Shoe Quality Control: Common Issues and Solutions
Selling low-quality shoes can be detrimental to your brand. You should sell high-quality shoes that meet industry regulations and customer expectations. Hence, every shoe seller or manufacturer must take shoe quality control seriously to ensure the success of their business.
The detailed guide discusses common shoe quality control issues and provides solutions. Implementing the solutions ensures you manufacture aesthetically pleasing, safe, comfortable, and durable shoes.
Common Quality Control Problems in Shoes and Solutions
Shoe Quality ControlA shoe with no excessive gluing
Unfortunately, some common problems can occur during shoe manufacturing. However, you can prevent or minimize most of these problems.
Excessive glue
Most shoe parts are either stitched or glued using strong adhesives. Workers applying too much glue can cause the glue to overflow from the joints, leaving an ugly defect. The shoe’s surface appearance will often have a residue that appears as a stain.
Workers often use a lot of glue when the quality is low to achieve durable bonds.
Solution:
You can quickly eliminate this defect by training workers to apply the right amount of glue or use the correct application procedure. Implement a process that can help detect excessive glue use for timely, suitable corrections.
Investing in high-quality adhesives also helps minimize the chances of glue residue formation. High-quality glues eliminate the necessity of applying massive amounts to achieve permanent bonding.
Weak bonds
The upper parts and the sole comes apart after bonding/gluing, either after short-term use or when packaging due to weak bonds. Using the wrong type of or incorrect application leads to weak bonds.
Unfortunately, this type of effect is not easy to detect with a visual inspection. You’ll need to introduce proper testing techniques to detect the defect.
Solution:
One way to solve this issue is to ensure the use of correct, high-quality glues and adhesives. You should also ensure the right amount of glue and the proper application. Consider using advanced testing equipment to check the durability of the shoe bonds.
You can test the strength of the glue by following proper ISO standards (ISO 17708:2018 and ISO 24266:2020). Employ a professional quality control expert who will let you know the correct tests and standards for the specific shoe type you want to manufacture. HYD Shoes makes use of high-quality glue for bonding.
Surface Imperfections and Scuff Marks
Scruff marks occur due to mishandling of shoes with a specific surface. Glossy shoe surfaces and leather commonly get scruff marks. Imperfections affect the overall appearance of the shoes.
Imperfections include stains, holes, discoloration, scratches, and scars.
Solution:
Find out at which stage of the production process the scruff marks occurred to correct the mistakes. Train your workers in proper material handling to prevent marks and dents.
Quality control at each stage will help identify and correct scruff marks or imperfections. To minimize the appearance of blemishes, you can also use specialized treatment products such as polishers and leather conditioners.
Asymmetry
All the shoe parts must align appropriately during the assemblage process. The seams joining the right and left halves should run perfectly straight. A defect arises if the seams run parallel or in a crooked line.
Solution:
Have a quality control person(s) after the stitching stage to detect the defect early. You can have a checklist of all the features the QC person should check. Give the perfect shoe sample so that they can compare.
Remember that if the defect passes this stage and a customer detects it, they may post negative reviews, damaging your brand.
Size
Shoe packaging
Customers specify their desired shoe sizes and expect the exact physical dimensions. However, mistakes in handling and packaging can result in your clients getting the wrong shoe sizes.
Worn-out tooling can also produce the incorrect size.
Solution:
Ensure that workers inspect the shoes before shipping. If the problem occurs regularly, you need to find out the challenges in the packaging department. Start by implementing measurement guidelines for the factory workers to follow.
Provide the workers with the correct size measurements and samples to help with counterchecking. Your quality control team should also have the exact client requirements. Ensure you provide adequate training to your staff to help accurately determine shoe sizes.
Regularly calibrate your measuring tools and equipment. Alternatively, use 3D scanning technology or fit testers to ensure constant sizing.
Sole Separation
A Shoe Sole
When the bond between the sole and the upper part breaks down, separation of the parts occurs.
Solution:
A proper inspection will help identify separate or gapped parts. Once the quality control team identifies the problem, they return the shoe for adequate bonding or stitching.
Metal contamination and sharp points
Stitching is one of the procedures that shoe manufacturers use to put different shoe parts together. Chances are that the needle can break and remain in the shoe. Incorrect flattening of the tacks and nails can leave sharp points.
Solution:
Workers should use a metal detector to identify the metal contaminants if there are no other metal parts by design. However, the inspection stage team should check for sharp protruding points if there are metal parts by design.
Uneven Stitching
Uneven stitching occurs often when different shoe parts don’t align properly. You’ll notice inconsistent stitch lengths.
Solution:
The worker’s keenness during the stitching process is one of the solutions to uneven stitching. Proper alignment of the stitching equipment will help in keeping the stitches even.
Workers should also use appropriate stitching techniques.
Footwear Testing: Common Types
Lasts or Shoe molds
It is not possible to correct the above defects once they occur. The only solution is to conduct a thorough quality inspection and testing process. You’ll need to test the shoes’ physical attributes and chemical compositions before shipping them to the customers.
In the table below, we highlight the most common footwear tests.
| Test | Description |
| Sole Bonding Strength | It tests the adhesive strength between the upper part and the sole. |
| Shoe manufacturers use a tensile strength testing machine. | |
| Colorfastness | You test a shoe’s resistance to color bleeding or fading when cleaning or being worn. |
| Rub a wet and dry cloth against the shoe and see if it will have any color. | |
| Slip Resistance | The ability of a shoe to provide proper traction on different surfaces, incredibly slippery ones. |
| You’ll have different floor surfaces; choose either water or glycerin and pour it on the floor surface. Put the shoe in the last/mold and try to slide it across the floor surface. | |
| Durability and Wear Testing | You subject the shoes to rigorous wear tests evaluating their durability and performance. |
| Chemical and Substances Testing | Ensure that the shoes are free from the use of harmful chemicals or substances during the manufacturing processes. The tests ensure that you comply with industry-standard regulations. |
| Perform a chemical analysis of all the materials and products you’ll use. | |
| Shoe fit assessment | It tests whether the shoe fits and is comfortable, ensuring a good user experience. |
| Putting the shoe in various shapes and sizes in a mold will fit comfortably and offer proper support. | |
| Waterproof test | It helps in evaluating the degree of a shoe’s water resistance. |
| Apply a certain amount of water and see if the shoe material will absorb the water. | |
| Marking tests | The test assesses the potential for the sole of the shoe to mark the floor surface when worn. |
| Cut out the sole of a shoe specimen and stick it to a metal holder fixed on the underside of a pendulum. Raise the pendulum and release it with the test specimen, striking the surface of a standard flooring material. Check to see if there is any marking on the floor material. | |
| Metatarsal Protection | The metatarsal area is the toe area to the top of the foot. Internal or external metatarsal guards help fix this problem. |
| Fit a wax form into the shoe before weighing it on the metatarsal area. Then, proceed to measure the height of the wax form. | |
| Electric Shock Resistance | It tests how the shoe will protect the wearer from electric shock. |
| The workers will fill the shoes with tiny spheres and place a metal platform (electrode) inside. Place the shoe on another metal platform before applying a high-voltage current to measure leakage or resistance. | |
| Static Dissipation | The test assesses if the shoe can prevent the conduction of static charge from the body to the ground. |
| Workers place small metal spheres inside the shoe (wet and dry) on an electrode plate. |
Best Practices for Quality Control in Shoe Production
A Magnifying Glass
Quality control measures are essential to manufacture high-quality shoes. Hence, every shoe manufacturer should consider the following best practices for quality control.
- Define Quality Standards: Have precise specifications and standards for your shoes. Some of the quality standard specifications include construction, safety, and materials. At HYD Shoes, we have a detailed guideof the shoe manufacturing process. Ensure that these standards meet not only customer expectations but also regulatory standards and industry best practices. Know the various certification programs that provide guidelines.
- Supplier Evaluation: Having reliable suppliers for raw materials and other components is essential. You’ll need to know their quality control procedures and whether they adhere to relevant standards. Ensure that you only partner with suppliers who hold industry certifications.
- Incoming Material Inspection:When receiving materials or other components from suppliers, you should verify their quality. Check to see if they have defects and if they conform to your specifications. Chemical analysis is also essential to avoid using harmful materials against industry standards.
- In-Process Quality Control for Shoes: Have quality checks in all stages of shoe manufacturing. Inspect the raw materials of the shoes after stitching/bonding, assembly, and packaging. That way, you can detect defects in real time and make corrections or minimize the production of defective shoes.
- Pre-shipment Inspection for Shoes: Before packaging, conduct a thorough shoe inspection to ensure that you only send high-quality shoes to your clients. The shoes should be fit, durable, and free of surface defects.
- Performance and Safety Testing for Shoes: Conduct various safety and performance tests to confirm if the shoes meet industry standards. Some tests include colorfastness, waterproofing, slip resistance, durability, and wear testing. If possible, partner with third-party testing laboratories.
- Documentation and Traceability: Have clear records of all the quality control processes, incidences during the manufacturing processes, and test results. The records help you trace the history of every shoe so that you can perform corrective actions.
Tools and Technologies for Shoe Quality Control
Shoe manufacturing has moved from manual tools to new and more advanced technologies in the last few years. New technologies have brought greater versatility, transitioning to many companies automating their manufacturing processes.
- Software Solutions: Using CAD( computer-aided design) and CAM (computer-aided manufacturing) in CNC machines has changed manufacturing processes. It is now possible to manufacture shoes on a large scale with precision and accuracy. Both software have made the automation process more manageable for most shoe manufacturers. Workers no longer have to perform repetitive tasks, which can often cause errors.
- Inspection Tools: There are various inspection tools that you can use throughout the manufacturing process to identify defects. Magnifying glasses, tape measures, rulers, callipers, abrasion testers, tensile testing machines, durometers and pH meters are some of the inspection tools you can use.
- Automated Systems: Shoe manufacturers eliminate human errors and variations in their manufacturing processes by using automated machines and systems. You can program the machines to give you uniform output. Automated systems ensure that you get real-time data.
How Do We Ensure Quality Control at HYDShoes?
Different Tools
1. Setting High Standards
- Defining Quality Benchmarks: We have specific criteria for each product aspect, document them, and provide them to our employees. There are detailed guidelines for material selection to ensure we only use high-quality materials for our products.
- Regular Reviews: We regularly review and update our guidelines to include new technologies and customer feedback.
2. Selecting Premium Materials
- Supplier Evaluation: We comprehensively evaluate all our suppliers, concentrating on their quality control measures, production capabilities, and reputation. Our suppliers must have industry-standard certifications, and we review their consistency in delivering high-quality materials.
- Material Testing: We take our materials through rigorous wear and tear simulations to withstand prolonged use without compromising on quality. The materials should be flexible enough to provide comfort and support without deforming or breaking. We also perform various tests to check for harmful chemicals and to comply with safety regulations.
3. Rigorous Manufacturing Processes
- Skilled Workforce: We hire experienced artisans with a strong background in shoe manufacturing and ensure to conduct thorough interviews and skills assessments. We have also developed comprehensive training programs covering various aspects of quality control and shoe manufacturing.
- Precision Equipment: We have invested in advanced cutting, stitching, assembling and finishing machinery. Our machines maintain high precision and control.
4. Comprehensive Inspection and Testing
- Visual Inspections: Our workers perform visual inspections in the various stages of shoe manufacturing. We have a detailed checklist of potential defects and train them to identify and assess them accurately. We provide continuous and keep our workers updated on new techniques and standards.
- Functional Testing: We simulate different conditions, such as extreme temperatures, walking, and wet conditions, and test the shoes. We also evaluate metrics such as support, grip, and flexibility. Subjecting the shoes to repeated stress checks durability.
- Lab Testing: We use advanced laboratory equipment such as electron microscopy, spectrometry, and chromatography for detailed chemical analysis.
5. Ensuring Comfort and Fit
Different shoe sizes and shapes
- Size and Fit Consistency: We have a comprehensive sizing chart based on industry standards for various foot shapes and sizes. Our workers use precise measurement tools and technologies to ensure accurate sizing. Our employees also regularly calibrate the tools to maintain their accuracy. We also conduct fit testing for a large number of individuals that represent our target markets.
- Wear Testing: We distribute sample shoes to a diverse group of wear testers and ensure they use them in different real-life conditions. We then provide the wear testers with a structured feedback form to get feedback on fitness, durability, comfort and other issues.
6. Implementing a Robust Quality Control System
- Quality Control Plan: We have standard operating procedures (SOPs) for each shoe manufacturing stage. Every product must meet an acceptance checklist before shipping, and we also have protocols for handling shoe products with defects.
- Inspection Points: We have identified the stages in the manufacturing process where quality issues occur the most and developed specific inspection criteria for these points. We use random sampling, frequent inspections, and various inspection techniques.
- Documentation and Reporting: We keep records of all inspections and tests to make it easy to trace a product through all the stages of the manufacturing process. The creation of standardized forms and templates has also made it easier for our employees to record. For traceability, we ensure that every batch has a unique tag.
7. Addressing Common Challenges
- Proactive Problem Solving: We can identify defects in the earlier stages of manufacturing by conducting raw materials inspections. The defects will affect the shoe products’ results. We have partnered with reliable suppliers who have strict quality control processes.
- Continuous Improvement:We always request feedback from our clients so that we can look for ways to improve. We also conduct regular audits and circulate a quality audit checklist to our employees.
8. Leveraging Technology
- Quality Control Software: We use different software programs to manage the bill of materials (BOM), multi-level inventory, and production schedules. Using advanced sensors or cameras to inspect every aspect of the shoes helps to improve efficiency.
- Automated Systems: In some areas, we have 3D printing and CNC machines to prevent our workers from performing repetitive tasks, which can lead to many errors. Other automated systems include automated cutting and stitching machines,
9. Training and Development
- Employee Training: We conduct various training sessions for the employees so that they can better understand quality standards, learn how to use quality control techniques and tools, and use quality management software. We also allow employees to give us regular feedback to help improve their quality control skills.
- Skill Development: We conduct cross-training sessions in different areas of control control. Thus, the employee expands their skill set. For example, training a production lineworker in quality control helps them to detect errors and defects in real-time.
Conclusion
Following shoe quality control procedures ensures that you manufacture high-quality shoes. The various footwear tests will help the quality control inspection team and the workers to detect defects on time and implement corrective measures where possible. HYD Shoes has a support team that consults on shoe quality control strategies.