The manufacturing of polyurethane (PU) bags is a complex, detailed process that combines modern technology with traditional craftsmanship. XinRui Leather specialize in creating high-quality PU bags that are not only stylish but also durable and sustainable. Here, we outline the detailed steps and numerical parameters involved in our PU bag manufacturing process.

1. Material Selection

The first step in the manufacturing process at XinRui Leather involves selecting high-grade PU leather. We source our materials from trusted suppliers who meet our stringent standards for quality and environmental responsibility. PU leather is chosen for its durability, ease of maintenance, and its ability to be crafted into a variety of designs. The thickness of the PU leather used typically ranges from 0.8mm to 1.2mm, ensuring the final product is sturdy yet flexible.

2. Design and Pattern Making

Once the material is selected, our design team at XinRui Leather creates detailed sketches and patterns for each bag model. This involves using CAD software to design the bags and generate precise cutting patterns. The patterns are usually scaled on a 1:1 ratio with an accuracy of +/- 1mm to ensure that every cut is exact, minimizing material waste and ensuring consistency across all products.

3. Cutting

The PU leather is then cut according to the patterns created in the previous step. We use a combination of traditional hand-cutting techniques and advanced automated cutting machines. Our cutting machines are calibrated to maintain a cutting precision of +/- 0.5mm, which is crucial for the aesthetic and functional quality of the bags.

4. Stitching and Assembly

The cut pieces are stitched together using industrial sewing machines. The thread used is typically polyester, known for its strength and colorfastness, with a tensile strength of approximately 6.5 grams per denier. Stitch length is critical and is usually set between 3.5 to 4.5 stitches per centimeter, which offers the best balance between seam strength and visual appeal.

In this stage, components like zippers, lining materials (often a polyester blend with a weight of about 70gsm), and hardware are incorporated. Our assembly line at XinRui Leather is composed of skilled artisans who ensure that each component is perfectly aligned and securely attached.

5. Quality Control and Finishing

After assembly, each PU bag undergoes a rigorous quality control process. This includes checking the stitching, material integrity, and functionality of the zippers and clasps. Each bag must pass a series of durability tests, such as the handle strength test, where it must withstand up to 15kg of weight for 60 seconds without showing signs of wear or damage.

The bags are then cleaned, and any stray threads or imperfections are corrected. The final step involves applying a protective coating to the PU leather to enhance its resistance to water and UV rays.

6. Packing and Dispatch

Once the bags meet all quality standards, they are carefully packed. Each bag is placed in a protective cloth bag, then boxed with a moisture-absorbing silica gel packet to prevent dampness. The boxes are stored in our warehouse with a controlled environment, where temperature and humidity are maintained at approximately 22°C and 55% RH, respectively.

Conclusion

The manufacturing process of PU bags at XinRui Leather is a testament to our commitment to quality, precision, and sustainability. As a recognized bags factory, we pride ourselves on creating products that are not only beautiful and functional but also manufactured with the utmost respect for the environment and our workers.