What is 2K Injection Molding?

Today, we share the knowledge of 2K plastic Injection Molding.

1.Definition

2K mold,double injection&#;which is known as 2 material 2 shot molding, is an innovative manufacturing process used to produce complicated molded parts from two different materials.

2.Benefits

2.1 Time

The molding process reduces the secondary processing time.

2.2 Reduced Post-Processing

 The two-shot injection process is all-encompassing, everything is done in one move, and this cuts down the need for further processes like post-processing, which usually increase the cost, time, and energy consumption for nothing.

2.3.Appearance

The 2K injection moulding technique can be more attractive from an aesthetic point of view because the 2 components fit together seamlessly as product can be made in 2 colours (2K) in one production process.

What other advantages you may think about, welcome to leave your comments~~ Richael Liu

Inox 2k Injection Mold

Are you having a hard time looking for a reliable 2k injection mold solution provider in China? Explore no more since you are now in the right place! Inox Casting is a professional 2k injection mold popular provider with rich professionalism in this industry.

2k Injection Molding is also recognized as twin shot injection molding, two-shot injection molding, dual shot injection molding, bi injection molding, co-injection molding, and two-color injection molding. This process combined 2 different colors or plastics into one. The finished plastic product can have different properties, hardness levels, colors, and designs.

The benefit of preferring the 2k injection mold process conducted by Inox Casting is that it can reduce assembly times and set-up in integrating purposes. It can also be effective in reducing work steps and material.

The process of 2k injection molding creates a good quality connection through the benefits of 2 materials. With this process, components can include movable segments, transparent windows, integrated gaskets, vibration reduction, or water shields.

During the 2k mold manufacturing, we use the UG to manufacture and create designs for molds. This is the right technology we used to get done a design in accordance with 3D mold.

Some advantages of 2k injection molding:

• High efficiency & stable production process
• Lower part cost with assembling parts
• Stable part & high precision quality
• Improved cosmetic product properties
• Enlarge design tendencies
• Enhance the touch feel

Inox Cast has been supplying complete 2k injection mold solutions for more than 20 years. We have the competence to build and designs, recondition tooling, and update engineering to your specific request.

Our broad experience in the 2k injection mold business shows in the quality level of your finished product. We, Inox Casting experts always assure you of qualified products. We are your one-stop service provider, that surely meets every need of customers.

If you`re interested in our 2k injection mold, contact us right away!

2K Injection Mold: The Ultimate FAQ Guide

If you are looking for any information about 2k injection mold, you will find it right here.

This guide will help you understand everything about 2K injection mold &#; from design, applications to specifications.

Keep reading to learn more.

What Is 2K injection Mold?

A 2K injection mold is a modern technology that allows you to create complex molded parts from a pair of contrasting materials.

2K injection Mold

When using this mold type, you carefully regulate materials injection such as two distinct resins, into a single mold with multi-chambers.

A 2K injection mold executes two injections in a single cycle. First, you inject a plastic into a mold via a nozzle.

Thereafter, you execute another injection for a different plastic through a second nozzle upon rotating the mold.

Using a 2K injection mold allows you to develop a strong molecular link through optimizing material co-polymerization.

This results in the formation of a part bearing multiple benefits for use in different industries.

How Does A 2k Injection Mold Work?

In utilizing a 2K injection mold, you mix two different materials or with different color into a single final plastic product.

You can employ this machine to combine two completely distinct polymers into a unitary finished product.

In joining two materials into a single formation, you require a chemical bonding procedure. Therefore, material selection is central to the project&#;s success or failure.

What Are The Different Methods You Employ In 2K Injection Mold?

When using a 2K injection mold you can employ the following methods:

• Core-back Overmolding: This applies to only highly particular linear geometries.

The mold has a sliding part you can reset after injection of the first material to facilitate injection of second material.

core back overmolding

• Rotational Overmolding: Also automated, here you move the mold through injection stations allowing substrate and overmolded materials injection.
• Transfer Overmolding: This automated process involves mechanically lifting parts of a substrate from one mold and replacing them in a larger mold.

While forming the next substrate in the initial mold, you inject the overmolded material to occupy the void in the succeeding mold.

What Are The Processes You Undertake When Using A 2K Injection Mold?

The injection molding process in a 2K injection mold takes the following cycle:

i. Plastication: The process starts with a screw rotation that allows melt transport into the screw chamber ending when there&#;s enough material for molding.

ii. Closing the mold: Facilitated by the clamping unit movement forward such that the halves are close.

iii. Injection and Cooling: Commences by forward screw movement without rotation moving melt into the cavity.

Cooling of molded part precedes melt addition to counter volume contraction.

iv. Ejection: Ejection follows sufficient cooling of the mold marking the end of plasticating process.

What Should You Consider Before Employing The 2K Injection Mold?

When employing the 2K injection mold, you need to keep in mind the following:

• Before constructing a mold, identify any potential flaws in the process and eradicate them.
• Check that the first injection&#;s structural strength can sustain the second shot&#;s injection pressure.
• Ensure the first injection results in creation of the design&#;s structural element.
• Performance of a flow simulation analysis before commencing mold fabrication ensures you have the right design.

2K injection mold

• Take into account both materials shrinkage with the first injection material determining overall shrinkage.
• Take into account the locations of molded-in logos to avoid damage during any stage of the process.
• The initial injection component can be oversized resulting in the second injection having a higher pressure and consequently, stronger bond.
• The sub gate should be capable of turning off the respective runners throughout certain stages of the procedure.
• Verify that the injection setup&#;s parameters can deliver the needed pressure, flow rate, and cooling capabilities.

What Are The Advantages Of Using A 2K Injection Mold?

You find the following benefits in employing a 2K injection mold:

• Less waste when employing 2K injection mold means using this technology is environment friendly.
• Products you develop with 2K injection mold are light weight allowing replacement of metal portions with insignificant difference in strength.
• The 2K injection mold technology&#;s durability and strength are significant with products capable of tolerating harsh circumstances comparable to metal parts.
• The flexibility of the 2K injection mold technology is unparalleled allowing you to assign any plastic attribute you desire.
• There is the possibility of creating complex geometry by employing correct tool design and molding methodology to optimize process.
• Using a 2K injection mold is highly effective due to optimization of the manufacturing process and design.
• Using this technology is cost-efficient eliminating processes such as plastic part combination and over-embellishment and reducing the need for costly tooling adjustments.
• You achieve parts with extremely high precision due to the technology&#;s accuracy of +/-.001 inches that is repeatable across various processes.
• You can work with multiple plastic types simultaneously using the 2K injection mold which is difficult with conventional approaches.

What Are Some Common Products Of 2K Injection Mold?

You can employ the 2K injection mold to make the following products:

• Containers: This method can make plastic storage containers with different colors and even lid composition.
• Electronic Products: Using 2K injection molding, you can make plastic electronic items with LEDs included in the design.
• Gardening Implements: You can make softer seal surfaces by coupling with hard-wearing base sections.
• Medical Supplies: Medical equipment like bone saws with rubber grips are possible via 2K injection molding.
• Toiletries: You can make a toothbrushes with greater grip and colour, via combining a hard base plastic with a softer rubber.
• Toys: Where you can employ different colors and textures.

What&#;s The Difference Between 2K Injection Molding And Overmolding?

Overmolding is another injection molding type that permits combination of two or more distinct materials into a single product.

You top a stiff plastic base component with a malleable, thin rubber-like thermoplastic elastomer or other material.

You find the following differences between 2K injection molding and overmolding:

• In the overmolding process, the material used must cool before removal.

However, in 2K injection molding, you can work the polymer while still hot and flexible.

• Overmolding is common in small-scale manufacturing whereas 2k injection molding is common in large-scale production.
• The 2K injection molding technique can accommodate use of multiple materials, resulting in a high-quality end product.

Appling the same in overmolding can create compatibility concerns, particularly with plastics.

• You can only over mold a metal with a plastic and in few instances plastic over plastic. There are no such restrictions with 2K injection molding.
• You find a product from over-molding encompassing mechanically locked substances. In 2K injection molding, the bond is chemical with molecular linkage.

Overmolding

What Materials Do You Employ With A 2K Injection Mold?

Materials you employ in a 2K injection mold can form products for use across various industries.

Some of these materials include plastic and polymer variants such as:

• Acrylonitrile Butadiene Styrene (ABS)
• Biodegradable Polymers
• Composites/Blends
• High Impact Polystyrene (HIPS)
• Polyamide (PA)
• Polybutadiene Terephthalate (PBT)
• Polycarbonate (PC)
• Polyether Ether Ketone (PEEK)
• Polyethylene (PE)
• Polymethyl Methacrylate (PMMA)
• Polyoxymethylene (POM- Acetal)
• Polypropylene (PP)
• Polystyrene (PS)
• Polyurethane (PU)
• Styrene Acrylonitrile (SAN)

What Criteria Do You Employ For Material Selection For 2K Injection Mold?

In considering the material for use with your 2K injection mold, the following is important:

• Avoid using amorphous and crystalline materials together.
• Choose materials with the similar or matching shrinkage rate.
• Choose resins that are chemically comparable.
• Inject materials with higher molding temperature first to avoid wash-out and winkle.
• Reduce wash-out by always shooting the translucent layer first.
• Using a lower viscosity substance for the second injection helps to avoid wash-out.

What Sequence Do You Employ For Materials During Injection In A 2K Injection Mold?

It&#;s crucial to consider chemistry of the materials when using 2K injection molding.

While some materials establish an extremely strong molecular link, others exhibit imperfect bond.

You inject materials in a 2K injection mold in a sequence with the following guidelines:

• The harder of the two plastics should constitute the first shot.
• If you&#;re using both transparent and opaque materials, start with the transparent.
• The material with higher molding temperature goes first.

What Is A Draft Angle In 2K Injection Mold?

The draft angle describes an injection molded part&#;s slope imparted to the sides of most features.

This angle is towards the mold&#;s pull and parting line and aids in part removal from the mold.

It is uncommon for a part component to not require drafting as with some low-friction materials, like nylon variants.

However, including a draft in your design largely ensures success in part production.

Draft angle

It may seem insignificant to have quicker mold ejection, but draft is critical to producing quality components.

Minus draft, serious issues can develop in the injection molding procedure, lengthening production time and cost.

What Are The Design Basics For The 2K Injection Mold?

You find the following integral in the design of a 2K injection mold:

• Avoid blind pockets or ribs that are deep and without vents.
• Consider the TPE viscosity which is shear dependent during mold design and conditions setting.
• Have gradual transitions between wall thicknesses to avoid flow issues like backfills and gas traps.
• Position gates at the thickest part of the TPE wall.
• Prevent warpage by employing a TPE thickness less than or equal to the substrate thickness particularly for flat and long geometries.
• Use long draws of 3-5° per side to facilitate ejection of components.
• You get the best cycle time and eliminate shrink marks, when you have uniform product wall thickness.

What Should You Consider For The Shut-Off Design In 2K Injection Mold?

You have two shut-off design types, each with the goal of limiting TPE flashing or risk of delamination. You can design the overmold such that you reduce the chance of peeling by considering the following guidelines:

• The TPE surface should be flush with the substrate&#;s non-over molded part.
• The TPE edge should be deeper than the non-overmolded substrate surface.
• In limiting mold flushing, the overmold should be have a 0.4 mm &#; 0.8 mm deep groove along the substrate edge.

shut off design

What Problems Can You Encounter When Using The 2K Injection Mold?

You experience three common issues when using the 2K injection mold: poor adhesion, low temperature and low injection speed.

For the former, ensure you have the right material for your substrate.

You can also solve the speed issue by examining the tool and its fit with the mold.

Also possible is to re-cut the tool to achieve full shutoff with a minimum substrate interference of 0.05 mm.

Counter the injection speed by reducing the pressure of the initial injection and the time taken to fill the mold cavity.

Lowering the melt temperature by 10 degrees at a time also helps.

Why Is The Wall Thickness An Important Design Consideration For 2K Injection Mold?

You employ different tool sets in 2K injection molds. For a rotating platen design, the tools share the core but not the cavities.

The wall thickness is a significant design factor when designing parts for a variety of reasons:

• Because of the second step&#;s molding pressure, the substrate walls must be thick enough to bear the stresses without collapsing.
• To avoid defects stemming from uneven cooling, walls should be within typical thickness guidelines.
• Wall thickness shouldn&#;t fall below a particular minimum to ensure thorough and accurate material flow into all cavity regions.

 Why Is Bonding Important In 2K Injection Mold?

Bond strength is critical where the material combination is such that one is an elastomer that can separate from the substrate.

This is true for both thermoplastic elastomers and thermoset polymers which soften upon reheating or not respectively.

Bonding keeps the resin layers together and these bonds can be under various pulling forces depending on part design.

Some of these forces are:

• Shearing generated by a pull that is parallel to the surface of bonding initiating lap joint separation.
• Peeling that usually starts at an edge and spreads across the materials&#; interface.

What Bonding Methods Do You Observe In 2K Injection Mold?

Component design, selection of material, mold design, and technique of molding influence bonding. You find the layers adhere to each other in one of two ways:

Chemical Bonding

Occurs at the interface of the two resin layers on a molecular level under the influence of various factors.

One of these factors is the injected overmolded material&#;s capacity to moisten the substrate.

Wetting causes increased contact between the materials enhancing the bonding process.

The component temperatures, overmolded material viscosity, and materials roughness and porosity influence wetting.

Adhesion can occur at the interface in three ways:

• Co-crystallization
• Entanglement of polymer molecules mechanically
• Polymer chains chemical reaction

Mechanical Bonding

Mechanical bonding is dependent on the physical geometry of the contact surface.

Flow of overmolded resin into the substrate holes initiate bonding with the cooled overmolded material.

You can improve the mechanical bonding by folding the overmolded material over the substrate.

You can also expand the surface area of interaction by using posts, grooves, bosses or pickets.

Using a substrate that is porous creates holes of entry for elastomer to form a mechanical bond. Exposing the overmolded material&#;s edges results in peeling.

Where you raise the substrate material edge, you afford protection against peeling to the overmolded elastomer edges.

More Resources:

Die Casting Process

Metal Injection Molding

For any questions or inquiry about 2k injection mold, contact us now.

1.Definition

2K mold,double injection&#;which is known as 2 material 2 shot molding, is an innovative manufacturing process used to produce complicated molded parts from two different materials.

2.Benefits

2.1 Time

The molding process reduces the secondary processing time.

2.2 Reduced Post-Processing

 The two-shot injection process is all-encompassing, everything is done in one move, and this cuts down the need for further processes like post-processing, which usually increase the cost, time, and energy consumption for nothing.

2.3.Appearance

The 2K injection moulding technique can be more attractive from an aesthetic point of view because the 2 components fit together seamlessly as product can be made in 2 colours (2K) in one production process.

What other advantages you may think about, welcome to leave your comments~~ Richael Liu

Inox 2k Injection Mold

Are you having a hard time looking for a reliable 2k injection mold solution provider in China? Explore no more since you are now in the right place! Inox Casting is a professional 2k injection mold popular provider with rich professionalism in this industry.

2k Injection Molding is also recognized as twin shot injection molding, two-shot injection molding, dual shot injection molding, bi injection molding, co-injection molding, and two-color injection molding. This process combined 2 different colors or plastics into one. The finished plastic product can have different properties, hardness levels, colors, and designs.

The benefit of preferring the 2k injection mold process conducted by Inox Casting is that it can reduce assembly times and set-up in integrating purposes. It can also be effective in reducing work steps and material.

The process of 2k injection molding creates a good quality connection through the benefits of 2 materials. With this process, components can include movable segments, transparent windows, integrated gaskets, vibration reduction, or water shields.

During the 2k mold manufacturing, we use the UG to manufacture and create designs for molds. This is the right technology we used to get done a design in accordance with 3D mold.

Some advantages of 2k injection molding:

• High efficiency & stable production process
• Lower part cost with assembling parts
• Stable part & high precision quality
• Improved cosmetic product properties
• Enlarge design tendencies
• Enhance the touch feel

Inox Cast has been supplying complete 2k injection mold solutions for more than 20 years. We have the competence to build and designs, recondition tooling, and update engineering to your specific request.

Our broad experience in the 2k injection mold business shows in the quality level of your finished product. We, Inox Casting experts always assure you of qualified products. We are your one-stop service provider, that surely meets every need of customers.

If you`re interested in our 2k injection mold, contact us right away!

2K Injection Mold: The Ultimate FAQ Guide

If you are looking for any information about 2k injection mold, you will find it right here.

This guide will help you understand everything about 2K injection mold &#; from design, applications to specifications.

Keep reading to learn more.

What Is 2K injection Mold?

A 2K injection mold is a modern technology that allows you to create complex molded parts from a pair of contrasting materials.

2K injection Mold

When using this mold type, you carefully regulate materials injection such as two distinct resins, into a single mold with multi-chambers.

A 2K injection mold executes two injections in a single cycle. First, you inject a plastic into a mold via a nozzle.

Thereafter, you execute another injection for a different plastic through a second nozzle upon rotating the mold.

Using a 2K injection mold allows you to develop a strong molecular link through optimizing material co-polymerization.

This results in the formation of a part bearing multiple benefits for use in different industries.

How Does A 2k Injection Mold Work?

In utilizing a 2K injection mold, you mix two different materials or with different color into a single final plastic product.

You can employ this machine to combine two completely distinct polymers into a unitary finished product.

In joining two materials into a single formation, you require a chemical bonding procedure. Therefore, material selection is central to the project&#;s success or failure.

What Are The Different Methods You Employ In 2K Injection Mold?

When using a 2K injection mold you can employ the following methods:

• Core-back Overmolding: This applies to only highly particular linear geometries.

The mold has a sliding part you can reset after injection of the first material to facilitate injection of second material.

core back overmolding

• Rotational Overmolding: Also automated, here you move the mold through injection stations allowing substrate and overmolded materials injection.
• Transfer Overmolding: This automated process involves mechanically lifting parts of a substrate from one mold and replacing them in a larger mold.

While forming the next substrate in the initial mold, you inject the overmolded material to occupy the void in the succeeding mold.

What Are The Processes You Undertake When Using A 2K Injection Mold?

The injection molding process in a 2K injection mold takes the following cycle:

i. Plastication: The process starts with a screw rotation that allows melt transport into the screw chamber ending when there&#;s enough material for molding.

ii. Closing the mold: Facilitated by the clamping unit movement forward such that the halves are close.

iii. Injection and Cooling: Commences by forward screw movement without rotation moving melt into the cavity.

Cooling of molded part precedes melt addition to counter volume contraction.

iv. Ejection: Ejection follows sufficient cooling of the mold marking the end of plasticating process.

What Should You Consider Before Employing The 2K Injection Mold?

When employing the 2K injection mold, you need to keep in mind the following:

• Before constructing a mold, identify any potential flaws in the process and eradicate them.
• Check that the first injection&#;s structural strength can sustain the second shot&#;s injection pressure.
• Ensure the first injection results in creation of the design&#;s structural element.
• Performance of a flow simulation analysis before commencing mold fabrication ensures you have the right design.

2K injection mold

• Take into account both materials shrinkage with the first injection material determining overall shrinkage.
• Take into account the locations of molded-in logos to avoid damage during any stage of the process.
• The initial injection component can be oversized resulting in the second injection having a higher pressure and consequently, stronger bond.
• The sub gate should be capable of turning off the respective runners throughout certain stages of the procedure.
• Verify that the injection setup&#;s parameters can deliver the needed pressure, flow rate, and cooling capabilities.

What Are The Advantages Of Using A 2K Injection Mold?

You find the following benefits in employing a 2K injection mold:

• Less waste when employing 2K injection mold means using this technology is environment friendly.
• Products you develop with 2K injection mold are light weight allowing replacement of metal portions with insignificant difference in strength.
• The 2K injection mold technology&#;s durability and strength are significant with products capable of tolerating harsh circumstances comparable to metal parts.
• The flexibility of the 2K injection mold technology is unparalleled allowing you to assign any plastic attribute you desire.
• There is the possibility of creating complex geometry by employing correct tool design and molding methodology to optimize process.
• Using a 2K injection mold is highly effective due to optimization of the manufacturing process and design.
• Using this technology is cost-efficient eliminating processes such as plastic part combination and over-embellishment and reducing the need for costly tooling adjustments.
• You achieve parts with extremely high precision due to the technology&#;s accuracy of +/-.001 inches that is repeatable across various processes.
• You can work with multiple plastic types simultaneously using the 2K injection mold which is difficult with conventional approaches.

What Are Some Common Products Of 2K Injection Mold?

You can employ the 2K injection mold to make the following products:

• Containers: This method can make plastic storage containers with different colors and even lid composition.
• Electronic Products: Using 2K injection molding, you can make plastic electronic items with LEDs included in the design.
• Gardening Implements: You can make softer seal surfaces by coupling with hard-wearing base sections.
• Medical Supplies: Medical equipment like bone saws with rubber grips are possible via 2K injection molding.
• Toiletries: You can make a toothbrushes with greater grip and colour, via combining a hard base plastic with a softer rubber.
• Toys: Where you can employ different colors and textures.

What&#;s The Difference Between 2K Injection Molding And Overmolding?

Overmolding is another injection molding type that permits combination of two or more distinct materials into a single product.

You top a stiff plastic base component with a malleable, thin rubber-like thermoplastic elastomer or other material.

The company is the world’s best china insert moulding supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

You find the following differences between 2K injection molding and overmolding:

• In the overmolding process, the material used must cool before removal.

However, in 2K injection molding, you can work the polymer while still hot and flexible.

• Overmolding is common in small-scale manufacturing whereas 2k injection molding is common in large-scale production.
• The 2K injection molding technique can accommodate use of multiple materials, resulting in a high-quality end product.

Appling the same in overmolding can create compatibility concerns, particularly with plastics.

• You can only over mold a metal with a plastic and in few instances plastic over plastic. There are no such restrictions with 2K injection molding.
• You find a product from over-molding encompassing mechanically locked substances. In 2K injection molding, the bond is chemical with molecular linkage.

Overmolding

What Materials Do You Employ With A 2K Injection Mold?

Materials you employ in a 2K injection mold can form products for use across various industries.

Some of these materials include plastic and polymer variants such as:

• Acrylonitrile Butadiene Styrene (ABS)
• Biodegradable Polymers
• Composites/Blends
• High Impact Polystyrene (HIPS)
• Polyamide (PA)
• Polybutadiene Terephthalate (PBT)
• Polycarbonate (PC)
• Polyether Ether Ketone (PEEK)
• Polyethylene (PE)
• Polymethyl Methacrylate (PMMA)
• Polyoxymethylene (POM- Acetal)
• Polypropylene (PP)
• Polystyrene (PS)
• Polyurethane (PU)
• Styrene Acrylonitrile (SAN)

What Criteria Do You Employ For Material Selection For 2K Injection Mold?

In considering the material for use with your 2K injection mold, the following is important:

• Avoid using amorphous and crystalline materials together.
• Choose materials with the similar or matching shrinkage rate.
• Choose resins that are chemically comparable.
• Inject materials with higher molding temperature first to avoid wash-out and winkle.
• Reduce wash-out by always shooting the translucent layer first.
• Using a lower viscosity substance for the second injection helps to avoid wash-out.

What Sequence Do You Employ For Materials During Injection In A 2K Injection Mold?

It&#;s crucial to consider chemistry of the materials when using 2K injection molding.

While some materials establish an extremely strong molecular link, others exhibit imperfect bond.

You inject materials in a 2K injection mold in a sequence with the following guidelines:

• The harder of the two plastics should constitute the first shot.
• If you&#;re using both transparent and opaque materials, start with the transparent.
• The material with higher molding temperature goes first.

What Is A Draft Angle In 2K Injection Mold?

The draft angle describes an injection molded part&#;s slope imparted to the sides of most features.

This angle is towards the mold&#;s pull and parting line and aids in part removal from the mold.

It is uncommon for a part component to not require drafting as with some low-friction materials, like nylon variants.

However, including a draft in your design largely ensures success in part production.

Draft angle

It may seem insignificant to have quicker mold ejection, but draft is critical to producing quality components.

Minus draft, serious issues can develop in the injection molding procedure, lengthening production time and cost.

What Are The Design Basics For The 2K Injection Mold?

You find the following integral in the design of a 2K injection mold:

• Avoid blind pockets or ribs that are deep and without vents.
• Consider the TPE viscosity which is shear dependent during mold design and conditions setting.
• Have gradual transitions between wall thicknesses to avoid flow issues like backfills and gas traps.
• Position gates at the thickest part of the TPE wall.
• Prevent warpage by employing a TPE thickness less than or equal to the substrate thickness particularly for flat and long geometries.
• Use long draws of 3-5° per side to facilitate ejection of components.
• You get the best cycle time and eliminate shrink marks, when you have uniform product wall thickness.

What Should You Consider For The Shut-Off Design In 2K Injection Mold?

You have two shut-off design types, each with the goal of limiting TPE flashing or risk of delamination. You can design the overmold such that you reduce the chance of peeling by considering the following guidelines:

• The TPE surface should be flush with the substrate&#;s non-over molded part.
• The TPE edge should be deeper than the non-overmolded substrate surface.
• In limiting mold flushing, the overmold should be have a 0.4 mm &#; 0.8 mm deep groove along the substrate edge.

shut off design

What Problems Can You Encounter When Using The 2K Injection Mold?

You experience three common issues when using the 2K injection mold: poor adhesion, low temperature and low injection speed.

For the former, ensure you have the right material for your substrate.

You can also solve the speed issue by examining the tool and its fit with the mold.

Also possible is to re-cut the tool to achieve full shutoff with a minimum substrate interference of 0.05 mm.

Counter the injection speed by reducing the pressure of the initial injection and the time taken to fill the mold cavity.

Lowering the melt temperature by 10 degrees at a time also helps.

Why Is The Wall Thickness An Important Design Consideration For 2K Injection Mold?

You employ different tool sets in 2K injection molds. For a rotating platen design, the tools share the core but not the cavities.

The wall thickness is a significant design factor when designing parts for a variety of reasons:

• Because of the second step&#;s molding pressure, the substrate walls must be thick enough to bear the stresses without collapsing.
• To avoid defects stemming from uneven cooling, walls should be within typical thickness guidelines.
• Wall thickness shouldn&#;t fall below a particular minimum to ensure thorough and accurate material flow into all cavity regions.

 Why Is Bonding Important In 2K Injection Mold?

Bond strength is critical where the material combination is such that one is an elastomer that can separate from the substrate.

This is true for both thermoplastic elastomers and thermoset polymers which soften upon reheating or not respectively.

Bonding keeps the resin layers together and these bonds can be under various pulling forces depending on part design.

Some of these forces are:

• Shearing generated by a pull that is parallel to the surface of bonding initiating lap joint separation.
• Peeling that usually starts at an edge and spreads across the materials&#; interface.

What Bonding Methods Do You Observe In 2K Injection Mold?

Component design, selection of material, mold design, and technique of molding influence bonding. You find the layers adhere to each other in one of two ways:

Chemical Bonding

Occurs at the interface of the two resin layers on a molecular level under the influence of various factors.

One of these factors is the injected overmolded material&#;s capacity to moisten the substrate.

Wetting causes increased contact between the materials enhancing the bonding process.

The component temperatures, overmolded material viscosity, and materials roughness and porosity influence wetting.

Adhesion can occur at the interface in three ways:

• Co-crystallization
• Entanglement of polymer molecules mechanically
• Polymer chains chemical reaction

Mechanical Bonding

Mechanical bonding is dependent on the physical geometry of the contact surface.

Flow of overmolded resin into the substrate holes initiate bonding with the cooled overmolded material.

You can improve the mechanical bonding by folding the overmolded material over the substrate.

You can also expand the surface area of interaction by using posts, grooves, bosses or pickets.

Using a substrate that is porous creates holes of entry for elastomer to form a mechanical bond. Exposing the overmolded material&#;s edges results in peeling.

Where you raise the substrate material edge, you afford protection against peeling to the overmolded elastomer edges.

More Resources:

Die Casting Process

Metal Injection Molding

For any questions or inquiry about 2k injection mold, contact us now.

Contact us to discuss your requirements of china molding injection. Our experienced sales team can help you identify the options that best suit your needs.