A Comprehensive Guide To Thin Wall Injection Molding Process

Figure 1 Thin Wall Injection Molding Process

Figure 1: Thin wall injection molding process

Injection molding is a popular manufacturing process for producing plastic parts. With injection molding, businesses can produce high-volume production runs without breaking the bank. It’s an economical yet reliable process that yields strong components with precise dimensions and mechanical specifications. Moreover, it provides consistently uniform results for all of your projects.

For companies needing to form plastic components with thin walls, such as certain car parts or cell phone cases, thin wall molding is a viable solution. Thin wall injection molding is a revolutionary manufacturing process that has transformed how we create products. It offers an unbeatable combination of speed and precision, allowing manufacturers to make intricate parts quickly and cost-effectively.  

Well, thin wall molding comes with a host of benefits and some challenges also. This blog post shares a complete overview of the process, with all its advantages, as well as its difficulties. So let’s get started.

Thin wall injection molding process | A basic overview

Figure 2 Thin Wall Injection Molding

Figure 2: Thin wall injection mould

Thin wall injection molding is a specialized form of injection molding that involves producing parts with walls measuring less than 1mm in thickness. It produces plastic components for medical, consumer, and other industries. The process involves injecting a thermosetting material into a metal cavity at high pressure and temperature. This helps form the desired shape of the component.

A significant reduction in cycle time and cost is the primary advantage of thin-wall injection molding. Compared to thick-walled parts, this process allows manufacturers to produce components much faster and more efficiently. This helps businesses save on labor costs as well as energy consumption. Additionally, due to its precise nature, it also results in higher quality parts with fewer rejects.

In traditional injection molding, thin-wall injection molding is relatively new and has been gaining popularity in recent years. It has become an attractive alternative for many businesses as it helps them reduce their costs while producing higher-quality products. With its ability to produce intricate parts with close tolerances, this process has revolutionized the plastic injection molding industry.

Common benefits of thin wall injection molding

We truly believe that thin wall injection molding is the way of the future. Here are some of the most significant benefits of this powerful process:

  • High-speed filling:

Thin wall injection molding has been a great boon to the plastic injection molding industry. It offers significant advantages, such as high-speed filling of cavities, achieved through power-dense hydraulic systems rather than high-pressure injection, and reduction in clamping force requirements.  

With this increased speed, products can be quickly produced with little internal stress or deformation. While traditional machines offer 100 mm/s injection speeds, an oil pump can boost that rate by up to 25%, while doubling the pump increases it even more, up to 70%. Ultimately, these improvements mean more efficient manufacturing of thin wall products at a much better value.

  • Low inertia injection:

The high-speed injection is not the only factor to consider when achieving top-notch thin wall injection. Low inertia injection should also be considered, as it ensures that the screw accelerates quickly from a standstill to full speed.

For example, it reaches 400mm/s in just 0.05s with an acceleration rate greater than 8G. Otherwise, if the time it takes to accelerate is longer, the average speed won’t reach desired levels, and emphasis on low inertia injection should be taken into account.

  • Quality and Accuracy:

Using advanced technology and high production speeds, thin wall injection molding provides superior-quality parts with tight tolerances. In comparison to traditional injection molding processes, you can expect better accuracy and more uniform products using this process. 

Additionally, using the latest technologies in plastic injection mold design and manufacturing helps produce products with exceptional surface finishes, allowing for a wide range of aesthetic possibilities.

  • Short injection cycle:

Do you know what the best thing about thin wall injection molding is? Not only does it produce quality parts with accuracy and precision, but it also reduces overall cycle time. 

As a result, production costs are lowered significantly as well as energy consumption. This makes the process more attractive to businesses looking to create high volumes of components at faster rates; it also helps reduce the number of rejects and waste in production.

Some tips and tricks that can help you get the most out of it

The thin wall injection molding process is extremely useful for production processes, especially when creating delicate parts that require precise detail and often complex structures. But despite its advantages, you still need to understand and know the various tips and tricks for thin-wall injection molding.

Choose material wisely:

Material selection is of utmost importance when injection molding parts with thin walls. While some materials may be too sticky to fill molds properly, such as polycarbonate (PC), other thermoplastics allow for easier flow through narrow sections, including high-density polyethylene (HDPE), low-density polyethylene (LDPE), nylon (PA) and polypropylene (PP)

Additionally, liquid silicone rubber (LSR) will fill easily, although it can increase the risk of flash along your mold’s parting lines.

Figure 3 Thin Wall Materials

Thin wall injection molding materials

Keep the pressure up:

The key to successful thin wall molding is maintaining adequate melt pressure during the injection cycle. After all, this pressure pushes molten plastic into tight spaces for well-defined contours and intricate details to be achieved. 

To ensure your parts are molded correctly, you need to run your injection molding machine’s pressure at a higher rate than normal, and you may also need to adjust the screw diameter or tip.

Have uniform wall thickness:

Due to the nature of the thin wall injection molding process, parts must have uniform walls throughout. This means that you should avoid varying wall thicknesses as it can create unacceptable inconsistencies in part. 

Additionally, if a part has multiple sections with different wall thicknesses, you’ll need to use separate tools for each section and combine them after the parts have been molded.

Pay attention to temperature:

Temperature is another critical factor in the thin wall injection molding process as it needs to be on the lower end of the melting point spectrum. This is because too high a temperature may cause warpage or even collapse, while too low a temperature will result in poor flow and inadequate filling. 

To maximize the performance of your tool, you should aim to augment coolant flow instead of lowering the temperature. Ensure that there is a maximum 10°F difference between delivered and returned coolant for optimal results.

Challenges of thin wall injection molding process

Thin wall injection molding can be a tricky task. As the name implies, thin wall molding requires precise measurements to ensure the plastic is effectively filled in any part of the mold or cavity. Here are some challenges associated with thin wall molding:

  • A poorly designed mould will break:

One of the biggest challenges with thin wall injection molding is that a poorly designed mold will easily break. This can be due to improper material selection, incorrect cooling and heating element placements, and other design flaws. 

To get the most out of your thin wall injection molding process, it’s important to have a well-designed mold that will stand up to the extreme pressures and temperatures associated with the process.

  • No margin for error:

The thin wall injection molding process also requires precise measurements, as there is no room for error. If the plastic does not fill every part of the mold or cavity, it could lead to a poor-quality product with parts that don’t fit. 

This can be avoided by ensuring that all components are made to exact specifications and that any changes to the mold or process are carefully tested before implementation.

  • High capital investment:

Finally, thin wall injection molding requires a high capital investment due to the specialized equipment and materials needed. This can be especially true if you’re investing in expensive multi-cavity molds that require more setup time than single-cavity molds. However, the payoff of higher production volumes may often outweigh this initial investment.

Thin wall injection molding process conclusion:

Thin wall injection molding is an incredibly versatile manufacturing technology that offers various benefits for businesses in various industries. Whether you’re producing small, intricate parts or large-scale components with complex shapes and designs, thin wall injection molding can provide the perfect solution. 

Well, Go4mould is your best partner if you need to implement the thin wall injection molding process into your production process. We are specialized in thin wall mould including food container mould and wall container mould that require precision and high quality. We strive to provide our clients with the highest quality services, and we’re always happy to help you make the most of this amazing technology. 

So what are you waiting for? Contact us today, and let us show you how the thin wall injection molding process can revolutionize your production process.

We look forward to hearing from you.

Thin wall injection molding process FAQ

Why thin wall molding requires high pressure and high speed?

Thin wall parts necessitate a higher injection pressure as the amount of material that can flow is contingent upon its thickness. The higher injection pressure ensures that the material is fully compressed and evenly distributed. High-speed molding is also necessary to ensure a short cycle time, faster production, and reduced energy consumption.

What is the ideal wall thickness of an injection molded component?

The ideal wall thickness of an injection molded component will depend on the application. Generally speaking, most parts can be molded with a wall thickness between 1 mm and 4 mm. Thin walls are advantageous due to their lightweight nature and improved aesthetics.

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