Overview
ISO/TS 21256-4:2023 - "Fine bubble technology - Cleaning applications - Part 4: Test method for oil removal from polyester-based textile" specifies a reproducible laboratory procedure to evaluate oil removal performance from polyester-based textiles using fine-bubble water. The technique quantifies oil removal by measuring textile mass and brightness before and after exposure to circulating fine-bubble water, enabling objective comparison of cleaning effectiveness across bubble sizes, concentrations and process parameters.
Key topics and technical requirements
- Scope: Test method focused on polyester-based textiles (e.g., PET, PBT, PTT) to assess oil removal performance using fine bubbles.
- Measurement principle: Determine oil removal by mass difference of the textile sample before soiling, after controlled soiling, and after washing/drying; complement with ISO brightness (R457) to express cleanliness visually.
- Controlled contamination: Use coloured oils (e.g., lubricants and edible oil) dyed with Sudan Red III to standardize soiling and improve measurement repeatability.
- Equipment examples: Drying oven, precision electronic balance (high resolution), micropipette, beakers (250 ml and 2 000 ml), water diffuser/tripod, portable brightness meter and suspended stirring bar. Specific equipment performance (e.g., scale resolution, oven temperature control) is recommended to ensure reproducibility.
- Typical test parameters (from document): preset water flow 2 L/min, soaking duration 5 minutes, drying at 60 °C for 20 minutes, and a standard soiling mass (example 0.15 g coloured oil) - these provide a baseline protocol for comparative testing.
- Result reporting: Report initial and final masses, oil mass added, oil stain removal rate, brightness values, fine-bubble properties and any deviations from the procedure.
- Performance metric: Oil removal rate expressed as the fraction (or percentage) of oil removed based on pre- and post-wash mass measurements.
Applications and users
- Textile manufacturers and finishing houses assessing the effectiveness of fine-bubble cleaning for polyester fabrics.
- R&D labs developing fine-bubble generators, water treatment systems and low-detergent textile washing processes.
- Sustainability and recycling operations evaluating mechanical/physical cleaning (reduced detergent) for fabric recycling or pre-treatment.
- Equipment vendors and certification bodies comparing fine-bubble systems by standardized oil-removal performance.
Practical benefits include objective benchmarking of fine-bubble water against tap water, optimization of process parameters (bubble size, concentration, flow rate) and support for environmentally friendlier cleaning that reduces detergent use.
Related standards
- ISO brightness reference: ISO R457 (used for brightness measurement in this test).
- Other parts of the ISO 21256 series on fine bubble technology (see ISO website for the full series).
Keywords: ISO/TS 21256-4:2023, fine bubble technology, oil removal, polyester-based textile, test method, textile cleaning, oil stain removal rate, fine-bubble water, ISO brightness.