COLOR CONTROL IN RECYCLING
Color Consistency and Masterbatch Selection in Recycled Plastics
Color control in recycled resin starts by classifying the variable feedstock, fixing blend ratios, choosing a suitable masterbatch, and setting a realistic acceptance range.
Color Masterbatch Technical Team · 2026-08-13 · 10 min
Why Does Recycled Raw Material Change Color?
Recycled raw materials; may vary between lots in terms of source, previous use, separation quality, heat history and contamination. This change affects the undertone of the final color and the need for coverage.
Undertone and transparency
Gray, yellow or mixed undertones affect lighter colors more. It is risky to expect narrow tolerances with a single formulation without classifying the incoming raw material lots visually and measurably.
Pollution and heat history
Degradation due to foreign polymer, old pigment and reprocessing; It may cause spot, odor, surface and color problems. Color study does not replace material suitability checking.
How to Establish Color Consistency?
The goal is to divide the variable input into measurable classes and create tolerances with applicable formulations for each class. The raw material mixing ratio should be kept constant throughout production.
Lot classification
Incoming material is grouped in terms of color, brightness, contamination and flow. Uncontrolled mixing of many different lots requires constantly changing the masterbatch dosage.
Coverage and target color
Light pastel targets can be difficult with a variable dark undertone. A darker or more opaque color family may provide more technically and economically stable results.
Sample and Acceptance Plan
Color development can be achieved not only with clean laboratory raw material; It should be done with samples representing the subtone range that will be encountered in production.
Border samples
The working range of the formulation is seen by experimenting with the lightest, typical and darkest raw material lots. If necessary, two formulations are defined according to lot class.
realistic tolerance
The approved part, measurement method, light condition and acceptance range are determined together with the customer. When the raw material class changes, the formulation is checked again.
Short Technical Answers
Does recycled plastic produce the same color in every lot?
Very narrow tolerances become difficult if the input subtone and purity vary. Control range can be improved with lot classification, constant mix and boundary samples.
Does masterbatch cover pollution?
It can cover the color but does not eliminate the process and quality impact of foreign polymer, degradation or physical contamination. Raw material suitability should also be checked.
Is a light color or a dark color more stable?
Darker, more covering targets with a variable dark or gray undertone are generally more manageable; The final decision is made by sample and cost evaluation.
Send representative recycling raw material lots and target part; Let's determine the color working range and sample plan together.
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