Mould Release Agent Application

From simple bottle caps to complex air plane parts, manufacturers use injection moulding to make products out of anything, from plastics to metal to foam.

Although the variety is great, the basic injection moulding process isn’t.

1. It starts with a mould.
2. A mould release agent coats the inside of the mould
3. Material is injected into the mould.
4. The material solidifies.
5. The injection mould opens
6. The part comes out.

Let’s talk more about step 2.

A water-borne or solvent-based mould release agent must be applied before the material goes into the mould. The mould release acts as a non-stick agent that keeps the part from bonding to the mould.  

It is important that the mould release consistently coats the entire surface of the mould, which can have very unique shapes. If your mould release agent is applied…

• too lightly, the part will stick to the mould and be ruined
• too heavily, the mould release will bleed into the part, leaving discoloured blotches

Conventional spraying techniques make it hard to avoid mould release coverage challenges.

Electrostatic applicators provide the atomisation and transfer efficiency needed to apply just the right amount of non-stick agent inside of the injection mould.

• The spray gun produces very fine particles.
• The electrostatic charge attracts the particles to the mould, evenly coating the entire surface.

Electrostatically spraying mould release agents drastically reduces over-spray, wasted material, part defects, rejected parts and downtime.

• If you’re looking for a manual applicator, Graco has the Pro Xp60 WB Air Spray Manual Electrostatic Gun for mould release applications.
• For high volume operations that use reciprocators or robots, these automatic applicators can produce great results: Pro Xp Auto and Pro Xpc Auto electrostatic air spray guns, ProBell rotary bell atomiser.

Using a water-based mould release agent?

No problem. All of the above work well with HydroShield. The batch system isolates water-borne material in a cabinet, where it is charged. This allows the mould release agent it to be sprayed electrostatically in a safe, efficient manner.