conventional Types of Pin Hinges

3.11 Metal Inserts for Thermoplastic Encapsulation

3.11.1 Machined Metal Threaded Insert Tolerances

3.11.2 Thermoplastic Boss Wall Thickness for Metal Inserts

3.11.3 Press/Lock Slotted Metal Insert Installation After Molding

3.11.4 Cold Forged Metal Inserts for Encapsulation

3.11.5 Threaded Female Metal Inserts

3.11.6 Metal Inserts Anchorage for ThermoplasticEncapsulation

3.11.7 Metal Insert Encapsulating Process Problems

3.11.8 Special Metal Inserts Anchorage for Encapsulation

3.11.9 Electrical Lead Inserts for Encapsulation

3.11.10 Inserts Preparation for Molding Encapsulation

4 Thermoplastic Gearing Design

4.1 Classification of Gears

4.1.1 Gears Parallel to the Shaft Axis

4.1.2 Bevel Gears, Nonparallel and Intersecting Shafts

4.1.3 Hypoid Gears, Nonparallel and Nonintersecting Shafts

4.1.4 Gears for Straight Linear Motion

4.2 Standard Injection Molded Thermoplastic Gears

4.2.1 Selection of Thermoplastic Resins for Gears

4.2.2 Horsepower Equations for Gears

4.2.3 Spur Gear Terminology and Definitions

4.3 Properties Required for Injection Molded Thermoplastic Gears

4.4 Thermoplastic Spur Gear Design Requirements

4.4.1 Gating Effects on Thermoplastic Gear Roundness Dimensions

4.4.2 Multifunction Designs with Thermoplastic Gears

4.4.3 Mounting Thermoplastic Gears on Metal Shafts

4.4.4 Standard Spur Gears, Equations, and Calculations

4.4.5 Spur Gear Pitch Backlash

4.4.6 Standard Spur Gear Tooth Size Selection

4.4.7 Standard Gear Total Composite Tolerances

4.5 Tolerances and Mold Shrinkage of Thermoplastic Gears

4.6 Standard Helical Gears

4.7 Standard Straight Bevel Gears

4.8 Standard Worm Gears

4.8.1 Standard Worm Gear Analysis

4.10 Plastic Gearing Technology Designs

4.10.1 Spur and Helical Gears PGT-1 Tooth Design

4.10.2 Spur and Helical Gears PGT-2 Tooth Design

4.10.3 Spur and Helical Gears PGT-3 Tooth Design

4.10.4 Spur and Helical Gears PGT-4 Tooth Design

4.10.5 Plastic Gearing Technology Tooth Form Design Variables

4.10.6 Maximum Allowable Outside Diameter DO (Max.)

4.10.7 Spur Gear Tooth Form Comparison

4.10.8 Mating Spur Gears Tooth Form Comparison

4.10.9 PGT Spur Mating Gears Strength Balance

4.10.10 PGT Close Mesh Center Distance Between Spur Gears

4.10.11 Maximum Close Mesh Center Distance

4.11 PGT Helical Thermoplastic Gearing

4.11.1 PGT-1 Helical Mating Gears Strength Balance

4.11.2 PGT-1 Helical Mating Gears Center Distance

4.12 PGT Spur and Helical Gears Horsepower Rating

4.12.1 PGT Gear Horsepower Equation Basic Parameters

4.13 PGT Spur and Helical Gear Specifications

5 Plastic Journal Bearing Design

5.1 Introduction

5.2 Materials Used for Journal Bearings

5.2.1 Babbitt Journal Bearings

5.2.2 Bronze Journal Bearings

5.2.3 Sintered Porous Metal Journal Bearings

5.2.4 Plugged Bronze Journal Bearings

5.2.5 Carbon-Graphite Journal Bearings

5.2.6 Cast-iron Journal Bearings

5.2.7 Wooden Journal Bearings

5.2.8 Rubber Journal Bearings

5.2.9 Self-Lubricated Thermoplastic Journal Bearings

5.3 Hydrodynamics of Lubrication

5.4 Journal Bearings Design for Lubrication

5.5 Journal Bearing Design Principles

5.5.1 Journal Bearing Nomenclature and Equations

5.5.2 Thermoplastic Journal Bearing Axial Wall Thickness

5.5.3 Mounting Thermoplastic Journal Bearings

5.6 Split Bushing Thermoplastic Journal Bearings

5.7 Self-Centering Thermoplastic Journal Bearings

5.8 Journal Bearing Load Carrying Contact Surface (C)

5.9 Load Reaction Across the Length of Thermoplastic Bearing

5.10 Injection Molded Journal Bearings Process Defects

5.11 Factors Affecting Journal Bearing Performance

5.12 Factors Affecting Journal Bearing Dimensions

5.12.1 Length-to-Inside Diameter Ratio of Journal Bearings

5.12.2 Types of Service and Motion of Journal Bearings

5.12.3 Thermoplastic Journal Bearing Annealing Effects

5.12.4 Acetal Homopolymer Moisture Absorption Effects

5.12.5 TFE and Nylon 6/6 Moisture Absorption Effects

5.12.6 Temperature Effects on Thermoplastic Journal Bearings

5.12.7 Thermal Effects on Thermoplastic Journal Bearing Clearances

5.13 Journal Bearing Pressure-Velocity (PV) Limits

5.13.1 Methods to Determine the PV Limits of Plastics

5.13.2 Journal Bearing Coefficient of Friction

5.13.3 Journal Bearing Failures Due to Small Clearances

5.13.4 Definition of Different Types of Wear

5.14 Mating Material Hardness and Surface Finishing

5.15 Self-Lubricated Thermoplastic Journal Bearings

5.15.1 Vespel® Polyimide Bearings

5.15.2 Journal Bearing Pressure Equation

5.15.3 Vespel® Wear Factor Effects Caused by Temperature

5.15.4 Vespel® Wear Transition Temperature

5.15.5 Frictional Behavior of Vespel®

5.15.6 Vespel® Journal Bearings Length to Inside Diameter Ratio

5.15.7 Vespel® Thrust Bearing Ratio Between Diameters

5.15.8 Vespel® Journal Bearing Initial Clearance (cI)

5.15.9 Vespel® Journal Bearing Inside Diameter (dB)

5.16 Teflon® (TFE) Fabric Composite Bearings

5.16.1 Bearing Physical Properties

5.16.2 Bearing PV Limit Rating

5.16.3 Journal Bearing Clearances (c)

5.17 Thermoplastic Kevlar® Reinforced Bearings

6 Thermoplastic Molded Spring Design

6.1 Introduction

6.2 Thermoplastic Molded Spring Design Considerations

6.3 Thermoplastic Helical Compression Springs

6.4 Thermoplastic Molded Cantilever Beam Springs

6.5 Cantilever Beam Spring Design Analysis

6.5.1 Initial Modulus of Elasticity Cantilever Beam Analysis Method

6.5.2 Stress-Strain Curve Cantilever Beam Analysis Method

6.5.3 Empirical Data Cantilever Spring Analysis Method

6.6 Thermoplastic Cantilever Spring Applications

6.7 Thermoplastic Belleville Spring Washers

6.7.1 Acetal Homopolymer Belleville Spring Washer Analysis

6.7.2 Belleville Spring Washer Loading Rate

6.7.3 Belleville Spring Washer Long-Term Loading Characteristics

7 Thermoplastic Pressure Vessel Design

7.1 Thermoplastic Thin-Walled Pressure Vessels

7.2 Thin-Walled Cylinder Basic Principles

7.3 Thick-Walled Pressure Vessels

7.3.1 Lame’s Equation for Thick-Walled Cylinders

7.3.2 Maximum Stresses with Internal and External Pressures

7.3.3 Maximum Stresses for Internal Pressure Only

7.4 Designing Cylinders for Cost Reduction

7.5 Thermoplastic Pressure Vessels Design Guidelines

7.5.1 Preliminary Pressure Vessel Design

7.6 Testing Prototype Thermoplastic Pressure Vessels

7.6.1 Redesign and Retesting the Pressure Vessels

7.7 Pressure Vessel Regulations

7.7.1 ASME Pressure Vessel Code

8 Thermoplastic Assembly Methods

8.1 Introduction

8.2 Cold Heading Method

8.2.1 Cold Heading Procedure and Equipment

8.3 Electro Fusion Fitting System

8.3.1 The SEF-System

8.4 Hot Plate Welding Method

8.4.1 Hot Plate Welding Joint Design

8.4.2 Flash or Weld Bead

8.5 Solvent and Adhesive Bonding Methods

8.5.1 Solvents Used to Bond Thermoplastic Polymers

8.6 Adhesive Bonding Method

8.6.1 Adhesive Families

8.6.2 Adhesive Concerns

8.6.3 Adhesives Bonding Selection

8.6.4 Ultra Violet Curable Adhesives

8.6.5 Adhesive Surface Preparation

8.6.6 Adhesive Application and Curing Methods

8.6.7 Joint Design for Adhesive Bonding

8.7 Metal Fasteners Method

8.7.1 Thermoplastic Bosses and Self-Tapping Screws

8.7.2 Thread Forming and Thread Cutting Screws

8.8 Press Fitting Method

8.8.1 Press Fitting Interference

8.8.2 Circular Press Fitting Assembly Method

8.9 Snap Fitting Methods

8.9.1 Circular Undercut Snap Fitting Joints

8.9.2 Suggestions for Stripping Circular Undercut Snap Fitting

8.9.3 Cantilevered Latch Snap Fitting Joint

8.9.4 Cantilever Snap Fit Latch Design Guidelines

8.9.5 Cantilever Latch Snap Fit Mathematical Model

8.9.6 Cantilever Snap Latch Beam Permissible Deflection (?)

8.9.7 Cantilever Latch Beam Assembly Force (W)

8.9.8 Design and Material Considerations

8.9.9 Uniform Cross Section Cantilever Beam

8.9.10 Tapered Cross Section Cantilever Beam

8.10 Electromagnetic Welding Method

8.10.1 Electromagnetic Welding Process

8.10.2 Electromagnetic Welding Coil Design

8.10.3 Electromagnetic Welding Joint Design

8.10.4 Available Welding Gasket Shapes and Forms

8.11 Vibration Welding Method

8.11.1 High Frequency Vibration Welding

8.11.2 Vibration Welding Modes

8.11.3 Comparing Vibration Welding to Other Assembly Methods

8.11.4 Vibration Welding Equipment

8.11.5 Vibration Welding Joint Design

8.11.6 Vibration Welding Aligning and Fixturing

8.11.7 Vibration Welding Tolerances

8.11.8 Vibration Welding Equipment

8.12 Spin Welding Method

8.12.1 Applications

8.12.2 Basic Spin Welding Equipment

8.12.3 Spin Welding Variables

8.12.4 Types of Spin Welding Processes

8.12.5 Spin Welding Joint Designs

8.12.6 Spin Welding Process Suggestions

8.13 Ultrasonic Welding Method

8.13.1 Ultrasonic Welding Basic Principles

8.13.2 Ultrasonic Welding Basic Components

8.13.3 Ultrasonic Welding Equipment

8.13.4 Ultrasonic Welding Process Variables

8.13.5 Ultrasonic Welding Joint Designs

8.13.6 Ultrasonic Welding Energy Director Butt Joint

8.13.7 Ultrasonic Welding Method Design Limitations

8.13.8 Weldability of Thermoplastic Materials

8.13.9 Effects Caused by Thermoplastic Additives on Ultrasonic Welding

8.14 Ultrasonic Insertion

8.14.1 Applications

8.14.2 Ultrasonic Insertion Configurations

8.14.3 Ultrasonic Insertion Product Design

8.14.4 Ultrasonic Insertion Equipment Requirements

8.14.5 Ultrasonic Insertion Process Guidelines

8.15 Ultrasonic Stud Staking Method

8.15.1 Ultrasonic Stud Staking Joint Design

8.16 Ultrasonic Stud Heading Method

8.16.1 Thermoplastic Stud Profiles for Ultrasonic Heading

8.17 Ultrasonic Spot Welding Method

8.17.1 Hand-Held Ultrasonic Spot Welder

9 Thermoplastic Effects on Product Design

9.1 Polymer Melt Behavior

9.1.1 Thermoplastics Glass Transition Temperature

9.2 General Characteristics of Polymers

9.2.1 Critical Properties of Thermoplastics

9.3 Polymer Reinforcements

9.3.1 Types of Fiber Reinforcements

9.3.2 Isotropic Warpage of Fiber Reinforced Resins

9.3.3 Fiber Glass Reinforcement Limitations

9.3.4 Injection Molding Process Effects on Fiber Glass Orientation

9.3.5 Tensile Stress Effects Caused by Fiber Glass Orientation

9.3.6 Flexural Modulus Effects Caused by Fiber Glass Orientation

9.4 Chemical and Environmental Resistance

9.4.1 Effects of the Environment

9.5 Types of Degradations

9.5.1 Oxidative Degradation

9.5.2 Radiation Degradation

9.5.3 Photo Oxidation

9.5.4 Mechanical Degradation

9.5.5 Microbial Degradation

9.6 Moisture Effects on Nylon Molded Parts

9.7 Aqueous Potassium Acetate for Moisture Conditioning Nylon

9.8 Injection Molding Cycles

9.9 Mold Cavity Surface Temperature

9.10 Mold Cavity Temperature Control

9.10.1 Mold and Post-Mold Shrinkage

9.11 Process Condition Effects on Mold Shrinkage

9.12 Post-Mold Shrinkage

9.13 Weld Lines

10 Injection Mold Design

10.1 Classification of Injection Molds

10.2 Effects of Product Design on the Injection Molding Process

10.2.1 Uniform Wall Thickness

10.2.2 Balance Geometrical Configuration

10.2.3 Smooth Internal Sharp Corners

10.2.4 Draft Walls

10.2.5 Feather Edges

10.2.6 Proportional Boss Geometries

10.2.7 Gate Type and Location

10.2.8 Molded Product Ejection Surface Area

10.2.9 Molded Product Tolerances

10.2.10 Surface Finish of Molded Product

10.3 Effects of Mold Design on the Injection Molding Process

10.3.1 Runner System

10.3.2 Mold Cooling System

10.3.3 Ejector System

10.3.4 Mold Venting

10.3.5 Other Mold Devices

10.4 Design Considerations for Injection Molds

10.4.1 Preliminary Mold Design

10.4.2 Detailed Mold Design

10.5 Types of Steels Required for Injection Molds

10.5.1 Major Steel Families

10.6 Steels for Thermoplastic Injection Molds

10.6.1 General Steel Selection Procedures

10.6.2 Properties and Characteristics of Tool Steels

10.6.3 Effects of Alloying Elements on Tool Steel Properties

10.6.4 Chemical Composition of Steels Used for Molds

10.6.5 Effects of Alloying on Tool Steels

10.6.6 Effects of Heat Treatment on Tool Steel Properties

10.6.7 Prehardened Tool Steels

10.6.8 Carburizing Tool Steels

10.6.9 Oil and Air Hardening Tool Steels

10.6.10 Stainless Steels

10.6.11 Steels Used in Thermoplastic Injection Mold Components

10.7 Mold Cavity Surface Finishing

10.7.1 Mold Surface Finishing Process Procedures

10.8 Thermoplastic Injection Mold Bases

10.8.1 Standard Mold Base Components

10.8.2 Functions of the Mold Base Components

10.8.3 Types of Standard Mold Bases

10.9 Types of Thermoplastic Injection Molds

10.9.1 Two-Plate Molds

10.9.2 Round Mate® Interchangeable Insert Molds

10.9.3 Master Unit Die Interchangeable Insert Molds

10.9.4 Three-Plate Mold Cold Runner System

10.9.5 Vertical Insert Mold for Thermoplastic Encapsulations

10.9.6 Hot Runner Molding Systems

10.9.7 Hot Runner Mold Temperature Control Systems

10.9.8 Hot Runner Mold Gates (Drops)

10.9.9 Types of Hot Runner Molding Systems

10.9.10 Thermoplastic Stack Injection Molds

10.9.11 Lost Core Thermoplastic Injection Molds

10.10 Number of Mold Cavities

10.10.1 Cavity Number Limitations

10.10.2 Number of Mold Cavities Equation

10.11 Mold Parting Line

10.11.1 Flat Mold Parting Line

10.11.2 Non-Flat Mold Parting Line

10.11.3 Balancing of Mold Parting Line Surfaces

10.12 Mold Ejection Systems

10.12.1 Ejector Plate Assembly

10.12.2 Ejector Plate

10.12.3 Retaining Plate

10.12.4 Ejector Sleeves

10.12.5 Types of Mold Ejection Systems

10.13 Injection Mold Cooling

10.13.1 Mold Temperature Control

10.13.2 Factors Affecting Mold Cooling

10.13.3 Effects Caused by Elevated Mold Temperature

10.13.4 Effects Caused by Too Low a Mold Temperature

10.13.5 Mold Heat Transfer Methods

10.13.6 Mold Cavity Insert Cooling

10.14 Injection Molding Machine Nozzle

10.14.1 Mold Cold Runner System

10.14.2 Determining the Injection Pressure Needed

10.14.3 Cold Runner Flow Tab

10.15 Mold Cavity Gating

10.15.1 Types of Mold Cavity Gates

10.15.2 Different Types of Hot Runner Gates

10.16 Gate Molding Effects

10.17 Mold Venting Systems

10.17.1 Product Design for Venting

10.17.2 Venting Characteristics of Thermoplastic Polymers

10.17.3 Mold Deposit Problems

10.17.4 How to Avoid Venting Problems

10.17.5 Planning Mold Venting

10.17.6 Mold Venting Process Problems

10.17.7 Mold Venting Design

10.17.8 Mold Venting Using Sintered Porous Insert Plugs

10.17.9 Logic Seal (Negative Coolant Pressure) Mold Venting

10.17.10 Mold Cavity Vacuum Venting System

10.18 Mold Cavity Insert Contact Area Strength

10.18.1 Cavity Insert Sidewall Strength

10.18.2 Methods to Calculate the Strength of Cavity Insert Sidewall

10.19 Mold Layout Case Studies

10.20 Mold Support Pillars

10.21 Tolerances for Thermoplastic Molded Parts

10.21.1 Factors Affecting Dimensional Control Tolerances

10.22 General Specifications for Mold Construction for Thermoplastic Injection Molding Resins

10.22.1 Mold Design Requirements

10.22.2 Mold Drawing Standards

10.22.3 Required Types of Tool Steels for Mold Construction

10.22.4 Mold Construction Requirements

10.23 Mold Tryout – Debug – Approvals – “MQ1” Requirements

10.23.1 Mold Tryout or Evaluation

10.23.2 Mold Debug Procedures

10.23.3 Approval of Molded Parts and Pre-Production Molding Process

10.23.4 Mold Cavity and Core Surface Temperatures

10.23.5 “MQ1” Requirements

11 Performance Testing of Thermoplastics

11.1 Property Data Sheet for Thermoplastics

11.2 Tensile Testing (ASTM D-638)

11.2.1 Tensile Testing Equipment

11.2.2 Tensile Test Specimen

11.2.3 Specimen Conditioning

11.2.4 Tensile Strength Test Procedures

11.2.5 Tensile Modulus and Elongation

11.2.6 Molecular Orientation Effects

11.2.7 Crosshead Speed Effects

11.2.8 Temperature Effects

11.2.9 Moisture Absorption Effects

11.2.10 Stress-Strain Effects Caused by Creep

11.3 Flexural Testing (ASTM D-790)

11.3.1 Apparatus

11.3.2 Test Procedures and Equations

11.3.3 Modulus of Elasticity

11.4 Compressive Strength Testing (ASTM D-695)

11.4.1 Compressive Testing Apparatus

11.4.2 Test Specimens and Conditioning

11.4.3 Test Procedures

11.4.4 Stress-Strain Tension and Compression Curves

11.5 Shear Strength Testing (ASTM D-732)

11.5.1 Test Specimen and Apparatus

11.5.2 Test Procedures

11.5.3 Significance and Limitations

11.6 Surface Hardness Testing

11.6.1 Rockwell Hardness Testing (ASTM D-785-60T)

11.6.2 Barcol Hardness Testing (ASTM D-2583)

11.6.3 Factors Affecting the Test Results

11.7 Abrasion Resistance Testing (ASTM D-1044)

11.7.1 Taber Abrasion Testing

11.7.2 Theoretical Analysis of Wear

11.8 Coefficient of Friction (ASTM D-1894)

11.8.1 Coefficient of Friction of Thermoplastic Materials

11.8.3 Effects of Lubricants

11.9 Mold Shrinkage Test (ASTM D-955)

11.9.1 Purpose of the Mold Shrinkage Test

11.9.2 Factors Affecting Mold Shrinkage

11.9.3 Injection Molding Effects on Shrinkage

11.9.4 Requirements for Sampling

11.9.5 Test Procedures

11.10 Specific Gravity Testing (ASTM D-792)

11.10.1 Test Procedures

11.11 Density Gradient Testing (ASTM D-1505)

11.12 Water Absorption Testing (ASTM D-570)

11.12.1 Test Specimen

11.12.2 Test Procedure

11.13 Impact Resistance Testing

11.13.1 Pendulum Impact Tests

11.13.2 Charpy Impact Testing (ASTM D-256)

11.13.3 Chip Impact Testing

11.13.4 Tensile Impact Testing (ASTM D-1822)

11.13.5 Drop Weight Impact Testing (ASTM D-3029)

11.13.6 Falling Weight Impact Testing

11.13.7 Instrumented Impact Testing

11.14 Creep, Rupture, Relaxation, and Fatigue

11.14.1 Tensile Creep Testing

11.14.2 Flexural Creep Testing

11.14.3 Procedure for Applying Creep Modulus

11.15 Melting Point Test (ASTM D-795)

11.16 Vicat Softening Point (ASTM D-1525)

11.16.1 Melting Point, Glass Transition Temperature

11.17 Brittleness Temperature (ASTM D-746)

11.17.1 Test Apparatus and Procedures

11.18 UL – Temperature Index

11.18.1 Relative Thermal Indices

11.18.2 Long Term Thermal Aging Index

11.18.3 Creep Modulus/Creep Rupture Tests

11.19 Heat Deflection Temperature (ASTM D-648)

11.19.1 Apparatus and Test Specimens

11.19.2 Test Procedure

11.19.3 Test Variables and Limitations

11.20 Soldering Heat Resistance

11.21 Coefficient of Linear Thermal Expansion Testing

11.21.1 Test Procedure

11.22 Thermal Conductivity Testing (ASTM C-177)

11.23 Melt Flow Testing

11.23.1 Moisture Content

11.24 Melt Index Testing (ASTM D-1238)

11.24.1 Melt Flow Rate

11.25 Capillary Rheometer Melt Viscosity Testing (ASTM D-1703)

11.25.1 Melt Viscosity vs. Shear Rate Curves

11.26 Electrical Properties Testing

11.26.1 Underwriter’s Laboratories (UL) Yellow Cards

11.26.2 How to Read and Interpret the “UL Yellow Card”

11.26.3 “UL Insulation Systems Recognition”

11.27 Electrical Insulation Properties

11.28 Electrical Resistance Properties

11.28.1 Volume Resistivity Testing (ASTM D-257)

11.28.2 Surface Resistivity Testing (ASTM D-257)

11.28.3 Dielectric Strength Testing (ASTM D-149)

11.28.4 Dielectric Constant Testing (ASTM D-150)

11.28.5 Dissipation Factor Testing (ASTM D-150)

11.28.6 Arc Resistance Testing (ASTM D-495)

11.28.7 High Voltage Arc Tracking Rate (UL-746 A)

11.28.8 Comparative Track Index Testing (ASTM D-3638/UL 746 A).

11.29 Self and Flash Ignition Temperature Testing (ASTM D-1929)

11.29.1 Test Description

11.29.2 High Current Arc Ignition Testing (UL 746A)

11.29.3 Hot Wire Coil Ignition Testing (UL 746A/ASTM D-3874)

11.29.4 Hot Mandrel Testing

11.29.5 Glow Wire Testing

11.30 Flammability Characteristics of Polymers

11.30.1 Inherently Flame Retardant Polymers

11.30.2 Less Flame Retardant Polymers

11.30.3 Flammable Polymers

11.31 UL 94 Flammability Testing

11.31.1 Horizontal Burning Testing, UL 94HB

11.31.2 Vertical Burning Testing, UL 94-V0, UL 94-V1, UL 94-V2

11.31.3 Vertical Burning Testing, UL 94-5V, UL 94-5VA, UL 94-5VB

11.31.4 Factors Affecting UL 94 Flammability Testing

11.32 Limited Oxygen Index Testing (ASTM D-2863)

11.32.1 Test Procedures

11.32.2 Factors Affecting the Test Results

11.33 Smoke Generation Testing

11.33.1 Smoke Density Testing (ASTM D-2843)

11.34 Weathering Tests for Thermoplastic Materials

11.34.1 Weathering Creep Factors (Degradation)

11.34.2 Ultraviolet (UV) Radiation

11.34.3 Temperature

11.34.4 Moisture

11.34.5 Oxidation

11.34.6 Micro-Organisms

11.35 Accelerated Weathering Testing (ASTM G 23)

11.35.1 Exposure to Fluorescent UV Lamp, Condensation (ASTM G 53)

11.35.2 Accelerated Weather Testing, Weather-Ometer®

11.35.3 Exposure to Carbon Arc Light and Water Testing (ASTM D-1499)

11.35.4 Exposure to Xenon Arc Light and Water Testing (ASTM D-2565)

11.35.5 Outdoor Weathering Testing of Thermoplastics (ASTM D-1435)

11.36 Fungi Resistance Testing of Thermoplastics (ASTM G 21)

11.37 Bacteria Resistance Testing of Thermoplastics (ASTM G 22)

11.38 Fungi and Bacteria Outdoor Exposure Resistance Limitations

12 Thermoplastic Product Cost Analysis

12.1 Injection Molding Process

12.2 Molding Cycle Time

12.3 Material Handling (Regrinds)

12.4 Capital Equipment

12.5 Injection Molding Machine Size

12.6 Injection Molding Machine Cost

12.7 Machine Installation and Safety Considerations

12.8 Auxiliary Equipment and Automation

12.9 Mold Cost

12.10 Molded Products Cost Analysis

12.10.1 Cost Analysis Basic Method

12.10.2 Cost Analysis Graph Method

12.10.3 Advanced Cost Analysis Method

12.11 Secondary Molding Operations

12.12 Additional Manufacturing Costs

Appendix

Acronyms for Polymeric Materials

Common Acronyms

Process Acronyms

Reinforcement and Filler Acronyms

Nomenclature

English and Metric Units Conversion Guide

Subject Index

About the Author