By over-molding, the production of the substrate parts is a standard injection molding process, which involves an aluminum mold with no heating or cooling lines running through it.

Cycle times are a bit longer, which allows our molders to monitor fill pressure, cosmetic concerns, and the basic quality of the parts.

When the total run of substrate parts are molded, then over-mold tooling is assembled to the press.

The substrate parts are placed by hand into a mold where each part is over-molded with either a thermoplastic or liquid silicone rubber material.

Advantages

  • Plastic over-molding offers various advantages, including:
  • Improving part strength and structure
  • Reducing secondary operation, assembly, and labor costs (Molded as one assembly)
  • Eliminating the bonding step in the manufacturing process (Improved component reliability)
  • Plastic over-molded components ensure proper alignment, prevent loosening and the plastic resin can provide improved resistance to vibration and shock
  • Enhancing design flexibility and multi-material components (Custom plastic over-molding allows for the production of parts molded of multiple thermoplastic materials)

Applications

Customizedovermolded plastics provide competitive advantages in a wide range of applications, including:

  • Medical devices and instruments
  • Parts with soft grip handles
  • Window reveal moldings
  • Knobs for appliances, controls, and assemblies
  • Encapsulated electronic devices and electrical components

(2)Plastic injection molding industry

Plastic injection molding is widely used in the production of plastic products – from medical equipment to toys.

In the aerospace industry and particularly the automotive industry, many parts are made with plastic injection molding.

The injection molding industry has seen a number of changes in recent years, including faster time to market.

One of the key business strategies for plastic injection molders is to work with tooling partners to decrease lead time.

HOW DOES THE PLASTIC INJECTION MOULDING PROCESS WORK?

The process of injection molding includes the following steps:

The mold is placed into the injection molding machine (IMM).

The molding machine closes the mold and, thanks to the clamping tools, the mold stays closed during the plastic injection molding.

The plastic is fed into the IMM in the form of granules or pellets.

The molding machine heats the plastic until it is liquid.

The nozzle of the injection molding machine then injects the melted plastic into the mold (injection pressure).

The cavity of the mold is now filled with the plastic liquid.

This will then cool down to form a solid product. Finally, ejectors push the cooled product out of the machine as a finished part.

The injection molding process is complete.

HOW TO SPEED UP PLASTIC INJECTION MOLDING

The cycle time of the plastic injection molding process can be broken down into the injection time, cooling time, and resetting or changeover time.

By reducing any of these times, the production cost is lowered.

Frequent mold changes allow inventory to be reduced and provide a faster response to market requirements.

The Quick Mold Change Systems from EAS lower manufacturing cost by reducing changeover time.

HOW TO LOWER COSTS OF INJECTION MOLDING WITH QUICK MOLD CHANGE SYSTEMS

One of the best practices requires a fully automated mold change.

Not only will this decrease change over time, but it will also make the manufacturer more flexible in the production quantity.