Why choose an injection molding machine?

Buying an injection molding machine is not a small expense. Choosing the right injection molding machine can save a lot of cost and time in the injection molding production process and improve the production quality. The right injection molding machine can help you be more competitive and secure long-term customer protection, so there are some key factors to consider when purchasing an injection molding machine.

1. you need to know the information of the plastic parts you are molding

There are many series or types of injection molding machines, we need to choose a suitable injection molding machine according to our own needs. For example, materials or products have different properties such as thermoset or thermoplastic, single-color, two-color or multi-color, interlayer or mixed color. Some products require higher production conditions, such as closed-loop, high precision, ultra-high injection speed, high injection pressure, and fast production speed. By analyzing the plastic and the finished product, we can decide the series of injection molding machines. Molded parts that don't fit the machine will result in ongoing quality issues, slow cycle times, and frustration with machine and mold damage.

Some informations you need to know:

(1) Types of plastic materials

(2) Size and weight of injection molded parts

(3) Production speed.

(4) Quality requirements

(5) Mold size and weight

2. Select the injection machine

(1) Hydraulic injection molding machine

Hydraulic presses have always been the only choice for injection molding machines. Hydraulic presses, although not very accurate, are the dominant type in most parts of the world, with the exception of Japan. If low power consumption is a priority, choose a hydraulic press with a servo pump, as this is the most energy efficient of all hydraulic presses. The servo pump only runs when the machine needs to move and uses minimal power the rest of the time. However, the purchase price is 10%-15% higher than a hydraulic press with a constant displacement pump or even a variable displacement pump.

(2) Electric injection molding machine

Electric presses, also known as motor technology (EMT), reduce operating costs by reducing energy consumption and also address some of the environmental concerns surrounding hydraulic presses. Electric formers have proven to be quieter, faster and more precise, but the machines are more expensive. Every movement of an electric injection molding machine is done by a direct-drive electric servo motor, which is powered only when movement is required, so they are very energy efficient. The motor is suitable for clean room operation.

(3) Hybrid injection molding machine

The hybrid injection molding machine adopts a combination of hydraulic drive and electric direct drive. Hydraulic drives are used to generate fast injection speeds when molding thin-walled parts. The rest of the machine uses electric drive servo motors, and each axis of the machine has its own dedicated motor.

Which one is right for you? It depends on your priorities.

3. Clamping force requirements

If there is not enough locking force, the mold will open, the raw material will leak, and even cause an accident to the mold and the operator. It is very critical to have sufficient locking force.

In order to find the tonnage using a simple calculation, the following part information is required:

(1) Plastic material

(2) length x width x height

(3) Projected area (length X width)

(4) Average wall section

(5) Gate location

(6) Maximum flow length from gate

(7) Number of mold cavities

There are several ways to calculate locking force:

According to the product size, we can obtain the projected area of the mold opening and closing directions.
High pressure inside the mold = projected area (cm2) * cavity number * cavity pressure (kg/cm2), where the cavity pressure varies with different materials.

4. Injection unit size

For a specific tonnage of the machine, the manufacturer will usually provide you with a choice of 2 injection units. These two units typically offer 3 different screw and barrel assemblies. In order to select the correct components, the shot size must be calculated as a percentage of the shot capacity and must be between 25% and 65% in order to produce high quality parts. The chosen screw diameter is critical to long-term part quality and productivity.

Through the above content, you can basically master the little skills when choosing an injection molding machine, but we still need to pay attention:

(1)Don't use a large injection molding machine to make small plastic items.

(2)New combinations need to be considered when the standard machine specifications cannot meet the injection molding requirements.

Choose the right injection molding machine manufacturer, the quality and price of injection molding machines in China are the best, most reliable and most trustworthy, welcome to contact DENICE.