Color is changing while molding

[MRFARRAN]

hello everyone,
we are using recycled polypropylene to mold trash can, we have problem with color that while molding product, color the going to be more light that is because of the specific gravity of masterbatch is more than raw material.
how do you solved this problem?

thanks in advance

[Suhas]

You can try and use purging compounds. Google ASA clean or Dynapurge.
Suhas

[JayDub]

Use a gravimetric blender to add the masterbatch to the resin right at the feedthroat?

[MRFARRAN]

thank you for your reply
I couldn't understand how can purging compounds be helpful in this issue.

[MRFARRAN]

we have dosing controller on all machines but we are using it to add softening materiel. I don't think my boss is ready to buy gravimetric blender for all machines.

[chrisprocess]

because of the specific gravity of masterbatch is more than raw material.

What do you mean by this? The density of the regrind is higher than the virgin material? Or are you referring to the size of the pellets? or are you molding two completely different materials?


Can you filter your regrind through a wire mesh to get the the desired size 'pellets' when adding to the virgin material