EN
A private-label brand in the UK opened a carton of 60 black 1680D backpacks and found pale grey lining panels with grey-brown smudges where the laptop sleeve rubbed the shell. Every bag in the carton had it. The fabric mill had supplied good shell, the lining was within tolerance, and the interaction between the two had never been tested by anyone in the chain. Colour tests are the cheapest insurance in bag sourcing and the most commonly skipped.
Why Crocking Shows Up After the Sale
Crocking is colour transferring from a fabric surface onto another surface by rubbing. On a backpack it happens in four places: the back panel against a white shirt, the shoulder strap against a light jacket, the lining against a laptop.
Mechanismus est mechanicus, non chemicus. Colorans residet in superficie fibrae; superficies abraditur, et particulae colorantis mobiles sunt. Tincturae nigrae cum onere magni colorantis sunt pessime, et coloratio pigmenti vilis est peior quam coloratio vasorum aut coloratio reactiva, quia pigmentum residet in superficie fibrae potius quam intra eam.
Saccus potest transire inspectionem visualem in fabrica et deficere in tertia hebdomade apud mercatores. Hoc est cur crocking tractamus ut portam approbationis materialis, non ut experimentum de rebus finitis.
Crocking Siccum et Humidum: Methodus et Notae
Crocking siccum sequitur AATCC 8 aut ISO 105-X12. Textilis albus ex cotone adhibetur ad fricandum specimen per 10 cycli, quod est 20 fricationes, sub onere circa 9 N, uno cyclo per secundum. Textilis experimenti tum comparatur ad scalae griseae et notatur a 1 ad 5, ubi 5 significat nullam transferentiam.
Crocking umidus utit eadem machina cum panno experimentali humectato ad 65 percentum absorptionis. Resultata umida semper sunt inferiora quam sicca, quia humiditas fibras inflat et colorantem emittit, et quia pannus madidus pigmentum superficiale facilius tollit.
Nostri valores acceptationis pro telis sacculorum pro computatoribus portatilibus:
Tela externa, toni nigri: crocking siccus minimus 4.0, crocking humidus minimus 3.0
Tela externa, toni clari et non tincti: crocking siccus 4.5, crocking humidus 3.5
Tela interna contra computatorem portatilem vel tabulam: crocking siccus 4.5, crocking humidus 3.5, nulla exceptio
Fasciculi textiles, qui tota die in vestimentis fricantur: crocking siccus 4.0, crocking humidus 3.0
Superficies textilium cum recubitu PU: crocking siccus 4.0, plus examen separatim adhaesionis, quia recubitus abrumpitur ut pellicula, non ut colorans
Numeri 4.0 et 3.0 sunt severiores quam 3.0 et 2.5, qui in multis certificatis fabricarum apparent. Nota 3.0 significat maculam visibilem in albo colli camisiae, et collum camisiae magis valet quam marginis sacculus pro computatore portatili.
Praeparatio exemplorum determinat utrum numerus verus sit. Exempla ad 21 gradus Celsius et 65 percentum umiditatem relativam condicionantur per minus quattuor horas antequam examinentur, et ex tribus diversis positionibus in rotulo secantur, non omnia ex eodem metro. Variatio coloris ab orlo rotuli ad centrum rotuli communis est in polyestere Oxford 600D, et unicum exemplum centrale eam celat.
Firmitas ad lavationem et sudorem
Firmitas ad lavationem magni momenti est, quia emptores sacculos dorsales saepius lavant quam industria supponit. Sacculus scholasticus aut pro viatoribus in machinam ad 30 vel 40 gradus cum detergente mittitur, et sacculus qui effundit colorem internum pallidum in roseum in una lavatione vertit.
Nos ad normam AATCC 61 methodum 2A vel ISO 105-C06 examinamus ad 40 gradus Celsius per 30 minuta cum 10 globis ferreis, deinde mutationem coloris et maculas in fasciculo multifibro notamus. Porta nostra est 4.0 pro mutatione coloris et 4.0 pro maculis in omnibus fibris pro tegumento et intus; cingula 3.5 habent, quia onus coloris grave in polypropileno tenere difficilius est.
Perspiratio est examen quod emptores obliviscuntur. AATCC 15 aut ISO 105-E04 ponit textilium contra solutionem acidam et alcalinam quae sudorem simulat, deinde incubat. Tabula dorsalis sarcinae ad dorsum sudans per horas adhaeret. Tegumentum quod hic notam 3.0 obtinet discolorabitur in parte ubi spuma tangit, et cliens maculam fuscam intus in sacco videt, non foris.
Stabilitas ad lucem claudit hanc seriem. AATCC 16 aut ISO 105-B02 ad 20 unitates evanescendi est norma nostra pro omni sacco vendito in regione sole plena. Nylon niger 1680D saepe facile hoc praestat. Polyester ruber vivus aut croceus in tinctura vilissima duos gradus scalae griseae in 40 horis expositionis ad arcum xenonem amittit.
Migratio tincturae in lineamentis claris
Migratio est defectus diversus ab attritione, et est ille qui celeriter maxime damnum marcae inferre potest, quia in omni unitate expeditionis apparet.
Duo mechanismi id causant. Primus est sublimatio, ubi colorans dispersus in obscura polyestere tectura vaporizatur per calorem et rursus depositur in levi intus tectura quae ei adiacet. Secundus est migratio plasticis, ubi mollis PVC aut infima qualitatis PU lamina liberat plasticem qui colorantem in adiacentem laminam vehit.
Classicus casus est niger 600D polyestere tectura cum claro griseo 210D polyestere intus tectura. Utraque materia recta est in suis certificatis. Mittantur in continente quod aequatorem transgreditur, ubi temperaturae internae 60 gradus Celsius per dies attingunt, et intus tectura maculata exibit.
Noster scrinium est examen coctionis. Adhaeremus fragmentum testae 100 per 100 mm ad fragmentum linimentum et in fornace retinemus ad 60 gradus Celsius per 48 horas sub levi pressione, deinde notamur maculas in linimento secundum scalae griseae. Quicquid infra 4.0 est reprobatum; tunc aut mutamus linimentum ad obscuriorem tonum, aut addimus barrierae pelliculam PE crassitudinis 0.02 mm, aut mutamus classis tinturae testae. Pellicula barrierae addit circiter USD 0.11 per saccum ad 3 000 unitates, quod est minimum pretium trium emendationum.
Pro longo mari itinere etiam praescribimus sacculum internum anti-migrationis in programmatibus cum interioribus claris, plus unum sacculum desiccantis per cartonem. Transitus per tropicos 20 ad 25 dies sine desiccante est unica maxime fidabilis via ad causam migrationis producendam.
Index probandi textilium quem ipse agere potes
Hunc indicem utare cum molendinum vel suppeditator certificatum mittit, et inspice ut documentum ad omnes lineas respondeat:
Methodus examinis nominata, incluse versionis anni, non modo "coloris stabilitas superata"
Ratings for dry crock, wet crock, wash colour change, and wash staining given as numbers
Specimen count and where the specimens were cut from the roll
Conditioning conditions before testing, temperature and humidity
Grey scale reference stated as AATCC or ISO, because the two evaluate differently
Migration or sublimation result where a dark shell meets a light lining, stated separately from crocking
Light fastness result in fading units or hours, not as a verbal claim
Dye class named, such as reactive, vat, or pigment, since dye class predicts behaviour better than a single test number
One thing a certificate cannot tell you is how the fabric behaves after 20 washes and a summer in a car. We treat lab ratings as a screen and add a 3-wash in-house verification on any new lining colour before we approve a bulk order.
At Tianqin, we hold a 300 mm by 300 mm retained swatch of every shell and lining lot used in production, labelled with the lot number and mill, and we keep them for 18 months. When a claim arrives, we can test the exact material that went into the bag rather than a substitute from the mill's current stock. We also run the 60 degree bake test on every new shell and lining pairing before sampling, because this failure is cheaper to prevent at the material stage by a wide margin.
A buyer told us plainly that he had never asked a supplier for a migration test and had paid for two recalls. He now puts the requirement in the purchase order.
Lock Colour Requirements Into the Specification
Send us the shell shade, the lining shade, and the destination market. We will tell you which dye class and which lining construction can hold a 4.5 crock rating against a laptop, and what the barrier film costs if it is needed.
Contact [email protected] or visit www.tianqinbag.com ad petendum specimen cum datis de crocking et migratione, ad obtinendum citatum fabricae, aut ad incipiendum projectum OEM/ODM cum Quanzhou Tianqin Bags Co., Ltd. Fabricatio speciminum tempus 7–15 dies operativos occupat; testum coctionis in tua conchae et linimento paribus per rotam speciminum facere possumus. Septemdecim annos fabricatio sacculorum in Quanzhou; exportationes OEM et ODM in plus quam 50 nationes; relationes examinis SGS pro petitione disponibiles.
Nuntii Calidi
