Black color to White or Natural Color

[dmsr]

Dear All,

We are using plastics recycle scrap blended with virgin for some application. This recycle scrap will be genereally in Dark Gray or close to Black color.

Is it possible to convert recycle scrap from Black color to White or nearest colors by adding some materials?

Our target is to cnovert from Black color to Parrot Green or C gray.

Pl.advice and suggest.

Thanks & Regards
DMSR

[Len]

DMSR<

No, there is no additive that can erase or bleach out the black, it is only possible to dilute the black, not eliminate it. It is possible to over color the black, another form of diluting the black, but not eliminate it.

If you'll take the time and effort to sort your scrap, segregate the lighter colored and non-black colored scrap from the dark colors, grays, and straight black materials, you may be able to add a green color M/B to the lighter colored scrap stream and get a fairly good result.

Your feed stock and your efforts on the front end to sort out the darker color scrap will determine your success on the back end.

A little black will act as a green against some yellow pigments.

Len

[Indy]

I’m not sure but you might be able to find some results with the use of a colorant, would advise to speaking with some suppliers.

Best Indy

[Len]

I think you can try some optical brighteners. Even it is impossible to make recycled material very white, but it do can improve the appearance. We have some customers like you using optical brighteners. Just for your reference!

This suggestion is a total waste of time.

Len

[Len]

Dear Bigrain 11,

Believe it or not there are some people who think that if you "improve black appearance by using optical brighteners" is the same as "convert recycle scrap from Black color to White or nearest colors." Wasn't the latter the original question?

Throwing an optical brightener into a black resin to make it white or the nearest color to it is ambitious, to say the least.

Len
BTW - I live in Georgia, and we could use some "bigrain."

[Dr. Dick]

You need to understand the nature and science of color to know you can't make a black turn to white. (or a Pig's ear into a Silk Purse. )

One thing to understand is that "clear" is not the same as "white" . The terms White, Gray and Black refer to pigmented materials. The other colors can be applied to clear(use a dye for the color) or pigmented materials.

Black absorbs all frequency's of light whereas White reflects all frequency's. Even over molding of a black with a white often does not work as the black substrate affects the white overcoat. Have you ever tried to cover a Black paint with a white paint? It usually takes several coats to cover the black.

Optical brighteners will make the color richer in that they convert non-visible frequencies into visible ones.

There are a number of reference books on color as well as the use and principals of colorants. Recomend you check one out from your nearest technical library if not actually buying one.

[dmsr]

Dear All,

I thank you all very much for the valuable suggestions and advice. We will make an attempt to implement as suggested by Mr.Len ( For Color segregation) & Mr.Bigrain for using Optical Brightners.

Mr. Bigrain - As suggested by you, I will contact Mr. Kevin of Zhejiang for sample procurement.

Dr. Dick - Is it possible to get lighter shade by exposing palletized scrap granules under sun light for 2 weeks continuously ( I mean all day time) and by use of optical brightners, can we get required color.

I am clear that, my requirement calls for converting Black or Dim ( mixed color) to Parrot Green color.
And we dont require transperancy. If it is opaque , it is absoultely OK.

Pl. comment.

Thanks & Regards
DMSR

[DwightDixon]

It is highly unlikely that you will ever achieve anything close to the Parrot Green color when you are starting out with Black. If you started out with white or clear the story would be different. Work with your local pigment suppliers and they will either assist you in meeting your goals or tell you to stop wasting your time.