Appropriate size of airway in plastic injection molds

You are injection moulding a plastic part, and need the part to have very tight tolerance in one particular dimension. The part is made from ABS plastic, which has been measured to have a linear coefficient of thermal expansion of 90 x 10-6 m.(m.°C)-1. The material will contract from its melting temperature of 190 °C, back to 20 °C, at which point it must measure precisely L0 = 20 mm. How large should this dimension be made in the mould? Give your answer in mm  to at least 3 decimal places

The method used to insert an artificial airway is called

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

Describe the process of injection moulding