I. Injection Molding: The Cornerstone of Manufacturing
Injection Molding (IM) is one of the most vital and widely used processes in modern plastic manufacturing. It involves melting plastic resin and injecting it at high pressure into a precisely designed mold cavity, where it cools and solidifies into the final product. This process is the preferred technology for mass-producing complex plastic parts due to its high efficiency, exceptional part repeatability, tight tolerance capabilities, and wide material selection, making it central to OEM custom plastic product services.
II. The Three Core Materials: ABS, PP, and PC
In the realm of OEM custom plastic products, Acrylonitrile Butadiene Styrene (ABS), Polypropylene (PP), and Polycarbonate (PC) are the most frequently utilized engineering plastics. Their unique properties dictate their suitability for various industrial applications.
| Material | Full Name | Key Characteristics | Typical Applications |
| ABS | Acrylonitrile Butadiene Styrene | Toughness, rigidity, excellent impact resistance; easy to plate and paint; high dimensional stability. | Consumer electronics casings (e.g., computers, TVs), automotive interior parts, household appliances, toys (e.g., LEGO bricks). |
| PP | Polypropylene | Lightweight, excellent chemical and fatigue resistance; low cost; can be manufactured with living hinges. | Food/drug containers, automotive interior components (e.g., bumpers), housewares, packaging materials. |
| PC | Polycarbonate | Extremely high transparency, outstanding impact resistance ("bulletproof plastic"); good heat resistance; high dimensional stability. | Automotive headlamps, safety helmets, protective eyewear, lighting diffusers, transparent water bottles, electronic connectors. |
III. The Heart of Injection Molding: Mold Design and Tooling
The mold is the critical factor determining the quality and cost of injection molded products. A high-quality mold requires meticulous design consideration for the following elements:
Mold Materials: Steel (long lifespan for high volume) and Aluminum (faster machining, lower cost, suitable for prototyping or low-volume runs).
Mold Structure:
Runner System: Ensures uniform and rapid filling of the cavities.
Cooling System: Crucial for even and quick part cooling to prevent warping and shrinkage, thereby minimizing cycle time.
Venting System: Allows air and gases to escape, preventing defects like short shots or burn marks.
Ejection System: Ensures smooth removal of the finished part without damage.
Multi-Cavity Molds: Used in high-volume OEM production to produce multiple parts per cycle, drastically reducing per-part cost.
IV. Quality Assurance in OEM Custom Services
A top-tier injection molding OEM service goes beyond mere processing; it involves a systematic quality control process:
Design for Manufacturing (DFM) & Mold Flow Analysis (MFA): Simulating the plastic's flow behavior before cutting steel to predict and resolve potential filling or cooling issues, which is key to reducing iteration costs.
Process Control: Precisely controlling injection temperature, pressure, holding time, and cooling time to ensure consistent dimensional accuracy and mechanical performance.
Tolerance Management: Utilizing high-precision tooling and metrology equipment to guarantee the final parts meet the client's strict dimensional and geometrical tolerances.