Complete Guide to Types of Injection Molding Machines

"Drive Type" isn’t everything. Most guides for injection molding machines focus on how the machine moves—the motors, the pumps, and the electricity bill. In this guide, YIZUMI is moving past the basic "101" tutorials. We are providing a comprehensive map for choosing equipment based on your specific material requirements.

What Will Happen If Your Injection Molding Machine Doesn't Match Materials

Every plastic resin has its own "personality"—a unique combination of viscosity (how it flows), corrosivity (how it eats away at metal), and thermal sensitivity (how easily it burns). An injection molding machine's "DNA" consists of its screw geometry, barrel metallurgy, and control software. If these don't match your material's properties, you'll face a nightmare of defects:

1. Corrosive resins (like PVC) will pit and destroy a standard steel screw in weeks.

2. Shear-sensitive materials (like PET) will degrade and turn yellow if processed with too much friction.

3. High-viscosity rubbers (like LSR) will leak and "flash" through standard seals like water.

Processing Thermoplastics: From Generalists to Specialists

Thermoplastics represent the vast majority of the global molding market. However, they are applied from a plastic spoon to an engine component. As an engineer, one requires understanding where your material falls on the complexity scale while choosing the machine.

All-Rounders: PP, PE, PS

PP, PE, and PS are relatively "easy" to mold, but they are applied to the production of items like housewares, toys, and simple containers, which have slim profit. Therefore, any fluctuation in part weight or a spike in energy costs can ruin the profitability.

YIZUMI Solution: A6 Series. This is the quintessential "all-rounder." It doesn't just move plastic; it manages it. Its most critical feature for commodities is Intelligent Weight Control, which automatically adjusts the injection profile if it detects a change in material viscosity, ensuring that every part is identical to the last.

Engineering Plastics: PA66, PC, PBT

Materials like PA66, PC, and PBT are used for structural parts that must not fail. They have high melting points and high viscosity. They require immense pressure to flow into complex molds and extreme thermal stability to prevent the polymer chains from breaking down. For these materials, an injection molding machine with a high-torque screw drive and a barrel capable of maintaining precise, high-temperature zones is the best.

PET: Quality Beyond the Shape

Polyethene Terephthalate (PET), the gold standard for beverage packaging, is known for being temperamental to process. Why? If PET is overheated or "sheared" too aggressively by the screw, it produces Acetaldehyde (AA), which can migrate into the beverage, changing its taste and smell.

YIZUMI Solution: SPET Series. YIZUMI engineered the SPET series specifically to solve the PET paradox. It features a low-shear screw design and high-output plasticising.

"Specialized Material" Machines

While standard machines handle everyday plastics, high-margin manufacturing often requires processing materials with "difficult" personalities. To dominate this category, a machine must be engineered around the material's chemical and thermal behavior.

Liquid Silicone Rubber (LSR) Machines

Unlike thermoplastics, LSR is a cold liquid that must be heated to cure (vulcanize). The large challenge is that it has an incredibly low viscosity (like honey), easy to leak through the tiniest gaps while processing.

YIZUMI Solution: Specialized LSR machines feature a water-cooled barrel and a high-precision shut-off nozzle. YIZUMI’s dedicated LSR series integrates a vacuum pump system to remove air bubbles before injection, ensuring the "Zero-Defect" quality required for medical-grade seals and baby-care products.

PVC & Corrosive Material Machines

Polyvinyl Chloride (PVC) is a staple for construction and pipes, but it releases corrosive hydrochloric gas when heated. On another hand, standard steel screws will pit and corrode within weeks of processing PVC, leading to contaminated parts and machine failure.

YIZUMI Solution: YIZUMI’s PVC-specific machines utilize bi-metallic, chrome-plated screws and barrels that are virtually immune to acid erosion. Additionally, the machine is equipped with high-power cooling fans on the barrel to maintain a hyper-strict temperature profile, preventing the material from degrading into a toxic state.

Multi-Component (2K/3K) Machines

Modern product design often requires a "soft-touch" grip on a hard plastic body (like a toothbrush or a power tool handle). Injecting two different materials (e.g., TPE and PP) into the same mold requires precise timing and specialized hardware to ensure they bond together without leaking.

YIZUMI Solution: M-Series. This series feature independent injection units and a rotating platen. This allows the machine to inject the first material, rotate the mold 180 degrees, and inject the second material onto the same part—eliminating the need for secondary assembly and reducing labor costs by up to 40%.

DCPD & Thermoset Composites

For massive parts like truck body panels or heavy machinery covers, manufacturers use Dicyclopentadiene (DCPD). These materials are often processed at lower pressures but require massive clamping forces and precise temperature control across a very large surface area.

YIZUMI Solution: Leveraging their expertise in heavy-duty machinery, YIZUMI provides specialized clamping units designed for high-tonnage thermoset molding, ensuring that even the largest composite panels have a perfect surface finish and structural integrity.

Understanding the types of injection molding machines is the first step; seeing them in action is the second. Whether you are dealing with the corrosive nature of PVC or the high-speed demands of PET, there is a "Material-First" solution waiting for you.