Common Injection Molding Tool Surface Treatments and How to Choose the Right One

Common Injection Molding Tool Surface Treatments and How to Choose the Right One

In manufacturing, selecting suitable injection molding tool surface treatments is paramount yet often overlooked. This article demystifies various surface treatments such as plating, nitriding, and carburizing.

Understanding these treatments is crucial in enhancing tool life and product quality. With this knowledge, you’ll be better equipped to make informed decisions in your injection molding processes.

Stay tuned to navigate the complexities of this crucial aspect of manufacturing.

Why is Injection Mold Treatment Important?

Injection mold treatment serves a crucial role in the manufacturing process. It directly influences injection molding tools’ performance, longevity, and overall cost-effectiveness.

Here’s why:

Firstly, it significantly enhances the tool’s durability. Surface treatments like plating or nitriding form a hard, protective layer on the tool’s surface, reducing wear and tear during injection molding. This effectively prolongs the tool’s life, reducing costs over time.

Secondly, mold treatment improves the product’s quality. A well-treated mold minimizes surface defects on the molded parts, ensuring a smooth, high-quality finish.

This is especially important in industries with critical product aesthetics, such as consumer electronics or automotive parts.

Lastly, some treatments can reduce the tool’s maintenance needs. For example, coatings like PVD or CVD create a low-friction surface, making the mold easier to clean and reducing the frequency of necessary maintenance.

In a nutshell, injection mold treatment is essential in optimizing the injection molding process. It ensures the production of high-quality parts, extends tool life, and can lower overall manufacturing costs.

Types of Surface Treatment for Plastic Injection Mold Tools

1. Plating:


Plating is a widely recognized surface treatment technique to prepare injection molding tools. The process fundamentally involves depositing a metallic layer onto the tool’s surface.

This is accomplished through an electrochemical process where metal ions in a solution are reduced onto the tool’s surface, forming a robust metallic coating.

This coating considerably augments the tool’s inherent hardness, wear, and corrosion resistance. These enhancements are critical in prolonging tool life and reducing the frequency and intensity of maintenance required, thereby increasing the overall efficiency of the injection molding process.

One of the most frequently employed plating processes is chrome plating. This process involves depositing a layer of chromium onto the tool’s surface.

Chromium is renowned for its exceptional hardness and wear resistance, making it an excellent choice for the rigors of the injection molding environment.

Check Out: Chrome Plating 101: And Ways to Remove Chrome Plating

2. Nitriding:


Nitriding is a sophisticated heat-treating process that infuses nitrogen atoms into the surface of a metal, typically under a controlled high-temperature environment.

The result of this procedure is forming a case-hardened surface, a thin layer of metal that’s significantly harder than the core.

This hardened surface substantially improves the hardness and wear resistance of the injection molding tool, significantly enhancing its operational life. The nitriding process has the distinct advantage of promoting corrosion resistance.

It does this by forming a nitride layer on the tool’s surface that is a barrier, preventing corrosive substances from reaching its core material. This feature of nitriding makes it highly suitable for tools subjected to aggressive or corrosive processing environments.

Furthermore, nitriding is particularly beneficial for tools used to mold specific materials like Polyvinyl Chloride (PVC).

Due to its chlorine content, PVC is known to release corrosive gases during molding. These gases can lead to accelerated tool wear and corrosion.

3. Carburizing:


Carburizing, also known as case hardening, is a high-temperature thermochemical process that enriches the surface layer of a metal tool with additional carbon.

During the process, the tool is heated to high temperatures in a carbon-rich environment, typically consisting of either a solid, liquid, or gas, depending on the specific method of carburization employed.

The carbon atoms diffuse into the surface of the metal, penetrating to a specific depth that is carefully controlled by adjusting the process parameters. This carbon infusion results in a drastic increase in the hardness of the tool’s surface.

This is achieved as the additional carbon transforms the surface layer into high-carbon steel, significantly harder than the low-carbon or medium-carbon steel that typically forms the tool’s core.

Moreover, this hardened case significantly boosts the tool’s fatigue resistance, increasing its ability to withstand the cyclical stresses involved in repeated molding cycles without failure.

Notably, one of the critical advantages of carburizing is the degree of control it offers. By adjusting the duration, temperature, and carbon potential of the carburizing environment, the hardness level and the depth of the hardened layer can be accurately tailored.

4. PVD Coating:

Physical Vapor Deposition (PVD) is a sophisticated vacuum coating process in material science. It leverages thermodynamic principles to deposit a thin yet extremely durable film on the surface of the injection molding tool.

During PVD, the target material is evaporated and subsequently transported in the form of vapor within a vacuum environment. This vapor condenses on the tool’s surface, forming a solid, adherent coating.

A primary advantage of PVD coatings is their ability to significantly enhance the hardness of the tool, reducing the possibility of deformation under high-pressure molding conditions.

This ensures dimensional accuracy in the molded parts, a critical factor in maintaining consistent quality.

PVD coatings also offer a remarkable reduction in friction. This decrease in surface friction not only improves the efficiency of the molding process by facilitating smoother mold release but also reduces wear and tear on the tool, thus extending its operational lifespan.

PVD coatings also allow for a high level of detail in the molded products. The thin yet hard coating enables the precise replication of intricate tool designs in the final molded product, making PVD an ideal choice for molding complex, detailed parts.

Additionally, PVD coatings are not limited to a single aesthetic. They can be produced in a wide range of colors, providing an opportunity to add aesthetic value to the tools, which can be particularly beneficial in consumer-facing applications.

5. CVD Coating:

CVD Coating

Chemical Vapor Deposition (CVD) is a sophisticated vacuum coating procedure involving a distinctive coating application approach, distinguishing it from processes like PVD. The core mechanism of CVD consists of the decomposition of volatile precursors within a high-temperature environment.

These decomposed molecules then react with the tool’s surface, forming a dense, high-quality coating that integrates firmly with the underlying substrate. This close-knit chemical bond imparts the tool surface with exceptional wear and corrosion resistance.

CVD coatings are especially beneficial when dealing with molding tools intended for abrasive materials. The robust nature of the CVD coating not only minimizes surface wear caused by the abrasive interaction but reduces the friction between the mold and the material, facilitating a smoother molding process.

One of the defining characteristics of CVD coatings is their uniformity and smoothness. CVD can evenly coat complex and intricate geometries with high precision, unlike other coating methods. This attribute benefits molds with intricate designs and structures, ensuring a consistent, high-quality surface.

By adjusting the precursor materials and deposition conditions, CVD coatings can be tailored to a range of characteristics, such as hardness, corrosion resistance, and friction coefficients. This level of adaptability allows for a highly customizable solution, making CVD a versatile choice for various injection molding tool applications.

Read Out: Injection Mold Tooling- Making The Perfect Molds

Considerations for Mold Treatment

Choosing the proper mold treatment is crucial in optimizing the injection molding process. However, the choice isn’t always straightforward.

Here are some considerations to help guide this decision:

1. Material Compatibility:

Material Compatibility

The first consideration is the compatibility of the treatment with the material used for molding. Some materials, such as PVC, are corrosive, requiring treatments like nitriding for the tools.

Others might be abrasive, demanding more wear-resistant coatings like those achieved through CVD.

2. Tool Lifespan:

The lifespan of the tool is another key factor. Treatments like carburizing and PVD coating can significantly enhance the tool’s durability, making these treatments a good choice for long production runs.

If the tool is only needed for a short run, a less durable (and typically less expensive) treatment may suffice.

3. Product Quality:

The desired quality of the final product also influences the choice of treatment. If high-quality, detailed parts are required, treatments that produce a smooth, low-friction surface (like PVD and CVD coatings) can improve the final product’s finish.

Similarly, treatments that facilitate a smoother mold release (like plating) can also enhance the quality of the final product.

4. Cost Considerations:

Cost Considerations

Cost is always a factor in manufacturing decisions. While more robust treatments like nitriding or PVD may extend the tool’s life and reduce long-term costs, they also come with a higher upfront cost.

It’s essential to balance these costs with the expected benefits and determine what’s most cost-effective for your specific situation.

5. Environmental Impact:

Environmental Impact

Lastly, the treatment’s environmental impact is increasingly being considered. Some treatments require hazardous chemicals or produce harmful waste. If environmental sustainability is a concern, you may want to opt for more environmentally friendly treatment options.

Choosing the proper mold treatment can seem complex, but considering these factors can guide you in making an informed decision. Always keep in mind the specific needs of your molding process and balance these against the costs and benefits of each treatment.

Kemal Plastic Injection Molding Services

Kemal Plastic Injection Molding Services

Regarding top-notch plastic injection molding services, Kemal is a name you can trust. With over 20 years of experience in the industry, Kemal excels in providing tailor-made solutions for your molding needs.

Our team of experts understands the intricacies of injection molding. It leverages this knowledge to recommend the optimal surface treatment for your tools.

Moreover, Kemal’s commitment to customer satisfaction doesn’t end with delivering top-quality molds. We also provide comprehensive support, assisting you at every stage, from mold design and material selection to choosing the proper mold treatment.

If you’re looking to optimize your injection molding process, considering the myriad factors in mold treatment can be overwhelming. Why not let the experts at Kemal handle it for you?

Contact us for more information on our injection molding services and how we can help streamline your manufacturing process.


Surface treatments in injection molding tools increase the tool’s lifespan, improve the quality of the final product, and reduce the tool’s maintenance needs.

Treatments like plating or nitriding enhance the tool’s durability and wear resistance, which leads to longer tool life.

The choice of surface treatment can significantly influence the overall cost of the injection molding process.

While treatments like nitriding or PVD coating may involve a higher initial cost, they can reduce long-term costs by extending the tool’s lifespan and reducing maintenance needs.

Balancing these factors is crucial in choosing a cost-effective treatment.

Nitriding is a heat-treating process that infuses nitrogen into the surface of the metal tool. This process creates a case-hardened surface that improves the tool’s hardness and wear resistance.

Nitriding is particularly effective for tools used for molding corrosive materials like PVC, as it minimizes the risk of corrosion and enhances tool durability.

Carburizing is a thermochemical process where the tool’s metal surface is enriched with carbon. This enhances the tool’s surface hardness and fatigue resistance, making it more durable and suitable for long production runs.

The carburizing process can be precisely controlled to achieve the desired hardness and depth of the hardened layer, allowing for the customization of the tool to specific requirements.

Some mold treatments require hazardous chemicals or produce harmful waste, which can impact the environment.

If environmental sustainability is a concern, choosing a more environmentally friendly treatment option may be desirable.

This could involve choosing a treatment that uses less hazardous chemicals or produces less waste or implementing measures to manage and dispose of any waste produced effectively.

While both PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) are vacuum coating processes used to apply a thin film to the tool’s surface, they differ in how the coating is applied.

The coating is transported as a vapor to the tool’s surface in PVD. On the other hand, CVD involves a chemical reaction at the tool’s surface that results in the deposition of the coating.

Plating is a popular choice for several reasons. Firstly, it enhances the tool’s hardness, wear resistance, and corrosion resistance. This leads to an improved tool lifespan and reduced maintenance.

Secondly, a well-executed plating process can result in a smoother surface, facilitating a more accessible release of the molded part and improving the final product’s quality.

Lastly, the plating can also offer an aesthetic appeal, with options like chrome plating providing a shiny, attractive finish.

Specific mold treatments can significantly reduce the maintenance needs of the tool. For example, PVD and CVD coatings create a low-friction surface, making the tool easier to clean and reducing necessary maintenance frequency.

Similarly, treatments that enhance the tool’s corrosion resistance, like nitriding or plating, can reduce the need for regular maintenance checks for corrosion.

Yes, the choice of mold treatment can impact the speed of the injection molding process. Specific treatments can create a smoother, low-friction surface that facilitates a quicker release of the molded part from the mold, speeding up the overall process.

Additionally, treatments that reduce the tool’s maintenance needs can minimize production downtime, further enhancing the efficiency of the injection molding process.


In conclusion, the choice of injection molding tool surface treatment can profoundly impact your product quality, tool lifespan, and overall manufacturing efficiency.

It’s vital to weigh these considerations carefully and select the best treatment for your needs.

Have you considered how the proper treatment could elevate your injection molding process? Visit Kemal Manufacturing today and let our experts guide you to an optimized solution.

Put your parts into production today

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