Production process of EVA first aid kit

Production process of EVA first aid kit

1. Preliminary preparation

1.1 Material selection and procurement
The production of EVA first aid kits has strict requirements on material selection, and the quality of materials directly affects the performance and service life of the product. In the procurement process, enterprises need to consider from multiple aspects.
Material performance: EVA material has good flexibility, waterproofness and antibacterial properties, making it an ideal choice for first aid kits. Its flexibility can ensure that the first aid kit can be used normally in various environments, its waterproofness can prevent internal items from being damaged by moisture, and its antibacterial property helps to maintain the hygiene inside the first aid kit. According to relevant industry standards, the flexibility of EVA materials should reach a certain tensile strength and elongation at break, for example, the tensile strength must be above 5MPa and the elongation at break must be above 300% to meet the use requirements of first aid kits.
Supplier selection: Selecting a reliable supplier is the key to ensuring material quality. Enterprises need to conduct strict evaluations of suppliers, including their production equipment, quality control system and supply capacity. By conducting comparative tests on products from multiple suppliers, such as testing the physical properties and chemical composition of the materials, ensure that the purchased EVA materials meet national and industry standards. For example, when a well-known first aid kit manufacturer selects an EVA material supplier, it will conduct a one-month performance test on the samples provided by the supplier, and only suppliers that pass the test can enter the procurement list.
Cost control: Under the premise of ensuring material quality, cost control is also an important part of material procurement. Enterprises need to conduct market research to understand the price levels of different suppliers and negotiate in combination with the purchase volume to obtain the most favorable price. At the same time, enterprises can also reduce procurement costs by optimizing the procurement process, reducing intermediate links. According to statistics, through effective cost control measures, enterprises can save 10% – 15% of costs in the material procurement link.
1.2 Fabric lining and EVA bonding
The bonding of fabric lining and EVA is a key step in the production process of EVA first aid kits, which determines the overall structure and appearance quality of the first aid kit.
Bonding process: At present, there are two common bonding processes: hot pressing bonding and glue bonding. Hot pressing bonding is to make the fabric, lining and EVA material tightly bonded through high temperature and pressure. The advantages of this method are firm bonding, not easy to fall off, and no chemical residue. Glue bonding requires the use of special environmentally friendly glue. Its advantage is that the glue formula can be adjusted according to different materials to achieve the best bonding effect. In actual production, companies will choose the appropriate bonding process according to the specific requirements of the product and the cost budget. For example, for high-end first aid kit products, hot pressing bonding process is usually used to ensure the quality and environmental protection of the product; while for some mid- and low-end products, glue bonding process is used to reduce costs.
Quality control: Quality control is crucial in the bonding process. Companies need to establish a strict quality inspection system and conduct random inspections on each batch of bonded products. The inspection content includes the firmness, flatness and appearance quality of the bonding. For example, the firmness of the bonding is tested by tensile testing to ensure that the fabric and EVA material will not separate under normal use conditions; the appearance quality of the first aid kit is guaranteed by flatness testing to avoid defects such as wrinkles and bubbles. According to industry standards, the firmness of the bonding should reach a certain tensile value, such as the tensile value per square centimeter must be above 10N, and the error range of flatness should be controlled within ±1mm.
Environmental protection requirements: With the enhancement of environmental awareness, the production of EVA first aid kits also needs to meet environmental protection requirements. In the bonding process, whether it is hot pressing bonding or glue bonding, it is necessary to ensure that the materials and processes used meet environmental protection standards. For example, the glue used for glue bonding must be environmentally friendly glue, and its harmful substance content must meet relevant national standards, such as formaldehyde content must be less than 0.1mg/g, and benzene content must be less than 0.05mg/g. Enterprises also need to properly handle waste in the production process to reduce the impact on the environment.

2. Cutting and molding

2.1 Cutting according to product size
Cutting is a crucial part of the EVA first aid kit production process, which is directly related to the dimensional accuracy and appearance quality of the product.
Cutting equipment: Advanced cutting equipment is the key to ensuring cutting accuracy. At present, the commonly used cutting equipment in the industry are CNC cutting machines and laser cutting machines. CNC cutting machines can accurately cut out the required shape and size according to the preset program, and its cutting accuracy can reach ±0.5mm. Laser cutting machines use laser beams for cutting, which not only has high cutting accuracy, but also can achieve complex pattern cutting, and its cutting accuracy can reach ±0.2mm. For example, a large first aid kit manufacturer uses laser cutting machines to meet its diverse product design needs while ensuring cutting quality.
Cutting process: During the cutting process, it is necessary to accurately cut out various components such as EVA materials, fabrics and linings according to product design drawings and size requirements. When cutting, ensure that the edges of the cut pieces are neat, burr-free, and the size is accurate. For complex cutting shapes, such as pockets, compartments and other parts of the first aid kit, special attention should be paid to the accuracy and consistency of cutting. For example, when cutting the main bag part of the first aid kit, the dimensional error of its length and width must be controlled within ±1mm to ensure that the subsequent molding process can proceed smoothly.
Quality inspection: The cut pieces need to undergo strict quality inspection. The inspection content includes the dimensional accuracy, shape integrity and surface quality of the cut pieces. By using professional measuring tools such as calipers and gauges, the size of the cut pieces is accurately measured to ensure that they meet the design requirements. At the same time, check whether there are scratches, breakages and other defects on the surface of the cut pieces. If there are unqualified cut pieces, they should be processed or replaced in time. According to statistics, in the quality inspection of the cutting link, the size unqualified rate should be controlled within 1%, and the surface defect rate should be controlled within 0.5% to ensure the overall quality of the product.
2.2 Hot pressing or cold pressing molding
The molding process is the key step to combine the cut parts into a complete first aid kit structure. Hot pressing and cold pressing are two common molding methods.
Hot pressing molding: Hot pressing molding is to bond the cut pieces together through high temperature and pressure to form a stable structure. During the hot pressing process, the temperature and pressure parameters need to be precisely controlled according to the characteristics of the material and the requirements of the product. For example, for EVA materials, the hot pressing temperature is generally controlled between 120℃ – 150℃, the pressure is between 5 – 10MPa, and the hot pressing time is 3 – 5 minutes. The advantages of this process are strong bonding and good molding effect, which can ensure the structural strength and durability of the first aid kit. After hot pressing, the tensile strength of the bonding part of the first aid kit should reach more than 15N/cm², and it can withstand various pulling and extrusion in normal use.
Cold pressing: Cold pressing is to bond the cut pieces together by pressure at room temperature. Compared with hot pressing, cold pressing does not require high-temperature equipment and has relatively low cost, but the bonding strength is relatively weak. During the cold pressing process, special adhesives are usually required to enhance the bonding effect. For example, the bonding strength of cold pressing with polymer adhesives can reach about 8N/cm². Cold pressing is suitable for some first aid kit products that do not require high structural strength, or when costs need to be saved during the production process.
Molding quality control: Whether hot pressing or cold pressing is used, strict quality inspection of the first aid kit after molding is required. The inspection contents include the firmness of the bonding parts, the stability of the overall structure, the appearance quality, etc. Through methods such as tensile testing and pressure testing, check whether the bonding parts are firm, whether there are degumming, cracking, etc. At the same time, check whether the overall appearance of the first aid kit is flat and beautiful, and whether the size meets the design requirements. According to industry standards, the bonding firmness of the first aid kit after molding should reach more than 90% of the design requirements, and the appearance quality defect rate should be controlled within 1% to ensure the product’s qualified rate and market competitiveness.

3. Sewing and assembly

3.1 Sewing molding
Sewing molding is an extremely critical link in the production of EVA first aid kits, and its quality directly affects the durability and functionality of the first aid kits.
Sewing equipment and technology: Modern sewing equipment, such as high-speed flat sewing machines and overlock sewing machines, is the basis for ensuring the quality of sewing. The sewing speed of high-speed flat sewing machines can reach more than 3,000 stitches per minute, which can efficiently complete the sewing work of the main part of the first aid kit and ensure the uniformity and firmness of the sewing stitches. The overlock sewing machine is mainly used to process the edge of the first aid kit to prevent the edges of the fabric and lining from loosening. The sewing quality directly affects the appearance and service life of the first aid kit. During the sewing process, it is necessary to select the appropriate stitch length and stitch according to the design requirements and material characteristics of the first aid kit. For example, for the main bag of the first aid kit, the stitch length is generally controlled at 10-12 stitches per inch, and the stitches are double-thread flat stitches to enhance the firmness of the sewing. For pockets and compartments of the first aid kit, the stitch length can be appropriately adjusted to 8-10 stitches per inch to ensure the flexibility and beauty of the sewing.
Quality control: The control of sewing quality is crucial. Enterprises need to establish a strict quality inspection system to conduct random inspections on each sewn first aid kit. The inspection content includes the firmness of the sewing, the uniformity of the stitches, and the appearance quality. For example, the firmness of the sewing is tested by tensile testing to ensure that the stitches will not break or derail under normal use conditions; visual inspection is used to ensure the uniformity and appearance quality of the stitches to avoid defects such as skipped stitches and broken threads. According to industry standards, the firmness of the sewing should reach a certain tensile value, such as the tensile value per square centimeter must be above 20N, and the uniformity error range of the stitching should be controlled within ±0.5mm. According to statistics, in the quality inspection of the sewing link, the unqualified rate of sewing firmness should be controlled within 0.5%, and the unqualified rate of stitching uniformity should be controlled within 1% to ensure the overall quality of the product.
3.2 Edge treatment
Edge treatment is a key step in improving the aesthetics and durability of the first aid kit production. It can effectively protect the edge of the first aid kit and prevent wear and looseness.
Edge material and process: The edge material is usually selected from fabrics or special edge tapes that match the main material of the first aid kit to ensure the overall aesthetics and coordination. The edge process includes manual edge and mechanical edge. Manual edge can provide higher flexibility and fineness, and is suitable for some high-end first aid kit products or edge treatments with complex designs. Mechanical edge has higher efficiency and consistency, and is suitable for large-scale production. During the hemming process, it is necessary to ensure that the hemming material fits tightly to the main body of the first aid kit without wrinkles and bubbles. For example, for the opening part of the first aid kit, the hemming width is generally controlled between 5-10mm to ensure a balance between beauty and practicality. The hemming stitching needs to use a strong stitch, such as double-thread flat seam or triple-thread overlock seam, to enhance the durability of the hemming.
Quality inspection: Quality inspection after hemming is equally important. The inspection content includes the firmness, flatness and appearance quality of the hemming. The firmness of the hemming is tested by tensile testing to ensure that it will not loosen or wear during normal use; the appearance quality of the hemming is guaranteed by flatness testing to avoid wrinkles and unevenness. According to industry standards, the firmness of the hemming should reach a certain tensile value, such as the tensile value per square centimeter must be above 15N, and the error range of flatness should be controlled within ±0.5mm. According to statistics, in the quality inspection of the edging process, the unqualified rate of edging firmness should be controlled within 0.5%, and the unqualified rate of flatness should be controlled within 1%, so as to ensure the overall quality and market competitiveness of the product.

4. Internal filling and accessories installation

4.1 Loading first aid supplies
The first aid supplies filled inside the first aid kit are the embodiment of its core function, and the process of loading these supplies needs to be carried out strictly in accordance with standards and specifications.
Types and specifications of first aid supplies: Common first aid supplies include Band-Aids, gauze, bandages, sterilized cotton balls, tourniquets, tweezers, scissors, medical tape, etc. The specifications and quantities of these supplies should be determined according to the purpose and usage scenarios of the first aid kit. For example, a standard home first aid kit usually comes with 10 Band-Aids, 5 gauze, 2 rolls of bandages, 10 sterilized cotton balls, 1 tourniquet, 1 pair of tweezers, 1 pair of scissors and 1 roll of medical tape. For first aid kits for outdoor adventures or professional medical purposes, the types and quantities of first aid supplies will be more, and some special first aid equipment will be included, such as portable oxygen cylinders, multi-functional first aid pliers, etc.
Loading process and quality control: When loading first aid supplies, first ensure that the quality of all supplies is qualified and meets national medical device standards. During the loading process, various supplies should be neatly placed in various compartments and pockets of the first aid kit in a certain order and layout, so that they can be quickly taken when used. For example, small items such as band-aids and disinfected cotton balls should be placed in the small inner pocket of the first aid kit for quick access; larger items such as gauze and bandages should be placed in the main bag to ensure that they are fixed and do not take up too much space. After loading, a quality inspection is required to ensure that all supplies are placed correctly and that the zippers and buckles of the first aid kit can be opened and closed normally without affecting the access to first aid supplies. According to statistics, through strict quality control, the qualified rate of first aid supplies should reach more than 99% to ensure that the first aid kit can be used normally in an emergency.
4.2 Installing accessories such as zippers and buckles
The installation of accessories such as zippers and buckles not only affects the appearance of the first aid kit, but more importantly, it affects its use function and sealing.
Selection and quality requirements of accessories: Zippers should be made of high-quality nylon or metal zippers with good smoothness and durability. Buckles include snaps, magnetic buckles, nylon buckles and other types. Choose the right buckle according to the design of the first aid kit. For example, for first aid kits that need to be opened and closed frequently, metal zippers are more durable and smooth; while for some small first aid kits, nylon buckles are more convenient and quick. The quality of accessories directly affects the service life and sealing of the first aid kit, so it is necessary to ensure that its quality meets the relevant standards. For example, the pulling strength of the zipper should meet certain standards, such as the tension value per square centimeter must be above 10N, and the fastening strength of the buckle should also meet the corresponding standards, such as the fastening strength of the snap buckle must be above 5N.
Installation process and quality inspection: When installing the zipper, ensure that the zipper is firmly sewn and tightly combined with the fabric of the first aid kit to avoid loosening or falling off. When installing the buckle, ensure that the buckle is accurately positioned, tightly fastened, and easy to operate. After installation, the accessories need to be strictly inspected for quality. The inspection content includes the smoothness of the zipper, the fastening strength of the buckle and the flexibility of operation. For example, the smoothness of the zipper is tested by repeatedly closing and zipping it to ensure that it will not get stuck or damaged during normal use; the firmness and flexibility of the buckle are tested by repeatedly closing and unclipping it to ensure that the first aid kit can be quickly opened or closed in an emergency. According to industry standards, the smoothness of the zipper should reach more than 95%, and the fastening firmness and operational flexibility of the buckle should reach more than 98% to ensure the normal use and sealing of the first aid kit.

5. Quality inspection

5.1 Check appearance and size
The inspection of appearance and size is the basic link of the quality inspection of EVA first aid kits, which directly affects the market acceptance and user experience of the product.
Appearance inspection: The appearance inspection focuses on the surface quality, color uniformity, pattern clarity and overall aesthetics of the first aid kit. The surface of the first aid kit should be free of obvious flaws, scratches, stains or damage, and the pattern should be clear and accurate without fading or blurring. For example, for first aid kits with brand logos or first aid signs, the printing quality of the logo is particularly important, and its clarity and durability should reach more than 95%. In addition, the overall shape of the first aid kit should be regular, without deformation or distortion, to ensure its convenience and practicality during use.
Dimension measurement: Dimension measurement is a key step to ensure that the first aid kit meets the design requirements and usage standards. Use professional measuring tools, such as tape measures, calipers, etc., to accurately measure the key dimensions of the first aid kit, such as length, width, and height. According to industry standards, the dimensional error of the first aid kit should be controlled within ±2mm. For example, for a standard home first aid kit, the design size is 300mm×200mm×100mm, and the actual measured size should be within the range of 298mm-302mm, 198mm-202mm, and 98mm-102mm. Through strict dimensional measurement, ensure that the first aid kit can adapt to various usage scenarios and storage spaces, while ensuring the rationality and functionality of its internal structure.
5.2 Inspection of the quality of first aid supplies
First aid supplies are the core functional components of the EVA first aid kit, and their quality is directly related to the effectiveness and reliability of the first aid kit in emergency situations.
Integrity of first aid supplies: When inspecting the quality of first aid supplies, first ensure that all kinds of supplies in the first aid kit are complete and meet the specifications. According to the design purpose and standard configuration of the first aid kit, check the types, quantities and specifications of the first aid supplies one by one. For example, an outdoor first aid kit should be equipped with at least 15 kinds of first aid supplies, including Band-Aids, gauze, bandages, sterilized cotton balls, tourniquets, tweezers, scissors, medical tape, etc. The quantity and specifications of each item should meet the requirements of the product manual. According to statistics, during the quality inspection process, the integrity inspection pass rate of first aid supplies should reach more than 99% to ensure that the first aid kit can provide comprehensive first aid support in an emergency.
Effectiveness of first aid supplies: In addition to checking the integrity of first aid supplies, it is also necessary to inspect their effectiveness and safety. For pharmaceutical first aid supplies, such as sterilized cotton balls, Band-Aids, etc., it is necessary to check their production date, expiration date and packaging integrity to ensure that they are within the validity period and not contaminated. For instrument first aid supplies, such as tweezers, scissors, etc., it is necessary to check their sharpness, cleanliness and disinfection to ensure that they can be used normally and will not cause secondary harm to the user. For example, the bacteria content of disinfected cotton balls should be lower than the national standard, and the stickiness of band-aids should meet certain standards and be able to fit the wound firmly. Through strict inspection, we ensure that first aid supplies can play their due role in emergency situations and provide users with timely and effective first aid support.

6. Packaging and Storage

6.1 Single Product Packaging
The packaging of a single EVA first aid kit is an important part of ensuring the integrity and cleanliness of the product during transportation and sales.
Packaging material selection: Usually waterproof, dustproof and strong packaging materials such as polyethylene film or composite wrapping paper are used. These materials can effectively protect the first aid kit from the influence of the external environment and ensure that the first aid supplies inside remain in good condition during the shelf life. For example, the waterproof performance of polyethylene film can reach IPX7 level, which can prevent moisture penetration and protect the dryness of the first aid kit inside.
Packaging method: A common packaging method is to put a single first aid kit into a plastic bag or paper box and then seal it. Plastic bag packaging has the advantages of low cost and easy operation, which is suitable for mid- and low-end products; paper box packaging is more beautiful and environmentally friendly, suitable for high-end products. During the packaging process, it is necessary to ensure that the packaging is tight to prevent the first aid kit from shaking inside the packaging, and at the same time ensure the sealing of the packaging to prevent air and dust from entering. According to statistics, the use of appropriate packaging methods can reduce the damage rate of first aid kits during transportation to less than 0.1%.
Labels and logos: The relevant information of the product needs to be clearly marked on the packaging, such as product name, specification model, production date, expiration date, manufacturer, instructions for use, precautions, etc. This information is crucial for consumers to use the first aid kit correctly. The printing quality of the label should meet certain standards, such as clear text, accurate pattern, bright color and not easy to fade. For example, the printing resolution of the label should not be less than 300dpi to ensure the readability and aesthetics of the information.
6.2 Overall packing and warehousing
Overall packing and warehousing is the last step in the production process of EVA first aid kits, which is directly related to the warehousing management and logistics distribution efficiency of the product.
Packing standard: According to the specifications and quantity of the product, choose a suitable carton for packing. The size and strength of the carton should meet the requirements of transportation and warehousing, while ensuring the compactness and stability of the packing. For example, for a standard size home first aid kit, usually 50 pieces per box, the size of the carton is 500mm×300mm×400mm, and the compressive strength of the carton should reach more than 500kg to ensure that it will not be damaged during stacking and transportation.
Packing process: When packing, the individually packaged first aid kits should be neatly placed in the carton in a certain order and direction to avoid gaps and looseness. An appropriate amount of filler, such as foam board or bubble film, can be placed in the carton to further protect the product. After packing, the carton should be sealed and the product information, quantity, batch and other labels should be marked on the surface of the carton to facilitate warehouse management and logistics distribution. According to statistics, a reasonable packing method can increase the utilization rate of storage space by 20% – 30%, while reducing the damage rate in logistics transportation.
Storage conditions: The storage environment of the first aid kit has an important impact on its quality and validity period. The storage warehouse should be kept dry, ventilated and clean, with the temperature controlled between 10℃ – 30℃ and the relative humidity not exceeding 60%. These conditions can effectively prevent the medicines and equipment in the first aid kit from getting damp, deteriorating or damaged. For example, for some first aid kits containing medicines, if the storage environment humidity exceeds 70%, the active ingredients of the medicines may decompose, causing the first aid kit to fail. Regular monitoring and maintenance of the storage environment to ensure that it meets the standard requirements is an important measure to ensure the quality of first aid kits.

7. Summary
The production process of EVA first aid kits is a complex and delicate process, covering multiple links from material selection to final packaging and storage, and each link has a vital impact on the quality and performance of the product.
In the material selection and procurement stage, strictly control the material performance indicators, such as flexibility, waterproofness and antibacterial properties, to ensure that EVA materials meet national and industry standards. At the same time, optimize the procurement process to reduce costs and lay the foundation for subsequent production. The choice of lamination process between fabric lining and EVA directly affects the structure and appearance quality of the first aid kit. Hot pressing lamination and glue lamination have their own advantages and disadvantages. Enterprises need to make choices based on product positioning and cost budget, and strictly control the lamination quality to ensure that environmental protection requirements are met.
The cutting and molding links determine the dimensional accuracy and appearance quality of the first aid kit. Advanced cutting equipment such as laser cutting machines can achieve high-precision cutting to meet complex design requirements. At the same time, strict quality inspections ensure that the size and surface quality of the cut pieces meet the requirements. Hot pressing and cold pressing processes have their own characteristics. Hot pressing has strong adhesion and is suitable for products with high requirements for structural strength, while cold pressing has low cost and is suitable for some mid- and low-end products. The quality inspection after molding further ensures the structural stability and appearance quality of the product.
Sewing and assembly are the key to the production of first aid kits. Modern sewing equipment and strict quality control system ensure the firmness of sewing and the uniformity of stitches. The hemming treatment improves the beauty and durability of the product. Through precise process control and quality inspection, the unqualified rate is effectively reduced, ensuring the overall quality of the product.
Internal filling and accessory installation are directly related to the functionality and practicality of the first aid kit. First aid supplies are loaded in strict accordance with standards and specifications to ensure that their types, specifications and quantities meet the requirements. At the same time, accessories such as zippers and buckles are selected and installed with high quality, and strict quality inspection is carried out to ensure the normal use and sealing of the first aid kit.
The quality inspection link is the last line of defense to ensure product quality. From the inspection of appearance and size to the inspection of the quality of first aid supplies, every detail cannot be ignored. Through precise size measurement, appearance inspection, and strict inspection of the integrity and effectiveness of first aid supplies, the first aid kit can be ensured to function reliably in an emergency.
Finally, the packaging and storage links provide protection for the first aid kit during transportation and sales. Appropriate packaging materials and methods effectively reduce the transportation damage rate, clear labels and logos provide consumers with accurate product information, and reasonable packaging and warehousing and strict storage conditions further guarantee the quality and validity of the first aid kit.
In summary, the production process of EVA first aid kits is an interlocking and refined management process, and the quality control of each link is directly related to the final quality and market competitiveness of the product. By continuously optimizing the production process and improving the quality control level, the company can produce high-quality and high-performance EVA first aid kits to meet the first aid needs in different scenarios and provide reliable protection for people’s life and health.