Polypropylene bale wrap is the contamination class where a single strand costs the spinning mill more in a fabric claim than the entire bale was worth at goods receipt. White and transparent PP is the worst case: visible-light vision misses it, standard yarn clearers built for colored foreign fiber miss it, and by the time it appears as a shiny speck on knitted fabric after dyeing, the merchant who packed the bale is untraceable. The economics of the mistake always land on the spinner.
iFactory / Polypropylene bale wrap fiber
Catch White and Transparent PP Before It Reaches the Yarn Clearer
A camera at the opener sensitive to optically-brightened PP that closes the loop from bale wrap to the yarn-clearer FF-cut log — with the merchant on the scorecard.
White PP
most claim-heavy class
UV / VTECT
required for clear PP
Bale batch
→ merchant scorecard
15 defects
/20kg Texhong benchmark
The Problem on the Line
Bales packed in polypropylene or HDPE cloth shed tape and strand fibers that survive the opener and cannot be pulled out by mechanical cleaning. Colored PP is bad; white and transparent PP is worse, because visible-light vision misses it and yarn clearers built for colored foreign-fiber alone also miss it. Uster ships VTECT UV-LED sensors on the Vision Shield 2 for exactly that reason. Even where a mill runs Vision Shield in the blowroom and Quantum 3 clearers at winding — the Total Contamination Control setup Texhong reduced to 15 defects per 20 kg — the PP that gets through is disproportionately the wrap-fiber class that appears as shiny specks after dyeing.
What Escapes Into the System of Record Today
PP wrap contamination is the case where the system-of-record gap is most expensive per event, because a single specked-up fabric roll turns into a claim worth many multiples of what the bale price was.
Paper
Operator finds a PP strand at the opener, pulls it, drops it in a scrap pail. If they mark it on a shift log at all, they mark it as "PP" without a bale ID or a merchant.
WhatsApp
Photo of PP wrap fragment to the QA lead's phone. Bale ID sometimes attached, sometimes not. Merchant almost never named. Rolls out of the group chat within days.
Winder-only data
Quantum 3 with FD detection logs elevated foreign-fiber cuts on the affected winding position. The class is registered; the source bale — and the source merchant — is not.
Nowhere at all
Colored specks appear on knitted fabric after dyeing weeks later. The greige inspector on the loft writes it up as a shade defect or a foreign-fiber defect on the fabric grade sheet. Trace back to a bale wrap event never happens.
What the Camera or Agent Actually Sees
For the PP problem specifically, sensor selection matters. Visible-light vision alone will not catch optically-brightened PP. The value of the vision-plus-write-back approach is that the sensor is chosen for this contaminant class, and the SoR link is built around merchant attribution — the number that has to change at negotiation.
PP – Colored
Colored polypropylene strapping and tape — the easier class, catchable on visible-light color-signature vision, but the class that most often escapes manual pull at the opener.
Class: PP-colored
PP – White
White polypropylene woven-bag fabric strands, dye-different from cotton but low-contrast in white light — the class the mill needs UV or spectral sensing for.
Class: PP-white
PP – Optically-Brightened
Transparent or optically-brightened PP that fluoresces under UV — the class Uster's VTECT was purpose-built to catch and the class that most often reaches the yarn clearer undetected upstream.
Class: PP-clear + VTECT
HDPE / Rag
Related non-PP synthetic fragments — HDPE strapping, ribbon, rag cloth from packaging — classified alongside PP because their claim profile is identical downstream.
Class: HDPE / rag
What Gets Written Back
The SoR write-back for PP contamination is doing double duty: it feeds both the fabric-claim trace-back (was there a PP event on this bale batch?) and the merchant scorecard (how many PP events per shipment from this merchant?). Both are needed. Neither exists in most mills today.
QN Type F2 with Class
SAP QM
Quality Notification against the bale batch with PP subclass (colored / white / clear / HDPE), photo attachment, and the vision confidence score for the classification.
Merchant QN Rollup
SAP QM-IS
PP events per bale rolled up per merchant per month, per shipment, per country of origin — the granularity procurement actually needs to change price or contract terms.
Batch Status Hold
SAP MM
Mixing lot on restricted-use status where PP event density on the bale batch exceeds the mill's claim-risk threshold, released only on QA override with reason.
Fabric-Claim Trace
SAP Batch Genealogy
When a fabric PP-speck claim lands, the yarn batch traces to the mixing lot traces to the bale batches with any PP QN attached — so the claim resolves to a merchant, not to the spinner's reputation.
Pull your Quantum 3 or equivalent yarn-clearer FF-cut log for the last month. Cross-reference against bale receipts by merchant. If the mill cannot attribute an elevated FF-cut day to a merchant, the PP is winning. Book a plant assessment — we'll trace one week of PP events end-to-end.
12-Week Pilot Shape on One Station
One opener, one merchant with a known PP history, one 90-day claim window. The pilot is scoped to prove attribution — that the mill can walk from a fabric claim back to a merchant-and-bale event with a photo.
Weeks 1–2
Sensor Fit Check
Assess whether existing Jossi Vision Shield or T-SCAN coverage already includes UV or VTECT for optically-brightened PP. If not, sensor gap identified. If yes, integration path to SoR mapped instead of new hardware.
Weeks 3–4
Classifier for PP
Subclasses defined explicitly: PP-colored, PP-white, PP-clear, HDPE. Confidence thresholds tuned on the mill's actual PP wrap samples from the pilot merchant's recent shipments.
Weeks 5–8
Write-Back + Rollup
QN generation live against the bale batch, subclass-tagged. Merchant scorecard rollup active for the pilot merchant. Batch-status hold rules configured with the QA head's threshold.
Weeks 9–12
Claim-to-Merchant
First fabric claim in window is traced back through yarn batch to mixing lot to bale batches with PP QNs attached. First time the mill produces a merchant name and a photo instead of a hypothesis.
Who Owns the KPI
PP contamination sits between three roles: the person who ejects it, the person who logs it, and the person who negotiates the merchant contract. If any of those roles is not named on a KPI, the discipline unwinds.
Blowroom Sup.
PP QNs written per shift
Owns the operator confirmation workflow — when the auto-classifier is uncertain, the human names the class before the QN commits.
Quality Head
Fabric PP-speck claims per 20 kg
Owns the mill-level number Texhong-style benchmarks are built against. Reviews the trend monthly and adjusts thresholds where sensor performance drifts.
Procurement / GM
PP events per merchant per 100 bales
Owns the merchant scorecard and the annual negotiation. A merchant whose PP event density does not respond to feedback receives price or volume signal.
Sales / Claims
Claim $ recovered via bale-back-charge
Owns the loop-close on the P&L side. When a claim from a knitter is answered with a merchant-attributed QN chain, the back-charge conversation is fundamentally different.
FAQ
If my Jossi Vision Shield 2 already runs VTECT, what does this add?
If the Jossi VTECT is already ejecting optically-brightened PP from your fiber stream after the fine cleaner, the extraction problem is largely solved for the fragments that reach that point. What is still missing is the record: which bale, which merchant, how often. Vision Shield ejects; it does not write a merchant-attributable QN against a bale batch in SAP QM, and its data does not roll up into a vendor scorecard procurement can use in a negotiation. This is the SoR-layer that sits alongside your Vision Shield, not a replacement for it.
Isn't the answer to just move away from PP-wrapped bales?
Ideally yes, and the merchant industry has been discussing this for years. In practice, PP and HDPE bale wrap remains widespread from many origins because it is cheap, resilient in shipping, and available where cotton-friendly alternatives are not. Until that changes, the mill's realistic lever is to convert PP events into a merchant-visible cost — through a scorecard that produces price and terms discussion — rather than to absorb the events as an internal quality problem. The economic pressure on packaging comes from the SoR record, not the mill's complaint letters.
What's a realistic PP-defect target for fabric?
Uster's Texhong case study reports 15 foreign-fiber defects per 20 kg of fabric with Total Contamination Control — Vision Shield 2 in blowroom plus Quantum 3 at winding, fully integrated. That is a specific mill on specific yarn counts on specific end-use fabrics; your number will depend on cotton origin, yarn count, and knit or weave construction. What is transferable is the two-stage principle, and the additional principle this pilot adds: the SoR record from Stage 1 has to survive as a merchant-attributable QN, or the extraction becomes an operating cost with no commercial recovery.
Stop paying for PP wrap the merchant packed.
Trace One PP Event From Opener to Merchant Scorecard
Bring your last month of PP ejects and one merchant. We'll show the classifier subclass tags, the QN it would write, and the scorecard row it would produce — including the batch-genealogy view that answers a fabric claim.
