Electrostatic discharge(ESD) will produce slight sparks, which we can hardly notice with the naked eye, but for precision electronic parts, chips, high-concentration dust, chemicals, and gas oil, it is huge enough to cause failure and explosion. Therefore, it is necessary to take various measures to eliminate static electricity in the workplace to avoid disasters.
There are many anti static products on the market, such as professional static eliminators, anti static gloves, bracelets, anti static safety shoes, or anti static chairs…etc. Taking people as an example, because they often need to walk back and forth during work, there is a lot of friction between them and the ground. At this time, it is easy to cause static electricity to accumulate and then discharge. Therefore, a pair of ESD or anti static safety shoes is indispensable.
2.What is the difference between anti-static safety shoes and ESD shoes?
2.1 Anti static shoes
The resistance of anti static shoes is as low as 0.1 to 1000 megohms (MΩ). The use of anti static safety shoes can send these charges to the ground, thereby preventing the accumulation of static electricity in the human body, thereby preventing the sudden current generation between charged objects due to contact.
2.2 ESD shoes
The resistance of ESD (or electrostatic discharge) shoes is lower than that of anti-static shoes, ranging from 0.1 to 100 (MΩ). Using esd safety boots can safely lead the charge from the body to the ground, the purpose is to prevent excessive accumulation of static electricity on the body. Avoid hidden dangers caused by contact between the body and charged objects.
2.2.1 ESD standard
Static electricity accumulation and personal safety are not the only important considerations in the industry. Discharges need to be controlled to protect components and equipment. Here, another standard involving electrostatic discharge (ESD) comes into play: EN 61340-5-1 protects electronic equipment from electrostatic phenomena.
The upper limit of the contact resistance of ESD footwear defined in this table is 35 megohms. The lower limit of anti-static shoes is 100,000 ohms. Therefore, this tells us that ESD safety shoes require higher requirements than anti-static safety shoes, and they always have anti-static functions.
Due to the high standards of ESD, its logo must be affixed to the safety shoes separately. Generally, ESD shoes that meet the standard test will be affixed with a yellow ESD symbol. The anti-static function as a common function of safety shoes will be classified as S1 level.
3.What factors affect the contact resistance of shoes?
Of course, the performance of any shoe will be affected by the environment and produce some subtle changes. It may be affected by the environment, which may cause its anti-static performance or ESD performance to decline. This is a problem that we need to consider when buying safety shoes. Different materials to improve his function.
Sometimes safety shoes marked with an ESD mark fail the customer’s test. However, it cannot be completely concluded that the shoes do not have ESD function. There will be many external factors that affect the final test results. For example, temperature is a big influence factor. In winter, the contact resistance becomes higher due to the low temperature. Another possible reason is the use time. After using for a long time, the shoes will increase moisture due to sweating. This leads to an increase in discharge capacity. Other factors include whether the soles are dirty.
4.How to test the anti-static and ESD function of shoes
Testing the anti static performance of shoes requires testing in a professional testing environment and special equipment. Before the test starts, it is necessary to adjust the safety shoes in a certain period of time in a dry and humid environment. Then put a steel ball weighing 4kg into the shoe. This steel ball is connected to the device for measuring the contact resistance. Finally, the shoes is placed on the copper plate. When the safety shoes touches the resistance, 100V is applied for 1 minute. DC voltage, record resistance value
It is more difficult to test the ESD ability of shoes, mainly because the anti-static standards and ESD standards are different, so the required procedures are different. According to the EN 61340-5-1 standard, a tester is required. Put on the sample ESD safety boots, stand on the test electrode, put your hand on the metal plate, apply voltage, and test the resistance value. When the resistance value is less than 35 megaohms, it can be determined that this is a safety shoe with ESD function.
5.ESD safety shoes VS anti static safety shoes
5.1 Low cut good looking anti static safety shoes
The high-quality cowhide upper is used for low cut anti static safety shoes, which can effectively wear out, oil and water. The use of breathable inner lining can effectively reduce the sweat of workers’ feet. The double EVA/Rubber injection molded sole has good abrasion resistance and excellent anti-slip performance. The toe part of the shoe adopts the EU standard steel toe, and the midsole of the shoe adopts the Kevlar bulletproof fabric midsole. It is lightweight, puncture-proof and smash-proof. It can effectively protect workers’ feet safety shoes.
This pair of anti static shoes has anti-static function, mainly because they use anti-static comfortable insoles. The bottom of the insole uses a lot of anti-static thread, which can effectively prevent the damage caused by static electricity. The advantages of this pair of shoes are: low price, wear resistance, non-slip, and long life. Moreover, these shoes also have a CE certificate certified by the European Union, and the quality is guaranteed. If the quantity is larger, we will also provide you with a 6-month warranty.
5.2 Low cut breathable leather ESD safety footwear
This durable ESD footwear has a very nice white appearance. He used a durable leather upper. This pair of ESD safety shoes also have vents to increase the ventilation function of the shoes. The side end of the vamp is affixed with the exclusive ESD logo, which means that this safety shoe has fully complied with the ESD standard and is completely suitable for the special working scenes of some airports and laboratories.
These ESD work footwear have composite toes at the front, which can effectively prevent heavy objects from hitting the foot. A very light bulletproof fabric fiber is used between the sole and the insole of the work footwear to prevent sharp objects from piercing the sole of the feet.
The soles of this pair of ESD safety shoes use very wear-resistant rubber soles, which have good wear resistance and non-slip properties. Don’t worry about slipping in a humid environment. In addition, the insole is made of a special EVA elastic shock-absorbing material, which makes it very comfortable to step on. The bottom of the insole also uses anti-static wire, which can be used in environments with more static electricity. It has received a lot of recognition and good feedback.
The main advantage of this kind of shoes is that they can be worn for a long time. Ordinary sports shoes also do not have the anti-slip function of the sole. It can also protect workers’ feet from static electricity. Such a pair of safety shoes with so many functions is similar in price to ordinary sports shoes. Very cost-effective
6.How to choose anti-static safety shoes and ESD safety shoes
This requires us to choose according to our own working environment.
First, you need to understand the approximate size of static electricity in the working environment to choose anti-static safety shoes and ESD safety shoes. Secondly, choose other requirements of safety shoes according to other requirements in the environment. Choose according to the size and range of ohms we said. If static electricity is easily generated in the environment, we need to discharge static electricity at all times, and it is best to choose ESD safety shoes. If our working environment has relatively little static electricity, we can wear some equipment to avoid it, such as wearing anti-static gloves, a face mask, and anti-static safety shoes. At this time, we’d better choose anti-static safety shoes.
As long as you understand the specific conditions of your working environment, I believe you will easily choose a pair of anti-static or ESD safety shoes.