Eco Logo Print Kraft Shopping Bags

Material Verification:
Incoming kraft paper rolls are tested for GSM (±3% tolerance per ISO 536) using an electronic grammage balance. Burst strength is validated per ASTM D774 using a Mullen-type hydraulic tester-acceptance: 400–700 kPa depending on GSM grade. Moisture content is measured per ISO 287; acceptance range 7%–9% to prevent tearing or delamination during bag formation.

Print Quality Control:
Flexographic/offset print registration is verified using a 40x magnifying loupe. Color deviation must remain within ΔE <2.0 per ISO 12647-2. Each printed sheet undergoes 100% visual inspection under D65 standard lighting (5000K) for hickeys, scumming, and registration errors. Water-based ink adhesion is validated via tape peel test (3M 600 tape, 90° pull)-zero ink lift-off accepted.

Handle Attachment & Structural Testing:

Handle Pull-Out Test: Handles are subjected to a controlled pulling force using a universal tensile tester (UTM) with handle grip fixtures. Acceptance: flat handles ≥8kg, twisted handles with reinforced patch ≥12kg before detachment or paper tear.

Static Weight Bearing: Bags are filled with weighted sand to specified capacity and suspended for 24 hours. Acceptance: no handle detachment, no bottom seam separation, no side gusset tearing.

Drop Test (ISTA 3A): Finished bags (filled with product-simulating weights) are dropped from 760mm (30″) onto concrete in multiple orientations. Acceptance: no structural failure, no bottom seam rupture, handle attachments remain intact.

Dynamic Lift Test: Bags are filled to capacity and subjected to 10 consecutive lift-drop cycles. Acceptance: no handle failure, no seam separation.

Environmental & Food Contact Compliance:
All kraft paper and printing materials are screened for heavy metals (Pb ≤90 ppm, Cd ≤10 ppm per EN 71-3), phthalates (≤0.1% per REACH Annex XVII), and formaldehyde (≤75 mg/kg). Water-based inks meet FDA 21 CFR and EU food-contact standards. FSC chain-of-custody certification is maintained for all eco-grade material lots. A Certificate of Compliance is issued with every shipment.

Factory Traceability:
Each production batch receives a unique lot number printed on the outer carton, linked to paper supplier batch ID, printing press operator log, and QC test records. Retained samples (5 bags per batch) are archived for 24 months in climate-controlled storage (23°C ±2°C, 50% ±5% RH).