Introduction to Mold Engineering of Thermoplastic

most electrical, and home appliances made from plastic, one of technology to make plastic product is using mold, specially injection mold of thermoplastic, basically when thermoplastic material heated, they will change of state, thermoplastic material will become soft, melt and flowable, when cooled again, they become solid again.

What is Injection Mold ?
there are some definition of injection mold

is a manufacturing technique for making parts from both thermoplastic and thermosetting plastic materials in production (wikipedia.com)

A manufacturing process for forming objects, as of plastic or metal, by heating the molding material to a fluid state and injecting it into a mold.(www.answer.com)

Herbert Ress, 2002 : an injection mold is arrangement, in one assembly a number of cavity spaces built to shape of the desired product, with the purpose of producing plastic parts in large number

this blog define injection mold is manufacturing process to make plastic product that have cavity spaces to shape the product by heating and injection pressure.

Types of Injection Molds
based on how injection mold would be processed wikipedia.org devide injection mold as 7 types until now, they are
1. Reaction injection molding
2. Liquid injection molding
3. Gas assist injection molding
4. Co-injection molding
5. 2-Shot Injection Molding
6. Fusible core injection molding
7. Rapid injection molding

based on type of opening method and runner system, The DIN ISO standard 12165, "Components for Compression, Injection, and Compression-Injection Molds" classifies molds on the basis of the following criteria:
1. standard molds (two-plate molds)
2. split-cavity molds (split-follower molds) stripper plate molds
3. three-plate molds
4. stack molds
5. hot runner molds

depending on material to be injected classifies as :
1.thermoplastic injection molds
2.elastomer molds
3.thermoset molds
4.structural foam molds

picture below shown 3 plate mold type with cold runner system and ejection system
click the picture to enlarge




closed Condition
picture below shown 3 Plate Molds Types in 3D design, in closed position with support pin, puller bolts, leader pin or positioning pin.


you can also learn more about basic pin construction at post about pin in molds
Opening Condition
then the construction molds of 3 plate type when opening is like picture below

picture below is shown three plate condition when open


we also can learning more about ppening Sequence, why and how the molds open, and explaining each molds opening step or sequence at post about opening construction

those opening sequence is just for 3 plate type, 2 plate type is more easy becouse just have one opening parting line.