American Pulp and Paper Technology Association test standards



The Paper and Pulp Industry Technical Association (TAPPI) is the leading technical association for the global paper, pulp and carton processing industries. Since its founding in 1915, TAPPI has grown to become the world's largest professional organization serving the paper, pulp and carton processing industry.

TAPPI Standard Test methods are test procedures and related practices used in the measurement, evaluation and description of pulp, paper, corrugated boxes and other paper products, including raw materials used in their production, such as pulp wood chips. The industry association standard by the United States, Canada, Europe, Australia, Japan and other pulp and paper factories around the world for nearly a hundred years of discussion, demonstration, revision, and continuous professional update, has become a globally recognized pulp and paper industry international standards.

Typically, the TAPPI test methodology is updated twice a year after a meeting of the Standards Advisory Review Group (SARG). The SARG will finally decide whether to approve the new or modified method.

The following section is the modified or increased TAPPI test method approved in September 2005: Inner bonding strength (Z-stretchability) of T541 om-05 paperboard.

This method is used to describe the measurement of the internal fiber strength (Z-tensile strength) of cardboard. A sample of 6.45 square centimeters of cardboard was tested using a specific tool. First, both sides of the test sample are coated and pressure sensitive tape is used on both sides of the test sample. Then the sample is placed between two pressure plates, and uniform pressure is applied to the entire sample surface, so that uniform pressure appears in the vertical direction of the entire test surface, which affects the separation.

This method is suitable for testing cardboard and paper whose internal fiber bonding strength (adhesive strength) is weaker than that of tape. The press plate is made of materials that will affect the bonding strength between the press plate and the tape. When the tape fails or the adhesive is transferred to the sample, the test value will be high. The tape you choose also affects the test results. The adhesive strength of the tape is critical to the repeatability of the test results. New factory tape can be used to test the consistency of adhesive strength. The bonding strength can be tested by stripping with a test disc or by testing a reference sample of stable quality.

T 556 om-05- Bending strength of paper and paperboard (Lorentzen and Wettre test method)

The method is to use a vertical fixture on a mN 38 mm wide sample to determine its bending strength with a deflection of 15° or 7.5°. Test the bending strength of paper and paperboard when passing through the machine longitudinally and laterally. The standard bending Angle is 15° ± 0.1°. A deflection of 7.5° ± 0.1° can be used for samples that are cracked or unsuitable for bending angles of 15°.

T 560 om-05 CIE Paper and board whiteness and color test (d/0 geometry, C/2 Luminescence/observation)

This method is used to measure white or near-white samples with or without the CIE whiteness and color index (1) of a visible brightening agent. The whiteness of paper is different from the brightness of paper because the entire visual spectrum is included in the whiteness measurement, while the brightness test only includes the blue part of the spectrum.

T 560 om-05-CIE Paper and board whiteness and color test (45/0 geometry, C/2 Luminescence/Observation)

The following modifications and additions to TAPPI test methods were approved on March 23, 2005:

T 411 om-05 Thickness of paper, board and multilayer board

The method is used to measure the thickness of a single sheet of paper, cardboard and multiple layers of cardboard, including the thickness of each layer in the multiple layers of cardboard. "Multilayer board" includes corrugated board and fiber board.

Because the transverse passage length of the selected sample is longer than the actual use when performing this test, the test result will have a certain deviation in this direction.

Since a relatively high pressure of 50kPa (7.3psi) was used in this test, it may not be suitable for materials such as paper towels or other soft or low density materials, which are prone to cracking (low thickness) at pressure of 50kPa.

TAPPI T 551 Thickness of paper and board (Soft disk test method)

The method is to measure the effective thickness of paper and paperboard products by using a soft rubber pressure disc. The value obtained by this method is smaller than that measured by TAPPI T 411.

T 480 om-05 Gloss of paper and paperboard

The method is to measure the gloss of the paper at 75° conditions (with the horizontal plane of the paper as a horizontal line, 15° position). Although this method is mainly for coated paper, it is also suitable for testing uncoated paper.

This method is suitable for low gloss and high gloss paper. TAPPI T 653 - "Test paper and board gloss at 20°" gives the best results for very high gloss papers such as cast coating, gloss oil, heavily coated paper or wax and ink films with high gloss. The T 480 has been shown to be suitable for gloss testing on most papers or paperboards with ink film. The color and reflection coefficient of the ink film can be ignored. For example, when white and black surfaces are tested equally, the gloss value of the surface of the white material will be higher than that of the black material.

This method cannot be used to test the reflection quality of patterns.

Moisture absorption of T 831 om-05 Corrugated core paper - Water drop penetration test

The water absorption rate of corrugated core paper is based on dripping water on the surface of the sample and determining the time in seconds for the water drop to penetrate from the surface to the lower layer.

This method is suitable for corrugated core paper and has been applied to commercial production. Not suitable for comparison of paperboards produced from different gram weights of paper.

There are three alternative methods, which can be carried out simultaneously. Different methods give different values.

TAPPI T 432 absorbent paper and TAPPI UM 596

Non-absorbent paperboards have been used to measure the water absorption of corrugated core paper, but studies promoting this method have shown that it lacks repeatability and is very time consuming, especially for some samples with strong water resistance.

The following are the changes and additions to the TAPPI test methodology in March 2004:

T 453 Characteristics of drying and heating on paper and board materials

This method is suitable for printing and writing paper, but can also be used as a measurement standard for other types of paper and paperboard.

Compressive strength of T 826 short box board

This method is suitable for boxes with a width to thickness ratio of 5 or less.