oem cotton canvas makeup bags manufacturers

The manufacturing process for cotton canvas cosmetic bags balances durability and functionality:

1. Material Pretreatment

Canvas Base Material Selection

300D-600D cotton canvas (warp and weft density ≥ 60 threads/inch) is selected. Pre-shrinkage is used to eliminate the risk of subsequent deformation. Custom-shaped parts are precisely cut to the pattern using a laser cutter, and straight pieces are cut using a hydraulic cutting machine. Accessories must include rust-proof resin-toothed zippers and fully plated hardware (magnetic buckles, D-rings).

Structural Reinforcement

The lining is bonded using hot-melt adhesive. The back of the main fabric is laminated with pearl cotton or a rigid lining for enhanced stiffness. The edges are pre-coated with anti-fraying adhesive.

2. Sewing Process

Main Structure Sewing

The bag body is sewn using double-thread lockstitching. The speed is reduced to 800 stitches/minute at corners to prevent skipped stitches. The stress point (the base of the handle) is reinforced with a triangular cross stitch.

A dedicated presser foot is used for zipper installation, ensuring a 1.5mm gap between the seam and the teeth for smooth operation.

Functional Component Integration

The inner pockets feature backstitching for reinforced edges. The layered insert pockets utilize a "seam first, then flip" process. The mesh interlayers are ultrasonically cut to prevent snagging.

III. Surface Treatment

Decoration Process Control

Hot stamping temperature is strictly controlled at 180°C ± 5°C (pressure adjusted according to canvas thickness). Embroidery stitch density is ≥ 12 stitches/cm. The hem is trimmed with a 45° bias-cut tape, and high-frequency heat pressing ensures a tight fit between the tape and the canvas.

Personalized Processing

Digital printing requires proofing to verify color difference. Textile dyes require 24 hours of ventilation to set the color. Hand-painted designs require a fixing agent.

IV. Quality Inspection and Packaging

Three-Level Quality Inspection Process

Initial Inspection: Full inspection of the first 20 products for dimensional tolerance (≤ 0.3cm) and thread tension ≥ 50N;

Process Inspection: Hourly spot checks for smooth zipper opening and closing (≥ 100 times without jamming);

Final Inspection: Light inspection bench to check for stains and thread ends ≥ 0.2mm; oscillation impact test for handles bearing a load ≥ 5kg.

Moisture-Proof Packaging Strategy

High-end models are individually packaged in PE film with silica gel desiccant. Standard models are packaged in OPP bags (5 pieces/pack). The outer box is marked with a moisture-proof label and recycling mark.

Processing: Unshrinked canvas can shrink up to 3% when exposed to moisture. Digital printing requires a color difference of ΔE ≤ 1.5. Hot stamping with excessive temperatures can cause fiber carbonization.

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