"Riddle me this…”
Sometimes I can be flexible, but often I’m not. I’m a part of your everyday life – in fact, you’d have a hard time without me – but you might not always recognize me. I am what I am today because I couldn’t take the heat. What am I?
OK, I acknowledge this a tough one. I’ll give you another clue.
I can be used to fill cavities.
When I’m all fired up and under a lot of pressure, I mold into my surroundings.
The answer, my friends, is plastic!!!
Actually, there are many different kinds of plastics, but the one property they all share is “plasticity” (duh), which is an inherent pliability that allows us to form the material into a variety of different products or parts. From water bottles to phone cases to car bumpers, you interact with plastic every single day in any number of different ways.
Here at Idea Planet, we use plastic to manufacture custom collectibles, life-size characters, retail point-of-sale displays, figurines, and more. That may sound pretty simple, but there’s actually quite a bit of science involved depending on what we’re creating. Let’s start with what plastic is, more precisely. I’m not going to go all Einstein here, but just know that plastics are mostly manmade materials, made from polymers, which are long molecules built around chains of carbon atoms. That’s plenty of chemistry for today…
Suffice it to say, there are many different kinds of plastic characterized by:
How the polymers are structured (polyesters, polyethenes, polyurethanes, etc.)
Whether they’re natural or synthetic (cellulose vs. nylon)
Whether they’re recyclable (can be mixed with other plastics without contamination)
Whether they can be reheated to a melting state – or not (thermoplastics vs. thermoset plastics)
Since each type of plastic behaves somewhat differently, the specific polymer used in manufacturing will depend on the product requirements, which in turn, also inform the most appropriate manufacturing process. It’s our job to assess the function and form of the item we’re making to recommend the right plastic and process to deliver the desired outcome.
So, let’s take a look at the six different types of plastic manufacturing methods and their advantages. I promise not to get too technical on you!
One of the most used plastic
manufacturing methods on the planet is injection molding. It’s my personal favorite due to all its inherent benefits, especially for custom figurines, weapon replicas, and intricate packaging décor. In this process, thermoplastic resin pellets are melted through the intense pressure of an auger moving the plastic forward to fill the 3D cavity of a custom, steel mold. The material then cools to a solid state in the shape of the intended part design. Wallah!
See the action animation here: https://www.youtube.com/watch?time_continue=143&v=b1U9W4iNDiQ
The design and creation of the mold is critical in injection molding – it requires a greater investment of time and costs but results in very low unit costs when quantities are high.
Other benefits? Hold on to your hat, because there are several:
Attainability of complex designs & a high level of detail
Because injection molds are subjected to tremendous pressure, the melted plastic is pressed extremely hard against the inside walls of the mold. This excessive force makes it possible to incorporate more details into the design of the product or part. Complex, small, and intricate shapes are easily managed. Our product engineers work with the factory on mold design to ensure appropriate depth of detail and avoidance of undercuts that would interfere with extraction of the finished product.
And the icing on the cake is consistent accuracy and repeatability of this high level of detail. Injection molding is so precise that it’s virtually error-proof. In fact, accuracy is typically within 0.005 inches. This includes controlled wall thickness, which can be more challenging with other production methods.
Production is fast
Once the mold is made, actual mass production goes pretty quickly. Again, with the right mold, it’s simply a matter of cranking out the product. That means it’s perfect for large quantity production runs.
Since injection molding is a highly effective process, only as much plastic as is necessary is used. Any excess material, because it’s a thermoplastic, can be ground up and recycled for another use, thereby further reducing waste.