PRODUCTION OF PLASTIC MATERIALS. A RESEARCH PROJECT TOPIC ON CHEMICAL ENGINEERING
Generally, plastic is defined as long-chain organic material which can be formed into desired shape by the application of heat and pressure, also it extends to include so many organic metallic complex and also certain long-chain inorganic material based principally on silicon, phosphorus, nitrogen, aluminum or boron or mixtures of these. It is still however true to say that the bulk of current commercial plastic are modified organic chemical, and that the inorganic polymers and the organic-metallic are limited in production and used only for special purpose .plastic form a group of high polymers which have a fair range of deformability and mould ability particularly at high temperature. In plastic, the polymer formed don’t have the same molecular weight and since the polymer are not amenable to the ordinary method of separation. Injection molding process, of all other process such as, calendaring, casting , forming,expanding, coating decorating etc, was used because of its applicability in the production of several different types of products. It also reduces loses due to mouilding.The process involves the use of authomated injection machine which consist of two major part: injection section and clamping section . The injection section consist of the section pump which enable the feed (pellets of mixed co-polymer raw material and the colours) to be introduce into the feed hopper. It also has the hopper part that allows the fed pellets to enter into the ram chamber where it is pushed into the heating cylinder where the pellets are melted in the presence of high heat generated by the electric heat. The movement of torpedo backward and forward aids the inlet of the pellets, as it goes forward . On moving backward , the molten plastic enters the injection nozzle which pushes the molten plastic into the mould which is detachable, and also attachable depending on the type of product to be produced. The mould is aided with a cooling film that allows the molten moulded plastic to be cooled, and formed the shape of the mould.
The shaped molton plastic could come in form of either a seat, table, bucket, cup etc. the products will have some durable characteristics such as colour retainability, because of the anti-ultravident rays added to oppose the action of the ultra violent rays from the sun that causes the colour fade in some plastic. Several other additives were added such as plasticizers, extenders, lubricants, stabilizers, fillers, pigments and other miscellaneous additives, so as to obtain the best qualities such as flexibility, smooth, electric insulation and strength. The cost of this production is quite enormous considering the cost of raw materials and the colours, the cost of all the additives, the cost of the injection machines and moulds and other costs such as: transportation, installation of the machine, electricity and other overhead costs. Research cost and labour costs are not overhead. Utility cost (water, power and fuel) are also included.
Due to the liquid qualities introduce, such as machinability, low density, durability even in the presence of sun and chemicals, high creeping factor resistance even in the presence of heat, its inability to crack and graze in the presence of stress from environmental and its considerable strength, we affirm that the product is of high rating.
Before the advent of synthetic plastics, most forms of construction and production were dependent upon the use of natural materials such as metal, wood, rubber, tar and various minerals. These materials are still very much in evidence today, but in many instances they have been replaced by the new wonder materials called PLASTICS. Through the magic of the chemist, we now have plastics that can meet almost every engineering requirement.