Many businesses often hesitate when choosing between hydraulic and electric injection molding machines. The decision depends on the specific conditions and purposes of each business. Each type of machine has its own advantages and disadvantages. With many years of experience in the injection molding field, Anh Tu Plastic will analyze the pros and cons of each type to provide a clear, objective view, helping you choose the most suitable injection molding machine.
Hydraulic Injection Molding Machine
The hydraulic injection molding machine uses a hydraulic system to open and close the mold, maintaining the clamping force. This hydraulic system also controls the screw, allowing it to rotate, move back and forth, and create force for the ejector pin. The system comprises a pump, valves, motor, pipes, and an oil tank, etc.
Image 1 – Hydraulic Injection Molding Machine
Electric Injection Molding Machine
The electric injection molding machine uses a Servo motor to adjust mold opening, closing, clamping, and ejector pin actions. Some machines are also equipped with a Servo motor to control the back and forth movement of the screw. This type of machine appeared on the market around 2005 in Japan.
Image 2 – Electric Injection Molding Machine
Which to Choose: Electric or Hydraulic Injection Molding Machine?
Giving a precise recommendation for choosing between an electric and hydraulic injection molding machine is truly challenging. Each type of machine has its own strengths and weaknesses. The choice depends on the specific requirements of each task to achieve the highest economic efficiency. Below is a comparison of the two types based on several basic criteria to help you make the best decision.
Energy Consumption:
The electric injection molding machine saves 20-40% of energy consumption compared to the hydraulic injection molding machine. This is because hydraulic injection molding machines use a system of pumps and motors to recycle hydraulic oil for the entire system, even when not needed. In contrast, electric injection molding machines only operate and consume energy when necessary for mold opening, closing, or screw movement.
Work Efficiency:
Hydraulic injection molding machines have faster mold opening and closing speeds than electric ones due to the current lower speed of electric motors. This is a disadvantage of electric motors because prolonged mold opening and closing times can affect the injection cycle. However, for products that require a long cooling time, using an electric injection molding machine is not a disadvantage. Additionally, using a Servo motor for mold opening, closing, and screw movement ensures very precise and safe movements.
For products that require high injection pressure and clamping force, the electric injection molding machine is not a good choice as it is prone to parting line flash.
Machine Weight:
A significant advantage of electric injection molding machines is that they do not have hydraulic pumps, pump motors, valves, and pipes, making them lighter and more compact than hydraulic injection molding machines. A typical hydraulic injection molding machine requires about 300 liters of hydraulic oil to operate, which is a considerable cost. Additionally, electric injection molding machines operate more quietly than hydraulic ones.
Cost:
Electric injection molding machines use relatively new technology. Therefore, the cost to own this type of machine is significantly higher than that of hydraulic injection molding machines. Furthermore, if you want to buy a used machine, it is challenging to find a cheap electric injection molding machine due to the high model year of these machines. In the current Vietnamese market for used injection molding machines, a well-functioning hydraulic injection molding machine costs from 1 million to 1.3 million VND/ton, while you would need to spend from 1.8 million to 2 million VND/ton to own an electric injection molding machine.
The above information from Anh Tu Plastic about electric and hydraulic injection molding machines hopes to help your business choose the most suitable machine for your production capacity and consumption needs.