Testrite MK 5 Thermal Shrink Force Tester

Overview

The Testrite MK 5 Thermal Shrink Force Tester is a precision-engineered, portable instrument designed for the quantitative measurement of thermal shrink force and shrinkage percentage in polymeric films, heat-shrink tubing, labels, and packaging materials. It operates on the principle of controlled thermal exposure followed by real-time force transduction via high-speed load cells, enabling direct quantification of axial contraction force (in Newtons or % strain) as specimens undergo programmed thermal transitions. Unlike conventional single- or dual-channel systems, the MK 5 implements a synchronized four-channel measurement architecture—allowing concurrent analysis of up to four independent samples under identical thermal profiles—thereby enhancing throughput, inter-sample comparability, and statistical robustness in quality control and R&D environments. Its fully integrated microprocessor-controlled system eliminates dependency on external PCs during basic operation, while optional USB/RS-232 connectivity enables full computer-based protocol management and data logging.

Key Features

• Four-channel simultaneous testing architecture—reduces batch analysis time by up to 75% versus legacy dual-channel instruments
• Stainless steel ruggedized chassis with IP54-rated enclosure—engineered for field deployment, laboratory mobility, and long-term mechanical stability
• Zero-wait startup: No preheating required; thermal chamber achieves setpoint within <60 seconds and maintains ±0.25 °C uniformity across the full 20–250 °C operating range
• Integrated high-resolution LCD display with tactile, ergonomically spaced three-button interface—designed for gloved operation and low-cognitive-load workflow
• Low-acoustic operation (<55 dB(A)) achieved through brushless DC heating control and vibration-damped sensor mounting
• Self-contained operation: All critical functions—including timer (0.1–99.9 min), temperature ramping, force acquisition, and result calculation—are executed onboard without peripheral hardware
• Transport-ready design: Integrated telescopic handle and recessed casters housed in a shock-absorbing molded transit case (total gross weight: 25 kg)

Sample Compatibility & Compliance

The MK 5 accommodates standard ASTM D2732-compliant film strips (typically 12.7 mm × 100 mm), heat-shrink sleeves (up to Ø40 mm × 80 mm length), and label substrates with thicknesses ranging from 25 µm to 500 µm. Specimen clamping employs spring-loaded, parallel-jaw fixtures with PTFE-coated contact surfaces to prevent slippage or surface deformation during thermal contraction. The instrument conforms to ISO 11359-2 for thermomechanical analysis of polymers and supports traceable calibration per ISO/IEC 17025 requirements when used with accredited reference standards. Its operational envelope meets IEC 61000-4 electromagnetic compatibility criteria and carries CE marking for safety compliance within the European Economic Area.

Software & Data Management

While functional as a standalone unit, the MK 5 supports optional PC integration via USB virtual COM port. The companion software (Windows 10/11 compatible) provides full protocol scripting—including multi-step temperature ramps, dwell times, and conditional trigger logic—and exports CSV/Excel-formatted datasets with embedded metadata (operator ID, timestamp, ambient RH/T, calibration certificate ID). Audit trails record all parameter changes and result overrides in accordance with FDA 21 CFR Part 11 requirements when configured with user authentication and electronic signature modules. Raw sensor output (16-bit ADC resolution, 100 Hz sampling) is retained for post-hoc reanalysis, and report templates comply with GLP/GMP documentation standards.

Applications

• Quality assurance of shrink sleeve labels in beverage and pharmaceutical packaging lines
• R&D evaluation of novel polyolefin, PETG, and PVC-based shrink films under accelerated aging conditions
• Validation of thermal stability in medical device heat-shrink insulation tubing (ISO 13485 environments)
• Comparative shrink force profiling across supplier batches to detect resin formulation drift
• Field verification of shrink performance in cold-chain logistics packaging exposed to variable ambient temperatures
• Teaching laboratories demonstrating polymer viscoelastic response to thermal stimuli (ASTM D638/D882 correlation studies)

FAQ

Does the MK 5 require annual recalibration?
Yes—recommended annually or after 500 test cycles, using NIST-traceable force and temperature standards. Calibration certificates include uncertainty budgets per ISO/IEC 17025.
Can it measure both shrink force and shrinkage percentage simultaneously?
Yes—the four-channel system outputs real-time force (N) and dimensional change (%), calculated from calibrated linear displacement sensors synchronized with load cell readings.
Is the temperature chamber uniformity validated across all four channels?
Yes—uniformity mapping per ASTM E2203 confirms ≤±0.25 °C deviation at any point within the active zone during steady-state operation.
What sample preparation tools are included?
Standard kit includes stainless steel cutting template, digital caliper (0.01 mm resolution), and alignment jig for repeatable specimen positioning.
Is firmware upgradeable in the field?
Yes—via USB flash drive using signed binary files; version history and changelogs are published on Testrite’s secure support portal.