Ok, so today I’m going to talk about plastics. There are 7 types of plastics, which are all different. Some strong, some flimsy, but anyway, here are some thoughts on them. Some plastics seem more common than others. Here I have 5 piles of different types of plastics. My first pile is made up of the first kind of plastic, polyethylene terepthalate. It seems pretty common to me. My second pile is made up of the second kind of plastic, or High-density polyethylene. It makes up milk jugs and is strong enough to hold up a gallon of milk but not super heavy like metal or anything. Huh. The third pile contains the fifth type of plastic, or polypropylene. It looks to be rigid enough to be the caps of many different containers. Rigid enough that when you twist it, it doesn’t break into pieces. And finally, some unidentified plastics. The one on the left is metal combined with plastic, I’m pretty sure, so it can’t really be recycled, but the one on the right is some kind of rigid plastic that doesn’t break easily.
I know I didn’t go through all 7 of the plastics, but I didn’t have all of them on hand, okay? Anyway, let’s go on to identifying why exactly different plastics are used for different items. And the answer is that you always use the plastic that fits the situation. Such as how the plastic for a milk jug is strong enough to support the milk within, but also not be super heavy. And usually, you also always pick the cheaper option. So as a recap, the plastic with the best properties for the job and the cheapest would be picked. Let me just go over each of them. The first one is used in plastic water bottles and peanut butter jars because it’s expendable and cheap to produce, but it still gets the job done because it is hard to crush. The second plastic used in milk jugs and other items is made for its strength, as I’ve already talked about several times. The fifth plastic is also made for the fact that it is rigid enough to not break, but also able to be moved off of a container, as you can see all the lids. And the unidentified ones I don’t know about. But that is it for all of these, and I would talk about the others, but I don’t have them, so I won’t.