Shoes are an indispensable part of our daily wear. They come in a wide variety of styles, each with its own distinct functions, such as sneakers, beach slippers, and rain boots. Peel strength is a key metric in footwear quality testing, and an electric shoe stripping testing machine is a specialized device for this purpose.

An electric shoe stripping testing machine is suitable for testing the peel strength between the sole and upper of finished shoes. The machine clamps the finished shoe onto a last and uses a stripping knife to separate the sole and upper. The force required to separate the shoe is measured as the peel force, and the peel strength is calculated based on the peel force and the width of the blade.

Working Principle

The electric shoe stripping testing machine, based on the principles of material mechanics, simulates the actual peeling process between the sole and upper to quantify the bond strength. During the test, the finished shoes are fixed to the shoe last and clamped between the upper and lower fixtures. The blade cuts along the joint surface at a constant speed (such as 20mm/min). At the same time, the force sensor monitors the peeling force in real time, the displacement sensor records the moving distance, and the system automatically generates a force-displacement curve and calculates the average peeling strength. The equipment must strictly follow the standard positioning (such as the blade is ≥20mm from the edge of the sole, and the upward inclination angle is 5°~10°) to avoid slippage or stress concentration. Its technical features include high-precision servo control (speed resolution 0.1mm/min), multi-shoe adaptation and automatic data processing, which can accurately determine whether the product meets the national standard (such as men's shoes ≥70N/cm). The equipment provides a scientific basis for footwear quality control and helps optimize the bonding process and material matching.

Testing Notes

1. Prepare a finished shoe with an open top. Peel the shoe apart at the junction of the sole and upper, securing it with a special clamp. Test points should be determined as needed, and the peel strength should be calculated. This method is economical but can result in a high degree of error. We recommend using a computerized tensile testing machine for more accurate data.

2. Cut samples of equal width from the bond between the sole sidewall and the upper, and measure the peel strength. Note that this method may not be comprehensive, especially for shoes with complex exterior designs.

3. Cut the shoe apart, retaining a sample from the bond. Mark the test points, test it using a computerized tensile testing machine, and calculate the average force and displacement using a graph.

Note: The test result should be the arithmetic mean of the valid data, expressed in Newtons (N), with significant figures to the unit. If slippage, breakage, or deviation from the average exceeds ±10%, the data will be invalid and retesting will be required.

Steps for testing shoe peel strength

1. Prepare a finished shoe with a peeled opening. Peel the top (toe box) of the shoe away from the sole and upper. Clamp the shoe using a special clamp on a tensile testing machine. According to the customer's requirements, divide the shoe into several points and measure the peel strength at each point. Then, divide the peel strength at each point by the width of the point to determine the peel strength at each point. This is a relatively economical method, but it suffers from large errors and poor reproducibility. If conditions permit, a computerized tensile testing machine can be used. This allows for a clearer visualization of the peel strength and curve between the sole and upper, providing more convincing results.

2. Cut a 1cm section of uniform width from the bonding point between the outsole and upper, and measure the peel strength at each point. Based on years of experience, the peeling method is not comprehensive. Only a few points are selected throughout the entire shoe. Furthermore, many luxury shoe designs, especially sneakers and athletic shoes, prioritize the appearance of footwear. The junction between the outsole and upper is not clearly visible, making it difficult to locate during the peel test. For greater accuracy, the shoe can be cut into test specimens.

3. Cut the sole and upper of the finished shoe apart, leaving a 1-2cm gap where the sidewall of the sole meets the upper. Generally, mark 22 points evenly around the perimeter of adult shoes, and 12 points on children's shoes. Choose a computerized tensile testing machine and use the computer's displayed graph to calculate the force and displacement over the entire process, calculating the average value (this can also be increased or decreased based on customer requirements). If there is a large underline at the seam where the sidewall of the outsole meets the upper, remove it first. Then clamp the sample to the tensile testing machine and measure the peel force at each point, excluding the width of the bond between the sidewall of the outsole and the upper, to calculate the peel strength. This is a relatively economical tensile testing method, but its disadvantages are large errors, poor repeatability of each data point, and a high degree of human error in the test results.

Applications

Electric shoe peel testers are widely used in footwear manufacturing, quality control, and material research and development. In footwear production, they accurately measure the bond strength between the upper and sole by simulating the peel force experienced during actual wear, ensuring product compliance with national standards (e.g., ≥70 N/cm for men's shoes and ≥50 N/cm for women's shoes), guiding adhesive process optimization and improving material compatibility. Testing institutions use them for third-party certification to ensure market access quality. During the R&D phase, they are used to test the adhesion of new materials (such as EVA soles and PU coatings) to promote product innovation. Furthermore, by changing fixtures and adjusting test modes (e.g., 90°/180° peeling), the equipment can be expanded to assess the mechanical properties of materials in industries such as adhesive tape and plastic film, meeting diverse testing needs.

Maintenance

Electric peel testers require the following maintenance: First, keep the tester clean. After each use, remove any debris, dust, and other debris from the test bench to prevent these debris from entering the tester and affecting the proper functioning of its precision components. Secondly, regularly inspect key components of the testing machine, such as the clamps, for signs of wear or deformation. If so, replace or repair them promptly to ensure they can securely hold the sample. Furthermore, the testing machine's transmission components, such as the motor and belts, should also be regularly inspected to ensure smooth motor operation and belt slack. If any problems are found, adjust or replace them promptly. Furthermore, the testing machine's sensors are crucial for obtaining accurate test data and should be regularly calibrated to ensure measurement accuracy. The equipment should also be placed in a dry, well-ventilated environment to prevent moisture from corroding the electronic and mechanical components.

As the gatekeeper of quality inspection in the footwear industry, the importance of electric shoe peel testers lies not only in their accurate test data and wide range of applications, but also in their management throughout their entire lifecycle. From daily cleaning to maintenance of key components, from transmission system inspection to sensor calibration, meticulous operation at every stage directly impacts the reliability of test results. In the footwear manufacturing sector, it helps companies achieve process optimization and material innovation; in testing and certification, it builds a quality defense for market access; and in cross-industry applications, its flexible adaptability promotes the development of materials science. Scientific and standardized maintenance is key to ensuring stable equipment performance and extending its service life. Only by combining rigorous testing methods with systematic maintenance management can this "quality guardian" continue to safeguard the high-quality development of the footwear industry, ultimately achieving quality improvement across the entire supply chain, from production to consumption.