DESIGN OF MOULDS

1.  What is plastic processing?

Plastic Processing is one of the fastest growing segments of manufacturing plastic processing is a form conversion process

2.  Define injection moulding.

Injection molding is a process of producing parts form thermoplastics and thermo plastics.

3.  State the two units of a ram type of injection moulding process

Injection Unit

Clamping Unit

4.  What is the use of rotational moulding?

The rotational moulding process is used to make thin walled hollow parts.

5.  Define cycle time

The time interval covering the mould cycle is known as cycle time.

6.  What is the press tonnage of compression moulding?

The press tonnage requirement may range from 100-500 tones.

7.  What is called positive mould?

When the plastic is completely trapped between the male and female dies, it is called as positive mould

8.  What are the main advantages of thermoforming?

The main advantage of this process is low cost and quick process of making the Sheet.

9.  Classify extrusion die.

Die for solid section

Die for hollow section

10. State common impregnation liquids

Epoxy

Polyurethane

11. What are the elements considered for the construction of an injection mould?

Fixed half and moving half

Cavity

Core

Impression

Spur bush

Runner

Gate systems

Guide pillars and bushes

12. Mention the function of runner.

Runner is the primary channel carrying the plastic melt from spur to the gate systems in multiple cavities in a mould

13. What do gate systems do?

Gate is the secondary channel carrying plastic melt from runner to the mould cavity.

14. Classify cavity and core

1. Integer cavity and core plates

2. Cavity and core inserts

15. What are the types of cavity and core inserts?

1. Rectangular insets blocks

2. Circular insets blocks

16. List down the types of layouts followed in multiple impression moulds.

1. Multiple impression mould with circular layout.

2. Multiple impression mould with rectangular layout.

7. What is a bolster?

Bolster is the steel plate on which the cavity or core inserts are mounted. It is normally made up of mild steel.

18. Mention the types of bolsters.

1. Solid bolster

2. Strip type bolster

3. Frame type bolster

4. Chase type bolster

19. What is gate in injection moulding?

Gate is the channel or orifice connecting the runner with the impression

20. List down the advantages of ejector pin.

1. Service life is more.

2. It is easy to repair