Start With the Exact Blanket, Not the Approval Phrase
For a 170gsm polyester airline blanket, the file should begin with the finished article, not a generic phrase such as “airline approved.” Freeze the usable specification first: fibre content, knit or fleece structure, brushed or unbrushed face, GSM tolerance, finished size, edge finish, label type, packing method, colour, decoration and any softener, anti-static, anti-pilling, antimicrobial, water-repellent or flame-retardant finish.
A practical purchase line is: “170gsm ±5% 100% polyester brushed fleece blanket, finished size 100 x 150 cm ±3 cm, colour as approved lab-tested sample, edge by heat cut or 3-thread polyester overlock as tested, label and decoration only as tested, no post-test finish change, test evidence to 14 CFR 25.853 Appendix F Part I vertical flammability by an ISO/IEC 17025-accredited laboratory with the relevant method in scope, exposure time to be confirmed by operator or conformity reviewer before bulk production.”
That wording matters because a report on plain fabric is not automatically a report on a decorated, labelled or edge-finished blanket. A plain white fleece swatch, a navy blanket, a blanket with a woven label and a blanket with overlocked edges are different test articles. If the buyer wants a lighter reference construction, compare with 140gsm brushed polyester airline blankets with heat-cut edges; at 170gsm the buyer gains more cover and warmth, but burn behaviour is still driven by pile density, brushing level, dye system, seam construction and finish chemistry.
Treat the blanket as a controlled cabin-service article, even when it is not an installed interior component. Lock the yarn lot or yarn source, dye lot, colour family, brushing recipe, edge method, label material, finish recipe and packing state before testing. A later substitution can make the original report weak evidence for the shipped blanket, even if the sales description still says “170gsm polyester fleece.”
What Appendix F Part I Does, and Does Not, Prove
For loose service blankets, the safer wording is “test evidence to 14 CFR 25.853 Appendix F Part I, as requested by the operator, completion centre, ODA/DER reviewer or conformity inspector.” Appendix F Part I is a test method and evidence route for flammability performance. It is not a blanket certification, not a product approval by the FAA, and not automatic permission to use the article on every aircraft or route.
14 CFR 25.853 and Appendix F define flammability requirements and test methods for aircraft compartment interiors. A removable amenity blanket may not be treated the same way as a seat cover, sidewall panel, curtain or insulation system in an aircraft approval package. It can still be controlled by the operator because it is used in the passenger cabin and may be included in a cabin conformity file by contract or internal procedure.
For North American charter, completion and refurbishment projects, the common request is Appendix F Part I vertical flammability. The exact variant must be stated. Many buyers request the 12-second vertical Bunsen burner exposure for cabin textile-type materials where their reviewer accepts that route. The 60-second vertical exposure is stricter and is commonly associated with certain installed interior materials and locations. The supplier should not choose the variant alone; the operator, completion centre, conformity reviewer, DER/ODA representative or customer engineering authority should specify whether 12-second or 60-second exposure is required.
Ask the lab report to show the exact method reference, flame exposure time, specimen orientation, conditioning, specimen count and pass/fail basis. If the report only says “FAR 25.853 passed” without identifying 12-second or 60-second exposure, it is weak procurement evidence and may be rejected during document review. The PO, test request form and report should use the same article code and construction wording.
Pass Criteria Buyers Should Check
For the commonly requested 12-second vertical test under 14 CFR 25.853 Appendix F Part I, the usual screening criteria are: average burn length not more than 8 inches, average after-flame time not more than 15 seconds after the flame source is removed, and average flame time of drippings not more than 5 seconds after falling. The report should show individual specimen values and calculated averages, not only the word “Pass.”
For the 60-second vertical test, the usual criteria are tighter on burn length and dripping: average burn length not more than 6 inches, average after-flame time not more than 15 seconds, and average flame time of drippings not more than 3 seconds after falling. If a customer engineering specification sets a tighter maximum individual result, that customer requirement controls the PO even if the base regulation uses averages.
A buyer should screen every report for five data points before releasing bulk: exposure time, burn length, after-flame time, drip-flame time and sample identity. Missing data is a commercial risk. A blanket that passed in the lab can still be disputed if the report does not prove that the tested article was the same colour, edge finish, label construction, decoration and finish recipe as the shipment.
The report should also confirm whether the article was tested as received, after conditioning only, or after laundering. Appendix F pre-test conditioning is not the same as reusable-service laundry validation. If the blanket will be washed by an airline laundry, the buyer should decide whether evidence is needed as received, after laundering, or both.
Specimen-Level Details to Require
The test request should ask the laboratory to record specimen-level preparation. A defensible report normally identifies specimen dimensions, specimen count, test direction, face orientation, edge inclusion, label inclusion and conditioning. If the lab cuts only centre-panel fleece from a finished blanket, the report should say so. If specimens include overlock seams, heat-cut edges, woven labels or printed areas, the report should also say so.
Appendix F Part I vertical flammability specimens are commonly cut as narrow vertical strips around 3 x 12 inches, with the long direction aligned to the tested orientation. The buyer should not rely on memory or a supplier note; ask the lab to print the actual dimensions and tolerance used. For knitted fleece, request both machine direction and cross-machine direction if the article has visible pile lay, stretch imbalance or brushed channels. At minimum, the report should state which direction was tested.
Specimen count should be explicit. A typical vertical burn report uses multiple specimens per condition, often at least three, but the buyer should follow the method and customer engineering instruction rather than accept an unspecified “sample tested.” If the blanket has asymmetric construction, test planning should cover the face direction most likely to represent service risk: brushed face outward, pile direction up or down as mounted by the lab, and any decorated or labelled zone if the reviewer requires it.
Conditioning should be written as laboratory conditions, not a vague “conditioned before test.” Buyers should request temperature, relative humidity and duration, commonly around 21–24°C and 45–55% RH for at least 24 hours when the lab follows a standard textile conditioning practice. If the lab uses the exact Appendix F conditioning sequence or an internal method aligned to it, the report should identify that sequence. Wet, recently steamed or vacuum-compressed specimens should not be sent directly to flame testing without agreed conditioning.
Edges and labels deserve a written decision. For a heat-cut blanket, centre-panel testing alone may miss the melted edge. For an overlocked blanket, thread and lubricant residues may change ignition and dripping. For a branded blanket, woven labels, heat-transfer labels and screen print binders can behave differently from base fleece. The PO should state whether the approval sample sent to the lab is a finished blanket and whether the lab is instructed to include representative edge, label or decoration zones where practical.
170gsm Polyester Variables That Change Burn Behaviour
At 170gsm, a 100 x 150 cm blanket uses roughly 255 g of base fabric before edge loss, labels and packing. Finished packed weight often lands around 270–320 g depending on overlock thread, label, fold method, belly band and pouch. A practical GSM tolerance for brushed polyester fleece is ±5%; tighter control is possible but increases fabric rejection and may add cost without improving the evidence file.
Yarn and pile construction matter as much as nominal GSM. A 75D/144F or 100D/144F polyester filament system usually gives a softer, denser hand than coarser 150D yarn, but aggressive brushing can raise lint and create a more open surface. Loose pile can feed the flame front faster than a compact low-loft face. For reusable passenger service, ask for an agreed pilling method such as ISO 12945-2, commonly with a target around grade 3 or better after the buyer’s selected cycle count. Do not set a pilling target without wash and service expectations, because a hard anti-pilling finish can flatten the hand.
Colour is a real risk factor. Dark navy, black, deep burgundy and saturated red often carry heavier dye loads than ecru or pale grey. Fluorescent, metallic and very bright promotional colours may involve different dye or print systems. A navy sample report should not be used to clear a later red or black bulk order unless the customer’s reviewer accepts a written colour-family grouping. For higher-risk colours, require same-colour testing or at least worst-case colour testing agreed in writing before bulk dyeing.
Edge construction is another common failure point. Heat-cut edges reduce cost and bulk but can curl after laundering and create a harder melted perimeter. Overlocked edges improve durability but add thread, seam thickness and sometimes lubricant or finish residues. If the tested sample used 3-thread polyester overlock at about 3–4 stitches/cm, changing to cotton-rich thread, thicker binding tape, contrast thread, decorative whip stitch or a different sewing oil should trigger review. For a non-aircraft construction contrast, see 230gsm polar fleece stadium blankets with whipped-stitch edges; cabin-service files need tighter change control than promotional stadium throws.
Finishing chemistry should be declared by function and supplier. Softener, anti-static finish, anti-pilling resin, water-repellent chemistry, antimicrobial treatment and flame-retardant finish can all affect vertical burn behaviour. The buyer should require a finish declaration, SDS where applicable, and written confirmation that the lab-tested recipe matches bulk production. If a finish percentage, bath sequence, curing temperature or supplier changes, retesting or engineering review is the safer route.
If recycled polyester is introduced, keep recycled-content claims separate from flammability evidence unless the tested lot used the same recycled yarn source and finish recipe. Recycled yarn can vary in intrinsic viscosity, spin finish, dye uptake and shade depth. Require the recycled yarn supplier, lot, claimed recycled percentage and transaction documentation where the programme needs it. For recycled airline programme documentation, see how to specify recycled fleece blankets for airline amenity programmes.
When Laundry Validation Is Commercially Required
Appendix F conditioning is not a laundering durability protocol. For single-use, sealed amenity blankets, as-received flammability evidence may be commercially sufficient if the operator accepts it. For reusable airline, charter, rail or lounge blankets that will be laundered and returned to service, the buyer should decide whether post-laundry flammability evidence is required before approving bulk.
A defensible reusable-blanket protocol states the wash method, detergent type, wash temperature, drying method, number of cycles, specimen condition and acceptance criteria. For domestic-style validation, some buyers use ISO 6330 with a defined programme and 5 or 10 cycles. For industrial laundry, the protocol should mirror the laundry vendor’s process: typical wash temperature, alkali or peroxide use, tumble temperature, tunnel finishing if used, and the expected number of service cycles. The flammability report should then state “after X cycles” and identify the laundering laboratory or procedure.
Retest after laundering is most important when flame-retardant chemistry, softener, anti-static finish, antimicrobial finish or printed decoration is used. Wash-off finishes can reduce or change burn performance; heavy redeposition from commercial laundry can also affect handfeel and ignition behaviour. If the blanket is intended for 20–50 wash service life, a buyer may still test after 5 or 10 cycles as a screening point, but the limitation should be written in the approval file.
For care-symbol and washing-file discipline, see blanket care washing guide. Care labels, laundry instructions and flammability evidence should not contradict each other. If the care label says tumble dry high but the post-laundry flammability sample was line dried, the file invites questions.
What to Ask the Lab For
Use an ISO/IEC 17025-accredited laboratory with the relevant flammability method in scope. The report should identify the applicant, buyer if applicable, supplier, mill, sample receipt date, test date, method, exposure time, conditioning, specimen dimensions, specimen count, specimen orientation, colour, fibre content, construction, GSM, finished article description, edge finish, decoration status, label status and finish declaration.
The data table should show individual burn length, individual after-flame time, individual drip-flame time, averages and final conclusion. Ask for specimen photographs before and after testing where available. If the blanket has an overlocked edge, woven label, heat-transfer label or printed logo, the report should state whether specimens included those elements or whether only the base fleece was cut and tested.
For reusable blankets, define the laundering condition before testing. A report should say “as received/unwashed,” “after 5 ISO 6330 wash cycles,” “after 10 industrial laundry cycles,” or another agreed condition. Do not let a supplier imply laundry durability from an unwashed flammability report.
A complete buyer file should include more than the lab report: signed specification, approved pre-production sample record, bill of materials, yarn and fabric lot traceability, dye and finish declaration, SDS or finish safety documents where applicable, artwork or label drawing, packing specification, production QC record, AQL inspection result, shipment lot list, certificate of conformity matching PO line items and retained-sample log. For broader QC structure, blanket quality control inspection is the better place to standardise inspection records, AQL sampling and defect classification.
Procurement Acceptance Table
Use the table below as a buyer-side release checklist before deposit approval, bulk cutting and shipment. It is intentionally stricter than a sales quotation because a weak file can fail during operator review even when the blanket itself is well made.
PO wording: state article code, finished size, GSM tolerance, fibre content, colour, edge finish, label, decoration, finish chemistry, packing, required Appendix F Part I exposure time, lab accreditation requirement, laundering condition if any, retained-sample requirement and change-control rule. Reject or hold if the PO only says “FAR approved blanket” or “airline compliant” without the method variant and tested article identity.
Lab report fields: require method reference, 12-second or 60-second exposure, specimen dimensions, specimen count, orientation, conditioning, tested colour, tested construction, edge and label inclusion, individual burn data, averages and pass/fail conclusion. Reject or hold if the report only gives a summary pass, omits exposure time, omits sample identity, or tests a different colour or construction without written engineering acceptance.
Supplier documents: require bill of materials, yarn/fabric lot traceability, dye lot, finish declaration, SDS for functional finishes where applicable, production QC records, AQL inspection report, packing list by lot, certificate of conformity and retained samples. Reject or hold if the certificate of conformity does not match the PO line item, colour, report number or shipment lot.
Change-control triggers: retest or obtain written reviewer acceptance after colour-family change, yarn denier or source change, recycled yarn introduction, GSM shift beyond tolerance, brushing or shearing change, edge method change, label or decoration change, finish recipe change, laundry protocol change, subcontractor change or report-to-shipment identity gap. Reject or quarantine if bulk goods cannot be traced to the tested construction.
Inspection acceptance: for general workmanship, many blanket buyers use ANSI/ASQ Z1.4 or ISO 2859-1 sampling with AQL 2.5 for major defects and AQL 4.0 for minor defects, adjusted by customer risk. For cabin-service programmes, treat wrong colour, wrong construction, missing label, unapproved decoration, unapproved finish, mixed lots without traceability and damaged packaging as major or critical commercial holds, not cosmetic issues.
Evidence Management for Buyers
Set a retained-sample rule before production. For each tested construction, keep at least three finished retained samples: one with the supplier, one with the buyer or operator, and one sealed for dispute or repeat-order comparison. For higher-risk programmes, keep two extra lab-cut remnants or production-yardage references if the lab returns them. Seal each retained sample with PO number, item code, colour, lot number, test report number, date and inspector signature.
Use a lot numbering format that connects material and shipment records. A practical format is customer code, article code, colour code, yarn lot, dye lot, cutting lot and shipment sequence; for example, “OPR-170FL-NV-Y2406-D2407-C02-S01.” The exact format can differ, but it must let a buyer trace a carton back to yarn, dyeing, finishing, cutting and packing records.
Define report validity as a buyer policy, not a vague promise. Many buyers keep a report active only while the material, colour family, finish recipe, supplier site and construction remain unchanged. Some programmes also set a time limit, often one to three years, because dyehouses, chemical suppliers and lab expectations change. If the operator or reviewer sets a different validity rule, follow that rule in the PO.
Do not mix commercial sustainability claims into the flammability conclusion. A recycled-content certificate, chemical restricted-substance report and Appendix F Part I report answer different questions. The certificate of conformity can list them together only if each claim is backed by its own document and the lot numbers line up. For buyers comparing recycled sourcing routes, RPET polar fleece blankets with GRS documentation explains the separate chain-of-custody file.
FIELDLOOM Buyer Checklist
Before sampling: confirm whether the operator wants Appendix F Part I evidence, whether 12-second or 60-second exposure applies, whether laundering validation is required, whether colour-family grouping is allowed, and whether the tested article must include edge, label and decoration. Do this before ordering yarn or dyeing approval shades.
Before lab submission: send finished blankets from the intended construction, not loose greige fabric unless the reviewer accepts fabric-only testing. Mark each sample with article code, colour, edge type, label status, finish recipe, GSM and sample date. Include a written instruction asking the lab to record specimen dimensions, count, orientation, conditioning and whether edges or labels were included.
Before bulk production: compare the lab report against the approved sample and PO. Check exposure time, burn length, after-flame time, drip-flame time, specimen identity, tested colour and tested construction. If the bulk recipe differs, stop and obtain written acceptance or retest. Verbal approval is weak evidence when a conformity reviewer asks for the file months later.
During production: control GSM, shade, brushing, shearing, edge stitch density, label placement, packing and lot separation. For a 170gsm fleece blanket, typical in-line controls include GSM by cutter and balance, finished size after relaxation, visual shade check under agreed light source, edge seam appearance, loose-fibre removal and carton lot marking. Record the checks by cutting lot and packing lot.
Before shipment: issue a certificate of conformity that references the PO line, article code, colour, shipment lot, lab report number and any laundry condition tested. Attach the packing list, QC report and retained-sample log. If the buyer uses third-party inspection, align defect classification with the cabin-service risk: wrong construction, unapproved finish, untraceable lot or mismatched report identity should block shipment.
Frequently asked
Does a 14 CFR 25.853 Appendix F Part I report make a loose airline blanket FAA-approved? No. Appendix F Part I is a flammability test method and evidence route. It does not by itself create FAA product approval for every loose blanket. The operator, completion centre, conformity reviewer or engineering authority decides how the evidence is used in the aircraft or cabin-service file.
Should a 170gsm airline blanket be tested with 12-second or 60-second flame exposure? The buyer should not let the supplier choose alone. Many loose textile cabin-service requests use the 12-second vertical exposure when the reviewer accepts it, while the 60-second exposure is stricter and may be required for certain installed interior materials or customer specifications. The PO and lab request must state the required exposure time.
What specimen details should be visible on the lab report? Ask for specimen dimensions, number of specimens, direction or orientation, conditioning conditions, flame exposure time, whether the brushed face was oriented consistently, and whether edges, labels or decoration were included. The report should show individual burn length, after-flame time and drip-flame time, not only a pass statement.
Can one navy blanket report cover black, red and grey bulk colours? Only if the buyer’s reviewer accepts that colour grouping in writing. Dark or saturated shades can carry different dye loads and finishes. For high-risk programmes, test the same colour as bulk or agree a worst-case colour plan before dyeing.
When is post-laundry flammability testing needed? It is commercially needed when the blanket is reusable and the operator wants evidence after service laundering, especially if finishes, prints or labels may change during washing. Define the wash method, cycle count, drying condition and acceptance criteria before testing. An as-received Appendix F report does not prove post-laundry performance.
What supplier documents should accompany the lab report? Request the signed specification, bill of materials, yarn and fabric lot traceability, dye lot, finish declaration, SDS for functional finishes where applicable, production QC records, AQL inspection report, certificate of conformity, shipment lot list and retained-sample log. The document set should match the PO line item and tested article.
What changes should trigger retesting or written engineering review? Retest or obtain written acceptance after changes to colour family, yarn denier or source, recycled yarn content, GSM outside tolerance, brushing, shearing, edge method, sewing thread, label, decoration, finish chemistry, laundry protocol, production site or any item that breaks traceability to the tested sample.
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