Straubel Paper Company
Straubel Paper Company
Straubel Paper Company
Straubel Paper Company
Straubel Paper Company
Straubel Paper Company

Scrim Test Procedures

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Following are the test procedures presently used to test scrim tissue laminate. A sample, about 6 feet multiplied by full web width, is taken from the outside of each finished roll off the laminator. The roll number, order number and the date run on the laminator are recorded on the top of the sample. A sample for moisture content is also taken and placed in a polyethylene bag so the moisture content will not change before it is tested.

BASIS WEIGHT TEST...From the sample off the finished roll from the laminator or rewinder, cut on 24 inches x 36 inches sample which is then conditioned according to TAPPI procedure T-402 in the laboratory. Weigh the sample on the metric scale recording the results to two places after the decimal point. Convert to pound per 3000 sq. ft. using the following formula: Weight of Sample / 453.6 x 500 = pounds/3000 sq. ft.

Note 1: Sheet samples for weighing must be cut very accurately. A maximum error of 1/16 inches in one direction is acceptable. If error is greater that this, the area of the sheet must be measured and a correction in basis weight made using the following formula:
Measured area multiplied by basis weight calculated by dividing above formula by 864
Note 2: As long as samples coming from the scrim laminator contain less than 4.5 percent moisture, it is not necessary to precondition the samples.

C.D. WET TENSIL TESTING...Cut sample 10 inches long by 6 inches - 7 inches wide (long being in the cross direction). From these cut 9 samples on the strip cutter making sure each sample contains three continuous strings in the long direction. Condition the samples in the oven at 221 degrees Fahrenheit for 4 minutes.

Remove the samples from the oven. Fold the sample approximately in half and dip the folded end in distilled water approximately 1/8 inches. Shake off any excess water. Clamp it in the tensil tester making sure the ends are placed in the clamps so the clamped edges are parallel. Pull the samples to failure. Record the results of each of the 9 tests, record the individual test results, determine and record the average.

BIO-SCRIM™...When running BIO-SCRIM™, the wet tensil test is run the same way, except the sample is wet using a Finch cup testing device clamped in the tensil tester. The results are then divided by two to obtain the wet strength value.

Note: The Finch cup is used in testing BIO-SCRIM™ because the strength of rayon is much more sensitive to wetting than is nylon.

C.D. DRY TENSIL TESTlNG...Cut samples 10 inches long by 6 inches-7 inches wide. Condition the sheets in the laboratory until they reach equilibrium moisture per TAPPI Procedure T-402. As long as the moisture content of the material coming off the laminator is below 6.0 percent moisture, it is not necessary to precondition the sheets prior to testing them.

After conditioning, cut the samples on the strip cutter making sure that each sample contains 3 continuous threads. Cut 3 samples. Pull the samples in the tensil tester and record the results. Determine the average of the 3 samples and record.

WATER ABSORPTION CAPACITY...Condition samples in accordance with TAPPI T-401. (We find conditioning makes no significant difference, so for normal quality control testing this step may be omitted.) Weigh each sample of 4 inches x 4 inches, +/- 1/8 inches, immerse them in distilled water at 25 degrees C for 3 minutes, +/- 10 seconds. Remove the samples by lifting them at one corner until their surfaces are vertical to the floor and allow the excess water to drain off for 60, +/- 10, seconds. Place each in a tared weighing bottle and reweigh. Calculate the percent absorption to the nearest one percent as follows:

Wet weight - Dry weight divided by Dry weight multiplied by 100 = Absorption pct.

OIL ABSORPTION RATE...Follow the procedure as outlined above for water except use Drakeol 9 LT-N.F. (from R.M. Stefensen Company. Phone 810-474-7878) in lieu of water. Drain time for the immersed sample should be 20 +/- 2 minutes.

WATER ABSORPTION RATE...The test is run according to TAPPI procedure T-432, except that 0.1 mL of water is used. Cut samples 4 inches x 4 inches. Support so that the center is free, not touching anything. Drop 1/10 mL of distilled water onto the center of the paper. Determine and record the time it takes the shiny spot to disappear.

MOISTURE CONTENT...Samples for moisture determination will be delivered to the lab in plastic bags so that the moisture content does not change significantly between the time the sample is taken and the test performed.

The sample should weigh at least 10 grams. Weigh the sample and record the weight. Unfold the sample sufficiently so that it will easily dry in the oven at approximately 200 degress F. for 30 minutes. Then remove and reweigh the sample immediately. The weight loss, as a percentage of the sample weight, is reported as the moisture content. Report to one place beyond the decimal point.

TAPE TEST FOR BOND...A full web width is laid on a flat surface. A piece of 2-inch wide polypropylene tape is laid on top of the sample and pressed down hard, so it is well attached to the tissue. The tape is then pulled away from the laminate, starting at one side and pulling across the web so the there is an acute angle between the two outside surfaces of the tape. Both sides are to be tested. The result is valued at A, B, or C according to our bond standard. Anything lower than C is rejected.

STACK HEIGHTS... 100 sheets - 4 inches x 4 inches are cut from the sample and the height of the stack is measured twice. The first measurement is taken with no weight on the stack and the second is taken with the Stack Height Tester. Without the weight, the stack should be between 2 1/2 inches - 3 1/2 inches. With the weight, the stack should be no more than 1 1/8 inches for East Texas Lighthouse and no more than 1 1/4 inches for the other Lighthouses. (Whenever such information is required for other grades, this will be indicated on your specification sheets.)

A piece of each sample, full web width, by approximately 1-inch long, with identification, is retained in the lab. For material which we are required to certify properties, a sample of each finished, rewound roll is checked in the laboratory for all critical properties, the result recorded, and a piece of this sample is retained. The results of this test are recorded also.

Note: When testing samples off the scrim machines, it is only necessary to test every other roll. If, however, some property in the roll is out of specification, the intermediate sample that was not checked must be checked for that property.

Straubel Paper Company
Straubel Paper Company