Introduction to Plastics 8 11 09

8/3/2019 Introduction to Plastics 8 11 09

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PRODUCT MATERIAL AND METHODS


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MATERIALS


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TOOLING


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ASSEMBLY


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DECORATION


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INTRODUCTION TO PLASTICS

Objective

Overview of plastic materials and uses Choosing appropriate materials to balance design,

cost, safety and production requirements

Please read : Manufacturing Processes for Design Professionals

Introduction- 418-423 Plastics 423-447

Process, Material, Measurements- Page 84-85

The Not So Technical Technical Aspect of ToyDesign- Page 15- 80

Project- Design 3 toys, 0-6 month, 3+ and 8+. Specify materialsused and why appropriate. Sketch with various parts called out.


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HOMEWORK GUIDLINES

MUST BE 8.5 by 11 PAPER. NOTRACING PAPER-

MUST BE NEAT AND PRESENTABLE


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Grading

2 Quizzes -25%

Class Participation and Home work- 25%

Final 50%

This is of your Final Grade. The other

half will be in the electronics portion ofclass.


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What is Plastic?


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What is Plastic?

Plastic is the general common term for a wide range of synthetic orsemi synthetic organic solid materials suitable for the manufacture

of industrial products

Plastics can be clear or opaque, soft or hard, brittle or flexible, light

or heavy Versatile, can be low cost, easily used in mass production

They are either

THERMOSET or THERMOFORMED


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THERMOSET THERMOFORM


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Thermoset

Thermo set plastics cannot be reheatedto melt. These plastics cure to the finalstate by heating or chemical reaction.Once set it cannot be re melted.

Cannot be reground (recycled back intoraw material)

Very Rarely Used In Toys


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Used a long time ago


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STILL USED TODAY

HIGH HEAT, HIGH DURABILITY ENVIROMENTS


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Thermoformed

Thermoformed plastics can be heated and will soften andmelt. Can be reground.

MOST PRODUCT ARE THERMOFORMED

These include: Polyolefin's (PP, PE, EVA,)

Styrene's (PS, HIPS, EPS, ABS)

Arylic

Cellulosics (CAB)

PVC

TPEs (Thermoplastic elastomers) Polyesters (PET,PETG)

EVA

Engineering plastic such as PC, Acetal (POM), Nylon,Tritan


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Important properties

Safety and Age Appropriate

Impact Resistance

Hardness

Mold Shrinkage

Usable Temperature

Flexibility Paintability

Ability to be joined


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Protomold Resin Puzzle Protomold Cube

Protomold Demo MoldProtomold Torus

EXTRA CREDIT1 point per item


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Safety

Avoid Phthalates- Used in Plasticizers tosoften plastics (PVC)- Banned by CPSC-

Avoid BPA (Bisphenal A) for hand tomouth items disrupts the endocrinesystem-

Use age appropriate plastics. Infant toysshould be more durable, softer plastics


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POLYOLEFINS

A polyolefin is a family of thermoplasticsderived from the ethylene family of simpleolefins.

These plastics cannot be solvent joined Polyethylene (PE)

Polypropylene (PP)

Ethyl Vinyl Chloride (EVA)


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Polyethylene

LDPE- Cheap, High impact, Flexible, GoodESCR, usable temp 160 F

LLDPE- High impact, Stiffer, Better ESCR HDPE- Harder and Stiffer, Poorer ESCR,

SHRINK -.01 to .04


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Examples of PE


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Eero AarnioPUPPY2005

POLYETHYLINE (PE)

ROTATION MOLDED

.25 Wall Thickness

Rigid and Durable

Impact resistant

Many Colors


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Polypropylene (copolymer)

Lower cost than ABS,

High fatigue resistance,

Impact resistant

Dishwasher safe (high melting point320F)

Hard to deco

Easily friction/sonic welded but cannot besolvent joined.

Shrink rate- .010 -.025 in per inch


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Examples of PP (Copoly)

TIC TAC LID

Living hinge

Snap closure


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Playsets

Good for snap fits Large items

Has soft look/feel

Slightly translucent Hard to paint/deco,

needs additionalprocessing

Needs lots of ribs orreturns/flanges tomaintain structure


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Dishwashable


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Other PP uses


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Styrene

Poly Styrene (GPPS,HIPS,EPS) and ABS

Styrene (PS and ABS) can be:

Solvent, friction, sonic welded Clear or opaque (90% light transmission)

Easily decorated

Vac metalized

LOW SHRINK- .005-.010


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Poly Styrenes

GPS- General purpose Styrene Fair Mechanical strength, impact resistance,

Avoid using in childrens toys

HIPS- High impact (K-Resin) Better impact strength, Can be used toys

EPS- Expanded Poly Styrene (FOAMED)

Used for Packaging materials for cushioning Lightweight

LOW USEFUL TEMP- 140 MAX


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GPS MODEL KITS


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HIPS (K-RESIN)

Can be used in some toy application

Can be used for clear recessed parts


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EPS


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Acrylonitrile Butadiene Styrene(ABS)

Most common plastic in consumer goods High impact resistance

Naturally Translucent but can be made clear

High Gloss Great mechanical properties

Poor Fatigue Resistance

High Wear (can be used for snap fits) Can Decorated, Vac Metalized

BETTER THAN PS


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ABS TOYSDURABLE, CAN DECO


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Higgly Town Playground


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Acrylic

Higher cost than ABS

Used for Light piping

Not used frequently in toys for maincomponents due to higher cost andimpact strength (would use Clear HIPS,PETG)

Can be used in internal components andfor older age grade


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PVC

Can be soft or hard

Can mold with undercuts

Can be injection molded, roto molded Can contain phthalates (plasticizer)

Safer citrate based plasticizer can be

used Can be sonic, friction, solvent welded


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PVC Samples


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Packaging


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Figures

Solid injection molded figures,

Hollow, soft roto-molded figures

Hard PVC tubing (construction)Other examples--

Th l i l


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Thermoplastic elastomers(TPE)

Kraton, Styroflex, Pellethane (SBS)

TPE/TPO

Poly Urethane TPE More cost effective than Thermoset

rubber.


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TPE SAMPLES


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Thermo set Rubber


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POLYESTHERS

PET- Homopolymer Can be clear but difficult to keep clear

Used in blow molded bottles

High impact

PETG Copolymer High clarity

Easily injection molded High impact

NO Bisphenol A (PC contains Bisphenal A)


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EVA

Ethyl Vinyl Acetate

Soft

Flexible

Plasticizer free

Bisphenol A free


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Soft and Squishy


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Engineering Plastics

Acetal(POM)

Delrin/Celcon (trade name)

Self lubricating, low friction

Polycarbonate-

Nylons


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NYLONS AND ACETAL

Used for internal, high wear, high pressure parts

Strong and fatigue resistant.


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Polycarbonate

Amorphous (clear)

Temperature resistant

High Impact Contains Bisphenol A


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Summary

Types of plastics and uses

Appropriate materials to balance design,cost, safety and production requirement

Plastics and Safety


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Plastics and SafetyOverview

Avoid BPA

Avoid Pthalates in plasticizers

Choose correct plastics for Age Grade


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Introduction to Manafacturing

I t d ti t


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Introduction toManufacturing Methods

Session 7

Assigned reading: Process, Materials, Measurements

Chapter 3- Page 30 to 46

Manufacturing Processes for design Professionals Blow Molding- 22-29

Thermo-forming- 30-35

Rotational molding- 36-39

Injection Molding 50- 67

EDM- 254- 259 The Not So Technical Technical Aspect of Toy Design-

Chapter 16- Page 83 to103

Homework- Design at least 3 toys that use different manufacturemethods. Explain why method is used. Also label material used andwhy.

Most Common methods in To


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Most Common methods in ToyManafacturing

Injection Molding

Rotational Molding

Blow Molding


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COMMON TERMS

MOLD/TOOL- This is what the plastic is injected, poured or formedinto and gives it its final shape. Process will determine number ofparts and material the mold/tool is made.

CORE and CAVITY, SLIDES and CAMS- These parts make up theMold/Tool depending on part complexity.

UNDERCUT- This is a feature in the final part that will prevent theitem from being removed from the tool. Depending on the processand complexity of the tool and material used these features can bekept.

RIBS- Features that are added to strengthen a part. BOSS- Support that screws thread into. SINK MARKS- Surface deformation due to a rib on other side of

part. These can be minimized by adjusting rib thickness. WALL THICKNESS- Thickness of material at a given section. DRAFT- Angle that will allow part to be removed from tool.


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INJECTION MOLDING

Most item are injection molded.

Most thermoformed plastics can beinjection molded

Many different types-

Single shot injection Molding

Multi shot injection molding (over molding)

In mold Decoration

Reaction injection molding


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WHY INJECTION MOLDING?

Very tight tolerances for mating parts. Can design toolto compensate for material shrink. If the toy is made ofa lot of separate parts, injection molding the parts willensure a better fit.

Surface finish is excellent and can reproduce lots ofdetail. Detail is superior to any other method (rotationalmolding, blow molding, etc)

Can injection mold all thermo-form plastics

Can create undercut features by use of cams Can create a a single part that has 2 types of material(over molding, insert, molding)

Can create a part with decoration (in mold decoration)

B i P


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Basic Process


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Animated Injection Molding Machine


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Injection Molded Parts

Simple Single Direction Tool


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Simple Single Direction Tool(NO CAM/SLIDES)

ANIMATION

Multi Core and Cavity and parts


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Multi Core and Cavity and parts

Cavity Core

Parts on Sprue

Tool with Slides/Cams


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Tool with Slides/CamsAnimation

T l ith lid


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Tool with cams or slides


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These car bodies were injection moldedwith 3 or more slides.

Can you find the witness lines?


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ROTO MOLDING BASICS

USED TO MAKE HOLLOW PARTS

PLASTIC (pellets, powder, liquid) is put into tool.

TOOL is sealed and tranfered to heated

chamber TOOL is rotated in 2 axis to distribute material

and form consistant wall thickness

TOOL is moved to cooling chamber and rotatedin 2 axis and allowed to cool slightly

TOOL is opened and item is removed


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ROTO MOLDING RIGID PLASTIC

Use to create hollow parts.

Mold consist of at least 2 parts

Lower tool cost than injection molding PE and PP most common plastic

Low scrap (material is carefully

measured)


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Rigid Roto Products


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CASE STUDY


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Eero Aarnio

PUPPY2005

CASE STUDY


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ROTO MOLDING SOFT PVC


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ROTO MOLDING SOFT PVC

PROCESS SIMILAR TOROTOMOLDING RIGID PLASTIC

SOFT PVC PRODUCTS CAN BEMOLDED WITH LOTS OF UNDERCUTS

MOLD USUALLY MADE OF COPPER

MOLD IS USUALLY SINGLE PIECE

CREATE THE PATTERN


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CREATE THE PATTERN

APPROVED FINAL PATTERN SUPPLIED. THIS ISCALLED THE REFERENCE PATTERN

MAKE INVESTMENT PATTERN


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MAKE INVESTMENT PATTERN

REFERENCE SAMPLE IS DUPLICATED IN WAX AND MODIFICATIONSMADE TO ENSURE PROPER MOLDABILITY. THIS IS CALLED THE

TOOLING PATTERN

CREATE THE COPPER MOLD


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CREATE THE COPPER MOLD

PATTERN IS SUBMERGED INTO A COPPER BATH AND IS COATEDWITH COPPER UNTIL A SUFFICIENT WALL THICKNESS BUILDS UP.

THIS CAN TAKE UP TO 7 DAYS

FINISHED MOLD


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FINISHED MOLD

A HOLE IS MADE IN THE BOTTOM AND A REPLACABLE PLUG ISCREATED. THE WAX PATTERN IS MELTED OUT.

ADD PLASTEROL (PVC)


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ADD PLASTEROL (PVC)

PLASTEROL IS ADDED, PLUG REFITTED AND TOOL IS ROTATED INHEATING CHAMBER, THEN ALLOWED TO COOL.

It i d


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Item is removed

While plastic is still hot and pliable, plug is removed and a hook is insertedand item is removed through the opening. Item cools into final shape.

If more than 1 tool is needed (larger production runs) the final tools aremade from these vinyl patterns.

S ft PVC T


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Soft PVC Toys

Bl ldi


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Blow molding

Blow molding uses air to form the part.

Used for thin walled hollow part (bottles)

Less costly than injection molding Less detail than injection molding

Less detail than Rotational molding


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A i ti f Bl M ldi


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Animations of Blow Molding

A i ti f Bl M ldi


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Animations of Blow Molding

Samples Blo molded prod cts


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Samples Blow molded products

ASSEMBLY


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ASSEMBLY

Lecture 9


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Introduction to Assembly methods Objective

Overview of different ways to assemble toy. Please read :

Process, Material, Measurements- Page 51-53 The Not So Technical Technical Aspect of Toy Design- Page

107-110 Manufacturing Processes for design Professionals Vibration Welding 298-301 Ultra Sonic Welding- 302-307 Staking 316-319 Injection Molding 50- 67

Project- Disasemble some toys I brought to class. Take photos ofdescribe toy different methods used. Find 10 examples, at least 3different types (ie snap fit, sonic weld, screws)

DUE 2 weeks after lecture. Due Via Email.

Assembly Method


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Assembly Method

All multi part products need some type ofassembly

These include mechanical fasteners,

solvent bonds, heat welding, sonicwelding, insert molding,heat staking andconsumer assembly

Common Assembly methods


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Common Assembly methods

Screws

Rivits, Peened Axles ends,

knurled/ringed shaft

Snap fits

Spin welding

Ultra-sonic welding Solvent welding

Screws


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Screws

Screws


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Screws

Rivets Peens and Axles


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Rivets, Peens and Axles

Rivets are use to assemble 2 parts together thatcan not be screws or glued. Material may be tohard or thin to use self tapping screws.

Peens are flattened ends of axles or post thatcreate T or mushroomed end that prevents thepart from coming off.

Axles are used for parts that need to spin or

rotate. The ends of the axles can be knurled,ringed or peened over.


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Snap fits


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Snap fits

Used for one time assembly, break awayhinges for safety, consumer assembly

Requires no additional parts. Snap is

integrated into part.

Material used depends on if item will bedisassembled frequently


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Spin Welding


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Spin Welding

Uses the heat form rotational movement tofuse 2 parts together

Spin Welded Products


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Spin Welded Products

Ultra-sonic welding


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Ultra-sonic welding

Vibrates 2 thin parts by using a piezo discto fuse the 2 parts together.

Very efficient use of energy, little heat

generated, welds in about 1 second

Useful for joining 2 noncircular parttogether (cannot be spin welded)

Useful for joining clear plastic togetherwhere solvent welding may blemish part.

Material considerations


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Material considerations

Can Sonic Weld all thermoformedplastics

ABS, PC (poly carbonate),PS (poly

styrene) can be welded to one another

PP, PET, PE, can only be welded to thesame material (PP to PP, PET to PET,

PE to PE only)


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Solvent welding


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Solvent welding

Used to join similar plastics like styrenestogether.

Economical

Cannot Solvent weld PP,PE,acetal,nylons

LECTURE 9


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DECORATION

Objective Overview of process and types of decoration to enhance your

toy Please read :

Process, Material, Measurements- Page 46-50 The Not So Technical Technical Aspect of Toy Design- Page

113-118 Manufacturing Processes for design Professionals

Spray Painting 350-355 Vacuum Metalizing 372-373 Pad Printing 404-407

Hydro-Transfer 408-411 Foil Blockinging and Embossing 412-415 IInmold Decoration 62-63

Project- Design 3 toys using different decoration. DUE 2 weeks after lecture. Due Via Email.

DECORATION


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DECORATION


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Most items will have some sort of decorationto enhance the product.

This can be as simple and inexpensive moldedin decoration to after molding operations such

as tampo printing hand painting, andmetalizing.

Process include Molded in decoration, in molddecoration (IMD), label application, tampo or

pad printing, hand painting (masks andbrushes), Hydro graphics, hot stamping,vacuum metalizing,

Molded in and In mold decoration


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Molded in and In mold decoration

Molded in- textures, plastic color, coloradditives, glitter and metaflake, pearlescents,fluorescent, phosphorescent. There is noadditional cost other than material. Cost

effective way add value to an item In Mold decoration (IMD)- This is a process

during molding which a thin film is inserted intothe mold and the material is injected the film and

the material fuse together. It is high in costbecause of the labor to place the film and thecost per piece of each film.

Molded in Textures and Graphics


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Molded in Textures and Graphics

Examples of molded in decorationHOLGA CAMERA


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HOLGA CAMERA


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Pigments and Dyes


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Pigments and Dyes

You can add other material into plasticwhile molding.

Adds value with out labor cost

Can add, glitter/metaflake, dyes/tints (forclear items), Pearlescent,phosphorescent,

SHIMMER PHONE(LITTLE MS SPIDER)


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(LITTLE MS SPIDER)

In- Mold Decoration (IMD)


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In Mold Decoration (IMD)

Molding Process Preformed Film with Graphics inserted

into tool and material is injection molded

and part is fused together. Controllable Decoration and placement of

film

Need Special tools, higher labor cost,need to design Graphic and part shapeearly in design Process

IMD Process


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IMD Process


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LABEL ART


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LABEL ART

Label art cost effective way to introducecolor into product.

4 color process is most common. You

can can get as many colors you want forthe same cost.

Cost determined by label surface are andnumber of labels to be applied.

Good way to add color to PP, PE (cannotbe painted)

LABEL SAMPLES


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S S


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Tampo Process Overview


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Silicone Key pad Tampo


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TAMPO PRINTING


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Sharp Edges and lines. Great forGraphics

Can register multiple passes/color

Can wrap around curved surfaces (lessthan 180 degrees, about 150 degress)

Automated so less costly than handpainting

Not for applying to a large surface (max4x4 inches)

Tampo decoration


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p

Hand Painting


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g

Color is applied by hand

Can use masking techniques to avoidpainting unwanted surfaces

Can paint large or small surfaces

Can use brushes to hand paint stripes,highlights, small details


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Hydro Graphics


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y p

Also called water transfer, immersionprinting, aqua graphics

A cost effective way to wrap a graphic or

pattern around an entire part.

Pattern placement is approximate, cannotget a high degree of registration. Each

part will be different


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Hot Stamping


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Also called Foil Stamping

Similar to Tampo but uses heat and arigid tool to tranfer foil (on rolls) to a part.

Can give a part a metalic or chrome finish

Part surface cannot be too complex

Hot Stamp Overview


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Vacuum Metalize


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Also called Vac Metal or Sputtering

Can vac metal rigid plastics and metals.Flexible plastics are not suggested

because the finish will crack and flake off. Can apply any metal (aluminium, brass)

Must metalize entire part (cannot mask or

selectively metalize surfaces.


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Vac metal samples


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LECTURE 9DECORATION


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DECORATION

Objective Overview of process and types of decoration to

enhance your toy

Please read :

Process, Material, Measurements- Page 73-77 Manufacturing Processes for design Professionals

Rapid Prototyping 323-241

CNC 182-189


Injection Molding 50- 67 Project- Design 3 toys using differentdecoration.

DUE 2 weeks after lecture. Due Via Email.

LECTURE 10RAPID PROTOTYPING


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RAPID PROTOTYPING

Manufacturing Processes for designProfessionals

Rapid Prototyping 323-241

CNC 182-189


Injection Molding 50- 67

Introduction to Plastics 8 11 09

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Transcript of Introduction to Plastics 8 11 09