Contents
Complements Industry Standard Workflow

AATCC TM193 Test Method — Aqueous Liquid Repellency (Water/Alcohol Solution Resistance) on Textile Fabrics

Turn a TM193 visual grade (highest solution that does not wet) into quantitative contact angle (CA) margins, time dependence, and variability so internal QA/QC gates can tighten without changing the external standard report.

Who this is for
QA/QC teams, textile finishers (DWR / stain‑release / barrier treatments), and textile R&D groups running AATCC TM193 aqueous liquid repellency grading who need higher‑resolution, traceable decision thresholds for process control, product release, and troubleshooting.
Positioning
Dropometer does not replace TM193. It adds quantitative wetting data that explains and anticipates the TM193 solution grade (highest solution that does not wet within your method’s observation time), so you make fewer borderline calls and detect drift earlier.
Last updated
February 18, 2026
Request Dropometer Quote View AATCC TM193 Official Method
Written by
abhimanyu
No biography added yet.
Read More
Written By

No biography added yet.

Evidence box

Standard intent (what the test method measures)

AATCC TM193 evaluates resistance to wetting on fabrics using water/alcohol mixtures presented as a numbered solution series. Performance is reported as the highest solution number that does not show wetting/penetration within the observation time specified in the official method used by your lab.

Dropometer role in workflow

Providing quantitative upstream wetting signals (margin, stability, and uniformity) to anticipate/interpret TM193 outcomes; it does not replace TM193 when a customer/spec requires an official report.

Primary outputs

  • CA @ 2.0 s (median across ≥5 spots) — “margin” within the same TM193 outcome

  • ΔCA (2→10 s) — time dependence / stability (uptake, edge instability, wicking behavior)

  • Variability (IQR) — heterogeneity / non‑uniformity signal

Calibration requirement

Thresholds must be calibrated per fabric family and per benchmark solution number by correlating Dropometer outputs to your TM193 outcomes (10–20 swatches spanning performance). Recalibrate if weave/fiber/finish/cure/conditioning or the controlled edition/procedure changes.

Protocol defaults (starting point)

Use your TM193 controlled liquids (solution number + batch recorded). Capture at 2.0 s ± 0.2 s (optional 10.0 s ± 0.5 s); ≥5 spots; report median + IQR. Keep timing and handling aligned to your internal TM193 evaluation procedure.

Known limitations

Porous/rough textiles can show strong time dependence; contact angle can change quickly after deposition. Always report capture time because CA can drift during the decision window. Wrinkles/slack/topography can mimic “wetting” unless clamping is consistent.

Controls & Data Quality

Measure a known‑good control swatch every batch/run. Reject and re‑run a spot if droplet edge/fit QC fails (unstable baseline, irregular edge, immediate distortion from absorption). Record rejected spots for traceability.

How this page was created

Editorial and technical transparency notes for this page.

Transparency Details 3 checklist items
01

Drafting assistance

An initial draft was created with AI assistance (ChatGPT 5.2 Pro).

02

Verification steps

Standard identifiers, units, thresholds, and key procedural claims are checked against cited sources before publication

03

Updates

Reviewed every 12 months or when the underlying standard changes.

Executive Summary

AATCC test • aqueous liquid repellency • water/alcohol solution resistance

This page helps you answer one practical question: Within the same AATCC TM193 grade, how much margin do we have and is it drifting before we fail?

TM193 provides a defensible, widely recognized outcome. The limitation is resolution: many different “true margins” can map to the same reported solution grade. By adding time‑stamped CA data (plus ΔCA and IQR), you can set internal Green/Yellow/Red gates that correlate to TM193 outcomes while being more sensitive to drift and non‑uniformity without changing the external standard report.

Those outputs enable immediate action: you can pre‑screen lots (run TM193 now vs. hold/triage), detect drift using a known‑good control swatch, and target corrections upstream instead of running borderline TM193 checks repeatedly.

The Context

Why the TM193 grade matters (and why single-number results can lag)

TM193 is part of a family of repellency standards where small droplets of defined liquids are placed on a fabric and observed for wetting during a fixed decision window. This logic is commonly applied across apparel and technical textile categories because it offers an interpretable, graded challenge level.

A related international reference, ISO 23232:2009, describes the same core principle using water/isopropanol solutions and grading based on the highest numbered liquid that does not wet within its defined observation time (consult the ISO procedure for exact timing, solution tables, and apparatus requirements).

Why a single reported result can be a lagging indicator

  • It reports where the sample fails, not the safety margin to failure.

  • It can blur root causes (systemic process drift vs. local non‑uniformity vs. time‑dependent uptake).

  • It may not reveal early drift until a formal grade changes especially when performance sits near a boundary solution.

How Dropometer Fits the Workflow

We recommend using TM193 as your final customer/spec gate, and adding Dropometer upstream as a quantitative pre-screen and triage tool.

1

Pre‑screening (upstream “go/no‑go” before formal TM193 grading)

After finishing, during incoming QC, or after durability conditioning (when required by your product spec).

How: Select 1–2 benchmark solutions near your acceptance threshold and measure:

  • CA @ 2.0 s (margin feature)

  • CA @ 10.0 s and ΔCA(2→10 s) (stability feature)

  • IQR across ≥5 spots (uniformity feature)


Interpretation: In TM193 logic, “wetting” is a qualitative observation. The companion method quantifies the same physical change as time-stamped numbers.

2

Root‑cause triage (fast, practical rule‑out checks)

Use a “most likely cause + rule‑out check” approach:

  • Time‑dependence dominates
    Signal: High CA @ 2 s but large ΔCA by 10 s; edge instability.
    Rule‑out: Enforce timestamps; standardize placement height and clamping; compare to control.

  • Non‑uniformity dominates
    Signal: Acceptable median CA with high IQR; localized early wetting.
    Rule‑out: Inspect treatment uniformity/contamination; retest adjacent locations; compare face/back if relevant.

  • Chemistry/cure drift suspected
    Signal: CA @ 2 s shifts down across most locations; IQR remains modest; control trends similarly (or control identifies lab drift).
    Rule‑out: Verify add‑on %, cure profile, mixing, and line parameters.

3

Formal confirmation and reporting (when required)

Run and report the official AATCC TM193 laboratory procedure when required by customer/spec. Keep the Dropometer dataset as internal evidence for margin, troubleshooting, and traceability.

Validated measurement approach

Independent benchmarking and publication-based validation references.

Benchmark Validation

Our Contact angle and pendant‑drop surface tension methods have been benchmarked against KRÜSS DSA100E reference measurements.

See peer‑reviewed validation

Publication Evidence

Our instruments are referenced in peer‑reviewed journals, theses, and conference publications

Browse the full citations list

Calibration first (so your thresholds are defensible)

AATCC TM193 • aqueous liquid repellency

Numeric gates are only defensible after correlation to your fabrics, treatments, conditioning, and benchmark solution number(s).

Build your TM193 correlation in one shift

  1. Select 10–20 swatches spanning expected performance (intentionally varied add‑on/cure helps).

  2. For each swatch, run (and include the control swatch each run):

    • Dropometer: CA @ 2 s, CA @ 10 s, ΔCA, IQR (≥5 spots)

    • AATCC TM193 per your controlled testing procedures

  3. Output: a simple Green / Yellow / Red rule set that:

    • predicts TM193 outcome at your benchmark solution(s), and

    • flags “low‑margin” passes before the TM193 grade changes.

Re-calibrate when: weave/fiber changes, finish chemistry changes, cure recipe changes, conditioning changes, or when you adopt a new controlled edition/procedure.

Example output

Workwear polycotton + finish X (benchmark solution = No. 6)

Gate Typical TM193 outcome (at Solution No. [N]) CA @ 2.0 s (median) ΔCA = CA(2s) − CA(10s) IQR (≥5 spots) What to do
GreenPass with margin≥ [CA_Green]°≤ [ΔCA_Green]° drop≤ [IQR_Green]°Proceed; periodic TM193 confirmation
YellowPass / borderline[CA_Yellow_Low]–[CA_Yellow_High]°[ΔCA_Yellow_Low]–[ΔCA_Yellow_High]° drop[IQR_Yellow]°Check cure/add‑on; retest 1–2 swatches
RedLikely fail soon< [CA_Red]°> [ΔCA_Red]° drop> [IQR_Red]°Hold lot; triage before TM193

QC-ready quick protocol (SOP card)

Goal: repeatable numbers that correlate with TM193 trends without changing your official TM193 report.

Sample handling

  • Condition swatches per your laboratory procedure.

  • Use consistent coupon size and orientation; document face/back if relevant.

  • If durability is in scope, apply your defined conditioning (e.g., home laundering) and record cycle count.

Setup

  • Clamp/flatten consistently (same tension/orientation) to reduce artifacts from wrinkles and slack.

  • Always include one control swatch (known good) every batch/run.

 

Liquids (TM193 alignment)

 

  • Use the numbered water/isopropyl alcohol mixtures specified in your TM193 controlled copy.

  • Lock composition, temperature, and handling.

  • Record solution number + batch for traceability.

Measurement (baseline method)

  • Use the same droplet volume and dosing approach used in your TM193 practice (treat your controlled copy as the authority).

  • Capture CA @ 2.0 s ± 0.2 s, and optionally CA @ 10.0 s ± 0.5 s.

  • Replicates: ≥5 spots per swatch; report median + IQR.

  • Capture time-resolved data (video) to support ΔCA.

If your fabric is highly time-dependent, consider standardizing on two timepoints for that fabric family and always report both.

Decision tree (probabilistic) — triage + rule-out checks

Start: TM193 result trending down OR pre‑screen hits Yellow/Red.

Systemic chemistry/cure drift suspected

Signals:

  • CA@2s down across locations; IQR modest

  • Control swatch confirms a process/lab drift pattern (depending on what is trending)

Rule-out:

Verify add‑on %, cure profile, mixing, and line settings; compare to control and a retained “golden” sample

Non‑uniformity / localized effects suspected

Signals:

Median CA acceptable but IQR high; isolated early wetting behavior

Rule-out:

Inspect treatment uniformity and contamination; retest adjacent locations; compare face/back if relevant

Time‑dependent uptake dominates

Signals:

CA@2s acceptable but ΔCA large by 10s; edge instability

Rule-out:

Enforce timestamps; standardize clamping and placement height; consider reporting both timepoints for that family

Method Settings (SOP-Ready)

Parameter Recommended Setting Technical Rationale
Geometry Sessile Drop (Static) Static CA provides a fast, quantitative margin signal aligned to “wetting vs. non-wetting” behavior.
Benchmark solutions 1–2 solution numbers near your spec threshold Gates are solution-dependent; benchmark near the decision boundary for maximum sensitivity.
Timepoints 2.0 s (primary), optional 10.0 s Many textiles show time dependence (uptake/wicking); timestamps improve comparability.
Droplet volume Match your TM193 practice (controlled copy is authority) Keeps companion data aligned with your official grading logic and historical datasets.
Liquids TM193 numbered water/isopropyl alcohol mixtures Directly ties quantitative data to the same challenge liquids used for the TM193 grade.
Replicates ≥5 spots + median/IQR Fabric heterogeneity is real; spread improves correlation and flags non-uniformity.
Controls Known-good control swatch each run Drift detection and traceability across shifts/batches/instruments.

Interpretation

AATCC test method • aqueous liquid repellency

Contact angle at a fixed time (e.g., CA @ 2.0 s): Primary margin feature; higher CA is generally more robust within a calibrated fabric family and solution number.
Time dependence (ΔCA = CA @ 2.0 s vs CA @ 10.0 s): Stability feature; large negative shift suggests time‑dependent uptake/instability consistent with wicking behavior.
Variability (IQR across ≥5 spots): Uniformity feature; high spread suggests heterogeneous treatment, contamination, or substrate variation even when the median looks acceptable.

Business impact — Before/After Dropometer

Metric Before Dropometer With Dropometer
Lab Cycles TM193 loops to discover borderline behavior Fewer formal checks wasted on “low-margin” lots; faster screening near threshold solutions
Root Cause Pass/fail grade without margin CA@time + ΔCA + IQR separates drift vs. non-uniformity vs. time-dependent uptake
Scrap / Rework Failures discovered late Earlier drift detection using control swatch + numeric gates
Traceability “Looks wet” arguments Time‑stamped numeric QC evidence tied to solution number and batch

Instant ROI Snapshot

Calculate your savings in real time.

Result

≈0
hrs/month saved
≈$0
/month ROI

Where do these numbers come from? i You enter your current total time per test (dispense + record + analyze + save). The calculator assumes that our Dropometer reduces that workflow to ~1.1 minutes per test (dispense + capture + automated fit + export). Time saved per test = max(0, your time − 1.1 min). Monthly hours saved = (monthly tests × minutes saved per test) ÷ 60, and monthly savings = hours saved × labor rate.

Common Pitfalls & Limits

Always report timestamps. On porous textiles, CA without time is not comparable. Do not compare a 2‑second reading with a 10‑second reading.
Do not treat CA cutoffs as universal. Correlate per fabric family, solution number, and conditioning.
Contamination control matters. Handling residues can change response; keep gloves/tools consistent.
Geometry/topography matter. Wrinkles and slack can mimic wetting; consistent clamping improves repeatability.
Compliance clarity: Use the official TM193 grade for external reporting; use the companion method for internal control and technical troubleshooting.

Legal note (no certification claim)

This page summarizes a companion approach and does not reproduce copyrighted AATCC text, confer certification, or replace the official standard. Always consult the official AATCC TM193 document for full requirements and the official evaluation scale.

Request Dropometer Quote View AATCC TM193 Official Method

Report a correction

Spotted an issue in this summary? Send a correction request and our team will review it.

Correction Request

We work hard to keep this standards summary accurate and up to date. If you spot an error (wrong revision/year, missing requirement, incorrect interpretation, or broken link), tell us and we'll review it.

Contact us to report a correction

References

1. AATCC Tm193 Official listing
2. Dropometer datasheet

Download Experiment