Welcome back! In this entry, we are going to take a look at the diverse methods of plastic molding that have appeared over time. Some of them primed for industrial use, most of them used for custom creations. If you haven’t managed to grasp the versatility of this process take a good look at everything that is made with plastics around you: almost every single of those items is done using plastic injection molding. With that realization on the mind, let’s begin our journey!

Injection Molding

This is the process we have been talking on past entries. Is the modern method and one of the most used on industrial manufacturing, since it’s been explained previously we can use the space to tell that it’s also one of the methods most commonly used to craft toys, kitchen accessories, cell phone cases, keyboards and almost every single thing that is mass manufactured.

Blow Molding

Is a procedure that works very much like the injection method, the main difference between them is the molten plastic is vertically poured from a barrel to the molten tube as the mold closes down on it. This method is commonly used for plastic pieces that need hollow spaces such as containers, bottles, and pipes. It’s also a more expensive method of shaping plastic. Therefore the items tend to be more expensive.

Compression Molding

Hard plastics are used as the main resource for this method. The materials are handled by vertical presses that shape the parts into the desired forms using moderate heat along with pressure. There is no need for water cooling using this method, and it remains one of the safer ones with moderate costs.

Film Insert Molding

It’s a way to embed an image on the surface of a molded plastic piece. It’s used mostly to create certain shirts and acrylic ornaments.

Gas Assisted Molding

Is a craftier method of creating hollow plastic objects, the process for this one begins when molten plastic is offered shape using high-pressure gas to create a cavity around the desired shape?

Rotational Molding

This is one of the first truly custom methods of shaping plastics. A mold is filled with powdered plastic and secured to a spoke from a central hub that is brought to a closed furnace where the mold will heat up and melt the plastic. The mold needs to be turned over to receive even amounts of heat until all the plastic is melted. After cooling down the mold using water, tools are used on the end result to give it shape into a more refined final form.


This method along with Rotational Molding is one of the closest to being defined as “customs procedures” used in current times. In this one a sheet of rigid plastic is heated in horizontal positions and poured into one piece molds that turn solid after some time, the final form they get is the one offered by the mold, and it can be tempered around rough edges if needed by using special tooling.

Join us for our next entry where we’ll talk about ways to optimize your custom injection molding process.


Related Artilces:

Custom Plastic Injection Molding Processes Part 1

Custom Plastic Injection Molding Processes Part 2

Custom Plastic Injection Molding Processes Part 4

Custom Plastic Injection Molding Processes Part 5