Integrative Studio Week 13-14
As discussed last time,my design context for looking at the topic of injection molding had completely changed. I was now focusing on the technology and sustainability aspect of things. I was having trouble in expanding on a single part of injection molding, since it is a process and not an actual object. Thus I decided to work on the raw material that goes into this process instead, which is plastic. In particular, I explored bio plastics and how they could be used to change the production scenario today.
I began doing extensive research on bio plastics, their properties and how I could manipulate them. The most significant bio plastic used in the industry today is called poly lactic acid. This bio plastic is already widely in use,specifically for 3-D printing filaments. But I wanted to manipulate it to suit a need that has not been explored by the material yet.
So my first concept was to try and replace something that is made out of normal high density polyethylene with PLA. So I began reading into the requirements of injection molding, and tried to explore how the original process needed to be modified to suit the needs of bio plastics. This is a very important aspect to keep in mind, considering the fact that bio plastics are a lot more sensitive to temperature pressure and chemical changes.
So for me, this turned out to be more like a system intervention for the first iteration of my project. I wanted to create a system which still remains true to the normal injection molding techniques, but also can include bioplastics in it. For this I downloaded moulding manuals online for HDPE injection molding, as well as companies that promote bioplastic injection molding. Through this I also came to learn the applications of bioplastics. A very significant application of bio plastics, particularly PLA, is usage as screws parts or drug delivery systems in the human body. This is because it by it is biodegradable but it grades in the ideal time. Just like this I wanted to create something which could be degradable but is used in daily applications.
The first thing before putting the pellets inside the injection molding machine is that you have to create them. This is done by sourcing raw material like corn, sugarcane, or any other starch based substance, and then breaking it down, fermenting it to produce poly lactic acid. This then needs to be mixed with additives which would give it to the property desired for the usage.
After this the next important change was to design the mold properly. This is because the mold design determines a lot about how the final part will turn out. The draft angle of the mold, is a very important factor for ejection of the final part.There are several issues like short shot, streaks, or overfilling that may occur when a part is injection moulded. So this must be taken into consideration while moulding a PLA part.
My second iteration was in relation to creating something out of PLA that can be used on the daily. For this, I searched up landfill pollution, and the common household items that usually occupy landfills. One interesting item that I found in this case was printer ink cartridges. Even though printer ink cartridges can be refilled, most people tend to throw them out after one or two uses. And commercial printer stores which use these have no option but to throw them away often after several uses. But these are still made out of regular HDPE. So a very good solution to this would be creating the printer cartridge out of PLA, since it has an ideal degradation time of around six months to a year, and this is the maximum time that a commercial printer would use a printer ink cartridge for.
The third iteration was exploring a different material: Algae. I discovered that bioplastics can be made out of something as natural and commonly found as algae. And this is honestly a great option, not only because of it’s natural origin, but because of the fact that it does not need to occupy area needed for food crops to grow, like PLA did. Algae can grow in waste water, clean water, or practically anywhere, and is easy to synthetically produce. Seaweed and kelp are often washed on the shore as waste, and are available in abundance at a cheap price.
So this idea discusses how to incorporate algae in the injection moulding technique. My input was to introduce a way to process the raw seaweed/algae first, then extract agar from it, and then include an extensive drying process for it. Drying here is important since the raw material is hydrophilic, and all moisture must be sucked out before use. Once this is ready, it can be plasticized and mixed with additives , and then extruded into pellets. From here the process continues as described previously.
The last iteration was for creating something out of this algal bioplastic, and finding an application for it. I concluded that the best place to use this for would be clam shell fruit packaging. This is because of how short it’s shelf life is, and how quick we are to discard it. It is currently made out of regular plastic, but if made from this material it is perfect for quick disposal.
I sketched out all of these and put them up on my drive. You can check it by clicking on the drive link button.