Table of Contents

Pneumatic injection molding machine Report Download

Fabrication

The polymer material are converted into plastics and used as tubes, sheets, foams, rods, adhesives, etc., The theological properties, softening, tempering, stability, the size and shape are important in describing the method. These methods are different kinds of plastics. Broadly speaking the method may be discussed under the following headings,

a. Moulding Process
b. Foaming Process

Moulding process:

In this process the plastics are fabricated under the effect pressure and heat and both thermoplastics and thermosetting plastics may be starting materials.
Thermoplastics are produced by this method. In this the material is softened by heating and the hot softened plastic is forced under high pressure into the mold, when it is set by cooling and the mold is.

Foaming process:

This involves the blowing of a volatile organic liquid, which is entrapped into a polymer network resulting in the formation of foamed plastics. Foamed polystyrene are produced in this process.

Components

The main components of the pneumatic injection moulding machine are,
• Pneumatic Double acting Cylinder
• Hooper
• Barrel
• Heating Coil and regulator
• Direction control Valve
• Flow control valve
• L-Angle
• Nozzle
• Die and
• Hose connectors

Pneumatic injection molding machine Report Download

Pneumatic Double Acting Cylinders:

A double acting cylinder is employed in control systems with the full pneumatic cushioning and it is essential when the cylinder itself is required to retard heavy messes.
This can only be done at the end positions of the piston stock. In all intermediate position a separate externally mounted cushioning derive most be provided with the damping feature.

b. Hooper:
The hopper is used to pour the plastic raw materials in to the barrel.

c. Barrel:
The barrel is used to hold the molten and unmated plastic raw materials.

d. Heater and Regulator
The heating coil is used to melt the plastic raw materials to the molten Form which is inside the barrel
The heating coil regulator is used to regulate the temperature of heating coils according to the type of plastic raw materials used.

e. Direction Control Valve:

To control the to and fro motion of cylinder, the fluid energy has to be regulated, controlled and reversed with a predetermined sequence in a pneumatic system.
Similarly one may have to control the quantity of pressure and flow rateto generate the desired level of force and speed of actuators. To achieve these functions, valves are used. Valves are fluid power elements used for controlling and regulating the working medium.
The main functions of the valves are,
• Start and stop the fluid energy
• Control the direction of flow of compressed air
• Control the flow rate of the fluid
• Control the pressure rating of the fluid

f. Flow Control Valve:

These are used to control the rate of flow of a fluid through the valve.
A directional control valve on the receipt of some, external signal, which might be mechanical, electrical or a fluid pilot signal, changes the direction of stops, or starts the flow of fluid in some part of the pneumatic/hydraulic circuit. They can be used to carry out such functions as:
1. Controlling the direction of motion of an actuator
2. Selecting alternative flow paths for a fluid.
3. Stopping and starting the flow of fluid

Purpose: This valve is used to speed up the piston movement and also it acts as a one way restriction valve which means that the air can pass through only one way and it can‟t return back.
By using this valve the time consumption is reduced because of the faster movement of the piston.

g. L-angle:
Mild steel „L‟ type angle is used to fabricate the frame to mount the all the parts of the injection molding unit.

h. Nozzle:
The nozzle is used to inject the molded plastic material into the die.

i. Die:

The die is used to produce the required product. By using different Types of die different products can be formed.