An injection molding machine, also known as an injection machine, is a special machine for manufacturing plastic products. There are many injection molding machines, which the following methods can usually distinguish: drive mode, mold opening and closing direction, suitable raw materials, mold clamping structure, and injection structure.
What is an injection molding machine?
An injection molding machine, also known as an injection machine, is a special machine for manufacturing plastic products. Most injection molding machines are mainly composed of two parts: an injection unit and a clamping unit. The injection unit is responsible for heating the poured plastic pellets into a liquid. The mold clamping device carries the mold and provides the force required for mold clamping, clamping, and other actions. In general, injection molding machines have the advantages of fast processing speed and low cost.
How to choose an injection molding machine?
Special attention should be paid to the selection of injection molding machines. After thinking about the nature of the injection molding product, you must first understand the size of the mold and the product. Larger products require larger injection molding machines, followed by more specialized injection molding. The machine performance of the machine should pay special attention to the injection requirements such as mold opening stroke, mold clamping force, injection volume, screw compression ratio, injection speed, finished product appearance, and performance. A key point to consider and be aware of with every injectable product is to do your research before purchasing.
What are the types of injection molding machines?
There are many types of injection molding machines, which are usually distinguished by the following methods:
Classification method one: Drive mode
- Hydraulic Injection Molding Machine
The injection power of the hydraulic injection machine is mainly hydraulic. Because the hydraulic injection molding machine cannot run idle, it needs to keep running. Otherwise, the machine may be broken; when making plastic components, it is also necessary to control and adjust the temperature. Otherwise, it is easy to make and scrap.
- All Electric Injection Molding Machine
The price of the all-electric injection molding machine is higher than the hydraulic injection molding machine. Still, the all-electric injection molding machine does not need standby operation, nor does it need to adjust the temperature. Hence, injection molding products are relatively stable and can be more efficient. The all-electric injection machine has no hydraulic system, and there is no risk of liquid leakage.
- Hybrid/Servo Hybrid Injection Molding Machine
Hybrid injection molding machines are characterized by high efficiency and high economic benefits. It is a modified model that combines the advantages of the hydraulic and all-electric types. It is the plastic injection machine many companies use now, balancing the other two. Advantages and disadvantages of hydraulic presses, there are medium machine costs and energy costs. As we all know, energy cost is the main consideration in choosing an injection molding machine. For this reason, the servo oil-electric injection machine is equipped with a high-precision servo motor to achieve the same fuel-saving effect as the all-electric type. Considering the electricity cost, the machine and clamping mechanism are also simpler, more accurate, and more durable, greatly reducing the maintenance cost.
Classification Method Two: Switching Mode Trends
- Vertical injection molding machine
As the name suggests, a vertical injection molding machine is a vertical injection molding machine. It is usually used to make relatively small molds. Its advantage is that it can inject more products and save space. The vertical injection molding machine equipped with a turntable or a conveyor belt can effectively improve production efficiency.
- Horizontal Injection Molding Machine
Horizontal injection molding machines are the most widely used and most used models. It is characterized by a relatively low body, fast forming speed, and convenient operation and maintenance. Automatic production.
Classification method three: Applicable raw materials
- Thermoplastic Injection Molding Machine
Thermoplastics melt into liquids when heated and become solids when cooled. Common thermoplastics include PE, PP, ABS, TPU, etc. Generally, plastics that soften when heated are mostly thermoplastics. The thermoplastic injection machine utilizes the characteristics of thermoplastics to inject liquid plastic into the mold after heating the plastic particles. After cooling, the plastic returns to a solid state, and the plastic part is pushed out of the machine.
- Thermosetting Plastic Injection Molding Machine
Thermosetting plastics are characterized by changing from liquid to solid when heated. This transformation usually only occurs once and cannot be recycled like thermoplastics, so it is not environmentally friendly. Common thermoset plastics include FRP and melamine. The thermosetting plastic injection machine injects the processed plastic liquid into the mold and heats the plastic parts to solidify to complete the production.
- Powder Injection Molding Machine
Powder injection molding can also be called “metal injection molding” (MIM) or “ceramic injection molding” (CIM). The raw materials are fine metal or ceramic powders and bonding materials processed with precision. Common applications are portable products, smart devices, electronics, etc. Powder spraying is often used to manufacture small parts with high precision and complex appearance, especially metal. Parts produced by powder injection are characterized by high strength and density. After processing, the powder injection machine’s metal powder and bonding materials will become small-scale molding raw materials similar to plastic particles. Then the injection molding workpiece will be cleaned, heated, and other post-processing and the produced workpiece will be completed.
Classification method four: Clamping Mechanism
- Single cylinder/Double cylinder/four-cylinder direct pressure injection molding machine
Direct pressure injection machines are also divided into models such as single-cylinder, double-cylinder, and four-cylinder according to the number of hydraulic cylinders. Because the single-cylinder hydraulic cylinder has a large area, the production of parts will be more difficult, so there will be many problems when using a single-cylinder hydraulic cylinder on a mainframe. Accuracy is very important. More precision will directly affect the mold clamping precision. Multi-cylinder direct-pressure injection machines have gradually replaced single-cylinder direct-pressure injection machines. Dual-cylinder injection means that two cylinders inject parallel.
Generally, under the same pressure, the injection speed of the double cylinder will be slower than that of the single cylinder, but the injection pressure will increase. The template design of the four-cylinder direct pressure clamping is different. The oil cylinder also has an automatic balance correction function, so it does not affect the clamping accuracy and has a wide range of applications. In the past, the most common problem with the four-cylinder direct pressure mold clamping machine was the unbalanced force, resulting in mold damage and product size not meeting the requirements.
But as long as the components are processed accurately enough, most of this problem can be greatly improved. Compared with the toggle type, the direct pressure type has a long life, direct mold clamping, no resistance in the stroke, no need for frequent lubrication, and low maintenance cost. Although this machine is more expensive than the toggle-type injection molding machine, it is characterized by being more durable than the toggle-type injection molding machine.
- Toggle Injection Molding Machine
Acceleration and deceleration functions, simple operation, and low operating and machine costs characterize the toggle injection machine. The structure is also more complicated.
- Composite material direct pressure injection molding machine
The components injected by the composite direct pressure injection machine are the same as those of the direct pressure injection machine. The longer the machine, the greater the mold opening force, and a longer mold clamping stroke can be designed. The durability of components is a big challenge, and only a few manufacturers produce them in large quantities.
Classification method five: injection structure
- Single-component injection molding machine (Single-Component Injection)
Single-color injection molding means the whole plastic part is injected in the same color. The monochrome injection is currently the most used injection machine. The single-color injection can also inject two different colored products. The color injection molding machine injects the first semi-finished product with the first color and then processes the semi-finished product with the second color to complete the production.
- Multi-color injection molding machine (Multi-Component Injection)
The multi-color injection machine can inject plastic components of two or more colors simultaneously. The two-color injection molding machine is the most widely used multi-color injection molding machine. It is an application combined with LSR silicone rubber. In recent years, multi-color injection molding technology has gradually become a hot trend in the industry due to its environmental protection, high efficiency, and good performance.
Suppose you are worried about which injection molding machine should be used for the product you want to produce. In that case, you can first consider the characteristics of the product, the company’s budget, usage, and lifespan. Each type of injection molding machine has advantages and disadvantages. For example, if a company has a certain budget for energy expenditure, it can choose a power-saving injection molding machine model. If there is a certain requirement for molding accuracy, it can also be given priority in terms of quality.