Hard water, encrustation and the polymers that prevent it
Why fabric turns grey and stiff in hard water, and how anionic polymers such as SunRedep keep minerals and soil from settling back.
What hard water does in the wash
Hard water carries calcium and magnesium. During washing, with alkaline builders such as soda ash, these form insoluble carbonate crystals. Some stay in the fabric and build up wash after wash. That build-up is called encrustation.
What it looks like
Whites go grey, colours dull, towels feel harsh and stiff, and the machine scales up. Soil that the detergent loosened also settles back onto the fabric, which is called redeposition.
How anionic polymers help
Anionic polymers carry many negative charges along the chain. They attach to growing mineral crystals and stop them growing into hard deposits, and they hold loosened soil and minerals in suspension so they rinse away instead of settling back.
Where SunRedep fits
SunRedep is an anionic anti-redeposition and anti-encrustation polymer for detergent and cleaning-product makers. SC03 is a high-charge acidic liquid (pH 2.5 to 4.0); SC10 is a very-high-charge grade near neutral (pH 6 to 8), which suits formulations that must stay neutral.
Trial before you switch
Effective levels depend on water hardness, the builder system and the other ingredients. Run a small compatibility batch, check stability and clarity over a few days, then confirm performance with wash trials on your own test fabric.
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Read →Not sure which grade suits your water?
Send us a one-litre sample or describe your process. We test it in our lab free of charge and recommend a grade and starting dose, and quote within 1 business hour.