Many adhesives (glues) are thermosetting plastics Many adhesives (glues) are thermosetting plastics. A good example is ‘Araldite’ which is an epoxy resin that hardens when a second chemical is added (a catalyst). It will bond most materials including woods and metals as well as some plastics.   Polyurethane. This forms the basis of many paints and varnishes because it is very tough and has water resistant qualities. Melamine Formaldehyde. Used in the production of plastic laminates because of its smooth surface and hygienic qualities. It is also used in electrical plugs and sockets because it can be cast and it is an excellent insulator. Urea Formaldehyde (UF): Urea Formaldehyde has physical properties of high hardness and high toughness, making it suitable for strong, knock-resistant electrical fittings. It is also scratch resistant and a very good electrical insulator, making electrical fittings manufactured from this polymer safe to use. These plastics possess a common property, they soften when heated and are often used in schools to vacuum form shapes. Usually, when heated and formed into a shape - if reheated they return to their original shape. Acrylic. (PERSPEX® Lucite International's acrylic sheets) This is the most common plastic in a school workshop. It is purchased usually in the form of sheets and comes in a range of colours. It can be translucent (e.g. smoked), transparent or opaque. It is resistant to most acids and weather conditions. Please note, the brand name Perspex®, is owned by Lucite International (http://perspex.com/). Polythene. Can be moulded into almost any form due to its excellent moulding qualities. Used for the production of bottles, bowls, toys, tube etc... It is available in large sheets. There are two types: High density which is rigid and hard, and low density which is tough and flexible. Machine parts are generally made from high density polystyrene whilst bottles are made from the low density polystyrene. Polyvinyl Chloride. Better known as PVC. It is a tough material which can be purchased as a hard material or alternatively a flexible form. It can be welded or bonded with an adhesive. It has a range of uses including water pipes, raincoats, long play records, coating on electrical wires and many more. Polyethylene. The most common plastic in everyday life. Used in the manufacture of 'plastic' bottles, grocery bags, shampoo bottles and children's toys. MORE USEFUL PLASTICS Styrofoam. This is a light-weight dense foam. It is easy to shape with saws, files and abrasive paper and is ideal as a model making material. Expanded Polystyrene. An efficient insulator used in cavity walls and as decorative tiles and covering on ceilings. It can also be used for basic model making. Nylon. Is used in engineering to make gears and bearings. It’s oily nature means that friction is reduced between moving parts made from nylon.

Function

E4 made from plant-based PLA perfect for foods up to 50C safe and non-toxic light and strong compostable Poly(lactic acid) or polylactic acid or polylactide (PLA) is a biodegradable and bioactive thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States and Canada), tapioca roots, chips or starch (mostly in Asia), or sugarcane (in the rest of the world) Bacteria are able to degrade PLA. A purified protease

One Off Production/ job or customer production With this type of manufacturing we are concerned with individual products which will probably not have a number of pre-manufactured components in them. Most of the time no two products will be exactly the same. The units may often be to a customer's requirements. As a result each unit may prove to be expensive. High unit cost. Batch Production This form of manufacturing deals with larger production runs. According to the demands of the customers, batches of a product may be increased or decreased. This form of manufacturing may involve some lineproduction andsome standalone job production. For example this car scraper may be produced in batches of 100's over the period of a few hours. Jigs, formers, templates are used to create scrapers of exactly the same shape and size.There is an economy of scale because of standardisation. Early Mass Production (Line Production) The Model T was a prime example of a product sold in high volumes. The car moved along an assembly line with parts being added by different workers. Productivity was increased.  Significant economy of scale is achieved because of standardisation. The cost of each individual unit drops dramatically. Modern Mass Production / Flow or Continuous production Products that are sold in very high quantities (volume) and are sold in very high numbers every day are continually produced.  It would prove to be uneconomical to switch off the assembly line. Computer controlled robotics systems which are initially very expensive to purchase keep production rates extremely high. This brings the unit costs very low.  The term 24/7 refers to a machinery system being run 24 hours per day for 7 days per week.