What if I Don’t Have the Right Color Concentrate?

Orange Juice Concentrate

We all know that you should always try and run a color concentrate with a carrier resin that matches the material that you running it in. But what if you don’t have the right color concentrate?

If you don’t know, color concentrate is made up of pigments and additives that are encapsulated in a polymer carrier resin. Color concentrates are typically supplied in a pellet form. The polymer basically encapsulates the powdered pigments and additives. This makes color easy to handle and safer too. Powders can become airborne and when they do, they are an explosion hazard not to mention unhealthy for people to breath. Color concentrates are typically about half additives and pigments and about half carrier resin.

Whenever possible we like the carrier resin to be the same material that you are blending the color concentrate into. It doesn’t need to be the same grade, just the same material. Use ABS carrier in ABS or nylon carrier in nylon etc.

But, there are those times when you just can’t do this. You need something in a pinch and you don’t have the correct color concentrate available. Maybe you need to run some sample parts out of black ABS but you only have natural in stock.

What I want to do hear is to provide a list of color concentrates that you could use in a pinch. The first choice is always going to be a carrier resin that matches the material that you are molding. Accepting that your first choice is unavailable, I want to show what the second choice, third choice and fourth choices might be.

Here is the list, with notes below.

Material  you are molding          2nd Choice                  3rd Choice                       4th Choice

ABS                                                        SAN                                       PE                                           –

ABS/PC Alloy                                      ABS                                        PE¹

ASA                                                        ABS                                        PE

ASA/PC Alloy                                     ASA                                        ABS                                        PE¹

Acetal²                                                  PE                                           EVA

Acrylic                                                   PE                                           EVA

EVA                                                        PE          

Nylon 6                                                 ABS                                        PE                                         EVA

Nylon 6/6                                            Nylon 6                                 ABS                                        PE¹

Nylon 4/6, 6/10, 6/12, 6,6/6         Nylon 6

Polycarbonate                                   ABS                                        PBT                                        PET

PC/PBT Alloy                                      PBT                                        PE¹

Polyester (PBT)                                 EVA¹                                      PE¹

Polyester (PET)                                 PBT                                        PC                          

Polyethylene³                                   EVA                                        PP

PPO/PS (Noryl)                                 PS                                           ABS

PPO/PA (Noryl GTX)                       Nylon 6                                 ABS

Polypropylene                                  PE                                           EVA

Polystyrene                                        ABS                                        PE

PVC                                                        PE                                           EVA

TPO                                                        PP                                           PE                                         EVA

TPV                                                        PP                                           PE                                         EVA

SAN                                                       ABS                                        PE

SBC                                                        PE                                           PP                                          EVA

Note 1: This color concentrate might melt or get sticky at the typical drying temperatures for this material. Material must be dried before adding color concentrate and great care must be taken to prevent bridging in the feed throat.

Note 2: Acetal homopolymer carriers can be used in copolymers and vice-versa.

Note 3: HDPE, LDPE and MDPE are all compatible.

Keep in mind that you might have to take some special precautions when using some of the above non-ideal color concentrate combinations. Using a PE, or EVA color concentrate in a higher heat material like Nylon 6/6 or PET might be troublesome. The carrier resin might get soft in the dryer or in the feed throat of the molding machine. You might have to dry the material separately and blend in the color concentrate in a bucket and put small amounts in the machine. You would not do this for production, but in a pinch, you could do it for a small run.

On the other hand, some of these combinations will run surprisingly well, such as ABS color concentrate in Nylon. The problem is that you might be suffering some property loss without knowing it so this is still not a good long term strategy.

Also keep in mind that if the color concentrate has a carrier resin that is hygroscopic (absorbs moisture), such as ABS or nylon, it will need to be dried just like the material.

I hope this helps to clear up some of the confusion.

 

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