#test method

ASTM D3654 standard aims to measure the ability of pressure-sensitive tapes to remain adhered under constant load that is applied parallel to the tape’s surface.

A-H test method is included. Each test method points to different test materials and requires specialized testing instruments.

ASTM D3654 standard includes 8 test methods. The most advanced test method is Procedure H, which is processed under specialized conditions (at an elevated temperature and after a 10-min dwell time at the elevated temperature).

As the pressure-sensitive tape is applied to a vertical standard steel panel, a standard mass is attached to the free end of the tape and the time to failure is determined, and the value of shear adhesion is obtained. The durative time of procedure H is less than that of other procedures. The test method requires specified mass or 1000g±5g mass (include mass of clamp or hook).

In terms of ASTM D3330, there are six test methods with different conditions required and the type of pressure-sensitive.

Test method A measures the adherence of a single-coated tape which applies to a standard test panel with controlled pressure as the tape is peeled at 180 angles.

Test method B measures the adherence to the backing of a single-coated tape. Test method B is similar to test method A. The difference between the two is that one tape is applied to the backing of another tape. Then, the rest process is the same as that of test method A.

Test Method C is designed for double-coated tapes which consist of face side and liner side. To test adherence of the face side, the face side of the tape is down and applied to a stainless steel panel, remove the liner and put a trip of polyester film onto the liner side. The do the process as the test method A. Meanwhile, when testing the adherence of the liner side of the tape, put the liner side down and stick to the stainless steel, the face side is attached to a strip of polyester film.

Test Method D is for the measurement of the adherence of the release liner.

Test Method E refers to the adhesive transfer tape. The process of method E is the same as that of method C. It can be divided into two parts, one is for the face side, the other is the liner side.

Test Method F is getting the values of adhesion of single-coated tape as peeling at 90 angles. The tape is attached to a standard panel.

ASTM D3330 Instrument to Test Pressure-Sensitive Tape

Water Vapor Transmission, Water Vapor Permeance, Water Vapor Permeability

Water vapor transmission (WVT) is determined by dividing the rate of weight change by the area of the test specimen. Water vapor permeance is in general the degree to which a material admits water vapor. Water vapor permeability is related with the thickness of the material.

Calculation of Water Vapor Transmission, Water Vapor Permeance, Water Vapor Permeability

The permeance and permeability are calculated from the WVT. The permeance is calculated by dividing the WVT by the vapor pressure across the material under test. The permeability is calculated by multiplying the permeance by the thickness of the material.

ASTM D1653 standard and Test Method

ASTM D1653 standard determines the water vapor transmission rate of films of paint,lacquer,vanish, and other organic coatings. The films may be free films or be applied to porous substrates. Under ASTM D1653 standard, there are two test methods: dry cup method and wet cup method.

ASTM D1653 Wet Cup Method

By sealing a film of the test material to the top of a vessel that is filled with water or desiccant, WVT is determined. It is called wet cup method when the vessel is filled with water. The test determines how much water vapor is lost through the film. The dish loses water over the course of the test so that the plot tends downward. The wet cup method is the preferred one for obtaining values that is related to conditions of use where is high relative humid.

ASTM D1653 Dry Cup Method

When the vessel is completed with desiccant, it is called the dry cup method. Through the test method, it is obviously known how much water vapor the desiccant attracts through the film. Meanwhile, the plot points upward as the dish gets water over the course of the test. The dry cup method is the preferred one for obtaining values that is related with conventional dwellings where is lower relative humid.

Rules of ASTM D1653 Test Method

At the beginning of test, the dish may gains or loses weight quickly, and then goes into a constant rate of weight change. Certainly, the process depends on the material being tested.

Attention: By the wet cup method, the values obtained are higher than ones by the dry cup method under the same conditions of air temperature and humidity.

ASTM E96 standard and Test Method

ASTM E96 standard is used to test paper, plastic films, other sheet materials, fiber-boards, gypsum and plaster products, wood products, and plastics. ASTM E96 standard introduces two basic methods: the desiccant method and the water method.

ASTM E96 Desiccant Method

The desiccant method: the test dish contains a desiccant. Leave enough space so that the shaking of the dish to mix the desiccant, which have to be done at each weighing. The test specimen is sealed to the open mouth of the dish. The rate of water vapor movement is determined by periodic weighing of the test dish.

ASTM E96 Water Method

The water method: the dish contains distilled water. Water vapor permeates through specimen into the controlled atmosphere. Through the periodic weighing of the test dish, the values can be obtained.

ASTM E96 Test Method Attention

Under different test conditions, the valued obtained may not be equivalent. As this reason, select the test conditions which are the closest with the conditions of use.

The difference of ASTM E96 standard and ASTM D1653 standard

The testing scope of ASTM E96 standard is more wider, which can evaluate many materials, including coatings which is mainly tested under ASTM D1653 standard.

ASTM D1653 includes directions for preparation of a free film, whereas ASTM E96 does not.

ASTM E96 requires that permeance values exceeding 2 perm are corrected for resistance due to still air and specimen surface. ASTM D1653 does not specify the correction.

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IIL and IIH

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Continuity Test for DPS

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Example of Instances sheet with continuity test

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