advances in im

ADVANCESADVANCESINININJECTIONINJECTIONMOULDINGMOULDING

PRESENTED BY :LOKESH KUMAR GAHOI3rd BTECH PLASTIC TECHNOLOGYSR. NO. :- 459/10

CONTENTSCONTENTS INTRODUCTION ADVANCED INJECTION MOULDING

TECHNOLOGIES1. MULTI – COMPONENT INJECTION

MOULDING2. IN – MOULD LABELLING3. GAS ASSISTED INJECTION MOULDING4. THIN WALL INJECTION MOULDING5. MICRO INJECTION MOULDING

CONCLUSION

INTRODUCTION

• Injection molding technology continually develops, with major milestones including the introduction of the first thermoplastic materials, the reciprocating screw design, the first hot runner systems, engineering materials, the introduction of microprocessors for machine control and recently the application of expert systems for optimized machine setup.

• Injection molding of thermoplastics has emerged as the premier vehicle for delivering high quality, value added commercial products. Perhaps due to this success, there has been sustained pressure for increased standards of molded part quality while requiring reduced product development time and unit cost.

INTRODUCTIONINTRODUCTION

A large number of polymeric materials with different degrees of hardness and colours can be combined and processed This technology offers the possibility of combining various product features with low assembly cost. Greatest possible variety of combination options: up to six independent injection units on a single machine

CLASSIFICATIONCLASSIFICATION

According to the no of sprue , multi - component injection According to the no of sprue , multi - component injection moulding can be classified as : moulding can be classified as :

THE SANDWICH PROCESSTHE SANDWICH PROCESS

11. Injection of outer component = skin

2. Injection of core material into component 1.

3. Finished product with hard core and comparitively softer skin

CAVITY SEPERATION PROCESSCAVITY SEPERATION PROCESS

1. 1. Injection of outer component 1

2. Pulling back of slide

3. Injection of component 2

THE TURNTABLE PROCESSTHE TURNTABLE PROCESS

11. Injection of inner component

2. Rotation of moving mould half on turntable

3. Simultaneous injection of component 2 and component 1.1.THE TRANSFER PROCESSTHE TRANSFER PROCESS 1. 1. Injection of

component 12. Transfer of the

substrate to a new cavity.3. Injection of

component 2.Simultaneous injection of the next substrate.4. Final product

ADVANTAGESADVANTAGES

ENHANCED APPEARANCE• By incorporating multiple colored materials, creating soft touch

areas and enhancing fine detail and aesthetics improving product appeal.

COST REDUCTIONS• Combine two parts into one for savings in materials,

production, handling and inventory, and eliminating post molding assemblies such as snap fits, welding, adhesives, mechanical fasteners and seals.

INCREASED FUNCTIONALITY• Allows for new design possibilities with multiple components in

a single part, increased complexity and parts with movable segments or components using “in mold assembly”.

IMPROVED QUALITY• Two shot molding technology lowers tolerances, improves

bonding and ensures exactly the same part with every cycle resulting in improved product integrity.

APPLICATIONSAPPLICATIONS

Car sunroof with integrated assembly elements Colour sorted tooth brushes Housing of various items like powertools etc. Wind deflector with integrated gasket Automotive rear lamp cluster Handles of refrigerator doors

The technology was first developed by OWENS-ILLINOIS in cooperation with PROCTER & GAMBLE . This was first applied to HEAD & SHOULDERS shampoo bottles.

INTRODUCTIONINTRODUCTION

In the in-mold labeling process, a label or applique is placed in the open mold and held in the desired position by vacuum ports, electrostatic attraction or other appropriate means. The mold closes and molten plastic resin is extruded or injected into the mold where it conforms to the shape of the object. 

PROCESPROCESSS

Lower costs than other pre-decorating methods.No extra labeling step or equipment.Increased packaging line speeds.Reduces in-house container inventory.Reduced container weight.Improved appearance.Better stain resistance.Improved sidewall strength.Up to 5 color process in one shotHigher durability / scratch resistantImpervious to UV, power washing, gas, acid and other outdoor conditionsEnables shoot & shipLess scrap / waste

ADVANTAGEADVANTAGESS

APPLICATIONSAPPLICATIONS

Outdoor Durable and PackagingBarcode, including sequential barcodes (for tracking)Shampoo bottlesSingle and Multi-Cavity ApplicationsVacuum or Static Label Placement (direct or remote)Specialized Cup Automation Cells (singe and multi-cavity, two plate or stack mold)Label Nest (with/without motion)Custom Human Machine Interface (HMI)

IN MOULD BARCODE LABELS

• For the In-Mould Labeling process, special labels are placed inside the cavity of the injection-molding machine. The labels fuse completely with the plastic and are fully integrated onto the surface of the item. A special surface treatment makes these labels particularly resistant to wear and tear, UV light, cleaning products, weak acids and chemicals. The label is bonded to the container during the injection moulding process, leaving a smooth, rimless surface, which means that no dirt or moisture can get in underneath the label.

• In terms of durability and hygiene, this process is unsurpassed. It also meets the highest aesthetic demands

• Permanent identification of reusable containers

INTRODUCTION

This method is used  to create one or more hollow channels within an injection-molded plastic part.

Gas (N2) is injected into the still liquid core of the molding at the end of the filling stage.

Gas follows the path of the least resistance. Thick molten sections get replaced with gas-filled

channels. Finally, the gas is vented to atmosphere or

recycled.

G.A.I.M. PROCESSG.A.I.M. PROCESS

PROSPROS ANDAND CONSCONS

PROSPROS

Cycle time reduction and lower production costs Material saving for thick walls upto 80 % High rigidity due to hollow rib formation by design Lower clamping forces High flexural stiffness and torsional rigidity Reduction of sink marks.

CONSCONS

Not fully being able to control where the gas goes High cost of tooling and mould flow analysis Penetration of gas from gas channel into thinner section of the part Slow cooling time of Slow cooling time of mouldmould.

APPLICATIONSAPPLICATIONS

Door Hardware Module. Auto Side Mirror Housing. Auto Door Handle. Auto Bumper. Auto License Plate Holder. CD-ROM Tray. Power Amplifier Housing. Truck Air Filter Housing. Water Cooler Housing Panels. Hospital Bed Rails. Appliance Handle. Wheelchair Wheel. Washing Machine Agitator

INTRODUCTION

TWIM or Thin wall Injection Moulding has been paid more and more attention, especially in computer, communication and consumer electronic (3C) industries, due to economic and environmental concerns.

The reason is that thin-wall molded parts could be made lighter, more compact, less expensive, and quicker because of fast cooling Thin wall plastic food containers are becoming more and more popular. The thermoforming disposable containers are considered to cost more of electricity power consumptions and complex process. As you know, thermoforming process is two stages, it needs the shape forming from the plastic sheet, the plastic sheet extrusion molding are complex too. From the sheet being heated until the vacuum forming and deflashing…

Key Factors Conventional Thin-WallTypical Wall thickness, in.

0.080-0.120 0.050-0.080 <0.050

Machinery Standard High-end Custom

Inject. Pressure, psi

9000-14,000 16,000-20,000 20,000-35,000

Tooling Standard Better venting, heavier construction, more ejector pins, better polish

Extreme venting, very heavy construction, mold interlocks, precise surface preparation, extensive ejection features, mold costs 30-40% higher than standard.

Control System Standard Closed-loop on injection speed, hold pressure, decompression speed, screw rpm, backpressure, and all temperatures.

Same as at left, with resolution of 0.40 in. on speed, 14.5 psi on pressure, 0.004 in. on position, 0.01 sec on time, 1 rpm on rotation, 0.10 ton on clamp force, 2° F on temperature.

STANDARD VS. THIN-WALL PROCESSING

Thin wall parts require higher injection pressure because the distance that the material can flow is dependent on the thicknessof the part. As the following Illustration shows, the material Forms a frozen skin on the outside walls of the cavity first And then starts to solidify towards the centre. The centre of the flow is the last To solidify. If your wall section is very thin then this solidification occurs very quickly. Melt streams should reach all the boundaries of mould before melt freezes. Freezing time is proportional to cube of wall thickness. Therefore, for thinner wall, melt should flow fast enough to ensure that melt fills fully before it freezes. Hence, max injection rate of machine is important specification of machine todetermine spread of melt through longest flow ration.

THIN WALL INJECTION FLOWTHIN WALL INJECTION FLOW

Cheap, safe and clean plastic parts. Allows faster cycle times compared with thicker walled

plastic parts. Lighter parts reduce fuel emissions in automotive

applications. Thin wall molding reduces resource consumption and

cuts weight, reducing fuel usage and carbon emissions in shipping – further supporting sustainability efforts. 

Made from recyclable plastics such as polypropylene (PP) in food packaging.

Some thin wall parts can be made from sustainable plastics.

ADVANTAGADVANTAGESES

LIMITATIONSLIMITATIONS

• Environmental litter.• High capital investment cost for injection molders. Thin

wall molding requires specialized molding machines, injection molds and robots that can withstand the high stresses, fast cycle times and relentless 24/7 production schedules.

• To make thin wall parts we requires highly skilled molding

technicians and these are difficult to find and keep.

APPLICATIONSAPPLICATIONS

The following industries make use of thin wall molding:

food packaging ( eg. food containers and lids)

automotive (eg. both structural and non-structural car parts)

mobile telecommunications (eg. mobile phone housings)

medical (eg. syringes) 

computing equipment (eg. computer housings)

INTRODUCTIONINTRODUCTION

Micro Injection Molding is a special plastic moulding technique. The plastic parts made by means of micromolding have a weight less than 0.1 gr, or have structuraldimensions with less than 1 mm. This processing technology needs the use of quite special methods for the manufacturing of mold, and of course the injection of plastic material. One of the hurdles limiting the current technical capability in micro injection molding is that the molten polymer in a tiny cavity instantaneously freezes upon contacting the relatively cold cavity wall.The main objective is to develop a novel technology for successful micro injection molding with respect to lower cycle time, better replication and better mechanical and optical quality as compared to the existing technology. This objective will be accomplished by rapidly heating the mold surface so that the melt can fill the cavity isothermally and yet be processed within the normal injection molding cycle time

• LCP (Liquid Crystal polymers)• Acetal (polyoxymethylene POM)• Polyester• Polycarbonate• PEEK (Poly ether ether ketone)• Glass and Mineral filled compounds adds to therigidity and stability

• Materials like Nylons are not suitable for micromolding sincethey change size making it difficult to hold close tolerances

POLYMERS FOR

MICROMOULDING

2 STAGE MICRO INJECTION UNIT

ADVANTAGESADVANTAGES Tooling is less expensive. Typically a micro injection molding machine running 2 to 4 cavities

can compete with a standard molding machine having 16 cavities. Fewer cavities mean lower tooling cost and higher quality.

Parts are more accurate with less dimensional variability.

Cycles are very fast. Faster cycle times mean lower cost. Cycles typically run less

than 6 seconds and often as low as 3 and 4! Radical part geometries possible. Very thin walls with filled engineering materials are

possible. 

Defined colours

CHALLENGESCHALLENGES

APPLICATIONSAPPLICATIONSAUTOMOTIVE

TELECOMUNICATIONS

ELECTRONICS

MEDICAL

SENSORS

OPTICS

WATCH INDUSTRY

CONCLUSION

Due to the various advantages in multicomponent injection moulding , this method is used in wind deflector with integrated gaskets, automotive rear lamp cluster etc.

In mould decoration is a derivative of inmould labelling technique and is the future to decorative fashion and design.

Hollow articles of light weight with better finish can be produce by Gas assisted injection molding.

Thin-wall molded parts could be made lighter, more compact, less expensive, and quicker because of fast cooling

Micro and nano injection moulding is the future of moulding technology

REFERENCESREFERENCES

• www.arburg.com• www.raumedic.com• www.wikipedia.org• www.dakumar.com• www.4spe.org• www.mastip.com• www.milacron.com

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