Source： Link Testing Instruments Co.,ltd
Blister packaging is a commonly used form of packaging for pharmaceutical products. The two parts are heat-sealed and combined by a hard sheet and aluminum foil to form a closed space that can contain drugs. In view of the fact that the blister eyes of the blister pack are not connected, one of the blister eyes is damaged and will not affect the sealing of the other blister eyes. Therefore, whether it is during the storage of the medicine or after taking out part of the medicine, Both blister packs have a good protective effect on medicines. In the actual production process, the strength of this protective effect of blister packaging is closely related to the strength of the heat sealing (heat sealing) between the hard sheet and the aluminum foil. If the heat-sealing strength between the hard sheet and the aluminum foil is low, and the bonding fastness is poor, the independence of the blister will be weakened, and the sealing performance will be reduced. It is easy to cause the drug to absorb moisture or the active ingredients are oxidized, and the efficacy of the drug is reduced. When the medicine in a blister, the adjacent blister eye is also destroyed, and the medicine is scattered. The heat-sealing strength of the hard piece and aluminum foil is not only related to the heat-sealing temperature, heat-sealing pressure, heat-sealing time and other heat-sealing parameters, but also affected by the surface properties of the two heat covers. Therefore, strengthen the heat-sealing strength of the blister packaging hard piece monitoring is of great significance for improving the quality of hard film and finished blister packaging.
Test method and instrument
The relevant standard for the heat seal strength test of blister packaging is YBB00182004 "Aluminum/Polyethylene Cold Formed Solid Medicinal Composite Hard Sheet".
The test can be divided into two parts. First, it is necessary to heat seal the aluminum/polyethylene composite hard sheet sample provided by the company, and then test the heat seal strength of the heat sealed sample. The test equipment used in the heat sealing process is the LTH-H3 heat seal tester, and the test equipment used for the heat seal strength test is the LTS-05 intelligent electronic tensile testing machine.
Test sample and test process
Test sample: This time, an aluminum/polyethylene composite cold-formed rigid sheet for blister packaging produced by an enterprise was used as the test sample.
(1) Cut 2 specimens of 90 mm × 100 mm along the longitudinal direction of the aluminum/polyethylene composite hard sheet sample.
(2) Turn on the power switch of the LTH-H3 heat-sealing tester, and set the heat-sealing temperature, heat-sealing pressure, and heat-sealing time to 155 ℃, 0.2 MPa, and 1.0 s, respectively.
(3) After reaching the set heat-sealing temperature, place the cut two pieces of sample polyethylene layer (contact), and put the short side (longitudinal) of the sample into one of the upper and lower heat sealing heads of the heat sealing tester. Make sure that the heat seal head is parallel to the short side of the sample.
(4) Step on the foot switch to close the heat sealing head and heat sealing the sample. After the heat sealing time is reached, the heat sealing head will automatically separate.
(5) Cut 2 specimens of 90 mm × 100 mm along the transverse direction of the aluminum/polyethylene composite hard sheet sample, and heat seal along the short side (transverse) of the specimen according to the requirements of (3) and (4).
(6) Cut 5 specimens each with a width of 15mm from the heat-sealed specimens in the direction perpendicular to the heat-sealed part to obtain 5 specimens each in the vertical and horizontal directions.
(7) Turn on the power switch of the intelligent electronic tensile testing machine, set the clamp distance to 50 mm, test speed to 300 mm/min, and sample thickness and other parameter information.
(8) With the heat-sealed part as the center, open the sample to 180°, and clamp the two ends of the sample in the upper and lower clamps of the intelligent electronic tensile testing machine, so that the axis of the sample is aligned with the upper and lower clamps of the intelligent electronic tensile testing machine. The center lines of the lower clamps coincide.
(9) Click the test option, the test starts, the device automatically records and displays the force curve during the test and the final test result.
Test results and analysis
The heat-sealing strength values of the five specimens in the longitudinal direction of the sample are 9.601 N/15mm, 10.131N/15mm, 9.972 N/15mm, 9.369N/15mm, 10.273 N/15mm, and the test results are the average of the test results of the five specimens. It is 9.869 N/15mm; the heat seal strength values of the 5 samples in the transverse direction are 7.379 N/15mm, 7.691N/15mm, 7.186 N/15mm, 7.607N/15mm, 7.924 N/15mm, and the average value is 7.557 N/15mm .
The heat-sealing strength of the aluminum/polyethylene composite hard sheet directly affects the sealing performance of the blister package formed by it, and it is also an important factor affecting the quality of medicines.
For more details of the heat seal tester LTH-H3 and Auto Tensile tester LTS-05 please visit our website www.linktesting.org