Rizhao Zhengjia Plastic Co., Ltd.

The company mainly operates two core categories of plastic products: injection molding and blow molding. Its injection molding products mainly include catering supporting products such as plastic takeaway containers, sauce cups, milk tea cups, fruit buckets, in-mold labeling takeaway containers, and disposable cutlery including knives, forks and spoons for aviation use, supported by more than 80 professional production lines. Blow molding products cover packaging and daily-use products such as plastic packaging bags, garbage bags and disposable gloves, equipped with more than 40 sets of blow molding and bag-making production lines. The products are widely used in various scenarios including catering packaging, fresh food storage and general daily packaging, fully meeting the diversified needs of the market. Since its establishment, the company has been market-oriented, continuously promoting capacity upgrading and equipment renewal. It has now formed a large-scale production capacity for plastic products of various specifications and types, capable of efficiently undertaking customers' bulk customization and regular procurement demands, while ensuring delivery efficiency and consistent product quality throughout the process.

Production Process

The entire process of food box production Production process of plastic bags

The entire process of food box production

At this stage, relying on a fully automated production line, standardized production of the entire process of lunch boxes from molds to finished products will be achieved

  • 01

    Mold preparation and debugging

  • 02

    Raw Material Pre-processing and Injection Molding

  • 03

    Comprehensive Quality Control and Multi-stage Inspection System

  • 04

    Customized Post-processing

  • 05

    Finished Goods Warehousing and Secure Delivery

Existing molds: complete mold cleaning and accuracy verification to ensure that the size and structure of the food box meet the standards;

 

Customized mold: Complete mold opening, trial molding, and sample confirmation according to customer needs to ensure that the mold accuracy meets the standards before putting it into production.

Raw Material Inspection: Food-grade PP raw materials undergo compliance testing to ensure adherence to safety standards for food-contact materials, verifying they are free from impurities and odors.

Automated Injection Molding: The PP raw materials are fed into a fully automated injection molding production line. Through a process involving high-temperature melting, high-pressure injection, and cooling, the main body of the meal box and its lid are integrally formed in a single step, guaranteeing structural stability and dimensional precision.

Appearance Inspection: Screening for defects such as burrs, deformation, color variations, or physical damage to the meal boxes.

Dimensional Inspection: Verifying key parameters including length, width, height, capacity, and lid sealing integrity.

Safety Testing: Conducting random sampling to verify material compliance as well as high- and low-temperature resistance, ensuring full compliance with food-grade usage requirements.

Non-conforming products are immediately rejected and removed to prevent them from proceeding to the next stage of production.

Customized processing is performed according to client requirements. This includes custom colorization, in-mold labeling, assembly with accompanying cutlery sets, and various packaging options (e.g., individual wrapping or bulk carton packing) to meet specific branding and application needs.

Upon completion of production and final quality inspection, the meal boxes are moved to storage. Logistics and shipping are arranged in strict accordance with order specifications, with comprehensive measures in place to ensure transport safety. This guarantees that the meal boxes are delivered to the client's designated location on time, and exactly as specified in terms of quality and quantity.

Production process of plastic bags

Leveraging fully automated production lines, this stage achieves standardized production for plastic bags across the entire workflow—from raw materials to finished products.

  • 01

    Printing Plate / Mold Preparation and Calibration

  • 02

    Raw Material Pre-processing and Film Blowing

  • 03

    Printing Process (Customization Phase)

  • 04

    Bag Forming and Cutting

  • 05

    Comprehensive Quality Control and Inspection

  • 06

    Finished Product Packaging and Secure Delivery

Existing Plates: Complete cleaning and precision verification of printing plates to ensure that printed patterns and dimensions meet established standards.

Custom Plates: Based on client requirements, handle the creation, trial printing, and sample approval of new plates; production commences only after ensuring that printing precision and color fidelity meet the required benchmarks.

Raw Material Inspection: Conduct compliance testing on food-grade PE raw materials to ensure adherence to safety standards for food-contact materials—specifically, verifying the absence of impurities, odors, and excessive heavy metals.

Automated Film Blowing: Feed PE raw materials into a fully automated film-blowing production line, where they undergo high-temperature melting, extrusion, inflation, cooling, and shaping to produce plastic film meeting specific thickness requirements; this process guarantees uniform film thickness and ensures the material meets required toughness standards.

Execute multi-color printing operations in accordance with client specifications:

Utilize eco-friendly inks to ensure printed patterns are crisp, colors are durable, and the finished product remains odorless—thereby meeting safety requirements for food-contact materials.

Continuously monitor printing precision throughout the process to prevent issues such as registration errors, missing prints, or color deviations; any non-conforming products are immediately rejected and removed.

Feed the printed film into a fully automated bag-making machine to execute processes such as bag shaping, edge sealing, cutting, and—where required—perforation:

Precisely control bag dimensions and seal strength to ensure the bags meet required standards for load-bearing capacity and airtightness.

Simultaneously perform counting and stacking operations to prepare the finished bags for the subsequent packaging stage.

Implement a rigorous, multi-stage quality control system:

Visual Inspection: Screen bags for defects such as punctures, weak seals, printing flaws, or rough edges.

Dimensional Inspection: Verify key parameters including bag length, width, thickness, and load-bearing capacity.

Safety Inspection: Conduct spot checks on material compliance and ink safety to ensure full adherence to food-grade usage requirements.o Immediately reject and remove any non-conforming products to prevent them from proceeding to the next stage of production.

Upon completion of production and final quality inspection, the plastic bags are packaged—either individually or in bulk cartons—in accordance with client specifications. They are then moved to storage and subsequently dispatched via logistics services arranged according to specific orders. We guarantee the safety of the entire transportation process, ensuring timely delivery to the client's designated location, with full assurance of both quality and quantity.

Raw Material Inspection

Finished Product Testing

Production

Raw Material Testing

Production Process

The entire process of food box production Production process of plastic bags
  • Relying on excellent product quality and attentive full-process service, it has built a good reputation in the industry and won wide recognition from new and existing customers.

  • Relying on excellent product quality and attentive full-process service, it has built a good reputation in the industry and won wide recognition from new and existing customers.

  • Relying on excellent product quality and attentive full-process service, it has built a good reputation in the industry and won wide recognition from new and existing customers.

  • Relying on excellent product quality and attentive full-process service, it has built a good reputation in the industry and won wide recognition from new and existing customers.

  • Relying on excellent product quality and attentive full-process service, it has built a good reputation in the industry and won wide recognition from new and existing customers.

  • Relying on excellent product quality and attentive full-process service, it has built a good reputation in the industry and won wide recognition from new and existing customers.

We look forward toworking with you.

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