Pet Preform Injection Molding Colour Change with EasyPurge Purging Compound

Opaque White to Clear

Goal: Scrap and cleaning cost reduction


Machine: Husky Hypet 300

Extruder Diameter: 120 mm

Mould: 48 x 44.0grs

Material: PET

Colour: Opaque White 10% T. Oxide  to Clear 

Factory Location: Spain

Colour change current standings:

High scrap rates during colour changes when using purging compound in pellets.

Long downtimes due to the presence of colour streaks.

Normal results using virgin material: 

Time: 1:10 Hour

Scrap: 450 Kgs

Purging Compound consumed: 25 Kgs

Using EasyPurge Purging Compound:

Time: 30 Minutes 

Scrap: 200 Kgs

Purging Compound used: 1950ml

Pet Preform Injection Molding Colour Change

Pet Preform Injection Process

1. Seven shots were done injecting Virgin PET resin to remove the bulk of the colour contamination.

2. The dosing of Easypurge started automatically through the premixer using the automatic dosing device while the machine was still injecting preforms. 

3. Both screw and hot runners were cleaned using Easypurge at 1.5%.

4. The Easypurge Automatic Purging System stopped adding purging compound.

5. The cleaning colour changes procedure was finished using virgin material to remove the rest of the purging compound leaving the hot runners clear of colour contamination.




Purging compound used

Colour Time Change


Pellet Purging compound

25 Kgs

1:10 Hr

450 Kgs


1,9 Kgs

0:30 Hrs

200 Kgs

Comment by the Plant Manager:

“I said before the cleanup that nothing would be able to clean this stubborn opaque white. Easypurge got the job done reducing scrap by half”.

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Let’s improve quality and simplify your purging process while reducing change-over time, together.

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