This program will explain the various types of processing machines used to make a wide range of plastic products in use throughout our lives. A good start is injection molding. Injection molding is used to make plastic parts using two-part molds that, when closed, are injected with melted plastic to form individual parts. Here’s how it works: Material gravity flows into the injection machine screw where it is melted by the compressing motion of the screw and then inject into the mold to form the part or parts.
The mold is quickly cooled, letting the parts solidify. The mold opens to release the parts and the mold closes again to repeat the cycle, over and over again. Molding cycles can last anywhere from one seconds for tiny parts made in tiny molding machines, to minutes for large parts made in presses the size of a building. Extrusion processes use the same plastic melting operation as injection molding, but there is no mold, and the resin compressing screw rotates constantly, and the product is created continuously.
Extrusion uses a die, a hollow form that molten plastic is pushed through, to create its specific shape and thickness. A water bath or spray chamber then cool the extruded shape and often provide pressure and or vacuum controls to properly size the product as it passes through. Belts or cleated pullers apply smooth tension on the product and keep it moving in pace with the extruder. A cutter or saw creates the final product length, or a winder creates spools of the final product.
There are many variations to the extrusion process, but a mixture of extrusion and molding is found in the blow molding process, where plastic is continuously extruded into a tube shape and then clamped at a mold and blown into its shape with compressed air. It’s a process that often operates in a shuttle movement with a set of molds. Each mold takes a turn grabbing a section of an extruded tube called Sparacino and shuttling it to one side to blow it into a bottle shape, letting it cool, and then releasing it to be filled with product or shipped.
Each gold alternates with a second mold doing the same thing for maximum productivity. The same blow molding process can also utilize multiple extruders for what is called co-extrusion. Co-extrusion is used to create bottles made up of multiple layers, and each layer possesses special characteristics like suitability for food contact, an outside color for brand awareness, ultraviolet light protection for the long shelf life of the product, a layer of regrind for economical reuse of scrap, and many times, barrier and adhesive layers are included to separate and bond layers for a tough cohesivebottle.
A high-volume form of blow molding uses many molds mounted onto a continuously-rotating wheel mechanism. The extruder creates a hollow tube, and as the wheel rotates, each of its molds will open, grab a para con from the extruder die, blow the para can into a bottle, allow it to cool, and then place it onto a conveyor, producing a continuous stream of finished bottles originating from that continuous flow of plastic from the extruder. These wheel machines can also produce co-extruded bottles containing layers designed to meet the needs of the product and to use reclaimed material for maximum economy and recycling benefits.
The very popular sails of plastic bottles for carbonated beverages has created a unique process for blow-molded bottles made specifically from polyethylene terephthalate or PET. For PET blow molding, bottles are first created in a test tube shape, injection-molded pre-form, and then, in a separate operation, reheated and blown into their final shape. This two-stage process creates bottles that we, as consumers, know to be thin-walled yet capable of containing gaseous carbonated beverages without losing pressure or exploding, even if they are dropped.
In the blown film extrusion process, thin plastic material for products like garbage bags or the sheeting used in the construction industry and packaging is produced. A very thingie opening, which is often fed by multiple extruders, faces upward in around shape. A tall, thin continuous bubble is produced vertically by this process, and it’s cooled as it flows upward, typically 30 feet or more, where it is then folded and brought back down and placed onto rolls, or converted into popular film products. And all these processes from injection molding to film extrusion rely on Conair products to support their productivity and efficiency.
How do you convert this, for all this plastic waste, back into this? I’m Sanjeev Das I work as packaging director and food for Unilever. After consumers used the product the PET waste plastic is collected and shredded into small pieces. These small pieces are added into a chemical solution, containing the ionic magnetic catalyst. During this process the magnetic catalyst absorbs the color from the PET waste and also the reaction breaks down the waste into its molecular level. The liquid is then dried into a powder form, and this is where our second partner Indorama steps in, who converts this powder back into food-safe, high-quality identical to virgin PET plastic. And this is how this bottle is made back into this bottle. This is a truly circular solution that brings value to the otherwise non-recycled PET waste.
Adidas makes over 400 million pairs of shoes every year. Manufacturing that many shoes require a lot of resources. But constantly creating new materials isn’t great for the environment. So Adidas is turning to a different source. Experts predict that in 30 years, there will be more plastic in our oceans than fish. And one study estimates that90% of seabirds have consumed some form of plastic waste. All that pollution on beaches and in the ocean is harmful to both marine life and humans.
Adidas is trying to stop some of that plastic before it reaches the ocean. In 2015, Adidas partnered with the environmental organizationally for the Oceans. Their goal? To turn marine pollution into sportswear. And they’ve made huge progress. In 2019, Adidas expects to make 11 million pairs of shoes with recycled ocean plastic. That’s more than double what it made in 2018. Adidas says the partnership has prevented 2,810 tons of plastic from reaching the oceans. But how are these shoes made? It all starts at the beach.
Parley and its partners collect trash from coastal areas like the Maldives. The waste is then sorted, and the recovered plastic is sent to an Adidas processing plant. Adidas uses plastic bottles that contain polyethylene terephthalate, or PET. And if it’s something Adidascan’t use, like caps and rings? Those get sent to normal recycling facilities. The processing plant crushes, washes, and dehydrates the waste, leaving nothing but small plastic flakes. The flakes are heated, dried, and cooled, then cut into small resin pellets.
Normally, polyester is made from petroleum. But Adidas melts these pellets to create a filament, which is spun into what they call Ocean Plastic, a form of polyester yarn. Adidas uses Ocean Plastic from the upper parts of shoes and clothing like jerseys. Each item in the Parley collection is made from at least 75% intercepted marine trash. And they still meet the same performance and comfort standards as Adidas’ other shoes. Recycled polyester uses less water and fewer chemicals and helps prevent plastic pollution.
Adidas’ goal is to replace all virgin polyester with recycled polyester by 2024. Currently, more than40% of Adidas’ apparel uses recycled polyester. You may have seen Adidas’recycled sportswear without even noticing it. Clothing made with OceanPlastic has been used in college football, baseball, the NHL, the Australian Open, and more. But this doesn’t eliminate plastic pollution entirely. Washing polyester clothing can create microfibers, which may end up in the ocean.