Black HDPE→Natural HDPE

Colour Change & Decarbonisation on 8 ltr Accumulator

The Process

The majority of the colour was gone in 60 kg; large quantity of carbon coming out from the inside-outside line with black as well, proving that the colour was seeping in the carbon cracks

By the end of 100 kg the majority of the carbon was gone ( Left). Last full stroke shows no more residue of carbon/colour (Right).
The machine is switched off for decarbonisation

The photos show the build-up of carbon on the inside being removed by the decarbonising, on startup on Monday morning

Decarbonising of the outside. Large amount of carbon coming out.

Last purge with PolyClear HMEX (Left).
First Purge with Natural HDPE (Right)

First shot with a black shadow. Second shot with the shadow drastically removed.


Normal results:

Shut Down

  • Purge with HDPE

Start Up

  • Purge with HDPE at 350°C
  • First 24 hrs 100% scrap
  • 48 hrs till scrap level acceptable
  • Last Run in Natural before Black: 75% Scraps over run

Aquapurge results:

Shut Down

  • 140 kg Poly Clear HMEX (HT)

Start Up

  • 100 kg Poly Clear HMEX (HT)
  • 2% rejects on first 500
  • 1% rejects over production run

You can also read this Case Study here