Step 1: Lock the retail promise before naming the foam
The first RFQ mistake is asking for the “best foam” without defining the retail promise. A club store pallet mat needs broad family size, tidy carry format, stable shelf presentation and a landed cost that can absorb display tray, carton and pallet handling. That is not the same product as a compact beach sheet or a hiking ground mat.
Start with the finished construction. A typical 200x200cm retail picnic mat might use a 150D to 600D polyester oxford face, 2-5mm foam core, aluminium-film PE or PEVA/PE backing, 20-30mm edge binding, hook-and-loop flap, 25mm webbing handle and insert card. If the face is 420D oxford at roughly 120-160gsm and the backing is 0.08-0.12mm PEVA or 18-25gsm aluminium-film PE, the foam core carries most of the perceived cushioning and fold recovery.
Be precise with waterproof language. A PEVA, PE, coated oxford or aluminium-film backing can make the underside water-resistant. The finished mat is normally not fully waterproof because needle stitching, bound edges, handle attachments and any panel joins create water paths. If the claim must be “waterproof”, specify seam sealing or welded construction, define a hydrostatic head target such as ISO 811 at 1000-3000mm for the backing layer, and test the finished mat at seams and binding after folding. Without that, use “water-resistant backing” or “moisture-resistant underside”.
Finished-mat water checks should include more than a backing roll test. For a retail picnic mat, we normally propose: ISO 811 hydrostatic head on backing before lamination; 30-minute standing water dish test over stitched binding and handle attachment points; spray exposure on the finished mat face/back using AATCC 22 or a 10-minute inclined spray simulation; and visual inspection after 24-hour drying for delamination, water staining, backing whitening or trapped water at bound edges. If seams are not sealed, write the claim around the backing, not the complete mat.
Put these items on the RFQ line: finished size 200x200cm after binding, finished size tolerance +/-2cm, diagonal skew tolerance within 3cm unless artwork requires tighter control, core type and nominal thickness, foam density target or supplier-declared range, face fabric denier/GSM, backing film type and thickness, folded size target, packed unit weight target, carton quantity, barcode and insert card requirements, destination market, compliance scope and Incoterm.
For Tongxiang production shipping through Ningbo or Shanghai, FOB Ningbo/Shanghai is usually cleaner than EXW for overseas club programmes because inland delivery, export declaration and port handover are defined early. Use CIF only when the buyer wants freight included but can still manage destination charges. Use DDP only after carton dimensions, pallet loading and compliance documents are stable, because a 2-3cm change in folded pack height can change CBM and landed cost.
Step 2: Compare the five core choices without fake rankings
There is no universal winner. The right foam depends on whether the buyer values opening price, rebound, insulation feel, fold recovery, odour control, washable textile handfeel or low carton cube.
Compact comparison for 200x200cm picnic mat cores:
| Core type | Density range | Thickness | Cushioning | Fold recovery | Moisture risk | Odour/VOC risk | Carton cube impact | Best-use scenario |
|---|---|---|---|---|---|---|---|---|
| EPE | Often supplier-declared 18-28kg/m3 apparent density | 1.5-3.0mm, common 2.0mm | Basic | Fair; crease memory possible | Low in closed cells, but edges can trap water | Low to moderate if laminated with solvent glue | Lowest | Opening-price club, supermarket and promotional mats |
| XPE | Often supplier-declared 25-45kg/m3 apparent density | 2.0-5.0mm, common 3.0mm | Good | Good | Low; closed-cell | Low to moderate depending lamination adhesive | Medium | Premium family mat with better rebound |
| IXPE | Often supplier-declared 25-40kg/m3 apparent density | 2.0-4.0mm | Good, smoother feel | Very good if cells are uniform | Low; closed-cell | Usually low, still test adhesive and packaging | Medium | Smoother premium mats and tighter fold aesthetics |
| EVA | Often supplier-declared 50-100kg/m3 for sheet grades used in mats | 2.0-5.0mm | Rubbery, strong body | Good, but heavy grades can take compression marks | Low in sheet; water can enter edges and stitch holes | Higher risk; formamide, VOC, PAH and odour review needed | High | Heavy-duty premium mats where weight and compliance cost are accepted |
| Polyester sponge | Often supplier-declared 16-35kg/m3; verify by method if critical | 2.0-5.0mm | Soft textile feel | Fair to good depending compression set | Medium to high if edge wicking is not controlled | Low to moderate; adhesive still matters | Medium to high | Soft blanket-like picnic mats, wipe-clean casual use |
Density figures in many China foam quotations are supplier-declared apparent density, normally calculated from sheet weight and sheet volume. That is useful for costing, but it is not the same as a third-party density result unless the method, specimen conditioning and measurement pressure are defined. For cellular plastics, cite ISO 845 or ASTM D3575 where relevant. Ask the supplier to state whether density is declared from roll weight, in-house apparent-density measurement, or lab-tested density.
Typical China-market quoting ranges for 200x200cm mats, not QC acceptance limits: 2mm EPE at nominal 2.0mm and often 18-28kg/m3 apparent density; 3mm XPE at nominal 3.0mm and often 25-45kg/m3; IXPE at nominal 2.0-4.0mm and often 25-40kg/m3; EVA at nominal 2.0-5.0mm and often 50-100kg/m3 for sheet grades used in mats; polyester sponge at 2.0-5.0mm, with density, compression set and water absorption more important than a simple thickness claim.
Treat those ranges as sourcing references. The PO should state the approved sample plus numeric tolerances: core thickness +/-0.3mm for 2-3mm PE foams, +/-0.5mm for thicker or softer cores unless otherwise agreed, finished folded size +/-2cm in length/width and +/-1.5cm in height, packed unit weight +/-5% against sealed sample, and no foam joins unless approved on the pre-production sample.
Thickness must be measured after lamination, not only on the loose foam roll. Condition finished mats flat for 24 hours at 20 +/-2°C and 65 +/-5% RH where the lab can control it, or at least 24 hours in the QC room away from direct heat. Measure finished laminate thickness at nine points using a thickness gauge with a low-pressure presser foot suitable for compressible textiles; record the average and the minimum. Do not measure directly on bound edges, seam ridges or fold lines.
For a 200x200cm family mat, a 2mm EPE construction may finish around 0.9-1.3kg depending face and backing. A 3mm XPE construction often moves nearer 1.2-1.7kg. EVA can exceed that range quickly. Polyester sponge can feel premium in the aisle, but after wet grass exposure it may show slower drying, edge wicking or local compression marks unless the laminate and binding are specified tightly.
Step 3: Understand EPE, XPE and IXPE before approving substitutions
EPE is expanded polyethylene with larger, less uniform cells. It is light and economical, but it is easier to crush at fold lines and can show wavy lamination if the face fabric or backing is thin. For opening-price mats, this is acceptable if the buyer signs off the folded look and the return policy does not punish crease marks.
XPE is chemically crosslinked polyethylene foam. Chemical crosslinking improves melt strength during foaming, giving smaller cells, better resilience and higher heat resistance than basic EPE. In production terms, XPE usually gives a smoother laminate surface under 420D oxford or PEVA, and it tolerates repeated folding better. The trade-off is cost, thickness-related carton cube and minimum batch quantity for special colours or densities.
IXPE is irradiation-crosslinked polyethylene foam. Electron-beam crosslinking can create a finer, more uniform cell structure and a smoother surface than many chemical XPE grades. IXPE is useful where the buyer wants cleaner fold recovery, less orange-peel texture under thin films and a neater premium hand. It is not automatically stronger in every construction; lamination method, backing brittleness and thickness still decide bulk performance.
Sourcing difference matters. EPE is easier for short-run programmes and price promotions. XPE has wider availability for 2-5mm mat cores, but unusual density/colour combinations may need larger foam-sheet MOQ. IXPE can have tighter MOQ and longer lead time because irradiation processing and sheet colour are less flexible. If a supplier offers “IXPE” at the same price and MOQ as basic EPE, ask for material declaration and compare cell structure, density and compression recovery, not just the name.
Heat resistance is another practical difference. Hot containers can reach elevated temperatures during summer shipping. EPE may soften, crease or delaminate more readily if the adhesive is weak. XPE and IXPE generally hold shape better, but backing films can still block or crack. A 50°C ageing check for 24-48 hours on packed units is cheap insurance before a club-store order is packed into full containers.
Step 4: Use a buyer decision matrix
Decision matrix for common buying scenarios:
Opening-price promo club pallet: 2mm EPE with 420D oxford face and aluminium-film PE or PEVA backing; prioritise low carton cube, low unit weight and crease control.
Premium family mat: 3mm XPE or IXPE with 420D-600D oxford face; prioritise rebound, smoother lamination and clean folding.
Cold-weather picnic or stadium tailgate use: 3mm XPE or IXPE with aluminium-film PE backing; use “reflective backing” or “perceived warmth” unless thermal resistance is tested.
Washable textile handfeel: polyester sponge under fleece or suede face; specify wipe-clean or limited wash care honestly and test edge wicking.
Low carton cube target: 2mm EPE or thin IXPE; avoid EVA unless the buyer accepts fewer units per carton and higher freight cost.
Aluminium film should not be sold as proven thermal insulation unless the claim is supported. If the package says “helps reduce ground chill” or “reflective backing”, that is easier to support visually. If it says “thermal”, “insulated to X value” or “keeps heat X% longer”, ask for thermal resistance testing, for example ISO 11092 or ASTM C518 depending the claim and lab capability. Test the full laminate, not a single film layer.
If the buyer wants a soft blanket-like surface, the face fabric may matter more than the foam. A 190-240gsm brushed polyester or fleece face over 2mm EPE feels softer to the hand than 420D oxford over the same core, but it may collect grass, take longer to dry and need tighter colourfastness checks. For a heavier fleece picnic direction, compare construction logic with 240gsm fleece picnic blankets rather than treating foam as the only comfort lever.
If the buyer wants a hard-wearing outdoor face, 420D or 600D oxford gives better abrasion resistance and cleaner wipe-down, but it can feel stiff over thin foam. For large retail mats with thicker foam and oxford backing, 600D rPET oxford picnic mats with 5mm XPE foam core is the more rugged end of the same decision.
Step 5: Match foam to backing, because backing can override the core
The backing is not a passive layer. It changes stiffness, fold noise, edge behaviour, water resistance and cracking risk. A good foam choice can fail if the backing is too brittle, too soft or poorly bonded.
Aluminium-film PE: light, low cost and good perceived warmth. It pairs well with 2mm EPE and 3mm XPE for promotional and club mats. Main risks are whitening, pinholes, film cracking at tight fold lines, noisy handfeel and delamination where the adhesive line is uneven. We have seen bulk lots pass flat-panel inspection and then show aluminium cracking exactly on the retail fold grid after compression in export cartons. Use wider fold radii where possible and test fold cracking on the finished laminate, not only the backing roll.
PEVA or PE film, usually 0.08-0.12mm: quieter and more flexible than aluminium-film PE. It works with EPE, XPE and polyester sponge, but soft grades can block or stick in hot cartons, especially when packed before adhesive is fully cured. PEVA blocking appears as tacky contact marks, print transfer from insert cards or a squeaky peel when the folded mat is opened. REACH Annex XVII and phthalate review may be relevant depending chemistry and market. For PEVA-specific risk control, see REACH Annex XVII checks for 0.08mm PEVA backed picnic mats.
Coated oxford with PU, acrylic or PVC-free TPE coating: tougher and more textile-looking, but heavier and bulkier. It suits premium XPE/IXPE mats and some EVA constructions. Specify the coating weight or finished fabric GSM, not only “coated oxford”. A 150D acrylic-coated oxford may sit around 110-140gsm; a 600D PVC-free TPE-coated oxford can move far higher and change carton planning. Coated oxford can turn a light mat into a high-CBM outdoor blanket, so quote carton cube before artwork sign-off. For backing material choices, picnic blanket backing PEVA, PU and TPU options is the more detailed reference.
PVC-backed constructions: durable and cheap in some markets, but they raise weight, cold-crack and restricted-substance questions. If PVC is proposed, require phthalate, heavy metal and PAH review for the destination market before quoting retail packaging. A cold-crack check at -10°C or -20°C is sensible for winter distribution or unheated warehouses.
For a family retail mat, the cleanest wording is often “water-resistant backing” with a named material and thickness. If the buyer insists on “waterproof picnic mat”, define whether that means backing film performance, finished underside performance, or no leakage through stitched edges. Those are different tests and different costs.
Step 6: Define lamination method, peel strength and ageing risk
Most foam-core picnic mats fail from the interface, not from the foam alone. A buyer RFQ should name the lamination method or at least require the supplier to declare it on the quote sheet.
Flame lamination: the foam surface is lightly melted and bonded to fabric or film. It can reduce adhesive odour and add-on weight, but it is sensitive to foam type, line speed and scorching. Risks are uneven bonding, brittle surface skin and local shrinkage. It is more common for PE foam to textile layers than for every backing film.
Hot-melt lamination: adhesive web, powder or film is heated between layers. It gives cleaner process control and can be lower odour than solvent glue, but wrong adhesive selection can block in hot cartons or crack at folds. Ask whether the adhesive is EVA, PO, TPU or another system if the mat will face heat or cold.
Glue lamination: water-based or solvent-based adhesive is coated onto one layer before bonding. It can work on difficult substrates and large-width panels, but poor drying causes odour, VOC complaints, blocking and weak peel. If solvent glue is used, require airing time and residual odour control before polybagging.
Suggested peel and ageing checks: cut 25mm-wide strips from face-to-foam and foam-to-backing interfaces; test 180° peel by a lab method adapted from ISO 11339 or ASTM D903. For soft foam laminates, the result may be foam tear rather than clean adhesive peel, which is acceptable if the bond line remains intact. A practical acceptance target for many picnic mats is no clean delamination below 1.0N/25mm on lightweight film interfaces and preferably 1.5-2.0N/25mm or foam tear on premium oxford/foam laminates. Confirm targets against the approved sample because very soft foams do not behave like rigid laminates.
Ageing should be simple but measurable: condition samples at 50°C for 24-48 hours, then return to room condition for 4 hours and repeat peel, fold and odour checks. For winter markets, add a cold-fold check after 4 hours at -10°C or -20°C depending destination. Failure modes are backing cracks, adhesive whitening, edge curl, cell collapse, blocking and obvious chemical smell when the polybag is opened.
A factory-side failure we watch for is hot-container delamination. A mat may look good after sewing, but after one week packed tight in a summer warehouse the PEVA or aluminium film can release from the foam at corners and fold ridges. This is usually adhesive selection, insufficient curing or too much residual solvent, not a sewing problem. Do not approve bulk packing until aged samples are opened, sniffed, folded and peel-checked.
Step 7: Specify EVA and polyester sponge carefully
EVA is not just “better foam”. It gives rubbery cushioning and a dense feel, but it is heavier and more compliance-sensitive. For EU and family retail channels, flag formamide, VOC/odour, PAHs, heavy metals and any market-specific restricted substances before the buyer commits to packaging claims. EVA puzzle mats and children’s products have made retailers sensitive to formamide; even when a picnic mat is not a toy, family-channel buyers may apply stricter internal limits.
For EVA RFQs, state: nominal thickness, density or hardness, colour, odour grade, restricted substance scope, maximum packed-unit weight and carton cube target. Ask for a material safety declaration and third-party testing only against the actual destination market requirement; do not accept a generic “eco EVA” claim. For EU retail, REACH Annex XVII screening and PAH review are common buyer requests. For children or family positioning, discuss whether EN 71-3, CPSIA-related heavy metals or retailer RSL limits apply to prints, films, labels and adhesives, not only the EVA sheet.
Polyester sponge gives a softer textile hand, especially under brushed polyester, suede or fleece faces. The risk is moisture. Open or semi-open structures can absorb or hold water at cut edges; then the mat dries slowly and may smell after storage. Specify sponge density, compression set, water absorption and edge construction. A realistic RFQ might call for 2.5-3.0mm polyester sponge, supplier-declared 20-30kg/m3 density, compression set after 50% compression for 22 hours at 23°C below 10-15% where the foam grade can support it, and no visible water wicking more than 10mm from cut edge after a 30-minute edge dip test.
Anti-wicking construction matters more than a neat showroom sample. Use full binding coverage with sufficient seam allowance, avoid exposed sponge at corners, specify corner turn-in without gaps, and consider a backing layer that wraps slightly into the bound edge. After production, inspect bound edges by opening random reject samples: if the foam is visible or the stitch holes run too close to the edge, wet grass complaints are likely.
Drying-time checks are practical. Wet a 100x100mm finished laminate area with 10ml water on the backing side and repeat on an exposed cut edge sample; hang at room condition and record visible wetness at 2, 4 and 24 hours. For sponge-core family mats, no persistent damp feel or odour after 24 hours is a reasonable commercial expectation, though exact thresholds should match the approved sample and care claim.
Step 8: Build QC tests into the purchase order
A picnic mat QC plan should cover dimensions, appearance, lamination, folding, odour, restricted substances, colourfastness and packing. If the PO only says “same as sample”, the inspector has weak tools when bulk starts drifting.
Recommended QC checklist for 200x200cm foam-core mats:
Finished size: 200x200cm after binding, tolerance +/-2cm; check at least 13 points per AQL sampling lot where practical.
Diagonal skew: difference between diagonals within 3cm unless printed grid/artwork requires tighter control.
Thickness: average within agreed tolerance after 24-hour conditioning; record nine points away from seams.
Unit weight: within +/-5% of approved sample or PO target.
Folded size: within +/-2cm length/width and +/-1.5cm height; verify against retail display tray and carton.
Lamination: no bubbles over 20mm, no continuous tunnel delamination, no clean peel below agreed threshold.
Folding: 20 open/close cycles at room temperature, then inspect backing cracks, film whitening, edge splitting and handle stress.
Cold fold: 4 hours at -10°C or -20°C, one fold/unfold cycle within 60 seconds, no backing fracture or adhesive split.
Hot ageing: 50°C for 24-48 hours in folded pack, no blocking, severe odour, edge curl or delamination.
Odour: sealed bag or jar check after 24 hours at 40°C; no strong solvent, sour or rubber smell against approved control sample.
Colourfastness: ISO 105-X12 rubbing, dry grade 4 minimum and wet grade 3-4 minimum for most dark printed faces; ISO 105-C06 wash only if washable claim is made; ISO 105-B02 light fastness commonly grade 4 or higher for outdoor-facing prints where retail expects UV exposure.
Water resistance: ISO 811 on backing, plus finished seam/binding water dish or spray simulation as agreed.
Handle strength: static load 5-8kg for 1 hour on packed mat handle, plus 10 lift cycles; no bar-tack rupture or webbing tear.
For appearance inspection, AQL 2.5 for major defects and AQL 4.0 for minor defects is common for mass retail textile mats, but some club programmes require AQL 1.5 major. Major defects should include wrong size outside tolerance, open seams, loose handle, exposed foam, large delamination, severe odour, missing barcode, wrong care label and visible mould or contamination. Minor defects include small thread ends, slight binding waviness and small print shade variation within approved tolerance.
For colour and print, do not inspect only under warehouse light. Use D65 lightbox where possible and compare bulk to approved standard. Large 200x200cm panels expose shade bands and print repeat problems more than small blankets. If face fabric is cationic heather or yarn-dyed, define acceptable shade range before cutting. For general blanket QC structure, use blanket quality control inspection as the inspection framework and add foam-specific tests from this article.
For care claims, keep the label honest. Many foam-core picnic mats are wipe-clean only because machine washing can crease foam, crack aluminium film, deform PEVA and stress binding. If a buyer wants washability, test the finished mat under ISO 6330 or the retailer’s home-laundering protocol and expect a larger folded-size and appearance tolerance after washing. A care-label reference is available at blanket care washing guide.
Step 9: Check carton cube before approving the sample
For a 200x200cm mat, carton cube can move landed cost more than a small material saving. A thicker foam may be the right retail choice, but the buyer should see units per carton, carton CBM and pallet count before signing artwork.
Illustrative packing examples for 200x200cm mats, not guaranteed loading:
| Construction example | Estimated folded unit | Units/carton | Estimated carton size | Carton CBM | Pallet impact |
|---|---|---|---|---|---|
| 420D oxford + 2mm EPE + aluminium-film PE | Approx. 40x28x9cm | 8 pcs | 58x42x40cm | 0.097m3 | Higher carton count per pallet; better container utilisation |
| 420D oxford + 3mm XPE + PEVA | Approx. 42x30x12cm | 6 pcs | 62x44x45cm | 0.123m3 | Fewer units per pallet; better product feel |
| 600D oxford + 3mm XPE + coated oxford | Approx. 43x32x14cm | 5 pcs | 66x46x44cm | 0.134m3 | Retail shelf feels premium but pallet density drops |
| 420D oxford + 3mm EVA + PEVA | Approx. 44x32x15cm | 4-5 pcs | 66x46x46cm | 0.140m3 | Heavier cartons; check manual handling limits |
Real packing depends on fold map, handle placement, belly band or insert card, compression allowance and whether the buyer accepts vacuum or tight compression. We avoid aggressive compression for aluminium-film and PEVA-backed mats because it can set fold creases, cause blocking or crack the film. For club-store pallet displays, also check tray height, barcode visibility after stacking and whether the webbing handle creates an uneven pile.
Pallet planning should be done after the pre-production sample, not after bulk is packed. A typical export pallet may be limited by height, carton crush and retailer handling rules rather than floor area. Ask for a pallet diagram showing cartons per layer, layers per pallet, pallet height and gross weight. If the carton changes by 20mm in height after bulk folding, container and warehouse costing can change.
Step 10: Write the RFQ so factories quote the same mat
A good RFQ does not need to be long, but it must remove the common substitutions. Use material names, target ranges and tests, then let the factory suggest cost-downs separately.
RFQ wording example:
Finished picnic mat 200x200cm after binding, tolerance +/-2cm; 420D polyester oxford face, target 130-150gsm, buyer artwork printed; core option A: 2.0mm EPE, supplier-declared apparent density 20-25kg/m3; core option B: 3.0mm XPE, supplier-declared apparent density 30-40kg/m3; backing 0.10mm PEVA or 20gsm aluminium-film PE, water-resistant underside; 25mm polyester binding; 25mm webbing handle with bar-tack reinforcement; hook-and-loop closure; folded size and carton quote required; FOB Ningbo or FOB Shanghai.
Testing and compliance wording example:
Supplier to declare foam type, density basis and lamination method. Density to be supplier-declared from sheet weight/volume unless third-party ISO 845 or ASTM D3575 is specifically ordered. Backing hydrostatic head ISO 811 target 1000mm minimum before lamination, or agreed alternative for film backing. Lamination peel adapted from ISO 11339 or ASTM D903, no clean delamination below approved threshold. Finished mat hot ageing 50°C for 24-48 hours, cold fold -10°C where destination requires, odour check after sealed 40°C conditioning, ISO 105-X12 rubbing for printed face, finished seam/binding water check. Restricted substances according to buyer RSL and destination market.
Inspection wording example:
Final random inspection to ANSI/ASQ Z1.4 or ISO 2859-1 single sampling, normal inspection, AQL 2.5 major / 4.0 minor unless buyer standard is stricter. Critical defects not allowed: mould, wrong product, sharp contamination, missing legally required label, severe chemical odour, unsafe handle failure, restricted-substance non-compliance.
Ask for two samples: a showroom sample and a packed sample. The packed sample should include final fold method, insert card, barcode, polybag if used, carton loading and 48-hour compression. Many mat problems show only after packing: PEVA blocking, aluminium film cracking at folds, handle dents into the face fabric and foam not recovering to the approved thickness.
FIELDLOOM recommendation for club-store 200x200cm programmes
For opening-price pallet volume, we usually start with 420D oxford face, 2mm EPE, aluminium-film PE or 0.10mm PEVA backing, bound edge and webbing handle. The key controls are crease acceptance, backing crack test, odour and carton compression.
For a better family retail mat, 3mm XPE is the most balanced upgrade. It improves cushioning and fold recovery without the weight and compliance risk of EVA. IXPE is worth sampling when the buyer wants smoother hand, better fold aesthetics and can accept MOQ or cost implications.
Use EVA only when the brief needs rubbery density and the buyer accepts heavier cartons, tighter restricted-substance testing and odour control. Use polyester sponge when soft textile feel matters more than wet-ground robustness, and protect the edges against wicking.
Send FIELDLOOM the target retail price, destination market, desired folded size, face artwork, backing preference and Incoterm. We can quote EPE/XPE/IXPE/EVA/sponge alternatives on the same 200x200cm construction so the buyer sees unit price, packed CBM, test plan and risk notes side by side.
Frequently asked
Is 3mm XPE always better than 2mm EPE for a 200x200cm picnic mat? No. 3mm XPE normally gives better cushioning and fold recovery, but it increases material cost and carton cube. For opening-price club pallets, 2mm EPE can be the correct choice if crease marks, compression recovery and backing crack performance are approved before bulk.
How should foam density be written on a purchase order? State whether density is supplier-declared apparent density or lab-tested density. For cellular plastics, ISO 845 or ASTM D3575 can be cited where method-based density is required. Also keep an approved sample, because density alone does not guarantee cell structure, rebound or lamination quality.
Can a stitched foam-core picnic mat be sold as waterproof? Usually not without qualification. The backing layer may pass a hydrostatic head test such as ISO 811, but stitched binding, handle attachments and panel joins can leak. Use “water-resistant backing” unless the finished mat construction is sealed or welded and tested at seams and edges.
What is the main risk with EVA picnic mat cores? EVA adds weight and rubbery cushioning, but it needs stronger odour and restricted-substance control. For EU and family retail channels, review formamide, VOC/odour, PAHs, heavy metals and buyer RSL requirements before approving the material.
What AQL level is realistic for mass retail picnic mats? AQL 2.5 for major defects and AQL 4.0 for minor defects is common, with critical defects not allowed. Some club or family retail programmes require AQL 1.5 major. Define major defects clearly: delamination, severe odour, wrong size, exposed foam, failed handle, missing label and water-resistance failure if claimed.
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