injection moldingcustom plastic injction molding

Injection Molding:

PIM mold&engineering supplies integrated services to customers as turnkey solution, including plastic design, rapid prototyping,plastic mold making ,injection molding ,secondary operations and final assembly to satisfy the demands. For the injection molding operation, customers’ small  run manufacturing orders are always welcome . We often operate plastic injection molding manufacturing orders as low as 500 to 2,000 pcs. The small volume orders could be began within days of placing the order to ascertain the fastest turn-around times in the industry.

Of course ,client’s big plastic  manufacturing runs are really welcomed. Counting on the injection molded parts size, we could make 100,000′s to millions of products per batch. Really high volume production would acquire our razor sharp price.Contact us now for more information about how we can help you with plastic mold and plastic molding (blowing and injection molding)related services . We truly offer a complete package of experience and creativity for your plastic related needs.

PIM injction molding services application:

  • Computer/Business Equipment ;
  • Industrial ;
  • Lawn & Garden;
  • machinery;
  • consumer appliance ;
  • Electronics/Electrical ;
  • Agriculturalcustom injection molding

Raw material used:

  • ABS
  • Acetal
  • K Resin
  • Nylon 6/6
  • PET
  • Polypropylene
  • Polyethylene
  • Styrene (crystal clear and opaque)
  • TPE

Advantages of injection molding include the following

  1. High plastic product manufacturing rates. For example, a CD disk can be produced with a 10-12-s cycle in high melt flow index PC.
  2. Relatively low labor content. One operator can frequently take care of two or more machines, particularly if the injection molding parts are unloaded automatically onto conveyors.
  3. Parts require little or no finishing. For example, flash can be minimized and molding tools can be arranged to automatically separate runners and gates from the part itself.
  4. Very complex shapes can be formed. Advances in mold tooling are largely responsible.
  5. Flexibility of plastic part design for injection molding (finishes, colors, inserts, materials). More than one material can be molded through coinjection. Foam core materials with solid skins are efficiently produced Thermosetting plastics and fiber-reinforced shapes are injection molded.
  6. Minimum scrap loss. Runners, gates, and scrap can usually be reground. Recycled thermoplastics can be injection molded.
  7. Close tolerances are obtainable. Modern microprocessor controls, fitted to precision molds, and elaborate hydraulics, facilitate tolerances in the 0 .1% range on dimensions and weights (but not without a high level of operational skills in constant attendance).
  8. Makes best use of the unique attributes of polymers, such as flowability, light weight, transparency, corrosion resistance. This is evident from the number and variety of molded plastic products in everyday use.

Disadvantages and problems include:

  1. High investment in equipment and tools requires high production volumes. A 181- tonne clamp force/397-g shot size (200 ton/14 oz) fully automatic machine costs about $150,000. Add some necessities, such as a selection of screws and molds, and the cost of a medium size production unit is well over $250,000. (1994 prices in U.S. dollars)
  2.  Lack of expertise and good preventive maintenance can cause high startup and running costs.
  3. Quality is sometimes difficult to determine immediately. For example, postmold warpage may render parts unusable because of dimensional changes that are not completed for weeks or months after molding.
  4. Attention is required on many details requiring a wide variety of skills and cross-disciplinary knowledge.
  5. Part design sometimes is not well suited to efficient molding.
  6. Lead time for mold design, mold manufacture and debugging trials is sometimes very long. (It is getting shorter for CAD-CAM operations, using computer-aided mold design and drafting~CAD.)
  7. Because of the many factors involved, it is sometimes difficult to accurately predict costs for a molding job. If low-margined to start, a slightly inaccurate estimate can result in a loss. The more knowledge, the less the risk.


Injection Molding Process

With the injection molding process, you can manufacture plastic parts with highly complex geometries by injecting plastic resin with tight process control and precision. Injection molding is an automated process capable of producing parts with at very high speeds.

In this process, parts of any size and almost any plastic material can be made.

As part designers, it is important for them to recognize the fact that the way a product is designed will ultimately determine its ability to mold or its processability; these are factors that determine the tooling requirements and the cost for that manufacturing process.

Part designers must also take into consideration not only how the part will be molded, but also its overall shape and specific features and whether or not some minor modifications may be required for a lower cost.

A number of factors such as the design of the tool and manufacturing conditions will affect the properties of the molded plastic part and may contribute to the complexity of the resulting part.

Developing a quality part is a collaborative process between the part designer, the mold designer, the plastic material supplier, and the process engineer aiming to develop a part that is fully functional and can be moulded .

If these concurrent engineering practices are followed during the design process, it gives plastic part designers a greater chance of success.

Injection molding is a complex process driven by a series of sequential stages. These phases include filling the mold, packing the mold, press holding ,cooling and part ejection.

  • Filling

The melt is injected through the sprue and runs into the cavity of the mold after the mold is closed. The filling process takes place at the injection unit of the molding machine and can take several minutes.

  • Packing

Pressurizing and compressing the melt ensures complete filling and the replication of very fine details on the surface.

  • Holding

Once the gate solidifies, melt is no longer able to flow into (or out of) the cavity. Proper pressure is applied to the mold to compensate for shrinkage as the part cools.

  • Cooling

It cools down and contracts without shrinkage compensation, while the melt continued to cool.

  • Ejection

In most cases, a mechanical ejector is used to remove the cooled part from the core or cavity of the mold after it has been opened.

There are many design features that contribute to the design of a plastic part, depending on the phase in which the part is used. A plastic part must meet requirements for each of the five process handling phases for moldability.