Not much is known by the majority of the population when it comes to things like polymer extrusion process. I have recently been delving into the subject and have come up with a number of things to spark my interest and the interest of my fellow students. Being able to research something that helps to create literally hundreds of things that we as modern humans have grown dependent on has been such an experience. The injection molding process has fascinated me from start to finish. The process itself is incredible to watch work, and the years of inventive thought that it took to get to the spot that the industry is in today is inspiring, to say the least. It simply isn’t fair to forget about the ideas and people that allow us to live the comfortable lives we live today. Though we don’t realize it, these creative and ingenious improvements on our life have enabled us to industrialize and expand.

It’s better to first get you acquainted to the idea of injection molding. However, I don’t want to overwhelm you with the vast technical details at this particular time, as I will write about those in future essays. To put it simply, injection molding is defined as a process for making different parts from the materials thermoplastic and thermosetting plastic. Industrial designers and engineers design a product, then another specialist makes a mold out of the design from a metal byproduct (mostly steel, and often aluminum) and a machine comes in to form the features!

Now, let’s get into the history of the process. So many things happened over the 1800′s and 1900′s in order to get where we are in the process today. A number of people contributed to the development of injection molding and how to make the process quick and efficient. But let’s start with plastic itself; in Britain in 1851, Alexander Parkes invented the first synthetic plastic.

Parkesine, as might be expected for what is essentially the first of its kind, had several faults. First of all, and really most importantly, Parkesine was highly flammable. This led to an incredible amount of risk for all those working on it. Moreover, the finished products were expensive, but flimsy, and were widely known to crack and break. Thankfully, In 1868, American John Wesley Hyatt improved Parkesine.

With John Wesley Hyatt, injection molded products became realizable. Hyatt’s invention made it possible for his plastic material (celluloid) to be truly processed and still hold durable. In addition, John and his brother, Isaiah joined forces in order to release the world’s very first injection molding machine in the year 1872. The Hyatt brothers’ machines were much simpler than the complex ones we have today, but there’s no argument about this point in history being a huge stepping stone for injection molding.

Just like that, with the uncovering of the injection molding machine, demands on the industry shot to ridiculous new heights. Improvements on the machine, and the process in general, were continually being thought up. The industry was really on the rise, and Hyatts’ machines (as well as different varieties of them) were creating all sorts of new products everywhere from buttons to hair combs. It was an amazing growth for both producers and consumers alike!

Then World War II came, and with it, a huge increase in demands for a vast quantity of cheaper products. Another inventor from America, James Watson Hendry, revolutionized injection molding in 1945. What he did was introduce the screw injection molding machine. With his invention, specialists had a better handle on how to control the speed at which the plastic material was injected; the invention also upped the quality of the materials produced.

It was also found out that since the screw was now mixing the molten plastic products, other things could be mixed in with it. By adding different dyes, all sorts of new colorful products could be made, expanding the industry exponentially. Even now, most molding machines use a type of screw. Hendry also worked for thirty more years and release a molding machine that applied the use of gas, hugely reducing the use of important resources and creating storm shutters.

In retrospect, it really was a long road to get to the kind of polymer extrusion process that those in the field today are familiar with. Quality storm shutters did not come as easy as we seem to buy them now, and plastic molding companies have been forever trying to improve and cater to our needs. It’s important to sometimes step back and appreciate those who help to create things as taken for granted as bottle caps and and car dashboards.

- Elijah Mort

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