Different materials of injection molding machine parts

Different parts of an injection molding machine utilize different materials due to their distinct functions and operating environments. The following is a detailed introduction to the materials used in key parts of an injection molding machine:

1. Screw
The screw is the core component of an injection molding machine, responsible for conveying, melting, mixing, compressing, metering, and exhausting the plastic. Depending on the type of plastic being processed and the operating environment, a variety of screw materials are available:

HPT Fully Hardened Powder Alloy Screw: Made from tungsten-cobalt powder alloy tool steel, this screw undergoes a special process for hardening and molding, achieving uniform hardness both inside and outside. It is suitable for processing transparent products, precision products, and special high-temperature and highly corrosive plastics.

Dual Alloy Screw: Made from SACM645 or 38CrMoAlA as the base material, this screw features a tungsten carbide-nickel alloy ion-sprayed onto the threads or grooves, resulting in a high surface hardness and suitable for processing a variety of plastics.

Electroplated Screw: Also made from SACM645 or 38CrMoAlA as the base material, this screw is plated with hard chrome, nickel, titanium, and other elements on the outer surface, achieving high hardness and suitable for processing transparent materials and corrosive plastics. Stainless Steel Screw: Made from 9Cr18MoV special stainless tool steel, through-hardening and hardening treatment, it offers moderate hardness and excellent corrosion resistance.
SKD61 Screw: Made from Hitachi SKD61 material, molded through a special process, it offers excellent toughness and torsional strength.
Nitrided Screw: Made from SACM645 or 38CrMoAlA steel, molded through a special process, it boasts a moderately deep nitrided layer and high hardness, making it suitable for processing common plastics.
II. Barrel
The barrel is the component in the injection molding machine that heats and plasticizes the plastic, and its material selection is equally important:

Dual Alloy Barrel: Made from alloy steel, the inner bore is centrifugally cast with tungsten carbide alloy, tungsten carbide + cobalt alloy, or tungsten carbide + cobalt + nickel alloy. It is suitable for injection molding fiberglass engineering materials.
Nitrided Screw: Made from SACM645 or 38CrMoAlA alloy steel, it undergoes quenching and tempering, then nitriding treatment. It offers a moderately deep nitrided layer and high hardness, making it suitable for processing common plastics. 3. Other Components
In addition to the screw and barrel, an injection molding machine has several other key components, such as the mold plate, guide pins, and guide bushings. The material selection for these components directly impacts the performance and lifespan of the machine:

Mold plate: Typically made of high-strength, high-hardness alloy steel to withstand the intense pressure and deformation during the injection molding process.
Guide pins and guide bushings: Ensure precise alignment and sliding between the mold plates and are typically made of wear-resistant, corrosion-resistant alloy steel or stainless steel.
4. Materials for Other Auxiliary Components
Mold plate: Material: High-strength, high-hardness alloy steel.
Features: Able to withstand the intense pressure and deformation during the injection molding process.
Guide pins and guide bushings: Material: Wear-resistant, corrosion-resistant alloy steel or stainless steel.
Function: Ensure precise alignment and sliding between the mold plates.
Motor: Main components: Silicon steel sheets, copper wire, etc.
Features: High efficiency and energy saving.
Function: Provides the power required for the injection molding machine to operate.
Oil pump: Material: Wear-resistant, corrosion-resistant alloy steel or stainless steel. Function: Provides the hydraulic oil pressure required by the injection molding machine, ensuring its normal operation.
Cooling System Piping
Material: Corrosion-resistant and high-temperature-resistant alloy.
Function: Cools the injection molding machine and mold to prevent overheating.
Heating Element
Material: Typically resistance wire or electric heating tube.
Function: Provides the required heating temperature for the barrel and mold, ensuring uniform heating and melting of the plastic.
Control System Components
Material: Circuit boards, electronic components, etc.
Function: Controls the operating parameters and status of the injection molding machine, such as temperature, pressure, and time.
In summary, different parts of the injection molding machine are made of different materials depending on their function and operating environment. These materials are selected to ensure the performance, lifespan, and processing quality of the injection molding machine.