T 829 om-03

PROVISIONAL METHOD – 1989

OFFICIAL METHOD – 1996
REVISED – 2003
2003 TAPPI

The information and data contained in this document were prepared

by a technical committee of the Association. The committee and the
Association assume no liability or responsibility in connection with
the use of such information or data, including but not limited to any
liability under patent, copyright, or trade secret laws. The user is
responsible for determining that this document is the most recent
edition published.

CAUTION:
This Test Method may include safety precautions which are believed to be appropriate at the time of publication of the method. The intent of these
is to alert the user of the method to safety issues related to such use. The user is responsible for determining that the safety precautions are complete
and are appropriate to their use of the method, and for ensuring that suitable safety practices have not changed since publication of the method. This
method may require the use, disposal, or both, of chemicals which may present serious health hazards to humans. Procedures for the handling of
such substances are set forth on Material Safety Data Sheets which must be developed by all manufacturers and importers of potentially hazardous
chemicals and maintained by all distributors of potentially hazardous chemicals. Prior to the use of this method, the user must determine whether
any of the chemicals to be used or disposed of are potentially hazardous and, if so, must follow strictly the procedures specified by both the
manufacturer, as well as local, state, and federal authorities for safe use and disposal of these chemicals.

Score quality test

1. Scope

This procedure describes a qualitative method for evaluating the relative quality of scores in corrugated containers.

2. Significance

2.1 Set-up and case sealing of a corrugated KD box on production equipment will depend on various factors,
one of which is the quality of both panel and flap scores found on the corrugated box.
2.2 It is the purpose of this procedure to provide a consistent means for determining the relative quality of
scores in corrugated containers. This procedure determines the force required to break scored and unscored board, and
by calculating an abstract ratio (in %) of the force required to break the scored board to that of unscored board, relative
information on the quality of the score can be ascertained. By comparing this abstract tested ratio to an established range
of ratios based on materials that perform well, a pass/fail criteria can be determined by each manufacturer.
2.3 This method will not determine score spring-back force or board memory that may exist, nor does it
measure forces required to bend entire flaps or panels.
2.4 This procedure is intended to provide information on score quality for a given combined board and is
intended for single wall and double wall board. It may be used for triple wall, but with less reliability.

3. Apparatus1

3.1 A device capable not only of applying a force at a constant speed of 0.8 mm/sec (0.031 in./sec), but also
allowing a minimum of 12.7 mm (0.5 in.) travel, or a sufficient amount of travel to ensure a maximum 90° bend of the
test sample.
3.1.1 A U-shaped channel having an internal width of 27 mm (1.063 in.), an internal depth of 22 mm (0.87 in.),
a wall thickness of 1.6 mm (0.063 in.), and an edge radius of 0.25 mm (0.01 in.), with an overall length of 102 mm (4.0
in.) (see Fig. 1).

1
Names of suppliers of testing equipment and materials for this method may be found on the Test Equipment Suppliers List in the
bound set of TAPPI Test Methods, or may be available from the TAPPI Quality and Standards Department.

Approved by the Standard Specific Interest Group for this Test Method
TAPPI
T 829 om-03 Score quality test / 2

Fig. 1. Dimensions of test devices.

3.1.2 A pressure bar having a thickness of 1.6 mm (0.063 in.), and an edge radius of 0.13 mm (0.005 in.), with
an overall length of 102 mm (4.0 in.) (see Fig. 1).
3.2 Force gauge or load cell capable of measuring and indicating the applied force to within ± 1% or 2.5N
(0.56 lbf) whichever is greater and must have sufficient capacity so that all readings can be maintained in the middle half
of the scale.
3.2.1 Force gauge or load cell should be attached to the stationary (non-moving) member of the device.

4. Test specimens

4.1 From each test unit of a sample obtained in accordance with TAPPI T 400 “Sampling and Accepting a
Single Lot of Paper, Paperboard, Containerboard, or Related Products,” test specimens should be free of defects and will
include all unbroken scores, in both the machine and cross-machine direction.
NOTE 1: Samples should be taken at least 12.7 mm (0.5 in.) from any cut edge to eliminate any crushing influence.

4.2 Both scored and unscored test samples should be cut at least 25.4 mm (1.0 in.) in width (length of score)
and of sufficient length to allow enough board present to test a scored and unscored area from the same test sample (see
Fig. 2). If there is insufficient sample length to perform the unscored bend test, obtain an unscored board specimen, cut
to the same sample width as the scored specimen, from other unused sections of the board sample.
3 / Score quality test T 829 om-03

Fig. 2. Scores parallel and perpendicular to flutes.

5. Conditioning

5.1 Condition and test specimens in an atmosphere in accordance with TAPPI T 402 “Standard Conditioning
and Testing Atmospheres for Paper, Board, Pulp Handsheets, and Related Products.”
5.2 If TAPPI conditions cannot be achieved, report temperature, humidity and sample moisture content in
accordance with TAPPI T 412 “Moisture in Pulp, Paper, and Paperboard.”

6. Test procedure

6.1 Ensure gauge or lead cell is properly calibrated.

6.2 Place a scored specimen, single face upward, directly on top of the U-shaped support, so that the score
and pressure bar are both centered within the U-channel (see Fig. 3). This will determine score break force (i.e. bending
in direction of intended fold).

Fig. 3. Scored specimen.

6.2.1 If measuring the score prebreak force (i.e. bending in opposite direction of intended fold), the test sample
should be placed with DB (outside) liner up.
T 829 om-03 Score quality test / 4

6.3 Zero the force gauge.

6.4 Initiate test and record maximum load.
6.5 Repeat 6.2 - 6.4, this time positioning the specimen to determine the force required to bend an unscored
section of corrugated board (see Fig. 4).

Fig. 4. Unscored specimen.

6.6 Repeat steps 6.2 - 6.5 using established “control” board if available.

NOTE 2: When determining the force required to bend an unscored section of board in the cross-machine direction (scores parallel to flutes),
the pressure bar should be positioned directly over a flute tip (Fig. 4).

7. Sample quantity

7.1 Number of samples required to compare to an established range should be 10. In the event box size does
not allow obtaining 10 samples, a minimum of 5 samples should be used.

8. Interpretation of observations

8.1 The abstract score ratio is determined as follows:

Score ratio in % =
average force to break the score
× 100
average force to break unscored board

If the score ratio of suspect samples is outside of the agreed upon range a “fail” grade is given; if the score ratio is within
the agreed upon range a “pass” grade is given.

9. Report

9.1 The report shall include the following: specimen width used (length of score tested), number of samples
tested, and the pass/fail grade.
9.2 In the event that specimens were not conditioned to or tested at TAPPI T 402, report temperature,
humidity, and board moisture content, as determined in accordance with TAPPI T 412.
5 / Score quality test T 829 om-03

10. Precision

A precision statement is inappropriate for this method because of its qualitative nature.

11. Keywords

Scores, corrugated boards, container boards, corrugated boxes.

12. Additional Information

12.1 Effective date of issue: May 13, 2003.

Your comments and suggestions on this procedure are earnestly requested and should be sent to the TAPPI Director
of Quality and Standards. g