STH-3A Touchscreen Heat Seal Tester: Automatic Pressure and Printed Records for Documented QC

The STH-3A heat seal tester is operated from a touchscreen: sealing parameters are entered on screen instead of being set on dials. Sealing pressure is applied automatically, which removes manual pressure adjustment as a source of operator-to-operator variation. The temperature range is room temperature +10°C to 250°C with ±0.5°C accuracy — the highest temperature accuracy in the KHT STH line. A single 300 × 10 mm jaw makes one seal per cycle; the sealed specimen is then cut and peeled on a tensile tester to measure seal strength per ASTM F88.

A built-in printer outputs a paper record after each test, so the sealing conditions behind every specimen can be filed with the test report. For GMP-style documentation, printed records signed by the operator keep sealing parameters traceable alongside the ASTM F88 peel results from the tensile tester.

The STH-3A suits labs that seal at a defined temperature and need each run documented: (1) pharmaceutical packaging QC where printed sealing records support batch documentation; (2) flexible packaging film and laminate QC; (3) lithium battery pouch film checks at sealing temperatures around 200°C, within the instrument's 250°C range; (4) contract testing laboratories that need consistent, operator-independent sealing conditions across many client materials.

Choose the STH-3A when your sealing temperature is already defined and you want the tightest temperature accuracy (±0.5°C), automatic sealing pressure, and a printed record for every test. Choose the STH-5 when you need to find the sealing window: its five 40 × 10 mm jaws seal at five different temperatures in one cycle, mapping the seal curve and SIT in a single run. The two models serve different primary use cases — seal window development (STH-5) and documented routine QC (STH-3A).