Are all shoes that claim to be waterproof the same? From our perspective, NO! There are nuances behind this attribute. Let us break down the waterproofness test for footwear.
1. The principle and its execution
Waterproofness test is divided into dynamic and static test, with the difference being whether the product is tested in accordance with a certain speed and an angle flexure motion, so as to simulate a user’s walking motion. Usually waterproofness test refers to dynamic test, which could be carried out in Basin method, Trough method or spray method, with the former being the most commonly used.
Take Basin method for instance: the whole shoe is installed in the purpose-built testing machine, which will be dipped into a specific depth of water. The testing machine, tuned into different angles and frequencies, simulates our walking motion. The time and situation where there is a water infusion will be recorded.
Picture 1：Testing machine
Table 1: Comparison of commonly used testing standards parameters
2. The reason of water infusion and how to tackle the issue
According to our statistical analysis, we have some recommendations as follows:
━ Water in the Topline and tongue of shoes
Analysis：According to the experimental data, more than half of the cases occurred in the topline and tongue position. This phenomenon is mainly caused by the siphon effect of the upper material. The water extends up through the material and into the shoe through the topline/tongue.
Solution：The upper material should come with water-wicking treatment.
━ Water in the bending area
Analysis：While as expected, the occurrence rate is not very high. It is mainly because of the quality of waterproof layer in shoes, especially after repeated flexions.
Solution： the quality of waterproof layer should be looked into.
━ Water in other position
Water may enter through any part of the shoe, such as the heel, front edge, etc. As shown below
Analysis：This phenomenon happens very rarely and is more of an occasional occurrence. It is most likely due to quality defects and technological shortcomings.
Solution：Pay attention to the quality of production process.
To sum up, to improve the waterproof performance of shoes, it is necessary to choose waterproof materials with good quality and no defects; improve the processing technology and anti-siphon treatment of the upper material.