Hot Tack Tester
Hot Tack Tester - ToronHTT™ 1921
Hot Tack and Heat Seal Strength Tester for Flexible Packaging
The ToronHTT™ 1921 is a hot tack tester that measures the hot tack and heat-seal strength of flexible packaging films. The instrument seals a specimen between two heated jaws at a set temperature, pressure, and time, then peels the seal at a servo-controlled speed and records the force. Testing while the seal is hot gives the hot tack; testing after cooling gives the heat-seal strength.
The ToronHTT™ 1921 controls the sealing temperature to 300°C with independent upper and lower jaws, and a servo drive sets the peel speed over 0.5 to 3000 mm/s. A strain-gauge sensor holds the sealing pressure steady, and sealing and cooling times set to the millisecond. Hot tack, peeling, and overlay curves display directly.
Automatic clamps, sample auto-feed, and foot-pedal operation speed repeated tests, and the standard 0-100N force range extends to 500N as an option. The ToronHTT™ 1921 (Hot Tack and Heat Seal Strength Tester) suits flexible-packaging, film, and converting labs that set and verify sealing conditions. Ethernet and USB ports support data handling and traceability.
Hot Tack Tester - ToronHTT™ 1921 Applications
The ToronHTT™ 1921 measures sealing performance wherever a heat seal must form correctly and hold.
- Form-Fill-Seal Films: measures hot tack so seals hold product weight before cooling on form-fill-seal lines.
- Flexible Packaging Films: measures the heat-seal strength of packaging films and laminates.
- Sealing Window Development: maps seal strength against temperature to find the sealing window.
- Laminates and Coextrusions: tests multilayer structures with independent upper and lower jaw temperatures.
- Sealant and Resin Development: quantifies hot tack and seal strength for sealant formulation.
- Lidding Films and Trays: characterizes lidstock sealing to trays and cups.
- Medical and Food Packaging: verifies sealing conditions for pouches and sachets.
- Quality Control: verifies sealing performance against specification batch to batch.
Standards
The ToronHTT™ 1921 is designed to align with internationally recognized standards for hot tack and heat-seal strength testing.
- ASTM F1921 - Standard Test Methods for Hot Seal Strength (Hot Tack) of Thermoplastic Polymers and Blends Comprising the Sealing Surfaces of Flexible Webs
- ASTM F2029 - Standard Practice for Making Heat Seals for Determination of Heat Sealability of Flexible Webs as Measured by Seal Strength
- DIN 55571 - Testing of Packaging Materials: Hot-Tack Measurement of Heat-Sealable Webs
Hot Tack Tester - ToronHTT™ 1921 Key Features
The ToronHTT™ 1921 pairs servo-controlled peeling with precise temperature, pressure, and time control for sealing analysis.
- Hot Tack and Heat-Seal Strength: measures seal strength both while hot and after cooling on one instrument.
- Servo-Driven Peeling: a servo drive sets the peel speed over 0.5 to 3000 mm/s for accurate, repeatable results.
- Sealing Temperature to 300°C: independent upper and lower jaw temperatures suit asymmetric structures.
- Precise Time Control: sealing and cooling times set from 0.1 s with 10 ms resolution.
- Strain-Gauge Pressure Control: a strain-gauge sensor holds the sealing surface pressure steady and consistent.
- Selectable Force Range: a 0-100N standard range, with 0-50N, 0-250N, and 0-500N options.
- Automatic Clamps and Auto-Feed: air-activated clamps and sample auto-feed speed repeated tests.
- Direct Curve Display: hot tack, peeling, and overlay curves display directly for comparison.
- Touchscreen and Foot Pedal: a touchscreen and foot pedal give flexible, hands-free operation.
- Traceable Data: parameters are quantified, visualized, and traceable, with Ethernet and USB ports.
- Safety Guards: guards and safety switches protect the operator during sealing.
Theory and Method
Hot tack is the strength of a heat seal while it is still hot, before the sealed film has cooled and set. It matters on form-fill-seal lines, where a freshly made seal has to hold the weight of the product before it has time to cool. A weak hot seal can open under that load and spill the contents.
The instrument makes a seal by pressing the film between two heated jaws at a set temperature, pressure, and dwell time. It then peels the seal apart at a controlled speed and records the force. For hot tack, the peel happens immediately, while the seal is still hot; for heat-seal strength, the seal is peeled after it cools.
Running the test across a range of sealing temperatures builds a curve of seal strength against temperature, which shows the sealing window: the temperature range that gives a strong seal without burning or distorting the film. A servo drive sets the peel speed precisely, and independent upper and lower jaw temperatures suit asymmetric structures.
Hot Tack Tester - ToronHTT™ 1921 Technical Specifications
| Parameter | Specification |
|---|---|
| Sealing Temperature | Ambient to 300°C |
| Temperature Resolution | ±0.1°C |
| Temperature Accuracy | ±0.2°C |
| Sealing Jaws | 10 mm × 40 mm standard (5 mm, 15 mm optional) |
| Sealing Pressure | 0.1 to 4.0 N/mm² |
| Sealing Pressure Sensor | Strain gauge |
| Sealing Pressure Resolution | 0.01 kgf |
| Sealing Pressure Accuracy | 0.09 kgf |
| Sealing Time | 0.1 to 999.9 s (10 ms resolution) |
| Sealing Time Control | ±20 ms |
| Cooling Time | 0.01 to 999.9 s |
| Hot Tack Force Range | 0-100 N standard (0-50 N, 0-250 N, 0-500 N optional) |
| Hot Tack Force Accuracy | Max 0.01% FS |
| Peeling Speed | 0.5 to 3000 mm/s (servo controlled) |
| Sample Length | Greater than 300 mm |
| Sample Width | Less than 40 mm (standard) |
| Sample Thickness | Less than 1 mm (flexible) |
| Gas Supply | 5 to 8 bar (user-supplied) |
| Gas Interface | Ø6 mm |
| Voltage | 85-250 VAC, 50/60 Hz |
| Dimensions | 390 mm (L) × 420 mm (D) × 730 mm (H) |
| Net Weight | 79 kg |
Standard Delivery
| Item | Description |
|---|---|
| Main Unit | Servo-driven hot tack and heat-seal test instrument |
| Computer | Dedicated control PC |
| Foot Pedal | Foot-pedal control for hands-free operation |
Optional Accessories
| Item | Description |
|---|---|
| Strip Sample Cutter | Cuts test strips to width (10, 15, 20, 25.4 mm on demand) |
| Sample Plate | Sample preparation plate |
| High-Temperature Cloth | Protective cloth for the sealing surface |