State two things you must consider when designing a mould for a thermoset plastic

Read the passage about 3 types of plastic moulding and give short answer for the following questions with NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage.Types Of Plastic MouldingBlow MouldingThis method is ideal for when the plastic part has to have uniform wall thickness. The machine heats up the raw plastic until it becomes liquid and then injects air into it like a balloon. The plastic is blown into a shaped mould and as it gets bigger it presses against the mould walls and it starts to take its shape. After the liquid balloon fills the mould it is cooled to keep its shape. The process is very fast and can produce up to 1.400 pieces in a 12-hour work day.Common Uses for Blow MouldingBlow Moulding is mostly responsible for producing products like plastic bottles, drums, cases and even fuel tanks. This is a fast and economical friendly option with the mould prices ranging somewhere in between injection moulding and rotational moulding.Injection MouldingInjection Moulding is fairly similar to extrusion moulding. The difference here is that with injection moulding the melted plastic is injected directly into a custom mould. The injection is under high pressure so that the mould is filled and a solid part is made. As with the other methods, after the mould is filled, the plastic is cooled as to keep its new shape and then the mould is opened.Common Uses for Injection MouldingThis is a common method to produce a high volume of plastic parts like car parts or even parts for surgical applications. Products can also be made with increased flexibility to suit the needs of designers or engineers.Rotational MouldingAlso sometimes called rotomoulding, this method involves the resin or liquid being placed inside the mould and then being rotated at high speeds. The liquid then evenly covers the entire surface of the mould to create a hollowed part with all the walls evenly thick. After the mould is cooled and the liquid plastic has taken its new form it is then taken out of the mould.This method is very material efficient and very little goes to waste making it more economical and environmentally friendly.Common Uses for Rotational MouldingThe most common use for this method is for big and hollow parts. These parts include car parts, bins, kayaks, road cones, pet houses and storage tanks.The tooling costs with rotational moulding are lower than other methods like injection and blow moulding. This makes for lower start-up costs and more effective production costs even at low volume production.How many parts are manufactured with the blow moulding process half a working day? Which type of moulding is considered in between injection and rotational moulding? With injection moulding, which part is made when the mould is filled under high pressure? Which kind of plastic parts are manufactured with high volume using injection moulding? How much waste does the rotational moulding process make? What is considered as one disadvantage of rotational moulding in the last paragraph?

Plastics (will give) additional characteristics such as fire retardancy to allow them to be used in aircraft parts in the future. Injection-moulded parts (may include) glass or carbon fibres for strength. Plastics (can mould) with a foaming agent which (will reduce) the density and hence the weight of the final component and reduce the material required so reducing the cost. The list of plastics appears to be endless but they fall into two categories, thermoplastics and thermosets. Thermoplastics (can melt and recycle) into new parts. Thermoset plastics are stronger than thermoplastics but (cannot recycle) into new parts and have to be disposed of in other ways.

Plastics have replaced wood, paper, glass, steel, and aluminum as the materials of choice for many common objects used today. They usually have interior mechanical properties such as stiffness, strength, and temperature resistance to the materials they have replaced. However, plastics succeed because of their low density, toughness, and design flexibility. Much of this design flexibility is due to the manufacturing processes that have been developed to shape them into simple and complex forms that would be costly or even impossible to produce with traditional materials.Moulding processes have been around for a long time and are particularly suited to making plastic parts. Most of the processes can efficiently produce plastic parts in high numbers, but even where low numbers are involved, the complexity of the required shape may reduce the cost of moulding a part in plastic over machining a part from metals.Plastics production really started in the mid-20th century. Today there are hundreds of different plastics available, each one developed to have specific characteristics to meet the requirements of different users. The list of plastics appears to be endless but they fall into two categories, thermoplastics and thermosets. Thermoplastics can be melted and recycled into new parts. Thermosets are stronger than thermoplastics but cannot be recycled into new parts and have to be disposed of in other ways. Because plastics are not naturally biodegradable and not all plastics can be recycled, there is a real problem in disposing of plastic waste.To help answer this concern, bioplastics are being developed from plant materials. It is possible to produce a mouldable “plastic” with ground-up natural cellulose, other materials, and water. Drug capsules are made from starch-based bioplastics.Summary:Plastics are used for many common objects because they are strong, stiff and have (1) to temperature. The design flexibility of plastic makes it easy to be shaped into simple and complex forms, which is more expensive or impossible to manufacture with other (2) . Moulding process is a suitable method for making plastic parts. The cost of moulding a part in plastic is cheaper than one in (3) . Plastics are divided into two (4) . Thermoplastics can be heated and recycled into new parts but thermosets have to be disposed of in other ways. To solve the problem of disposing of plastic waste (5), are produced from plant materials. Drug capsules are made from this material.

With e_ _ _ _ _ _ _ _ moulding, hot melted plastic is pressed through a shaped hole to create a lengthy shaped plastic part

What is basic difference between a thermoplastic and thermoset plastic? Give anexample of both type with the corresponding structure.