How to make a cooler bag?

How to make a cooler bag?

Step 1: Material Selection & Preparation

• Outer Fabric: Common choices are 840D Oxford cloth or polyester. These materials are waterproof, wear-resistant, and easy to print patterns (usually using heat transfer technology) . Before production, the fabric is cut into preset sizes by automatic cutting machines to ensure consistency.
• Insulation Layer: The core thermal insulation component, typically pearl cotton (EPE) combined with aluminum foil. The pearl cotton provides thermal resistance, while the aluminum foil reflects radiant heat, forming a double insulation barrier . We use high-density pearl cotton (density ≥ 30kg/m³) for longer insulation duration.
• Inner Lining: Food-grade PE or PVC material is adopted for its non-toxic, waterproof, and easy-to-clean properties. It directly contacts food, so we strictly test it for compliance with FDA and EU food contact material standards.

Step 2: Pattern Making & Cutting

Step 3: Layered Bonding & Sewing

1. Bond the insulation layer to the inner lining using a hot-press machine, ensuring full contact without air gaps—this is key to preventing heat leakage.
2. Sew the outer fabric into the bag body shape, including adding details like side pockets, handles, or shoulder straps. The stitching density is controlled at ≥ 12 stitches per inch to enhance load-bearing capacity.
3. Combine the inner insulated layer with the outer bag body, and reinforce the seams with double stitching, especially at stress points like the handle connection.

Step 4: Installation of Accessories

• Waterproof zippers (to prevent external water from entering and maintain internal temperature);
• Sealing strips (for high-end models, to further enhance insulation);
• Name tags or information pockets (to meet the needs of corporate gifts or logistics tracking).

Step 5: Quality Inspection & Packaging

1. Initial Inspection: Check for material defects such as fabric scratches or insulation layer delamination.
2. Performance Test: Conduct a 24-hour insulation test—fill the bag with 0℃ ice cubes, and the remaining ice volume should be ≥ 60% after 24 hours to be qualified.
3. Final Inspection: Check sewing quality, accessory firmness, and whether the appearance meets the standard.