Understanding SOM PP Fabric Bags and Quality Control in Raw Materials

Sewn Open Mouth (SOM) PP Fabric Bags are a popular and versatile packaging solution used in various industries, particularly in agriculture, construction, and food products. These bags are known for their durability, cost-efficiency, and wide-ranging applications. However, the performance of SOM bags heavily depends on the quality of the raw materials used in their production. Maintaining strict quality control from raw material procurement through to storage is critical to ensuring the bags meet industry standards.

This blog will delve into the details of SOM PP Fabric Bags and explain how raw material quality control plays an essential role in their production. Additionally, we will discuss the process of selecting and testing high-grade raw materials like polypropylene (PP) and polyethylene (PE) plastic granules to ensure optimal bag performance.

What Are SOM PP Fabric Bags?

Sewn Open Mouth (SOM) Bags are a type of packaging bag made from polypropylene (PP) woven fabric. As the name suggests, they are sewn at one end and have an open mouth for filling, making them an ideal choice for packing granular or powdery products like rice, flour, fertilizers, and other bulk materials.

Key features of SOM Bags include:

• Strength and Durability: SOM Bags are designed to handle heavy loads, providing excellent strength to resist tearing and punctures.
• Cost-Effectiveness: Polypropylene material offers a cost-efficient solution for producing high-strength bags.
• Customizability: They can be customized in terms of size, color, and printing, which is beneficial for branding and meeting specific customer requirements.

Common Applications of SOM Bags

SOM PP fabric bags are used for packing a variety of products across different industries, such as:

• Agricultural Products: Seeds, grains, flour, and fertilizers.
• Construction Materials: Cement, sand, and gravel.
• Food Products: Rice, sugar, and flour.
• Chemical Products: Powdered or granular chemicals.

These versatile applications make SOM bags a widely-used packaging solution across multiple sectors.

The Role of Raw Materials in SOM Bag Quality

The quality of SOM PP fabric bags is primarily determined by the raw materials used in their production. Polypropylene (PP) and polyethylene (PE) plastic granules are the core components in manufacturing woven bags, and the properties of these materials directly influence the durability, flexibility, and tensile strength of the finished product.

Key Raw Materials for SOM Bags:

• Polypropylene (PP): The most commonly used polymer for woven bags, providing high tensile strength, durability, and flexibility.
• Polyethylene (PE): Often used in conjunction with PP, PE can be applied as a liner or for lamination, improving moisture resistance and enhancing the structural integrity of the bags.

To maintain consistent product quality, manufacturers must establish strict controls over the procurement, storage, and testing of these raw materials.

Quality Control in Raw Material Procurement

The procurement process is where quality control begins. It involves selecting reliable suppliers and ensuring that each batch of raw materials meets predefined specifications. The following steps are essential in this phase:

1. Supplier Selection and Evaluation

Choosing the right suppliers is a critical first step. Woven bag manufacturers often prioritize suppliers that provide high-grade, virgin polypropylene and polyethylene granules. These suppliers must demonstrate a proven track record of delivering consistent and reliable raw materials.

2. Batch Testing of Raw Materials

Once the materials are received, they undergo rigorous testing to confirm their quality. The following aspects are typically examined:

• Mechanical Properties: Tensile strength, elongation, and modulus are tested to ensure that the materials meet the mechanical requirements for producing durable SOM bags.
• Consistency and Purity: The raw materials must be free from contaminants, impurities, or recycled materials that could compromise the performance of the bags.
• Melt Flow Index (MFI): This test determines how easily the material flows during the production process, which influences the ease of weaving and extrusion.

3. Incoming Material Inspection

To maintain consistent quality, every batch of incoming material is inspected and tested. This ensures that no defective or substandard materials enter the production process. Detailed records are kept for traceability, which allows manufacturers to track any quality issues back to the specific batch of raw materials.

Test	Purpose	Standard
Tensile Strength Test	Ensures the material’s resistance to breakage	ASTM D5034
Melt Flow Index (MFI) Test	Determines material flow during processing	ASTM D1238
Density Test	Verifies the material’s density and consistency	ISO 1183
Purity Test	Ensures the material is free from contaminants	Visual and chemical examination

Quality Control During Storage

Proper storage of raw materials is equally important to maintain their quality over time. If not stored correctly, raw materials like PP and PE can degrade due to exposure to UV rays, moisture, and high temperatures.

1. Environmental Controls

The storage environment plays a vital role in preserving the quality of raw materials. Polypropylene and polyethylene granules must be stored in a dry, cool, and shaded environment to prevent degradation. Humidity and temperature levels should be monitored to ensure they remain within the recommended ranges.

• Temperature: PP and PE granules should be stored at temperatures between 20°C and 25°C to avoid thermal degradation.
• Humidity: High humidity can cause moisture absorption, which negatively impacts the extrusion and weaving process. The storage area should maintain a humidity level below 50%.

2. Inventory Management

To minimize the risk of contamination or degradation, manufacturers use a first-in, first-out (FIFO) system for managing inventory. This ensures that older material batches are used before newer ones, reducing the chances of material deterioration due to prolonged storage.

3. Protection from Contamination

Raw materials are often stored in sealed, labeled containers to prevent contamination. Proper labeling also helps in traceability, enabling manufacturers to trace any production issues back to a specific batch of raw material.

Production of SOM PP Fabric Bags

Once the raw materials pass the quality control checks, they move on to the production process. The manufacturing of SOM PP fabric bags involves several stages, from the extrusion of PP threads to the weaving and sewing of the bags.

1. Extrusion Process

In this step, the polypropylene granules are melted and extruded into fine threads, which will be used for weaving the fabric. Consistency in thread diameter is critical for ensuring uniform strength and durability throughout the bag.

2. Weaving

The extruded threads are woven into fabric sheets using high-precision machines. The tightness of the weave is an essential factor, as it influences the bag’s resistance to tears and punctures.

3. Sewing and Assembly

The woven fabric sheets are cut to the desired size and sewn into the final bag shape. For SOM bags, the bottom is typically sewn shut, leaving the top open for filling.

Customization Options for SOM PP Fabric Bags

SOM PP fabric bags can be customized in various ways to meet specific customer needs. Some of the most common customization options include:

• Size and Capacity: Customizing the dimensions of the bag allows manufacturers to create bags for different applications, from small packages to bulk containers.
• Thickness: Adjusting the thickness of the fabric increases or decreases the bag’s load-bearing capacity.
• Printing and Branding: SOM bags can be printed with custom logos and text, which is particularly useful for branding and identification.
• Lamination: Adding a laminated layer can provide extra protection from moisture and UV exposure, making the bags more suitable for outdoor storage.

Benefits of Using High-Quality Raw Materials

Maintaining strict quality control over raw materials offers several advantages:

• Increased Durability: High-grade PP and PE ensure that the bags can withstand heavy loads and rough handling.
• Consistency: Regular testing and monitoring ensure consistent product quality across different batches, reducing defects.
• Customer Satisfaction: Meeting quality standards ensures that customers receive reliable and durable products, which can enhance brand reputation.

Conclusion

SOM PP fabric bags are a versatile and durable packaging solution, and their quality is closely linked to the raw materials used in their production. From sourcing high-quality polypropylene and polyethylene granules to rigorous quality control during storage and production, woven bag manufacturers must take every step to ensure product performance. By implementing strict testing and storage protocols, manufacturers can guarantee that their SOM bags meet the demands of various industries, from agriculture to construction.

Sewn Open Mouth Woven Bags offer not only strength and durability but also customization options that allow them to meet a wide range of applications. Through a rigorous quality control process, woven bag manufacturers can maintain high standards and produce SOM bags that offer excellent performance and longevity.