We often talk about the top products imported from China. However, many importers also buy services and solutions.
Injection molding is now a common name in manufacturing. It involves injecting molten plastic into a metal mold to make products. It has become a popular manufacturing technique in industrial China.
People importing products from China often think about making custom products. That’s where injection molding services can come to help.
However, the sourcing process requires a lot of attention. Moreover, many steps are involved to ensure all the moving parts work. This article explores everything needed to make injection molds in China.
Key Highlights!
- Injection molding is compatible with over 25,000 unique materials. It can create everything from automotive parts to medical equipment and toys.
- Did you know there are two main types of injection molding systems? The cold runner system offers low costs. Likewise, the hot runner system provides fast production and less waste. So, which one suits your manufacturing needs?
- Have you considered how many production cycles your project requires?
- Is injection molding the right choice for your production scale?
- You can get affordable injection molding solutions with the help of a China sourcing service.
Keep reading this China injection molding guide for an overview of the process.
An Overview of Injection Mold and Its Potential Uses
Many manufacturers now rely on injection molds for their products. It is a process that creates various goods by injecting molten plastic.
The molds are typically made of solid materials, such as Aluminum and steel. Moreover, you can trust the technique to deliver enormous amounts of plastic products.
To fully grasp how to manufacture plastic injection mold in China, you need to know what it does. The injection molds have a wide range of applications. Here are the common examples across the different sectors:
| Industry | Injection Molding Application |
| Automobile | Plastics for the exterior and interior of the automotive |
| Electronics | The housing of devices such as smartphones and remotes. |
| Medical Equipment | Creates medical equipment such as syringes and others |
| Toys | You can create simple toys with an injection mold |
Note: It is the best method if you prefer to buy from China factory directly. You can make many different designs as long as you get a custom mold design in China.
Benefits of Sourcing Injection Molding from China
Many Chinese manufacturers flock to Injection molding. What is the appeal, and why is it a favored pick for many importers?
Well, Chinese manufacturers have invested heavily in equipment and quality control processes. They have decades of experience in plastic manufacturing.
Key Benefits of Sourcing Injection Molding from China:
- Lower labor and operational costs work in your favor. You get better pricing without compromising quality.
- Chinese manufacturers have well-established networks of material suppliers. It ensures efficient production and smooth global sourcing.
- They can handle both small-batch productions and high-volume orders.
How Does Injection Manufacturing Molds in China Work
To the elephant in the room, the mechanism of the admirable injection mold. This manufacturing technique has boggled many minds. Today, we take a closer look at how it functions to get insights on how to approach it.
It has a process similar to the die-casting process. Its entire cycle is done within a couple of minutes. Here are the five simple steps that Chinese mold manufacturers follow:
1) Clamping
Spray the two halves of the injection mold with release agents. This spraying ensures a seamless release later. However, depending on the plastic you are using, you might not have to add a release agent.
Then, they shut the injection mold. Both molds usually come attached to the manufacturing machine. One of the halves is fixed in place, while the other can slide to facilitate ejection.
2) Injection
Now, it is time for the injection. The molten plastic is poured into the mold cavity quickly and with loads of pressure. The amount of molten plastic injected into the mold is commonly known as a shot.
3) Cooling
Everything has to be cool. Water cooling aids the molten plastic in solidifying and cooling quickly. This process usually takes about 60% of the entire manufacturing time.
4) Eject
After cooling, ejection is the ideal next step. This process requires the release agent of the first step for a smooth release. Hence, the rule of thumb is to start with the release agent so the ending is less strenuous.
This step ends the cycle, and now the recurrent cycles can follow. Note that the recurrent cycles are just a repeat of all the first steps I have listed.
5) Post-production
While the ejection ends the cycle, manufacturing doesn’t end there. Finishing is necessary to ensure the products reach the desired nature. The post-production steps include several crucial steps.
Plastic varies in function, and the function often depends on specific customizations. Moreover, you might also need to paint or powder coat the product.
Current Techniques Injection mold factories in China Incorporate
Two main injection mold manufacturing techniques in China exist hot and cold runners.
Moreover, they have applications that they are better suited for. But so you don’t get lost, let me explain what runners are. The term “runners” refers to channels that transport molten plastic to the mold cavity.
1) Cold Runner System
This technique is the more traditional of the two. The molten plastic enters the mold through a channel known as spruce. Then, the molten plastic eventually makes it to the mold cavity. The runners aren’t hot. Hence, when the molten plastic is poured through them, much of it sticks to it. Therefore, after each cycle, there is always a need to scrape off the excess plastic.
| Pros | Cons |
| Less costs (tooling and maintenance)
It accommodates more plastic types Most flexible with changes in design and color |
Much slower production rate
Less production volume Increased waste rate More chores as it often requires the need of excess plastic removal Limited in terms of size The cold runner system is more suitable for electronic casing and keyboards. |
2) Hot Runner System
The hot runner system leverages heated channels. Hence, the molten plastic stays melted in the runners. This technique prevents the plastic from attaching to the runners and excessive waste.
| Pros | Cons |
| Quicker productions
Less waste, and ultimately, less post-production chore Needs less pressure Capable of higher volumes and large parts |
Requires more tools and maintenance
Select compatible plastic types It might lead to slight color changes in products More expensive parts The technique works for bottle covers, packaging, and phone cases. |
Technology has introduced some upcoming techniques. I have seen many Chinese suppliers adopting these techniques. So, I will also provide a concise overview of how these techniques are set to work:
Insert Molding: This technique involves molding plastic around an insert. It is quick and effective and is often used to produce syringes and wires.
Overmolding: This is adding molten plastic over existing material like insert molding. It is known as two-shot molding as it has two processes. Overmolding differs from insert molding in how the insert is inserted. This technique produces more colorful results.
How to Source Injection Molding from China?
I suggest you follow these systematic steps when sourcing injection molding services from China. It will help ensure a successful partnership with China suppliers.
Step 1: Define Your Requirements
Create detailed specifications for your product. It can include material requirements, dimensions, and expected production volumes. You can also research industry standards and ensure the design is optimized.
Step 2: Find Qualified Chinese Manufacturers
You can find a manufacturer in China through various platforms. Contact manufacturers with relevant certifications, like ISO 9001.
Step 3: Work with a Sourcing Agent
You will find many injection molding service providers in China. However, only a few of them are genuine. Consider partnering with a professional sourcing agent who understands this field. An agent can verify China vendors and handle quality control in China.
Step 4: Request Quotes
Send your specifications to shortlisted manufacturers. If hiring an agent, you can submit all requirements to their team. With this, you can request detailed quotes.
You can also ask for sample products or previous work examples. It will help you evaluate their manufacturing quality. Remember, ordering samples is easier when you hire a sourcing agent.
Step 5: Verify and Visit
You must check the business licenses and references of the selected manufacturers. If possible, arrange a factory visit. Hiring a sourcing agent is beneficial here as well. An agent performs a third-party quality inspection in China to verify manufacturing units.
Step 6: Negotiate Terms and Contracts
Clearly define all terms involved in any general contract, including;
- Pricing
- Quality standards
- Delivery schedules
- Intellectual property protection
Step 7: Track Production and Quality
Ensure you execute quality control measures throughout the production process. An agent will conduct regular audits and ensure consistency.
As you can see, hiring a sourcing agent will solve the majority of problems. Injection molding is a vast field that needs someone expert working on the ground for you. OwlSourcing will do this for you.
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Final Thoughts!
Injection Mold is a manufacturing technique that holds a lot of promise. It has incredible potential, like being compatible with over 25,000 materials. You might know this already if you are involved in plastic products sourcing from China.
However, you must be aware of the upfront costs. Getting a mold can be challenging.
Our team can help set up sourcing injection molds in China for the best product quality. Contact us today to connect with the China mold suppliers you need. You need not worry about maintenance and other concerns and get top-quality products.
FAQs:
1) What Is the Most Used Material with Injection Molds?
The title for the most commonly used material on the injection mold goes to nylon, a polymer fabric. Nylon is widely used because of its different nature.
2) How Long Can I Use An Injection Mold?
The life expectancy of an Injection Mold varies with the type you get. Typically, each injection mold can withstand from 500 to 1 million cycles. The amount of cycles depends on the class of the injection mold. Moreover, the material used also plays a crucial role.
3) What are the Downsides of Injection Molds?
Injection molds are costly to set up and often demand skilled workers to handle them. The Cost of injection molds in China makes them ineffective cost-wise. Also, they require skilled hands, and injection mold quality control can be a hassle.
4) How Do I Clean My Injection Molds?
You can clean your injection molds with chemical or laser cleaning. However, we recommend you hire a professional to ensure the mold gets the right maintenance.
5) What Is a Good Alternative to Injection Molds?
Addictive or 3D printing are great alternatives to injection molds. Undoubtedly, injection mold upfront costs can be terrifying. These options are suitable alternatives.
