Why should you choose the plastic parts manufacturer in China?

In recent years, we heard more and more reports about manufacturing industry moving out from China. Compare with 2014, the total amount of Chinese export fell by 7%, however, the export of plastic part increased by 3.1%. The data shows that even though some manufacturers are leaving China, but more buyers still choose to purchase plastic parts from China. Why the plastic manufacturing in China is still attracting?

Integrated Supply Chain

Nowadays, no factory can manufacture a product without purchasing any items from other suppliers. Take us(Jingwei industry) as an example, we are able to make moulds and process of injection molding, but we have to buy raw material, some standard mould components, kinds of oil for mechanical uses, knife tools etc.. All these suppliers constitute the supply chain. After 30 years development, China has not only the strong industry foundation, but also the integrated supply china. That’s why the product made in China is high quality with competitive price.

Most Hard-working Workers

It is no doubt that Chinese is the most hard working people in the world. Most of Chinese manufacturing workers have to work 12 hours per day and 6 days per week. The workers from the so called low human labor countries don’t like to work overtime. The common situation happened in southeast countries is that the workers disappeared after receiving the payment. Chinese workers only complain the overtime hours are too few to get more reward.

Upgrading Technology and Equipment

Chinese manufacturers are upgrading their technologies and equipments. Several years ago, many factory made the mould by turning and milling machines. Now, almost every mould maker even the small factory is utilizing the CNC milling machine and EDM. Mold flow analysis is widely used now. There upgradings help the Chinese manufacturers reach the higher quality requirement like the precision and stability.

Low Wage of Engineer

The wage of engineers in China is still lower than the averaged wage in the world. Still, China has the largest number of engineers. That’s why apple inc choose the China manufacturers to fabricate its electronic products.

Above all, if you want to get a product with high quality and cheap price, Made in China is still the first choice.Contact an experienced Chinese plastic injection molding company, Jingwei industry via info@jweimolding.com

The Importance Of Plastic Parts Design

Injection moulding is popular manufacturing method because of its high-speed production capability. Performance of plastic part is limited by its properties which is not as strong as metal. A well-designed plastic parts means that it was taken through many steps to solidify the mold you wish to create. It’s hard to change the specs and variables of a plastic part towards the end of the plastic part design process.Not only will you have to reassemble machine parts and measurements, it will be more time consuming and will cost more to fix the issues after production.Making changes during the design stage is relatively inexpensive. With today’s CAD software, being able to visualize, test, and change designs has never been easier.

These are just a few of the questions that should be asked during the plastic part design process.

• The Cost of Change
• A well designed plastic part has many variables that need to be taken into account.
• How will the mold come together?
• Can the part be ejected from the injection mold?(If the tools and machine aren’t sized correctly, it may be hard to eject the mold.)
• Are the walls too thick or too thin?(If the wall selections are too thin, it may break off in the tool and not fill correctly. Too thick of wall sections will take longer to cool and solidify before ejecting the mold, resulting in warped or cracked products.)

An improper design technique, if carried all the way to production, can have a negative result on the overall quality or appearance of the injection molded piece. The cost to fix issues observed after production are not only expensive but also time consuming.

It is important however to look beyond just the question “Can this part be injection molded successfully?” While this is an important aspect of the design, we must also be mindful of manufacturing costs. Because the tooling cost is closely related to the product design, it is crucial to have an understanding of the mold making process even during the design stages. Plastic part design can greatly vary the overall costs and in some cases out-price the project. Implementing cost saving design features while maintaining design intent, or just optimizing the design for injection molding will save you money and make for a more robust design. Jingwei industry has served the injection molding industry for over 20 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing.

Design points before production:

• Select the proper material for the building tools. The coefficient of thermal expansion must be taken into consideration; large differences in material and size can damage and uneven the components.
• Be sure the runner system is balanced. Unbalanced runner systems can cause filling disturbances and inefficient tool running.
• Choosing a gate design is similar to having a balanced runner system. The gate is the area where the polymer transits from the runner to the part. If this is wrong, the gate could cause restrictions, incorrect polymer flow, turbulence, or other defective filling issues.

Contact an experienced Chinese plastic injection molding company, Jingwei industry via info@jweimolding.com

How much does plastic injection molding cost?

Plastic injection molding is the most commonly used process in the factories as its demand in the market is quite high and is rapidly rising also with the each passing year. Because of its cheaper cost and fast manufacturing to gives the desired shaped results, it is very renowned among the people.

The manufacturing of an injection mold could possibly be the greatest expense a new product faces in the development cycle.The most common question we hear from designers and product engineers is, "How much will a plastic injection mold cost to make my product?"

Many factors play roles and directly affect the cost incurred to create an injection mold for your custom parts. In any case, a reliable injection molder should be able to provide an accurate estimate quickly from either a 3D CAD file, sketch or the general dimensions of your product.

Material cost

The material cost is determined by the weight of material that is required and the unit price of that material. The weight of material is clearly a result of the part volume and material density; however, the part's maximum wall thickness can also play a role. The weight of material that is required includes the material that fills the channels of the mold. The size of those channels, and hence the amount of material, is largely determined by the thickness of the part.

Production cost

The production cost is primarily calculated from the hourly rate and the cycle time. The hourly rate is proportional to the size of the injection molding machine being used, so it is important to understand how the part design affects machine selection. Injection molding machines are typically referred to by the tonnage of the clamping force they provide. The required clamping force is determined by the projected area of the part and the pressure with which the material is injected. Therefore, a larger part will require a larger clamping force, and hence a more expensive machine. Also, certain materials that require high injection pressures may require higher tonnage machines. The size of the part must also comply with other machine specifications, such as clamp stroke, platen size, and shot capacity.

The cycle time can be broken down into the injection time, cooling time, and resetting time. By reducing any of these times, the production cost will be lowered. The injection time can be decreased by reducing the maximum wall thickness of the part and the part volume. The cooling time is also decreased for lower wall thicknesses, as they require less time to cool all the way through. Several thermodynamic properties of the material also affect the cooling time. Lastly, the resetting time depends on the machine size and the part size. A larger part will require larger motions from the machine to open, close, and eject the part, and a larger machine requires more time to perform these operations.

Tooling cost

The tooling cost has two main components - the mold base and the machining of the cavities. The cost of the mold base is primarily controlled by the size of the part's envelope. A larger part requires a larger, more expensive, mold base. The cost of machining the cavities is affected by nearly every aspect of the part's geometry. The number of cavities you incorporate into your mold will directly correlate in molding costs. Fewer cavities require far less tooling work, so limiting the number of cavities in-turn will result in lower initial manufacturing costs to build your injection mold.

The quantity of parts also impacts the tooling cost. A larger production quantity will require a higher class mold that will not wear as quickly. The stronger mold material results in a higher mold base cost and more machining time.

One final consideration is the number of side-action directions, which can indirectly affect the cost. The additional cost for side-cores is determined by how many are used. However, the number of directions can restrict the number of cavities that can be included in the mold. For example, the mold for a part which requires 3 side-action directions can only contain 2 cavities. There is no direct cost added, but it is possible that the use of more cavities could provide further savings.

Contact an experienced Chinese plastic injection molding company, Jingwei industry via info@jweimolding.com

Plastic Injection Moulding Process Cycle

Injection molding is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection molding, which vary greatly in their color,size, complexity, and application. The injection moulding process requires the use of an injection molding machine, raw plastic material, and a mold. The plastic is melted in the injection molding machine and then injected into the mold, where it cools and solidifies into the final part. The process cycle for injection moulding is very short, typically between 2 seconds and 2 minutes, and consists of the following four stages:

Clamping - Prior to the injection of the material into the mold, the two halves of the mold must first be securely closed by the clamping unit. Each half of the mold is attached to the injection molding machine and one half is allowed to slide. The hydraulically powered clamping unit pushes the mold halves together and exerts sufficient force to keep the mold securely closed while the material is injected. The time required to close and clamp the mold is dependent upon the machine - larger machines (those with greater clamping forces) will require more time. This time can be estimated from the dry cycle time of the machine.
Injection - The raw plastic material, usually in the form of pellets, is fed into the injection molding machine, and advanced towards the mold by the injection unit. During this process, the material is melted by heat and pressure. The molten plastic is then injected into the mold very quickly and the buildup of pressure packs and holds the material. The amount of material that is injected is referred to as the shot. The injection time is difficult to calculate accurately due to the complex and changing flow of the molten plastic into the mold. However, the injection time can be estimated by the shot volume, injection pressure, and injection power.
Cooling - The molten plastic that is inside the mold begins to cool as soon as it makes contact with the interior mold surfaces. As the plastic cools, it will solidify into the shape of the desired part. However, during cooling some shrinkage of the part may occur. The packing of material in the injection stage allows additional material to flow into the mold and reduce the amount of visible shrinkage. The mold can not be opened until the required cooling time has elapsed. The cooling time can be estimated from several thermodynamic properties of the plastic and the maximum wall thickness of the part.
Ejection - After sufficient time has passed, the cooled part may be ejected from the mold by the ejection system, which is attached to the rear half of the mold. When the mold is opened, a mechanism is used to push the part out of the mold. Force must be applied to eject the part because during cooling the part shrinks and adheres to the mold. In order to facilitate the ejection of the part, a mold release agent can be sprayed onto the surfaces of the mold cavity prior to injection of the material. The time that is required to open the mold and eject the part can be estimated from the dry cycle time of the machine and should include time for the part to fall free of the mold. Once the part is ejected, the mold can be clamped shut for the next shot to be injected.
After the injection molding cycle, some post processing is typically required. During cooling, the material in the channels of the mold will solidify attached to the part. This excess material, along with any flash that has occurred, must be trimmed from the part, typically by using cutters. For some types of material, such as thermoplastics, the scrap material that results from this trimming can be recycled by being placed into a plastic grinder, also called regrind machines or granulators, which regrinds the scrap material into pellets. Due to some degradation of the material properties, the regrind must be mixed with raw material in the proper regrind ratio to be reused in the injection moulding process.

Contact an experienced Chinese plastic injection molding company, Jingwei industry via info@jweimolding.com

How to reduce the cost of your injection mould

Injection Mould is the biggest cost of manufacturing a plastic part. Here we share some advices about reducing the cost of mould making.

1.Reasonable Part Design

Part design is the most important factor to impact the cost of mould. Bad design is diaster for the mould maker. In many cases, the cost of Plastic Injection Mould  increases largely due to an unneccessary undercut design. It is benefit for a product designer to know more knowledge of mould. Adequate communication between designers and engineers can help to reduce the cost of mould making.

2.Design Alteration

We often meet the circumstances that we get the notice of design changing after we already confirm the structure of mould and purchase the mould base. It is ok for the tiny variety of design. But many times the change would be not small. Then we have to overthrow the confirmed structure of mould and redesign it. It is better to do more test of prototypes before starting the mould making.

3.Mould Design

For a experienced mould design team, there are many fixed structure of mould for some specific products. Their
experience can reduce the risk of failure and reduce the cost of mould. It is important for the product designer to
reach the right suppliers.

4.Number of mould trials

Before start up of mass production, the manufacturer would do some sample runs to test the mould performance, it was named mould trial. The higher number of mould trial, the higher cost of mould. Generally speaking, the ideal mould shop should have an experienced engineer to do the test.

5.Mould material and standard components

The high quality mould dependent on the high quality mould material and standard components. Some cheap material and components may result in many problems when manufactring the plastic parts.

Contact an experienced Chinese plastic injection molding company, Jingwei industry via info@jweimolding.com