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What is double injection molding? Simple Guide to 2 Shot Molding Process

April 21, 2021
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What is double injection molding definition?

double injection molding

Double injection mold, in some cases known as 2 fabric 2 shot molding and 2K molding, is an inventive fabricating handle that has an implementation in creating complex mold components from two diverse materials.

Through an exceedingly specialized and computerized handle, we carefully control the infusion of different materials, counting two diverse sorts of tars, into a single, multi-chamber mold.

What is double infusion?

Double infusion, one can do it in a single machine that has a modification to perform two infusions in one cycle. Within the beginning cycle, a spout infuses plastic into a form. The form is at that point consequently pivoted a diverse sort of plastic is infused into the form from a moment spout.

What is 2 shot injection molding?

2 shot injection molding optimizes co-polymerization of rigid as well as delicate materials to form a powerful molecular bond. The outcome could be a single portion with generation and highlight points of interest. It has an implementation for an assortment of item designs overall businesses.


Moreover, it permits molding utilizing clear plastic, colored designs, and smart warps up which progresses your item usefulness and commercial center esteem. Also stands for the double injection mold.

What is the two-color injection molding process?

Two-color molding is the one accessible prepare for overseeing item molding with two diverse materials and colors, utilizing concurrent molding forms within the same infusion machine to yield a single unit.

The double color machine has presently broad utilization for electronic parts, electric apparatuses, therapeutic parts, domestic machines, toys, and nearly all zones of plastic items.

Center stack revolving double shot into hot double color molding strategy seen in later a long time, contrasting from common two-color rotatory infusion molding, particularly within the car infusion molding segment, for items such as two-color entryway boards, and so on.

What is a double injection molding machine?

A double injection mold may be a plastic molding arrangement that two diverse materials or the same fabric with diverse colors are infused into one plastic portion at one time with an infusion molding machine with two sets of infusion frameworks. It is an imaginative handle of molding. It is much more complex than a single infusion shape.

Moreover, the expense of a twofold infusion shape is higher than a single infusion mold. Buttons in the computer and communication region are for the most part made by two steps, the primary step is molding the button without character, the moment step is that the character is printed on confront of the button.

What is a two-shot injection molding design guide?

The molds utilized in double injection mold comprise diverse infusion sets. In a turning platen setup, the devices share the same center but not the same cavities. When planning about parts the divider thickness is an imperative plan through for different reasons.


Due to molding weight from the second step, the substrate divider ought to be of sufficient thickness to resist the strengths without collapsing. Wall should not surpass routine to form defects crediting to sporadic cooling.

In arrange to guarantee exact and intensive fabric stream into all parts of the depression, divider, and thickness ought to not be lower than a certain minimum.

How to injection the material?

The material should be infused in a certain grouping and taking after into the following considerations.

  • The first shot ought to be the rigid plastic of the two.
  • If straightforward and dark material materials are utilized, infuse the straightforward fabric first.
  • In common, to begin with, infuse the fabric with a higher molding temperature.

For the shape and inserting design:

  1. Ensure the form is rotatable through 1800
  2. Any embeds ought to be symmetrical
  3. The thrust bar plate and ejector stick ought to be kept steady with a return spring to maintain a strategic distance from harm amid the turn of the mold.
  4. The cooling framework must be able to do adequately for primary and secondary shots.

How long does an injection mold last?

The lifetime of an infusion shape is measured in its anticipated number of generation cycles, that’s, how numerous times the mold is utilized to make a portion. So in pitch, a generation cycle straightforwardly relates to the number of parts an infusion shape will be able to create in its lifetime.

However, double injection mold lasts longer than single infusion molding.

The society of the plastics industry (SPI) classifies infusion molds based on their life expectancy.

Class 101

It has a life anticipation of 1,000,000 plus cycles. These are the foremost costly infusion molds.

Class 102

It's life anticipation not to surpass 1,000,000 cycles. These are expensive but not much.

Class 103

The life hope of class 103 is beneath 500,000 cycles.

Class 104 & Class 105

Life hope of class 104 is less than 100,000 cycles and the living hope of class 105 is less than 500. This classification is for model molds and these molds are the slightest costly.

Fair as with human beings and stock showcase, there’s no genuine way to anticipate precisely how numerous generations cycles a form will last. There are continuous shocks, indeed you have well design and superb mold. That being said, you ought to be able to urge an evaluated life expectancy based on a few variables. These variables are:

  • Cycle times
  • The time between production runs
  • Operating conditions
  • Injection mold type and material

What is co-molding?

Co-molding or over-molding alludes to two plastic materials to bond, which is ordinarily are a difficult fabric like ABS and a delicate fabric like TPE. However, it may well be the same difficult materials to bond together depending on the dissolving warmth.

double injection molding 2021

How thick can you injection mold?

On normal, the least divider thickness of an infusion molded portion ranges from 2mm to 4mm. It may be from 0.080 inches to 0.160 inches. Parts with uniform divider thickness permit the formed cavity to fill more absolutely since the liquid plastic does not need to constrain through changing limitations because it fills.

If the dividers are not uniform, the more slender areas are cool first. As the thicker segment cools and shrivels, stresses happen between the boundaries of a lean and thick divider. As the thick areas yield, twisting and bending of the portion happens, which may be responsible for breaks.

What are the types of injection mold?

Six main types of double injection mold are:

  • Thin wall molding
  • Gas-assisted molding
  • Metal infusion molding
  • Three-dimensional printing and
  • A unique material formulation as well as
  • Liquid silicone infusion molding

Why are the injection molds so expensive?

Infusion molds are subject to heavy pressure for each cycle. Due to this, the molds must be made from an exceptionally solid material that can withstand rehashed utilize without misshaping. The foremost common choice for infusion molds is steel. The steel which has utilization in double infusion mold is highly expensive.

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