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What Is Injection Molding?

injection molding companiesPlastic injection molding is a specific kind of manufacturing that utilizes plastic injection molds to create parts or products on a large scale. Essentially, a prototype is created and cast into a mold. Once the mold is made, melted polymer material is injected into the mold until it solidifies. After the product has cooled, it’s ready for further stages of production. Injection molding companies exist to produce plastic products on a large scale because many smaller companies (and some large ones) find it easier to outsource their injection molding projects.

Injection molding is one of the most common methods of production for the plastics industry. In fact, plastics transactions increased by 52 percent in the past year. Compared to other methods, plastics injection molding is cheaper and faster for larger amounts of production. For smaller projects, another method of molding may be a better option in the long run. There are several industries that require injection molded plastics on a regular basis:



  1. Plastic Packaging – The plastic packaging industry has grown exponentially since it was first introduced in the 1950s. In the past year, plastic packaging production has increased by 47 percent.
  2. Medical Equipment – Injection molding plastic has been used for medical equipment for some time, ever since it became easier to produce plastics that were the right material for medical purposes. The medical plastics industry has seen decent growth in the last year, growing by 7 percent.
  3. Industrial Parts – Creating plastic parts for industrial projects has been a common practice for many decades. With all the different varieties of plastic polymers, there are many different uses in the industrial market, which is why industrial parts transactions have increased by 30 percent.
  4. Automotive Parts – If you look inside your car, you’ll find that the majority of those parts are made from some form of plastic. Although the number of automotive injection molded plastics decreased by 11 percent last year, an increase is expected with the recovery of the automotive industry.


The Machinery Involved in Injection Molds

injection molding machinery

Without an injection mold machine, plastic mold injection companies would not be able to provide injection molding services. Injection molding presses come in varying sizes, and are used depending on the size of the part being made and the amount of parts that need to be made. Injection molding machines are highly specialized and have to be tooled to each specific project. There are three parts to an injection molding machine:

  1. Material hopper
  2. Injection ram or screw-type plunger
  3. Heating unit

Another necessary machine for injection molding manufacturing is a 3-D printer, especially during the prototyping stage. Once the product has been designed using CAD software, it can be printed on the 3-D printer. That way, the injection mold company will have an accurate prototype to create the mold from.

Hiring Plastic Injection Molding Companies

Plastics injection molding companies are there to assist any business with creating a product on time and with the best possible quality. Outsourcing to a plastic injection molding company is most likely the cheapest option because it simplifies the process of manufacturing.

Most non-molding companies, especially smaller companies, don’t have their own injection molding press or injection molding team. That is because they don’t have the level of production volume that would justify buying their own machine. Hiring an outsourced injection molding company is going to make the process easier on the company, as well as cheaper in the long run.

What to Look for in an Injection Molding Company

Not all injection molding companies are created equal. Some companies will give you a better price, but sacrifice quality. Other companies have a faster production timeline, but create a sloppy product. There are some things you simply shouldn’t compromise on, which is why you should consult this list when searching for an injection molding company:

  1. The staff has expertise. Companies that have a full-time engineer on staff, as well as an experienced operation crew will have the best expertise in the business. When you work with a company that is experienced, you will feel better about placing your product in their hands and the product will turn out better.
  2. The designer has flexibility in designing or creating a prototype. If you plan on consulting the molding company’s designer in creating a prototype, they will need to be flexible and concerned about your needs, so that your product can turn out just right.
  3. There is proper equipment to accommodate production volume. If you plan on ordering a larger amount of product, you need to be sure that the injection molding company can accommodate those demands without taking too long to manufacture your product.
  4. They have decent prices. Injection molding plastics companies have the expertise you need, but they should also be willing to work with you on pricing if necessary. Do your research and ask for quotes from different companies to compare.

Streamline Plastics Will Bring You Better Value than Other Injection Molding Companies

Streamline Plastics is one of the best injection molding companies in the industry because we are willing to work with you on whatever project you bring to us, at whatever stage. Plastic injection molding is a process that requires experience and expertise, which we can supply for you. Contact us today for a free quote.