I. Structure and Principle: A Scientific Multi-Layer Moisture-Proof Protection System

**Sturdy Support of the Substrate Layer**

The base layer of the moisture-proof aluminized woven bag uses polypropylene or polyethylene woven fabric. This structure, formed by the interlacing of plastic flat yarns, gives the packaging bag excellent mechanical strength. The density and thickness of the woven fabric can be adjusted according to the weight of the packaged goods and transportation requirements, ensuring structural integrity even when bearing 25-50 kg of contents. The surface of the woven layer undergoes a special corona treatment, increasing its bonding strength with the functional layers and laying a solid foundation for subsequent composite processes.

**Core Barrier of the Functional Layer**

An aluminum layer deposited on the woven substrate using vacuum coating technology constitutes the core of the moisture-proof function. This extremely thin metal coating forms a continuous and dense barrier network, effectively blocking water molecules from passing through. The thickness of the aluminum layer is precisely calculated to ensure barrier effectiveness while also considering the material's flexibility and economy. Test data shows that a high-quality aluminized layer can control water vapor transmission rate below 1.0 g/m²·24h, meaning that under standard environmental conditions, no more than 1 gram of moisture per square meter of packaging material per day will permeate.

Precision Protection of the Sealing Layer

The inner heat-sealing film is typically made of cast polyethylene or co-extruded polypropylene. This film has a low heat-sealing temperature range and a wide heat-sealing window, facilitating the formation of a uniform and robust seal during production. The specially formulated heat-sealing material also exhibits excellent anti-contamination properties, ensuring reliable sealing quality even when packaging products containing trace amounts of grease or dust. The surface friction coefficient of the inner layer material is optimized, facilitating filling operations and preventing slippage during use.

II. Performance Characteristics: A Comprehensive Embodiment of Protection

Moisture-proof Performance

A significant feature of moisture-proof aluminized Woven Bags is their excellent moisture-proof capability. Even in environments with a relative humidity of 90%, the interior of the packaging remains dry. This characteristic makes them particularly suitable for use in humid climates or maritime environments. Accelerated aging tests have verified that this type of packaging, under standard storage conditions, ensures that the contents are unaffected by moisture for 12-24 months.

Good Physical Strength

Thanks to the structural characteristics of the woven substrate, this packaging bag exhibits excellent tensile strength and puncture resistance. In tests simulating transportation environments, fully loaded bags remained intact after three free-fall drops from a height of 1.2 meters. Its edge crush strength and puncture strength reach over 80N/5cm and 8J respectively, sufficient to withstand various challenges in normal logistics environments.

Multi-functional Protective Effect

In addition to the primary moisture-proof function, the aluminum plating layer provides additional protective properties. Its light reflectivity reaches over 85%, effectively preventing quality changes in the contents due to light exposure. Simultaneously, the presence of the aluminum layer enhances the airtightness of the packaging and, to some extent, delays oxidation reactions. These comprehensive protective effects make it suitable for products with high requirements for storage environments.

III. Manufacturing Process: Quality Assurance Through Precision Manufacturing

Substrate Pre-treatment Process

During the production process, the woven fabric first undergoes rigorous cleaning and surface treatment. Corona treatment ensures the surface tension of the woven fabric reaches over 38 dyn/cm, guaranteeing a strong bond with the functional layer. The pre-treated substrate immediately proceeds to the next process to avoid affecting the treatment effect due to prolonged storage.

Precision Coating Process

Vacuum metallization is a crucial step in the production process. In highly automated coating equipment, aluminum wire evaporates under high temperature and vacuum, and metallic aluminum atoms are uniformly deposited as gas on the substrate surface. This process requires precise control of vacuum level, evaporation temperature, and deposition rate to ensure the uniformity and density of the metallized layer. An online detection system monitors the thickness and uniformity of the metallized layer in real time to ensure consistent quality across batches.

Lamination and Curing Process

The metallized substrate and the inner film are bonded together through an extrusion lamination process. In this process, molten polyethylene acts as an adhesive layer, firmly bonding the two materials. The laminated materials require curing treatment to fully solidify the adhesive and achieve the desired composite strength. Precise control of temperature, pressure, and speed parameters throughout the process is crucial to ensuring the quality of the lamination.

IV. Application Areas: Widely Applicable Protective Solutions

Chemical Industry Applications

In the field of chemical product packaging, moisture-proof aluminized woven bags demonstrate unique value. Chemical raw materials such as plastic granules, fertilizers, and industrial salt are extremely sensitive to humidity; this type of packaging effectively prevents product clumping and spoilage. Practical applications show that chemical products packaged in Moisture-proof aluminized woven bags maintain good flowability and performance even after long-distance sea transport.

Food and Feed Packaging

Feed, grains, and their processed products have particularly stringent moisture-proof requirements. Moisture-proof aluminized woven bags not only prevent external moisture from entering but also retain the original moisture content of the contents, preventing drying and cracking. In storage environments with relatively high humidity, this packaging effectively inhibits mold growth and extends the product's shelf life. An increasing number of feed production companies are using it as standard packaging for their export products.