Read the text about problems and solutions for plastic moulding and fill in each blank with NO MORE THAN TWO WORDS from the textPlastic Injection Molding Problems And SolutionsThe advantages of plastic injection molding for manufacturing parts methods include fast production speed, high efficiency, automation of operation, shapes, and size flexibility. Moreover, the injection molding products are accurate in size, easy to be replaced, and the mold parts can be formed into complex shapes. This eco-friendly method is suitable for the molding processing fields such as mass production and complex shape products.However, although the operators are familiar with specific machines and the operational skills in the molding process of plastic parts, the various rapid injection molding defects on mold design and materials are inevitable. The article aims to plastic injection molding problems and solutions, mainly as follows:Short ShotsShort shots are a phenomenon in which the mold cavity cannot be completely filled.Causes:- Die temperature, material temperature or injection pressure and speed are too low- Uneven plasticization of raw materials- Poor exhaust- Insufficient liquidity of raw materials- The part is too thin or the gate size is too small- Polymer melt is prematurely cured due to unreasonable structural designRemedies:Material: Use more fluid materialsMold design:- Fill the thick wall before filling the thin wall to avoid the retention phenomenon.- Appropriately increase the number of gates and runner size to reduce the process ratio and flow resistance- The position and size of the exhaust port should be properly set to avoid the phenomenon of the poor exhaust.Machine:- Check whether the check valve and the inner wall of the material cylinder are seriously worn- Check if the feeding port has material or whether it is bridged.Air TrapsAir traps is that air is trapped in the cavity to create bubbles in the part.Causes: It is caused by the air being unable to escape from the parting surface, the ram, or the vent when the two melt fronts meet.Remedies:- Structural design: Reduce thickness inconsistency and try to ensure uniform wall thickness- Mold design: (1) Add a vent at the last filled place (2) Redesign the gate and runner systemBrittlenessBrittleness is that the plastic part is easily cracked or broken in some placeCauses:- Dry conditions are not suitable; use excessive recycled materials- Injection temperature setting is wrong- The gate and runner system settings are not appropriate- The melting mark strength is not highRemedies:Material:- Set appropriate drying conditions before injection molding- Reduce the use of recycled materials and increase the proportion of raw materials.- Use high-strength plastic.Mold design: Increase the size of the main runner, branch runner, and gateMachine: Choose a well-designed screw to make the temperature distribution more uniform during plasticization- (1) molding is an eco-friendly method, which is reasonable for bulk production and complex shape products.- Three main problems of this process are short shots, air trap and (2) .- Short shots can caused by many reasons such as uneven plasticization and insufficient liquidity of (3) , insufficient exhaust , too thin part or small (4) , or the melting of polymer.- (5) happens when the air cannot be escaped from the parting surface, the ram, or the vent when the two melt fronts meet. This can be prevented by testing the (6) and (7) design.- The plastic part can easily (8) or broken in some place, it is because of unsuitable condition, injection temperature, in appropriate gate and runner system settings, or low (9) mark strength.

The plastic i _ _ _ _ _ _ _ _ molding process is a manufacturing method for producing plastic parts. Before the process begins, an experienced mold maker creates the mold or tool used to make the part. The first step of injection moulding process is that p_ _ _ _ _ _, or small pieces, of plastic are fed from the hopper into a cylinder. After the plastic pallets are fed from the h_ _ _ _ _, a container shaped like a V into a cylinder, they are pushed along the cylinder by a rotating screw, and heated. The molten polymer is pushed by the ram through the n_ _ _ _ _ (a small hole) into the mould, and becomes hard. The soft plastic is injected through the nozzle into a shaped c_ _ _ _ _, an empty space, between the two halves of a mould. R_ _ _ _ _ _ _ _ _ moulding is a high-temperature, low-pressure plastic forming process which uses heat and rotation along two axes to produce hollow, one-piece parts. After the soft, warm plastic is pushed toward a nozzle by the ram, it is then i_ _ _ _ _ _ _ through the nozzle into a shaped cavity between the two halves of a mould. Injection moulding uses a r_ _ , a machine part used to force molten plastic or rubber material into a mould cavity. After a product is designed, usually by an industrial designer or an engineer, m_ _ _ _ _ are made by a mould-maker (or toolmaker) from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. With e_ _ _ _ _ _ _ _ moulding, hot melted plastic is pressed through a shaped hole to create a lengthy shaped plastic part.

The first step of injection moulding process is that p_ _ _ _ _ _, or small pieces, of plastic are fed from the hopper into a cylinder.

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.

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.