DIP Moulding

DIP MOULDING:

In plastics processing, dip molding is a process of shaping of plastics by moulding. The coating of components with PVC has many applications. Plastic dip moulding is a technique where metal parts are coated with a plastic vinyl material. 

1. Dip moulding process involves dipping a preheated mandrel into plastisol followed by a high temperature cure. 

2. The cured plastisol is then removed from the mandrel resulting in a finished part. 

3. This part can be further enhanced by a variety of secondary operations including printing, hole punching, trimming and assembly.

4. Parts that are too large for dip coating, too costly to ship, or that require a removable protective covering, are excellent candidates for dip moulding. 

5. Also, parts whose volume does not justify the tooling costs associated with injection moulding are ideal for dip moulding. 

The plastic can be heated or not according to their physical state at room temperature. In the case of a powder, the plastic is fluidized. The following steps constitute the dip moulding process:

1. Mould heating

2. Heated mould dipped into the plastic material;

3. Removal of the mould;

4. Excess drainage;

5. Drying or curing of the plastics material still attached to the mould if it contained a solvent or was based reagents (monomers, prepolymers) reagents;

6. Cooling of the plastic still attached to the mould;

7. Releasing of the part from the mold after its solidification.

The part may need to be submerged several times to give the desired thickness.

Materials: Liquid plastisol

Plastisol is the most used material for dip moulding because it is easy to use and affordable. Other materials are used, such as latex, leneoprene,polyurethanes, silicones and even epoxy.

Advantages

1. Low tooling costs 

2. Quick and inexpensive prototypes 

3. Short lead-times on custom tooling

4. Innovative materials and textures 

5. More vibrant colours can be achieved with vinyl 

6. No internal stress moulded into parts 

7. Large parts can be made without significant tooling investment. 

8. Multi-Dipping capabilities allow to design products with two colours or materials on one part.

9. Used for making products with durable inside liners and more consumers friendly exteriors. 

Disadvantages

1. With the exception of internal dimensions, tolerances are often much higher than on injection moulded parts 

2. Limited exterior design possibilities and control.  

3. Price 

Application

The main applications are the bellows, gloves, balloons, Plastic coin purses, hand tool grips, shifter boots for trucks & automobiles, bellows.