How Much Thiourea Dioxide Would I Need per Tonne of Fabric?

Direct Answer

Direct Answer There is no single figure, because consumption depends on the process, liquor ratio, fabric weight and target performance. It can, however, be converted from the recipes in our technical data sheet.

Two ways of expressing the dose

• As a liquor concentration in g/L, tied to the liquor ratio and suited to recipe writing
• As a weight on fabric in g/kg or % owf, independent of liquor ratio and suited to comparison across machines

Confusing the two is one of the main reasons cost calculations go wrong.

Converted from the technical data sheet

Conversion logic: kg per tonne of fabric is approximately the g/L concentration multiplied by the liquor ratio figure. For example a 1:10 liquor ratio at 0.5 g/L gives about 5 kg per tonne.

Three factors that move the number

• The larger the liquor ratio, the higher the consumption per tonne at the same concentration
• The deeper the dye, the greater the stripping or clearing demand
• On a continuous washing line the consumption follows the liquor pick-up of the fabric and cannot be converted directly through the liquor ratio

A note on units

Machine cleaning is dosed against the machine bath volume, not against fabric weight, so the per-tonne figure does not apply.

Bottom line

Polyester reduction clearing uses about 5 to 15 kg per tonne of fabric and stripping about 20 to 45 kg. Set the recipe in g/L first, then convert through the liquor ratio.

Sources

1. 我司产品技术数据表《THIOUREA DIOXIDE Technical Data Sheet》（TDO-TDS，签发日期 2024-05-08）
2. US5958184A, Process for producing thiourea dioxide（还原当量质量比、碱中水解式、木浆与脱墨浆等当量漂白实施例），https://patents.google.com/patent/US5958184A/en
3. Effective reduction clearing parameters involving alternative reducing agent（2021），DOI 10.54693/piche.04916
4. Performance Evaluation of Hydrose and Thiourea Dioxide as Stripping Agents for Reactive Dyes，AJER 7(2), 2018，https://www.ajer.org/papers/Vol-7-issue-2/ZF070201250258.pdf