An EVA case serves as a widely used protective shell, known for its high performance. Crafted from EVA (ethylene-vinyl acetate copolymer) material, these cases are light, durable, and waterproof, making them ideal for protecting various items. Whether safeguarding electronics, medical devices, or outdoor sports equipment, EVA cases are indispensable across multiple industries.
As market demand for EVA cases continues to grow, their production has evolved into a highly industrialized and standardized process. Understanding how these cases are made not only helps consumers make informed choices but also showcases our production capabilities and technical expertise as a leading manufacturer.
In this article, we will delve into the detailed industrial production process of EVA cases, covering every critical step—from material selection and mold making to the final product packaging—giving you a thorough insight into how EVA cases are made.
EVA (ethylene-vinyl acetate copolymer) is a polymer created by combining ethylene and vinyl acetate monomers. This material is highly valued for its excellent physical properties and versatility. It offers superb flexibility, elasticity, durability, and waterproof qualities.
Additionally, the low density of EVA makes it easy to hot-press into various shapes and sizes, meeting diverse design needs.
Importantly, EVA is non-toxic and meets all environmental protection standards, making it a safe, eco-friendly choice.
Consumer Electronic Case
These attributes make EVA fabric a popular material for manufacturing protective cases for electronics, medical equipment, and outdoor gear.
*EVA case internal structure map shows it could customized any size.
Before starting EVA case production, manufacturers must undertake several pre-production steps. These preparations primarily involve designing and creating molds, as well as gathering the necessary raw materials for production.
When a company plans to develop a new EVA case style or customize one for a client, the design process must begin well in advance.
For instance, in the case of customer customization, the design process typically follows three main steps:
*Designer is drawing EVA case sample drawings.
Many customers prefer to work with a familiar design company to finalize their design ideas before approaching the supplier.
Once they have the design drawings, they can discuss them with the supplier, adjusting or eliminating design elements that might significantly increase production costs.
This approach streamlines the design process, making it more efficient. Given that cross-border communication can still pose challenges for many Chinese suppliers, face-to-face meetings and ongoing collaboration are often necessary to address complex design issues effectively.
Mold-making is a crucial step in the mass production of EVA cases. A well-crafted mold is essential for accurately reflecting the design, ensuring production efficiency, and controlling the defect rate. The quality of the mold depends on both the material and its precision.
*Cutting EVA case mold with CNC machine
Producing an EVA case involves coordinating various materials, with the most critical being the pre-preparation of EVA materials and essential accessories.
*Cutting EVA material into small pieces suitable for the mold size
*Workers select zippers and other necessary accessories such as lining material.
Once the mold design and production are finalized, and a suitable sample is made, it’s time to acquire the necessary materials for bulk production. This ensures that the EVA case manufacturing process runs smoothly and efficiently, ultimately saving time in the overall production process.
The compression molding process involves reshaping EVA materials under high temperature and pressure using hot compression molding technology. This technique shapes the material into the desired structure, and the process includes three key steps: preparation, molding, and cooling.
As can be seen from the above, the heating, pressurization, and cooling time of EVA materials are not fixed, because the EVA material itself has different hardness, and the final molded EVA shape is also different. Different product thicknesses have different requirements for heating time and cold cutting time. Whether to use natural cooling or water cooling is generally determined by the project schedule and budget. In normal production, natural cooling occupies the mainstream, and water cooling is relatively rare.
*Demolding and trimming the EVA case hot compression molding process
After demolding, each batch of hot-pressed molded products undergoes a preliminary quality inspection. This inspection includes:
These steps convert EVA materials into semi-finished products with specific shapes and functions, ready for the next stages of assembly and processing. This inspection is especially critical during the sampling stage or the first production batch. If the initial inspection reveals flaws, it indicates issues with the mold production or EVA materials, requiring a halt in production to revisit the mold or material selection.
*Quality inspection after demolding of EVA case.
Once the molding process is finished, the different parts of the EVA case are assembled and processed to create the final product. Most of this work is done manually using industrial sewing machines. This includes tasks such as shell splicing, installing the internal structure, and adding functional accessories.
In some EVA cases, different parts need to be spliced together. The first step is to position each molded part according to the design drawing, ensuring all parts are correctly aligned. Then, high-frequency welding or adhesive is used to securely join the parts, ensuring the shell's integrity and strength.
When it comes to shell selection, the most common materials are synthetic PU or high-strength nylon fabric. For instance, EVA combined with PU leather is a popular choice:
*EVA case shell selection
Choose appropriate lining materials, such as flannel, foam, etc., according to the purpose of the EVA Case. The lining material should have good protection and comfort.
First, cut the lining material into a shape that matches the internal size of the EVA Case, and then use adhesive or sewing technology to fix it inside the shell to ensure that the lining fits tightly.
There are three main choices for common linings:
The biggest advantage of this lining is Luxury & Soft case
Velvet is a short pile fabric. Its features are strong adhesion, a soft and fluffy surface made of short-cut yarn that is very soft and smooth to the touch. Soft wool protects products from scratches and damage. It is mostly used in the foam lining of custom shockproof EVA cases.
Common application areas: Such as jewelry case, precious equipment case, etc.
Features: Flexible & Adaptable
Spandex is a highly elastic synthetic fiber, so it has unique elastic properties. Similar to polyester fiber wrinkle resistance and stain resistance, smooth, and wrinkle-free. Spandex is good in quality, light in weight, flexible and adaptable, and low in price.
Common application areas: electronic product cases, photography case, etc.
Advantages:
Shockproof & Soundproof
Wave peak sound-absorbing sponge is a kind of sponge that has been specially processed by the equipment to form a concave-convex wave shape. It is filled with small voids and semi-open structures that absorb sound, shock, and moisture.
Common application areas: electronic product cases, equipment cases, gun cases, etc.
The most important component of the EVA case is the zipper. EVA Zipper Case is the most common and classic type of EVA Case. The zipper design provides convenience for users to quickly open and close the EVA case. Below we take the production process of the common EVA Zipper Case as an example to show the selection and installation of zippers, zipper fixing and testing, and other functional accessories such as handles and shoulder straps.
Zipper is generally made of high-quality and durable materials, usually made of nylon or metal, with good durability and certain waterproofness. When installing, according to the size and design requirements of EVA Case, first cut the zipper into a suitable length, and then sew it at the opening of EVA Case. After the zipper is installed, fix the two ends of the zipper, usually by sewing or gluing, to ensure that the zipper is tightly connected to the shell to avoid loosening or falling off.
Generally, after the installation is completed, the zipper needs to be opened and closed several times immediately to check the smoothness and durability of the zipper.
*Four kind zipper selection for EVA case
In addition to zippers, EVA Case can also add other functional accessories such as handles, shoulder straps, etc. according to specific needs to improve the portability and practicality of the product.
Choose durable handle materials, such as nylon belts or rubber materials, fix the handles on the side or top of the EVA Case, and fix them by sewing or fixing screws.
*Four normal handle selection of EVA case
According to the design requirements of the EVA Case, shoulder straps are installed on both sides to provide carrying function. The shoulder straps are usually designed with adjustable length to meet the needs of different users in different usage scenarios. By adding these functional accessories, the practicality and portability of EVA Case are further improved to meet the needs of users in different scenarios. In the next section, we will introduce the packaging and shipping process of EVA Case in detail.
*Sewing shoulder straps on EVA case
Choosing a suitable logo can not only improve the brand recognition of the product, but also enhance its market competitiveness. There are many ways to add a logo. In the process of OEM EVA case, you can choose an economical and reasonable way to add a logo according to the material of the product and the pursuit of quality.
Common ways to add a logo include screen printing, embroidery, heat transfer, embossing, embossing, rubber label, metal label, woven label and washing label.
*Nine normal logo option for EVA case
*EVA cases silk screen printing process.
2. Embroidery is a process of sewing stitches to form patterns, which is suitable for EVA cases covered with fabric. The embroidery pattern has a strong three-dimensional sense, looks high-end, and is highly durable and not easy to fade or wear. However, its cost is high, especially for embroidery of complex patterns, and it is mainly suitable for cloth or fabric surfaces.
*Embroidery on EVA case surface
3. Heat transfer printing transfers the pattern from the transfer paper to the surface of the EVA material through heat pressing. It can achieve delicate patterns and gradient color effects, and the pattern has strong adhesion and is not easy to fall off. However, the initial mold cost of heat transfer is high, the process flow is complex, and the equipment requirements are high.
*EVA case heat transfer printing process
4. Debossing is to press the pattern on the mold onto the EVA surface under high temperature and pressure to form a concave effect. Debossing can present a high-end three-dimensional effect, and the pattern is wear-resistant, but the design is limited by the complexity of the mold, and the initial mold production cost is high.
*Deboss logo on EVA case surface form a concave effect.
5. Embossing is similar to debossing, but the pattern is raised to form a relief effect. The advantage of embossing is that the raised pattern has a strong three-dimensional sense and the pattern is not easy to wear. However, the mold-making cost of this process is high, and complex designs are difficult to achieve.
*Embossed logo on EVA case surface form a relief effect.
6. Rubber Label is a rubber logo attached to the EVA case by pasting or sewing. Rubber labels are durable, not easy to wear, waterproof, and have outstanding visual effects. However, their production and installation costs are high and may increase the weight of the product.
*Rubber label logo on EVA case with outstanding visual effects.
7. Metal Label is a metal logo fixed to the EVA case by pasting or riveting. Metal labels have a high-end texture, are durable, and are not easy to wear, but the production and installation costs are high and may increase the weight of the product.
*Metal label logo on EVA case
8. Woven Label is a logo woven directly into a label through a loom and then sewn onto the EVA case. Woven labels can achieve delicate patterns, and good durability, and are not easy to fade or wear, but the cost is high, especially woven labels with complex patterns, and are mainly used on cloth or fabric surfaces.
*Woven label logo in EVA case.
9.Washing Labels are usually labels printed with logos and product information, sewn into the inside of the EVA case. Care labels can include information such as brand and instructions for use, and are inexpensive to make and install, but they are mainly used for internal marking, are not obvious from the outside, and may wear out after long-term use.
*Washing labels print logo and product information sew into the inside of EVA case.
In the production process of EVA Case, quality control and inspection are key steps to ensure product quality stability and customer satisfaction. The following introduces the supplier's quality inspection of each production link, comprehensive inspection of finished products, and solutions and preventive measures for common quality problems in the quality control process.
*Leaders inspect cuttings parts ensure product quality stability and customer satisfaction.
In the entire production process of the EVA case, a systematic and rigorous quality control process needs to be established. The standardization and process-based quality control process of setting inspection standards in stages can ensure the consistency of the entire batch of goods.
It not only ensures that every product shipped meets the customer's requirements and standards, but also improves the manufacturing efficiency and market competitiveness of the product for the manufacturer.
The quality control process generally includes:
*Workers inspect EVA raw material carefully
2. Targeted inspections are required at different stages of the production process:
*Inspect EVA mold-making process
*QC is inspecting finally finished EVA case
During the OEM production process of EVA (ethylene-vinyl acetate) cases, manufacturers may encounter a series of quality problems that affect the final quality of the product and the pass rate of customer inspection. These problems include appearance defects, size discrepancies, material problems, stitching problems, and functional problems. We list the following problems and propose some practical solutions from the perspective of actual production and cost.
*Surface scratches on EVA case
2. Dimension discrepancies: Dimension discrepancies of EVA cases are usually manifested as dimensional deviations and poor assembly. To ensure dimensional accuracy, high-precision measuring tools should be used during production, and a strict dimensional inspection process should be established to conduct random inspections of each batch of products. Poor assembly requires assembly testing during production to ensure that the EVA case can be well assembled with accessories or internal structural parts, and assembly guidance and adjustments should be provided according to customer needs.
3. Material problems: Material problems mainly include poor quality materials and odor problems. The use of inferior materials will lead to a decline in product performance, so it is necessary to strictly screen suppliers to ensure that the purchased EVA materials meet quality standards, and strictly inspect the incoming materials to prevent unqualified materials from entering the production process. Odor problems can be reduced by selecting low-VOC (volatile organic compound) materials, optimizing production processes, and maintaining good ventilation during production and storage to reduce odor accumulation.
4. Suture problems: Common suture problems include loose or broken sutures and exposed thread ends. To solve these problems, it is necessary to adjust the sewing machine parameters to ensure that the sutures are tight and uniform, and strengthen the training of sewing workers to improve their operating skills. The problem of unprocessed suture ends can be solved by trimming and processing the thread ends after sewing to ensure that the thread ends are not exposed, and heat sealing or other methods are used to process the thread ends to improve the aesthetics of the product.
5. Functional problems: Functional problems mainly include unsmooth zippers and loose internal structures. To ensure the quality of zippers, select high-quality zippers and perform zipper tests to ensure that the zipper function of each product is normal. The problem of loose internal structure can be solved by optimizing the internal design and production process to ensure that the internal structure is firm, and functional testing of the finished product is performed to ensure that the product can meet the functional needs of customers.
Through strict quality control and scientific production management, the occurrence of the above quality problems can be effectively reduced. As a manufacturer, it is necessary to find a balance between quality control and cost management to ensure the provision of high-quality and competitive products to meet customer needs.
After the EVA Case is produced, it needs appropriate packaging before it is finally delivered to the customer to ensure that the EVA case product is not damaged during transportation. We need to consider the entire process of finished product packaging, including the selection of packaging materials, the design of packaging methods, as well as shipment preparation and logistics arrangements.
EVA case's transportation packaging usually chooses sturdy and durable cartons. Five-layer corrugated cartons are sufficient to protect the EVA Case from squeezing and collision during transportation.
Generally, in the production process of large goods, customized corrugated cartons will be arranged. Under the premise of ensuring the safety of the goods, the volume of the goods will be compressed as much as possible to help customers save transportation costs. After all, in the process of international trade, transportation costs sometimes account for a large proportion.
If the customer has high requirements for transportation, some soft materials such as foam fillers or bubble films will generally be added to the carton to prevent the loss of goods caused by falling during transportation and handling.
These soft materials can also prevent the EVA Case from leaving scratches and stains due to friction with the outer box during transportation.
At the same time, the product name, quantity and weight information are marked on the box. This is called a mark in international trade, so that logistics companies and customers can identify and manage it, and it also improves the management and inspection efficiency of customers after receiving the goods.
*EVA case normal carton package
*EVA case with customized shipping marks cartons
Generally, manufacturers will choose to cooperate with logistics companies with good reputations and considerate service and choose appropriate transportation methods according to customer requirements for the delivery time, such as international express, air or sea transportation. Manufacturers generally also need to cooperate with logistics carriers to improve common documents in international trade to realize customs declaration and customs clearance processes.
*EVA case in logistics carriers warehouse
The manufacturing process of modern EVA case is very mature, and experienced manufacturers can grasp all aspects of the manufacturing process well, including design, material preparation, molding, assembly and processing, quality control and testing, packaging and shipment, etc., to ensure the quality of the final product and customer satisfaction.
Choosing a professional EVA Case manufacturer has obvious advantages, advanced production technology and equipment, strict quality control measures, stable and timely after-sales support, can meet the personalized product needs of the brand, and complete the production and delivery of EVA case in time.
