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The Handsheet Testing Manual
Pulp and Paper Centre, UBC
by George Soong
E-mail: [email protected]
Phone: 604-822-2530, 778-835-2298
Office: 321 at PPC
Rev 2 Updated May 2, 2012 by Nici Darychuk
Handsheet Inspection and Preparations:........................................................................ 2
Brightness and Opacity: ................................................................................................... 3
Thickness Measurement: ……………………………………………………………….6
Cutting the Handsheets: ................................................................................................... 7 Tear Test: ........................................................................................................................... 8 Tensile Test: ....................................................................................................................... 9 Burst Test: ....................................................................................................................... 11
Zero-span Tensile Test: .................................................................................................. 12
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Handsheet Inspection and Preparations:
1) Remove the weight from the top of drying ring stack. Carefully “pop” the
pressing disc out of the ring. Gently peel off the handsheet without folding,
creasing, ripping, or delaminating (part of the paper surface sticks to the disc) the
handsheet. Repeat for the other handsheets. Pressing discs can be polished by
silicon spray before wet pressing to prevent delamination.
2) Inspect for visible deformations including wrinkles, bulges, or areas of
delamination (see figure 1). Use red marker to mark the defected areas.
Deformations in the middle are most detrimental and are not used for testing.
Take the selected handsheets that pass visual inspection and go to the analytical
balance.
Figure 1: Wrinkle on the edge of handsheet because of improper ring stacking.
3) Weigh the handsheets using analytical balance in draft shield. Record their
weights to 0.001 gram, and write them down on the edge of each handsheet.
4) Review the weights and select the 5 closest weights. You should not select any
handsheet in either weight extreme (avoid highest and lowest weights) even
though they may be close to the targeted 60 g/m2 basis weight.
5) If you have visually deformed handsheets, take them outside with a PE bag and
weigh them with the analytical balance beside the speed dryer and record the air
dry weight. Then place them inside the oven separately. Let the handsheets oven
dry completely until constant weight is reached.
6) Tare the aluminum cup and lid at ambient condition before the weighing of oven
dried handsheets.
7) Collect the oven dried handsheets, fold and shove them to the cup and close the
lid immediately and record the weight. Find the moisture content and fraction of
dried pulp material. You can do this by comparing oven dried weights and the air
dried of the handsheet. For handsheets made from TMP, the dry content is
usually ~90% or expressed as ~10% moisture content in CTH Room (Testing
environment: 50 ± 2 % RH; 23±1 ºC).
8) Find the mean weight of selected testing handsheets and multiply that by the
fraction of dry content (e.g. 1.34 AD g × 90% = 1.207 OD g). Multiply this value
by 50 and you have your grammage value (i.e. 1.207 g × 50=60.35 g/m2). (Area
of handsheet is 200 cm2
)
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9) Arrange 5 handsheets selected for testing with smooth sides up in order from
heaviest to lightest, then flip the stack, so that they are ordered from light to heavy
with the rough sides up.
Brightness and Opacity:
1) 30 minutes before testing, turn on the power of the brightness and opacity meter,
Technidyne ColorTouch PC, and let it warm up.
2) Select Technidyne ColorTouch icon at the Desktop (username: ubc, password:
ubc), go to File, click Open, select the method “Brightness, Opacity, Scat and
Absorp.” The measuring platform of “CONTROL COLOR TOUCH PC” shows
up (see figure 2). At the lower – right corner, select C/2º for the
[Fr]Illum/Observer.
Figure 2: Technidyne ColorTouch PC brightness and opacity meter.
3) Daily calibration: Go to Sample, click New, enter EW-80-mm-dd (or, if that
doesn’t work, EW-80-mmdd) to the Name, increase to 5 at the Readings, check
C(ISO) at Pad of Measurement Types.
4) Gently clean EW-80 tile (in the drawer under the computer) with Kimwipes paper
and load it on top of the sample stand (see figure 3). Engage it gently; don’t let
the sample stand bounce back by itself. If the tile gets cracked or scratched, it is
not usable for calibration.
Figure 3: EW-80 tile on top of sample stand and then engaged to the aperture for
daily calibration.
5) You must follow the instructions step by step as described at 13) Brightness
measurement to complete the calibration. Record the data to the Excel file
“Daily Calibration” on the desktop and to the logbook.
EW-80 tile
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6) Once calibration is completed, check to see if the R(x), R(y), R(z) and Brightness
values from your calibration are close enough (within ± 0.3) to that of the initial
calibration (in green font) posted on the logbook.
7) If the calibration drifts away, Primary Calibration must be carried out before
any measurements. Contact the Lab Manager.
8) For your samples, use the same measuring method, at the lower – right corner,
maintain C/2º for the [Fr]Illum/Observer.
9) Go to Sample, click New, enter your sample name to the Name, increase to 5 at
the Readings, check C(ISO) at both Pad and Single of Measurement Types.
10) Click OK to start the Measurement procedure.
11) Take your 5 handsheets to the brightness and opacity meter. You must handle
them with extra care, never touch the surface and use two pieces of blotters to
hold them to prevent damage.
12) Check that the paper pad (5 sheets) has every handsheet arranged with the rough
side up, in order of lightest to heaviest (see figure 4).
Figure 4: Paper pad on top of sample stand and then engaged to the aperture for
brightness measurement.
13) Brightness measurement: Lower the sample stand and place the paper pad to the
center. Click Measure to start the Pad reading #1. Follow the instruction to
proceed to the second reading. Lower the sample stand and take the pad out. Place
the first handsheet to the bottom of the pad and reload the pad to the sample stand.
Click Measure for the second reading and repeat the procedure until all sheets of
the pad are measured. Pad measurement is completed. The Measurement will
proceed to Single after the fifth Pad measurement is completed. Take the pad out
and place the fifth handsheet to the bottom of the pad. The first handsheet is on
top of the pad again. Note: Do not take brightness and opacity readings at the
edge of the handsheet, take readings at least 2 cm away from the edge.
14) Opacity measurement: Mount the black cup (in wooden box in cupboard) to the
sample stand and place the first handsheet on top of it, rough side up, and engage
gently (see figure 5). Click Measure to start the first measurement of Single.
When it is completed, take the first handsheet out, place the second handsheet for
the second measurement and repeat the procedure until every single sheet is
measured. Single measurement is completed.
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Figure 5: Single sheet is placed on top of black cup and then engaged to the aperture
for opacity measurement.
15) Once the two measurements are done, all the data shows up. Double click the
N/A of Grammage and enter the averaged basis weight of your handsheet. This
allows the program to calculate some additional values.
16) Write down your values, or use Print Screen to open an image of your results in
Paint.
17) If desired, to acquire the data for individual handsheets, go to File and click Open,
select the method Statistics. Currently the individual data cannot be exported to
Excel. You must write down the numbers. The individual data will be lost once it
is saved or the software is closed, only averaged numbers will be shown next time
you open it.
18) Data export: Go to Tools, select Data Export, and select Manual Export. Data
Export shows up, click the file to be exported at the Samples and Technidyne
Export Format 2008-01-04 at Export Formats, click Export.
19) Data import: Open a new Excel worksheet or an existing file. Go to Data, select
Import External Data, then click Import Data, Select Data Source window
shows up. Double click Technidyne Data, change Files of types to All Files.
Click the file you want to import to worksheet, click Open. Text Import
Wizard-Step 1 of 3 shows up, click Finish, Import Data window shows up,
select Existing worksheet or New worksheet, then click OK.
First handsheet
Black cup
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Thickness Measurement:
1) Take the 5 selected handsheets and go to the micro caliper L&W
MICROMETER after brightness and opacity measurements are done.
a. Zero the machine by pressing ZERO or ↑. Press ONLINE and then select
USE SPEC NO. by depressing “-“ or “+” .
b. Navigate to SPEC No. 1 which is programmed to measure each single
sheet. Then depress YES to confirm Spec No., depress ONLINE again to
start the measurements, depress YES and place first handsheet under the
spindle.
c. Replace with second handsheet, press YES and repeat until fifth handsheet
is measured.
d. Press REPORT to get the result, if you wish, you may edit the data if you
find that some of the measurements are off.
e. Press ONLINE to return to Spec. selection menu.
2) SPEC No. 5 is programmed to measure 5-sheet pad and the single sheet thickness
will also be given at the printout.
a. Insert the stack of 5 handsheets; all smooth sides must face up or must
face down, so that no two smooth or rough sides of the handsheets will
touch each other.
b. Each time move the pad around and test a different location. Stay 2-3 cm
from the edges at all times. Take 10-15 or however many readings until
you are satisfied.
3) Do not change the programs without training and Lab Manager’s approval.
4) Printer paper rolls are in the second drawer under the machine.
Figure 6: L&W MICROMETER and the handsheet pad being measured.
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Cutting the Handsheets:
1) Apparatus: Double-knife, 15 mm wide cutter and a single-knife cutter equipped
with a guide to make the tear test specimens 63 mm wide.
2) On the double-knife cutter, place in the stack of 5 handsheets so that the edges of
the handsheets touch the lines marked on the platforms. Use fingers to press the
edge of the stack firmly. Lower the knife slowly until the pressing bar holds the
stack then cut them in a quick stroke. The first tensile test specimen is on top of
the anvil. Remove it carefully by pulling one end toward you. Slide in the right
hand side piece on the anvil, with the edge slightly over the anvil. Take another
cut for another tensile test specimen. The semi-circle pieces left are used for burst
test (see figure 7). Note which piece belongs to which handsheet and basis weight.
Figure 7: Sequence of cutting tensile test strips and burst test specimens.
3) Take the stack of cut handsheets at the left hand side to the single-knife cutter.
Align the flat edge with the brown guiding bar. Cut them and note which
specimen belongs to which handsheet and basis weight (see figure 8). You will
have 10 tensile test strips, 5 burst and 5 tear test specimens, each of which you
know the basis weight (from which handsheet it comes from).
Figure 8: Sequence of cutting tear test pieces and overall test pieces.
4) You can discard the small curved tops of the handsheets. The trapezoidal pieces
will be used for tear test. Select 4 of these, making sure you know their basis
weights as well.
5) Always handle them carefully, do not bend or twist, or even touch the testing
areas of these specimens with bare hands.
6) For these next three tests, make sure that all machines are properly calibrated and
inputted with correct parameters for testing.
Burst specimens
Burst
specimens
Tear
specimens
Tensile
specimens
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Tear Test:
1) Apparatus: Elmendorf Tearing Tester, based on Tappi Method T 414.
2) Take your four selected trapezoidal pieces out of the five cut handsheets and
gently tap them on the table to align them. Load the stack (with the shorter flat
edge on the bottom) into the clamps approximately 1 cm away from the
edge/corner of the shorter flat edge. You need to perform 4 tears so align them
evenly.
3) Select mNt and 4 PLIES for the test.
4) Lock the clamps by flipping the switch up, then use the swing-in knife to precut
the sheets. Release the pendulum by depressing the Pendulum Stop (see figure 12).
Note: when you release the pendulum, you must depress and hold the metal
bar/level (Pendulum Stop) at the base of the machine. Hold the bar down the
entire time! When the pendulum returns, catch it and release the bar to lock it
back in place. Record the value.
Figure 12: Sequence of tear test. On the left, clamp and precut specimens; in the
middle, depress the Pendulum Stop to let go of the pendulum to tear the specimen; on
the right, pendulum swings to tear handsheet pad.
5) Repeat for the other 3 tears (see figure 13). Note: acceptable tears should be quite
straight and perpendicular to the flat edges. Once you are done, press A for
average; S for standard deviation; D for difference of highest and lowest; I for
numbers of tears and sequence of individual result; RC for recall latest result; P
for printer; CM for clear memory.
Figure 13: Sequence of second tear test: clamp the larger pad that is left from the tear,
precut, then depress the Pendulum Stop to let go the pendulum.
6) If your result drifts away from normal range, please check the quality of
handsheets and the tear patterns. If nothing is wrong with handsheet and machine
setting, please call lab technician to carry out calibration check.
Precut Depressing
Pendulum
Stop
For second tear
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Tensile Test:
1) Apparatus: L&W Tensile Strength Tester based on Tappi Method T 494.
2) Daily calibration: Calibrate and set the parameters for the machine by reading and
following the instructions next to the machine. Use a ruler to make sure the span
is 10 cm (100mm) between the clamps.
3) Press CTRL 9 to exit a current program.
4) Depress PF5, enter 1 to Function Nr. Then depress YES to the multiple queries
that come up to carry out the calibration. Record REF. VALUE and CHECK
VALUE to the logbook. Depress STOP to exit the calibration procedure.
5) The parameter of tensile strength test of standard 60 g/m2 handsheets is based on
Tappi Method T 494.
6) Depress PF2 to call SPEC NO. 99 to carry out test by entering values as described
below. Or, depress PF1 to set up your own parameters for a specific test method.
7) Depress PF2; SPEC No. 99 YES: COMMUNICATION? NO; No. OF TEST
PIECES: 10 YES; POSSIBLE TO QUIT BEFORE FULL COUNT: YES; PRINT
REPORT: YES; MEAN VALUE: YES; PRINTS OF INDIVIDUAL RESULTS:
YES; PRINTING OF NON APPROVED: YES; INDEXED PRINTOUT: YES;
trigF%: 1 YES; deltaF: 1 YES; RESOLUTION MICRO METER: 10 YES;
RUPTURE LEVEL %: 50 YES; TIME s: 20 YES; VELOCITY mm/min: 25
YES; LOAD CELL 200N?: YES; GAIN 1: YES; BREAKING LENGTH: YES;
STIFFNESS EVALUATION: YES; dF/dL UPPER END %:100 YES; dF/dL
LOWER END %: 0 YES; STIFFNESS POINTS: 10 YES; TEST SPAN mm: 100
YES; STRIPWIDTH mm: 15 YES; GRAMMAGE g/m2: 60 (or exact value of
handsheet being tested) YES; THICKNESS µm: 100 (or exact value of handsheet
being tested) YES; SAMPLE No. 001 YES; EXTRA IDENTIFIERS: NO;
EXTRA HEADERS: NO; DRY SAMPLES: YES; MACHINE DIRECTION:
NO; CROSS DIRECTION: NO; TEST PIECE No. 1? Place the strip in the
clamps (see below) then press YES to start the test.
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8) See Figure 9. Slip in the strip by pushing both ends into the L-shaped hydraulic
clamps, and make sure that the strip is aligned properly along the inscribed line or
the back of the clamps. Depress YES to start the first piece when asked TEST
PIECE NO 1? Repeat for the other 9 strips. Again, make sure you know which
strip came from which handsheet and basis weight. Note: If breaking line occurs
closer than 1 cm to one of the clamps, the reading may be affected. If data seems
off, discard that reading.
Figure 9: Sequence of tensile strength testing. On the left, slip in the tensile strip; in the
middle, the strip is being tested; on the right, slip out the broken strip.
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Burst Test:
1) Apparatus: Mullen Tester, based on Tappi Method T 403.
2) Turn on power of control panel and motor.
3) Place the handsheet semi-curve piece over the diaphragm, making sure that the
area of testing is well away from the edges. You must perform two tests per sheet
so leave enough room for a second burst test. Lock it into place by sliding down
the aluminum ring at the compressed air inlet, the plunger engages (see figure 10).
Press METER RESET to zero value. If it is not exactly zero, Switch the TEST
MODE to TRACK then turn the ZERO knob to bring the reading to 00.0. Switch
the TEST MODE back to PEAK. Press METER RESET again. Turn the red
needles of pressure gauges to 0.
4) Pull the level bar to the START. When the sheet bursts, pull the level bar to the
REVERSE until the diaphragm deflates then bring the level bar to the middle.
Record the burst value and check the value of control panel and the gauge
positions.
Figure 10: Engage the clamp to hold the test piece in place for the first burst.
5) Release the plunger by pulling up the aluminum ring, then flip the semi-curve
piece over and repeat the above steps. Adjust the position of testing area so there
is no clamp mark within it. Overall, there will be 5 readings on smooth side and 5
readings on rough side (see figure 11).
Figure 11: Flip the test piece to carry out second burst test on the other side.
6) If your results drift away from the normal range, please check the quality of
handsheets and ZERO setting first. If nothing is wrong with handsheets and
machine setting, please call Lab Manager to carry out calibration check.
Engage
clamp
Flip to the
other side Burst on each side
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Zero-span Tensile Test:
1) Apparatus: Pulmac Zero-span Tensile Tester based on Tappi Method T 231.
2) Switch power on (left side wall) and check the compressed air is at 60 psi.
3) Place the 2×10 cm strip over the platform, Slide in the strip by pushing both ends
into the hydraulic jaws and make sure that the strip is aligned properly and hit the
back of jaws (see figure 14).
Figure 14: Pulmac Zero-span Tensile Tester and the jaws assembly.
4) Flip the TEST switch to On (leftward) to have jaws engaged. Disengage the jaws
by flipping the TEST switch to Off (rightward) and remove the broken strip out of
the jaws (see figure 15). Repeat for the other 9 strips.
Figure 15: Left: Jaws clamp on the strip and pulling it apart; Right: The breaking
line at the center of strip.
5) For wet zero-span tensile test (Tappi Method T 231), use a dropper to drop just
enough water to wet the central area of the strip after it is placed under the jaws.
Testing procedure is the same as step 4).
***End of Handsheet Testing***