Production Process of Customized Biodegradable Bags

Understanding Raw Materials: PLA and PBAT

In the production of custom biodegradable bags, the choice of raw materials determines the environmental performance, toughness, and user experience of the bags. Guanzhong mainly uses a composite modified material of PLA (Polylactic Acid) and PBAT (Polybutylene Adipate Terephthalate). This combination balances biodegradability and mechanical performance.

• Characteristics of PLA: PLA is a biopolymer derived from corn starch or sugarcane, with excellent transparency and thermoplasticity. It has high strength and stretchability and can completely degrade into water and carbon dioxide under industrial composting conditions in about 90 days (Source: European Bioplastics, 2022). These properties make PLA an ideal choice for eco-friendly bags while meeting food contact safety requirements.
• Characteristics of PBAT: PBAT is extremely flexible and can effectively improve the brittleness of PLA, making the bags tear-resistant and stretch-resistant. With PBAT, the bags remain sturdy and reliable even when carrying heavy loads, suitable for shopping bags, trash bags, and pet waste bags.
• PLA+PBAT Composite Advantages: Guanzhong uses a scientific ratio (typically 6:4 to 7:3) to ensure both biodegradability and bag toughness, providing a stable and reliable material base for biodegradable shopping bags wholesale and custom biodegradable bags.
• Performance Data: ASTM D6400 tests show that the composite bags can achieve an 85% degradation rate under industrial composting conditions within 120 days. Tensile strength ranges from 25~35 MPa, and puncture strength is 12~15 N. These metrics guarantee durability during use while ensuring rapid degradation in composting environments without secondary pollution.

Production Process

Guanzhong strictly controls each stage of the custom biodegradable bag production process, ensuring environmental friendliness, durability, and suitability for various customization needs. The production process includes the following key steps:

• Raw Material Drying and Preprocessing: PLA and PBAT are sensitive to moisture. The raw materials are dried at 60–80°C for 4–6 hours to reduce moisture content below 0.2%. This ensures the materials do not form bubbles or lose strength during extrusion and molding, and prevents degradation at high temperatures.
• Composite Mixing and Extrusion: Dried raw materials are mixed according to precise ratios, with the addition of toughening agents, antioxidants, and processing aids. A twin-screw extruder evenly blends the materials at 160–190°C with screw speeds of 50–100 rpm. This produces uniform composite pellets that form a stable material base for film production.
• Film Blowing and Multi-Layer Lamination: Composite pellets are extruded into films with precise thickness control between 20–50 microns. Multi-layer lamination enhances mechanical performance, barrier properties, and tear resistance while maintaining biodegradability. This step is essential for uniform strength and appearance.
• Printing and Functional Processing: Films can be printed with eco-friendly water-based inks on one or both sides, including company logos, brand marks, patterns, or text. Functional enhancements such as reinforced handles, bottom strengthening, leak-proof features, and zip seals can be added to make the bags practical, attractive, and environmentally friendly.
• Cutting and Bag Formation: Films are cut to the required dimensions to produce various bag types: vest bags, partition bags, roll bags, trash bags, and pet waste bags. Heat sealing is performed at 140–160°C to ensure strong seals while preserving biodegradability. Guanzhong’s 25 bag-making production lines have a monthly capacity of approximately 1,500 tons, supporting both bulk biodegradable shopping bags wholesale and custom biodegradable bags orders.
• Quality Testing and Packaging: Every batch undergoes tensile, puncture, heat-seal, and thickness tests to ensure mechanical performance and batch consistency. Qualified products are sorted, packed, labeled, and shipped according to customer requirements, guaranteeing high-quality delivery for bulk or customized orders.

Quality Assurance and Environmental Certification

Guanzhong implements strict quality management and environmental testing for each batch of custom biodegradable bags, ensuring compliance with international standards and customer requirements.

• Domestic Certifications: Products meet GB/T 20197, GB/T 19277.1, and GB/T 4806.7 standards for biodegradability and food contact safety, ensuring material safety and environmental compliance.
• International Certifications: ASTM D6866, ASTM D6400, DIN EN 13432, BPI industrial composting certification, and U.S. FDA food contact testing ensure global market compliance.
• Degradation Performance: Under industrial composting conditions, Guanzhong bags can fully degrade into water and carbon dioxide in approximately 120 days without harmful residues, aligning with sustainable environmental practices.
• Mechanical Performance: Each batch undergoes tensile, puncture, heat-seal, and thickness testing to guarantee stability and durability during use.
• Process QA/QC: Guanzhong monitors raw material storage, production, and finished goods packaging to ensure consistent quality across batches, providing reliability for biodegradable shopping bags wholesale and custom biodegradable bags clients.

Customized Biodegradable Bag Workflow

Guanzhong offers a complete customization workflow to ensure every bag meets customer-specific requirements while remaining environmentally friendly and practical.

• Requirement Communication: Customers provide bag type, size, thickness, color, and printing patterns. Guanzhong’s professional team provides feasibility analysis and optimized proposals to ensure bags are attractive and eco-friendly.
• Design and 3D Modeling: Bag structures are designed and 3D modeled based on customer requirements, optimizing capacity, functionality, and material usage while maintaining biodegradability.
• Mold Production: Heat seal molds or printing molds are produced based on design, with a typical mold cycle of 7 days, ensuring rapid response to customer customization needs.
• Sample Confirmation: Small batches of samples are produced for customer approval, including bag type, thickness, print quality, and overall performance, ensuring accuracy before mass production.
• Mass Production: After sample approval, full-scale production includes raw material preparation, film extrusion, cutting, heat sealing, and quality testing, ensuring batch consistency and high-quality output.
• Packaging and Delivery: Finished products are packaged, labeled, and shipped according to customer requirements, supporting both biodegradable shopping bags wholesale and custom biodegradable bags bulk or customized orders.

Guanzhong’s Customization and Wholesale Advantages

Guanzhong has clear advantages in both the custom biodegradable bags and wholesale markets, with professional capabilities and production strength leading the industry.

• Customization Capabilities
  • Bag Types: Vest bags, partition bags, T-shirt bags, roll bags, trash bags, and pet waste bags.
  • Sizes and Capacities: Length, width, bottom width, and weight capacity fully customizable.
  • Thickness: Film thickness adjustable between 20–50 microns to suit different uses.
  • Colors and Transparency: Single color, dual color, gradient, transparent, semi-transparent, or opaque.
  • Printing and Patterns: Single/double-sided printing with logos, brand marks, patterns, or text; multi-layer laminated films enhance print quality.
  • Functional Designs: Reinforced handles, strengthened bottoms, leak-proof features, zip seals, and other functional options for diverse requirements.

• Production Strength
  • 50 film extrusion lines and 25 bag-making lines, monthly capacity approx. 1,500 tons, supporting both bulk biodegradable shopping bags wholesale and large-scale custom biodegradable bags orders.
  • 3 bio-based modified material extrusion lines and 5 masterbatch lines, monthly capacity approx. 2,000 tons, providing stable raw materials for films and bags.
  • Injection molding and blister forming lines produce approx. 2,800 tons per month for handles and specialized components.
  • 5 fully automatic straw extrusion lines, monthly capacity approx. 250 tons, complementing eco-friendly bag products.
  • High automation and stable output enable long-term support for wholesale clients and large-scale custom projects.
• Wholesale Advantages
  • Supports large-scale orders with reliable supply.
  • High degree of automation ensures consistent long-term production.
  • Offers diverse customization options to provide exclusive branding and functional designs for wholesale customers.

Guanzhong achieves full-process control from raw materials to finished custom biodegradable bags, through comprehensive production systems, scientific material management, and strict quality inspection. With extensive experience, advanced equipment, and multiple international certifications, Guanzhong provides high-quality custom biodegradable bags that meet both wholesale and customization needs, supporting global sustainability and environmental protection initiatives.