Strict Internal Inspection Standards in Fondofold - Introduction of FRI & Inspection Procedure

In the bag production process, quality control is a very important link that runs through from raw material procurement to finished product delivery. Among the many quality control links, the Final Random Inspection (FRI) is undoubtedly a key step to ensure product quality, as it serves as the last line of defense to prevent unqualified products from flowing into the market. This article will introduce in detail the importance, inspection content, implementation methods and practical cases of the final random inspection in the production process of bags. Since Fondofold Bags has been a professional cooler bag manufacturer since 2007, with rich experience in producing high-quality cooler bags for global customers, we will take cooler bags inspection as a typical example to elaborate on our internal FRI standards, which are even stricter than the industry average.

1. Introduction of FRI

The Final Random Inspection (FRI) refers to the process of sampling a certain proportion of products from the entire batch before the products are packaged and ready to leave the factory, and conducting a comprehensive inspection in accordance with the preset standards to confirm the quality level of the entire batch of products. Unlike the in-process inspection which focuses on a single production link, FRI covers all key quality indicators of the finished products, which can effectively reflect the overall quality of the batch, avoid batch unqualified products due to process defects, raw material problems or operational errors, and protect the interests of customers and the brand reputation of Fondofold Bags.

In practice, we once found through FRI that a batch of 10,000 cooler bags had uneven stitching at the handle connection, which might lead to handle detachment during use. We immediately suspended the delivery, reworked all the unqualified products, and conducted a second FRI. Finally, all products met the standards before delivery, which avoided customer complaints and potential after-sales risks. This case fully demonstrates that FRI is an indispensable part of ensuring product quality.

2. Inspection Procedure

During the final random inspection process, the bags need to be comprehensively inspected from multiple dimensions to ensure that every detail meets the design requirements and quality standards. The specific inspection content is as follows, combined with practical examples-cooler bags to make it more intuitive:

1) Appearance Inspection

The appearance of cooler bags not only affects the aesthetic feeling but also reflects the production craftsmanship. The inspection focuses on the following aspects:

50. Check whether the appearance of the cooler bag is beautiful and generous, whether there are obvious stains, scratches, holes, wrinkles or color differences. For example, if the surface of the cooler bag has oil stains or dust that cannot be cleaned, or if the color of the front and back of the bag is inconsistent (such as the main body is dark blue but the side is light blue), it is judged as unqualified.
50. Check whether the seams are flat, uniform and firm, and whether there are skipped threads, broken threads, open threads, loose stitches or thread residue. The seam is the key part to ensure the durability of the cooler bag.
50. Check whether the zipper is smooth to pull, whether there is jamming, slipping or damage to the zipper teeth; check whether other accessories such as buttons, handles, shoulder straps and buckles are firmly installed, whether there is looseness, deformation or missing parts.

2) Size Inspection

The size of the cooler bag directly affect its use effect, so it is necessary to conduct accurate measurement and verification: Use professional measuring tools (such as tape measures with an error of no more than ±0.1cm) to measure the length, width and height of the cooler bag, and ensure that the deviation from the design size does not exceed ±1cm. For example, if the design size of a cooler bag is 30cm (length) × 20cm (width) × 25cm (height), the actual measured size must be between 29-31cm in length, 19-21cm in width and 24-26cm in height. If the size deviation is too large, it may lead to the cooler bag not being able to fit the predetermined items (such as a lunch box of fixed size).

3. Insulation Performance Inspection

Insulation performance is the core function of cooler bags, so it is the focus of FRI. The main inspection index is the insulation time, which is tested through professional experiments:

The test conditions are set according to the actual use scenario: put 2kg of ice cubes (0℃) into the cooler bag, close the zipper tightly, place it in a room with a temperature of 25℃ ± 2℃, and record the time when the ice cubes are completely melted. Our internal standard requires that the insulation time of ordinary cooler bags shall not be less than 6 hours, and the insulation time of high-end cooler bags shall not be less than 12 hours. For example, in a test of a batch of high-end cooler bags, we found that the ice cubes were completely melted after 11.5 hours, which did not meet the 12-hour standard, so we required the workshop to replace the insulation material and re-produce, and re-tested until it met the standard.

In addition, we also check whether the insulation layer is evenly distributed, whether there is hollowing or agglomeration, which will affect the insulation effect. For example, if the insulation layer at the corner of the cooler bag is hollow, the local insulation performance will be reduced, leading to uneven temperature inside the bag.

4. Material Inspection

The quality of the material directly determines the durability, environmental protection and safety of the cooler bag. The inspection covers internal and external materials and insulation materials:

50. Outer Materials: Check whether the internal and external materials meet the environmental

protection requirements (such as complying with EU REACH and US CA & FDA standards), whether there is any pungent odor, and whether the material is durable and wear-resistant. For example, the external material of the cooler bag is usually Oxford cloth or polyester cloth, which needs to be tested for wear resistance. The fabric weight and color are consistent with the customer’s requirements and the approved sample.

50. Insulation Material: Check the quality of the insulation material (such as EPE or foam), ensure that it is

clean, free of impurities, and has good thermal insulation performance. For example, if the pearl cotton used as insulation material has uneven thickness or holes, it will affect the insulation effect. Our standard requires that the thickness of the insulation material shall not be less than 5mm, and the density shall meet the design requirements.

50. Internal Materials: Checked whether the fabric weight and color are consistent with the customer’s

requirements and the approved sample.

5. Functional Inspection

In addition to the above inspections, the functional performance of the cooler bag also needs to be comprehensively tested to ensure that it can meet the actual use needs:

50. Waterproof Performance: Through the water spray test, spray water on the surface of the cooler bag at

a pressure of 0.1MPa for 30 minutes, and check whether there is water seepage inside the bag. Our standard requires that there shall be no obvious water seepage in the inner lining and seams. For example, if the seam of the cooler bag seeps water after the water spray test, it means that the waterproof treatment of the seam is not in place, and it needs to be re-waterproofed and re-inspected.

50. Durability: Simulate the actual use environment to test the durability of the cooler bag. For example,

load 5kg of items into the cooler bag, carry the handle and shake it 100 times, then check whether the handle is loose, the seam is cracked, and the zipper is damaged; or place the cooler bag on the ground and drag it 50 meters (on a smooth cement floor), check whether the surface material is worn. Our standard requires that after the durability test, the cooler bag shall not have obvious damage and can still be used normally.

50. Other Functional Inspections: For cooler bags with special functions (such as built-in pockets,

adjustable shoulder straps, or temperature display), check whether these functions can work normally.

6. Packaging Inspection

All packaging must be clean, undamaged, and correctly labeled. Carton size, quantity per carton, product labeling, shipping mark, and bar code must comply with customer requirements and approved samples. We check for proper sealing, secure packing, and accurate shipping information to ensure safe transportation and avoid damage or loss during delivery.