Tel: +86-13771063101


Home > News > Content
Test Method For Glue Viscosity Of Protective Film
- Sep 26, 2018 -

The initial viscosity test of pressure sensitive adhesive tape and other products is carried out in accordance with the national standard GB / T4852-2002 of the People's Republic of China.

1 fundamental concepts

1.1 definition

When the contact time between the object and the viscous surface of the pressure-sensitive adhesive tape is short, the adhesive effect of the adhesive tape on the object is called initial viscosity.

1.2 task principle

Roll a ball of steel over the sticky tape on the inclined plate. The maximum steel ball size can be sticky according to the regular length of the sticky surface, and its initial viscosity is evaluated.

1.3 instrument structure

2.1 Inclined Rolling Ball Installation: This installation mainly consists of inclined plate, ball releaser, bracket, base and receiving box and other parts.


Steel balls: 32 kinds of steel balls with GCr15 bearing steel grade 0 and diameter of ~1 inch and accuracy not less than GB 308-77 Steel Ball Rule can be used as test balls.

The steel ball is made up of 32 times the diameter of its English diameter. A group of steel balls should be used for testing.

Steel balls should be stored in rust preventive oil. The ball with rust and scar must be changed in real time.

1.4 skills objectives

Adjustable inclination: 0~60 degrees.

Table width: 120mm

Test area width: 80mm

Specification steel ball: 1/32 inch to 1 inches.

Outline size: 320 (L) mm x 140 (B) mm * 180 (H) mm

Weight: 6kg

2 operation method

2.1 preparation task


The inclined ball is adjusted to the degree of position. Except for the extraordinary rules, the inclination of the inclined plate is adjusted to 30 degrees.


Wash both sides of the glass surface and the polyester film with a degreased gauze dipped in a cleaning agent, and then clean with gauze.


The steel ball wiped off the rust-proof oil is immersed in a container containing a detergent for several minutes. After removal, the steel ball is wiped clean with a clean cleaning agent and gauze, and then the steel ball is wiped clean with a clean gauze. After cleaning, the steel ball is taken with a clean bamboo (wood, bone) tweezers and other things.


As shown in Fig. 2, the adhesive tape is placed upward on the inclined plate. Polyester film is used as the help roll section in the regular area. The rolling section should be smooth and free of bubbles and wrinkles. The 100mm below the rolling stage is limited to the test section.


Glue the sides of the roller and the lower end of the sample to be fixed on the inclined board. If necessary, it can also be fixed along the edges of the test section with adhesive tape, so that the sample is flat and adhered to the board.


A deterrent is used to clamp the steel ball into the ball releaser and adjust the position of the ball releaser so that the center of the ball is located on the starting line of the roll-aid. Before the formal test, a sample promises to make repeated tests, but the left and right position of the ball releaser should be adjusted so that the track of the ball rolling each time does not coincide. When the specimen width is greater than 25 mm, the area with the 25mm width of the sample center is a useful test area.

2.2 preselected maximum steel ball


Slide the ball releaser quietly to see if the rolled ball can be stuck in the test section (stop moving more than 5 seconds below). From large to small, take the ball with different ball numbers and test it properly until the largest ball number that can be adhered to the test section is found.


The steel balls with the largest ball number and the two large and thin balls connected with the ball number are tested on a unified sample to confirm the maximum ball number.

2.3 formal testing

Take 3 samples and test the ball with the largest ball number. If a specimen can not adhere to the steel ball, the ball number can be used only less than its steel ball for one test, if still can not adhere to, it must be tested again according to 2.1.4-2.3.

3 experimental consequences

3.1 test results are revealed by steel ball number.

3.2 Of the steel balls adhered to by each of the three specimens, if three are the largest ball number, perhaps two are the largest ball number, and the other is only less than the largest ball number, the test results will be revealed by the largest ball number; if one is the largest ball number, and the other two are only less than the largest ball number, the test will be conducted. Try to disclose the performance of the ball with only a ball number smaller than the largest ball number.