Where ever you are at the moment, if you look around you will see plastic. If you are using a computer to read this article, you will probably be touching some. Plastic has revolutionized the manufacturing industry, and is continuing to do so every day. New uses for existing plastics are being found, and new types of plastics are being developed to fulfill needs. All of the things you see around you needed to be formed to their shape, in one way or another. This is usually achieved through one of several molding methods, below are a few of these methods, and why they are chosen.
Compression Molding
Compression molding is achieved when plastic is placed into a mold. The mold, which is in two parts, is heated and joined with a great deal of pressure, which in turn forces the plastic to the shape of the mold. The mold is held in place until the plastic cures, after which the molded item can be cooled and finished. The items formed using compression molding includes things like, car bumpers, and rubber boots. It is very useful method for molding large shapes.
Injection Molding
Injection molding is probably the most widely used molding technique. This is because it relatively fast, and because the high pressure used can help attain finer detail on the products. Raw plastic is heated until it has been melted, it is then forced into a cold mold under high pressure, once the plastic has cooled the mold is removed, and the molded shape can be finished for sale. You will find that your garden furniture, bottle tops, and combs, have all been produced this way. This is a great method to mass produce plastic items, especially as so many types of plastic can be used.
Extrusion Molding
Extrusion molding is used to create simple shapes, such as, sheeting and pipes. It is an ideal method for these types of shapes, because of the process itself. Raw plastic, like pellets or slugs, are heated and turned in a revolving drum. The heated plastic is then forced through a die, which gives the plastic its shape. Items made like this all have the same cross-section, and examples would be things like straws, plastic pipes and hoses, and curtain rails.
Thermoforming
Unlike other molding techniques, a hot sheet, or film is stretched over a mold to form the required shape. There is a thin gauge, and a thick gauge variant, with thin gauge giving us items like disposable cups, and thick gauge supplying things like car doors, and plastic pallets.
Here, you can see the diversity of forming methods that give us the everyday, and more unusual, plastic items we now use. Since the development of celluloid in the 1860's, up until the present day, plastics have needed to be formed into shape. These 4 methods are among the most common, but there are others that can be used. Perhaps next time I'll let you know what those ones are.
Compression Molding
Compression molding is achieved when plastic is placed into a mold. The mold, which is in two parts, is heated and joined with a great deal of pressure, which in turn forces the plastic to the shape of the mold. The mold is held in place until the plastic cures, after which the molded item can be cooled and finished. The items formed using compression molding includes things like, car bumpers, and rubber boots. It is very useful method for molding large shapes.
Injection Molding
Injection molding is probably the most widely used molding technique. This is because it relatively fast, and because the high pressure used can help attain finer detail on the products. Raw plastic is heated until it has been melted, it is then forced into a cold mold under high pressure, once the plastic has cooled the mold is removed, and the molded shape can be finished for sale. You will find that your garden furniture, bottle tops, and combs, have all been produced this way. This is a great method to mass produce plastic items, especially as so many types of plastic can be used.
Extrusion Molding
Extrusion molding is used to create simple shapes, such as, sheeting and pipes. It is an ideal method for these types of shapes, because of the process itself. Raw plastic, like pellets or slugs, are heated and turned in a revolving drum. The heated plastic is then forced through a die, which gives the plastic its shape. Items made like this all have the same cross-section, and examples would be things like straws, plastic pipes and hoses, and curtain rails.
Thermoforming
Unlike other molding techniques, a hot sheet, or film is stretched over a mold to form the required shape. There is a thin gauge, and a thick gauge variant, with thin gauge giving us items like disposable cups, and thick gauge supplying things like car doors, and plastic pallets.
Here, you can see the diversity of forming methods that give us the everyday, and more unusual, plastic items we now use. Since the development of celluloid in the 1860's, up until the present day, plastics have needed to be formed into shape. These 4 methods are among the most common, but there are others that can be used. Perhaps next time I'll let you know what those ones are.