How to source Molding Supplier in China? Read this FAQ Guide

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Q: What is the plastic injection molding process? A: The plastic injection molding process is similar to metal die casting. In this process, molten plastic is injected into a mold under pressure and held until it cools. Once solidified, the mold is opened, and the plastic part is removed. It’s a highly versatile, precise, rapid, and cost-effective method for mass-producing plastic products.

Q: What materials can be used in plastic injection molding? A: The process primarily uses thermoplastic and thermosetting plastics, each with its own advantages and limitations. The key difference is that thermoplastics can be melted and recycled, while thermosetting plastics cannot.

  • Thermoplastic Plastics:
    • Pros: Recyclable, cost-effective (waste can be reused), improved impact resistance due to flexibility.
    • Cons: Lower heat and chemical resistance (degrades faster).
  • Thermosetting Materials:
    • Pros: Higher chemical and heat resistance, higher mechanical strength, and dimensional stability.
    • Cons: Non-recyclable, lower impact resistance, and harder to process.

Q: What design input do I need for plastic injection molding? A: We require 3D files in STEP or IGES format for plastic injection molding.

Q: Where can I find plastic injection molding factories in China? A: Suppliers are located throughout China, depending on the plastic material you intend to use. Different factories have varying quality levels and expertise. It’s wise to collaborate with a reliable China sourcing agent who can locate factories, assess them, and manage production effectively through on-site inspections.

Q: How much do the tooling costs in plastic injection molding? A: Costs can range from a few thousand dollars for simple tools to several hundred thousand dollars for more complex multi-cavity tools.

Q: How long does the tooling last in plastic injection molding? A: Tool lifespan depends on the material but should handle around 200,000 cycles without issues.

Q: What is the average lead time for tooling in plastic injection molding? A: The average lead time for tooling typically ranges from 15 days to three months, depending on complexity.

Q: Do plastic injection molded products or their molds require any final processing? A: Final processing for injection-molded parts is not uncommon. This can include adding inserts (which can also be inserted during the molding process) or thread cutting. Final surface treatment, such as powder coating or painting, may also be required. Occasionally, tools themselves may need to add special surface textures, leaving imprints on the final injected parts, such as a brand name for premium skincare products.

Q: What are the pros and cons of plastic injection molding? Pros:

  • Consistent measurements.
  • Rapid production.
  • Low cost per unit.
  • Good surface finish.
  • Often recyclable due to waste material reuse.

Cons:

  • Processing costs.
  • Warpage and shrinkage.
  • Some thermosetting plastics or rubbers cannot be recycled.
  • Performance of recycled materials may not match that of new materials.

Q: What are the known challenges in the plastic injection molding process? A: Some suppliers may use recycled materials without informing you, which can affect physical properties and performance. The type of material used is crucial if you’re seeking specific physical characteristics or performance. Additionally, issues with shrinkage over larger surface areas can occur.