To determine the degree of shrinkage that will occur when polyolefin tape is subjected to heat for a specified length of time.

2.  Method PP (polypropylene) woven sack  tape

5 randomly selected tape samples are cut to the exact length of 100 cm (39.37”).  These are then put in an oven at a constant temperature of 270°F (132°C) for a duration of 15 minutes.  The pp sack tapes are removed from the oven and allowed to cool.  The tapes are then measured and the percentage of shrink is calculated from the difference between the original length and the reduced length after the oven, all divided by the original length.

3.  Apparatus

a)      A 100 cm base sample cutting board.

b)      Cutting blade.

c)      Magnetized pot (for PE tape only)

d)     Induction hot plate.  (for PE tape only)

e)      Tongs.  (for PE tape only)

f)       Oven at 270°F.  (for PP tape only)

g)      Stop clock.

h)      Calibrated Ruler with divisions in cm.

a)      Using the cutting board and taking care not to stretch the tape, cut from 5 randomly selected packages of pp woven tape, exact 100 cm lengths.

b)      Put the samples in the oven at 270°F and start the time clock.

c)      After 15 minutes, remove the samples from the oven and allow them to cool.

d)     Measure the length of the tapes and compare to the original length of 100 cm.  The percentage of shrink is equal to the difference between lengths divided by the original length.

e)      Record under the shrinkage column of the Quality Control Tape Results sheet the individual shrinkage of each tape and the average of the five values.

f)       Check the results against the average maximum percentage of shrink listed in the applicable product specification (TD 900 series).