DSS-M.02.05 — Squeegee Burn Lines (Friction Film)

Narrow, linear or banded appearance change that follows squeegee travel paths during window cleaning. Typically a friction-film or light burnish produced by dry/dirty rubber, residue-lubricant mismatch, or excessive pressure. Presents primarily as a visibility cue under raking/oblique light; may be non-tactile (film) or show trace relief where the surface has been lightly burnished. Use VIS inspection lighting/geometry and Non-Invasive Reveal to separate removable films from bonded/burnished appearance change.

• Parallel, evenly spaced narrow lines that match known squeegee strokes (top-to-bottom pulls or lateral finishes).
• Most apparent in reflection at oblique sweep with raking light; fades at normal incidence.
• On reveal, detergent/surfactant films may diminish; a true burnish/haze line can persist.

Surface-catch class (MSRT):

• SC-0 (film only) to SC-1 (trace burnish); one, light, non-marring pass only to sense relief-do not abrade. Prefer a polymer stylus on suspected coated faces.

Reveal/lighting/geometry:

• Inspect after Non-Invasive Reveal (clean & dry). View at 12 in, 36 in, 72 in at normal incidence and by 60°-120° oblique sweep under raking light.

Location/access:

• Worked/exposed face only; log product family and surface numbering (#1-#4; laminate-internal) on Forms:

• If post-reveal cue remains visible but non-tactile → trend CAT-1 (faint/non-relief film/transfer).
• If trace relief is detected (SC-1) with clean, fine edges and no chip flanks → CAT-2 (light).
• Presence of chip flanks, pits/craters, or modeled micro-texture elevates to CAT-3/4 per morphology (mechanical abrasion rather than mere film).
• If fixed parallax indicates between-pane look-alike → CAT-5 (out of in-place scope by location).

• Residual film / lubricant line: ~0 μm (SC-0).
• Light burnish (appearance change without edge flaking): ~0.1-0.5 μm equivalent (SC-0 to SC-1).
• Depth values are indicative and used only to align with VIS CAT ranges; acceptance remains appearance-based under VIS.

• vs. Detergent/surfactant film (R.04.01): films respond to reveal; true burnish persists post-reveal.
• vs. Micro-abrasion swirls / pad trails (M.02.01): swirls are arcuate/cross-hatch and not strictly linear; squeegee burn follows straight pulls and window edges. (Use VIS directional-patterning definitions.)
• vs. Coating rub/patchiness (Co.01/Co.03): coating anomalies are on coated worked surfaces and are disallowed at acceptance on coated faces; document coating presence in Forms:
• vs. True scoring (M.01.*): scoring shows clear catch and often chip flanks; escalate CAT accordingly.

• Photo set (VIS): 12 / 36 / 72 in at normal + oblique; include raking frames that show linearity parallel to squeegee travel; include a straight-edge reflection for alignment.
• MSRT result: record SC-0/SC-1 (single, non-marring pass; polymer stylus on suspected coatings).
• Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? Y/N/Unknown; reveal status; lighting/time; geometry checklist; photos attached.
• Classification call: CAT per cues above; note “film vs. burnish” basis (post-reveal, MSRT class, morphology).

• “Testing” with repeated hard passes can create the burnish you are trying to diagnose; MSRT is single-pass only.
• Treating a coating rub as a cleaning line-coating anomalies on worked surfaces are not permissible at acceptance; escalate appropriately.
• Calling a removable film “damage” without completing reveal.

• M.02.05 Squeegee Burn Lines (Friction Film) - Narrow linear bands aligned with documented squeegee travel, visible under VIS geometry after Non-Invasive Reveal. MSRT: SC-0 (film) / SC-1 (trace burnish) noted; no chip flanks/pitting. Classification: CAT-1 (non-relief film) or CAT-2 (trace burnish) per cues; no between-pane parallax. Photos at 12/36/72 in (normal/oblique; raking) attached; forms completed per VIS Appendix X3.