What are the standard test methods for anti-static adhesive tapes?

In today's era of rapid development of science and technology, anti-static adhesive tape in many fields are playing an indispensable role, especially in the electronics, semiconductor, pharmaceutical and other industries, its importance is self-evident. The production environment of these industries is extremely sensitive to static electricity, even a very small static discharge, may give the precise electronic components, fragile semiconductor devices or high-purity pharmaceutical products with disastrous consequences, resulting in product damage, performance degradation, and even the entire production process stagnation, which in turn caused huge economic losses.

The quality and performance of anti-static adhesive tape are directly related to the product quality, production efficiency and economic benefits of these industries. Through the comprehensive and systematic testing of anti-static adhesive tapes, we can find and solve potential problems in a timely manner, to ensure that they can be stable and reliable in a variety of complex environments to play the role of electrostatic protection, to provide a solid guarantee for the safe production and sustainable development of enterprises.

Below are some common standard test methods for anti-static adhesive tapes:

Electrostatic performance test

• Surface resistivity test: Use professional resistance tester, such as megohmmeter, place the electrodes on the surface of the adhesive tape according to the specified spacing, apply a certain voltage and measure its surface resistance. The test environment should be kept at temperature 23±3℃ and relative humidity 40%-60%±5%. According to GB/T 33375-2016 standard, the resistance value obtained through measurement should be within the specified antistatic range, and the general surface resistivity should be equal to or greater than 10⁵Ω/ square but less than 10¹²Ω/ square.
• Volume Resistivity Test: A similar test principle to the Surface Resistivity test is used, but the electrodes need to be inserted inside the adhesive tape to measure its volume resistance. This test provides a more comprehensive assessment of the anti-static properties of the tape, and its volume resistivity is generally required to be between 10⁴ - 10¹¹Ω・cm.
• Friction Voltage Test: A non-contact electrostatic voltmeter and specific friction electrodes are used for this test. The friction electrodes are cylindrical, 50mm to 60mm in diameter, weigh 1kg, have a volume resistance of more than 1×10¹³ ohm, and are wrapped in highly insulating nylon cloth. During the test, the friction electrode and the test object friction, unidirectional friction stops 20 times, in 10s with a static voltmeter in a non-contact way on the friction track charged voltage test. Different antistatic levels have different friction static voltage standards, such as level 1 requires less than 100V.
• Peeling Voltage Test: Paste the adhesive tape on the specified test board, and then peel off the tape at a certain angle and speed, and at the same time, use the electrostatic voltmeter to measure the electrostatic voltage generated during the peeling process. This test simulates the separation of adhesive tape in actual use and assesses whether excessive static electricity is generated during peeling.

Adhesive performance test

• Initial adhesion test: the commonly used method is the rolling ball method, that is, a certain size of the steel ball placed on the inclined adhesive tape specimen, observe the angle or distance when the ball begins to roll, in order to assess the initial adhesion of the adhesive tape. The smaller the angle or the shorter the distance, the better the initial adhesion. You can also use a professional initial adhesion tester to measure, according to the relevant standards for the conditions and steps to operate, to get accurate initial adhesion data.
• Adhesion test: According to GB/T 4851 standard, the adhesive tape will be pasted on the standard test board, the lower end of the hanging standard load, at a temperature of (23 ± 1) ℃, relative humidity of (50 ± 5) % of the conditions, after a period of time, the tape sliding distance or the tape adhesion time is measured, in order to assess the adhesion of the tape persistence. If the tape is not completely removed, it is also necessary to record its adhesion status, such as whether there are obvious traces of peeling or whether there is material transfer phenomenon on the surface of the tape.
• Peeling strength test: There are 180° peeling test, 90° peeling test, T-type peeling test and cylinder peeling test and other methods, of which 180° peeling test is the most widely used. The use of tensile testing machine, the adhesive tape on a stainless steel plate, stainless steel plate fixed in a fixture on the tensile testing machine, tensile testing machine, another fixture clamped on the free end of the tape, adhesive tape and stainless steel plate at an angle of 180 °, and then to the specified rate (5.0 ± 0.2mm / s) to pull open the tape, through continuous measurement of adhesive tape from the stainless steel plate on the peeling force required to be converted to Peel strength。

Physical Properties Test

• Tensile strength test: using a tensile testing machine, the tape is made into a specimen of the specified size, in a certain tensile speed on the specimen for the tensile until breakage, record the maximum value of the tensile force at the time of breakage, and calculate the tensile strength. Tensile strength reflects the ability of adhesive tape to resist tensile damage, for the need to withstand the application of large external force scenarios, such as fixing large electronic equipment, is of great significance.
• Tear Strength Test: Through a special tearing jig, one end of the adhesive tape specimen is fixed, the other end is torn at a certain speed, and the maximum force value during the tearing process is measured, i.e. the tear strength. This test can evaluate the tear resistance of the adhesive tape when subjected to localized external forces, to prevent the tape from edge breakage or uneven tearing in the process of use.
• Temperature resistance test: Place the adhesive tape in a high-temperature oven or a low-temperature test chamber, keep it under the specified temperature conditions for a certain period of time, and then take it out to observe the changes in its appearance, adhesion, size, etc., as well as to test whether its electrostatic properties are affected. For example, in a high temperature environment, check whether the tape is deformed, whether the viscosity is reduced, whether the surface resistance increases, etc., in order to determine its applicability in different temperature environments.

Chemical stability test

• Chemical resistance test: the adhesive tape will be immersed in different chemical solutions, such as common organic solvents, acid and alkali solutions, etc., after a certain period of time, take out and observe the tape's appearance, adhesion, size and other changes, as well as testing its electrostatic properties and mechanical properties of the changes in the situation, to assess its ability to withstand a variety of chemical substances.
• Environmental protection test: Detect whether the adhesive tape contains harmful substances, such as lead, mercury, cadmium and other heavy metals and PBB and other harmful flame retardants, usually using professional chemical analysis methods, such as atomic absorption spectrometry, gas chromatography - mass spectrometry, etc., to ensure that it meets the relevant environmental protection standards, to avoid harm to human health and the environment.

The testing of anti-static adhesive tapes is a key part of ensuring their quality and performance, and is of vital importance to electronics, semiconductors, pharmaceuticals and many other static-sensitive industries. Through comprehensive testing of anti-static properties, adhesive properties and other related properties, we can accurately assess the performance of adhesive tapes in a variety of complex environments, identify potential problems in a timely manner, and thus safeguard the quality of products and production stability.