A Comprehensive Guide on plastic injection molding with Hydraulic Machines

Aug 12, 2021

Hydraulic plastic injection machine

plastic injection molding

Hydraulic mold clamping machine

The hydraulic mold clamping machine is a plastic injection machine that uses a hydraulic system to open and close the mold and maintain that clamping force.

 The hydraulic system also makes the screw rotate, move back and forth and give force to the pushpin. This system includes a pump, valve, motor, pipeline, and oil tank. Etc.


Electric plastic injection machine

It is a plastic injection-based machine that uses a servo motor to adjust the mold opening, closing, and mold pliers, pushing the backing pin.

Some of these machines also come with a servo motor to control the back and forth movement of the screw. This machine does plastic injection molding. As far as I know, the electric plastic injection machine appeared on the market around 2005 in Japan.

The electric injection molding machine

A popular electric plastic injection machine on the market

Should you choose an electric plastic injection machine or a hydraulic plastic injection machine?

To give sincere and accurate advice in choosing an electric plastic injection machine or a hydraulic plastic injection machine is not easy. Each type of machine has its advantages and disadvantages.

Therefore, depending on the specific job, you can buy the appropriate plastic injection machine to bring the highest economic efficiency. Below I will compare these two lines of plastic injection molding machines according to the essential criteria so that readers can make the best decision.

About power consumption:

Electric plastic injection machines save you 20-40% of electricity consumption compared to hydraulic plastic injection machines. This is understandable because the hydraulic plastic injection machine uses a hydraulic system.

Construction of plastic injection molding

 It includes pumps and motors to recycle hydraulic oil to supply the whole system even when there is no requirement.  As for the plastic injection machine controlled by Servo motor, plastic injection molding only works and generates power loss when it is necessary to close, open the mold, and move the screw.

Work productivity

The hydraulic plastic injection molding machine has a faster opening and closing speed than the electric plastic injection machine because the efficiency of this type of motor at present has a lower rate.

How does plastic injection molding increase productivity?

Depending on the specific jobs is a disadvantage of the electric motor because if the opening and closing take too long, it will affect the injection molding cycle. However, if the products need a lot of time to cool, using an electric plastic injection machine is not a disadvantage. On the contrary, plastic injection molding will increase your productivity.

Electric plastic injection machines are not suitable for products that need considerable injection pressure and large mold clamping force. It is effortless to get bogged down with the parting surface.

Weight machine.

A considerable advantage of the electric plastic injection machine is that there are no hydraulic pumps, pump motors, valves, pipes. Hence, it is much lighter and neater than the hydraulic plastic injection machine.

A typical plastic injection molding machine needs about 300 liters of hydraulic oil to operate, also a small cost. In addition, during operation, I found that the electric plastic injection machine operates more quietly than the hydraulic plastic injection machine.

About the price.

Electric plastic injection molding machine is a relatively new technology. Therefore, the cost for you to own this type of machine is also much higher than that of a hydraulic plastic injection machine.

Besides, if you need to buy an old machine, it is not easy to find a cheap electric plastic injection machine because the life of this machine is very high.

Injection molding machines China

 In the market of plastic injection machines in China today, a hydraulic plastic injection machine priced from 1 million-1.3 million tons can run smoothly.

You have to spend 1.8 million-2 million tons to have the opportunity to own one—electric plastic injection machine. Making cheap plastic molds is often associated with poor quality – it is a thought ingrained in us.

Products and Services

When buying a cheap product or embroidering an affordable service, people often think of the quality of the product. Plastic injection molding service is cost-effective.


Making cheap plastic molds


However, when making cheap plastic molds, designers and builders know how to optimize improvements and optimize unnecessary costs. We can ultimately make a plastic mold at a low price but still ensure quality. Ensure the requirements that the customer wants.

plastic injection molding 2021

Factors affecting the price of plastic mold making

One factor that customers are often interested in is how much it costs to make a plastic mold. In this regard, our Plastic Mold Factory would like to advise customers on the factors that determine the cost of a plastic injection product.


Accuracy: This is perhaps the most important factor driving up the price of mold making. A plastic product made with plastic injection molding with a size that requires accuracy of 0.01mm - 0.1mm will cost much more than a product that requires accuracy of 1mm or more.

Products requiring precise mold components

 It can be understood as follows; “Products that need to be precise require more precise mold components. To be accurate, mold components require higher precision machining machines.

 The more precise the machine, the higher the purchase value… all of these factors drives up the cost of the mold.” Product shape: The simpler the product, the easier it is to make and achieve its intended use.

 Products with complex profiles in plastic injection molding

In contrast, for products with complex profiles such as undercuts, threaded products, products that need slides, products that require high gloss, etc.,

 The mold structure will be complicated, and it will take a long time to design the mold and process mold. And we have tested many times. This process requires some not small expenses.

Injection molding Product volume:

 The larger the product, the larger the mold it is simple rule. Therefore, as the mold material increases, the cost of the mold will also increase.

Above are the two main factors that determine the mold cost. However, if you make a mold, you can rest assured because you don't have to spend a lot of money to make a mold.

Final thoughts on plastic injection molding

In this article, I just mentioned some criteria for evaluation that are within the scope of my understanding.

Currently on the market, several hybrid machines combine the advantages of both of these plastic injection machines.