Heat Seal Testing Blog: Technical Resources for Packaging Labs
Practical guides, ASTM/ISO standard explainers, and application-specific tutorials written for packaging engineers, QC managers, and lab technicians.
Buying Guides & Model Comparison
How to choose the right heat seal tester for your lab, budget, and testing standard
Heat Seal Tester Buying Guide 2026: The Complete Lab Equipment Selection Framework
Choosing the wrong heat seal tester costs more than the price difference — it costs the time of repeated testing, failed qualifications, and equipment that doesn't match your standard. This 2026 guide walks through the five key selection criteria.
STH-3 vs STH-3A vs STH-5: Complete KHT Heat Seal Tester Model Comparison
All three KHT STH heat seal testers comply with ASTM F88 and F2029. The difference lies in gradient capability, data output, and interface. Here's the complete side-by-side breakdown.
Manual vs Digital vs Touchscreen Heat Seal Tester: The Definitive Comparison for Lab Managers
The control interface of a heat seal tester affects accuracy, traceability, throughput, and compliance capability. Here's exactly when each type makes sense.
Why 5-Position Gradient Testing Finds Your Optimal Heat Seal Window in One Run
Single-point heat seal testing answers the question 'does this seal meet spec?' Gradient heat seal testing answers 'what is our optimal sealing temperature, and how much safety margin do we have?' The difference is the difference between QC and process understanding.
Heat Seal Strength Tester vs Seal Integrity Tester: The Real Difference (and When You Need Both)
A dye-penetration seal test can pass at a resolution of about 0.002 inches and still miss a leak path several orders of magnitude smaller than that limit. A heat seal strength tester and a seal integr...
Heat Seal Tester Specifications: The Two Numbers That Actually Matter
We lost an inquiry from a US medical-device OEM before pricing ever came up. Their first email asked for a complete specification sheet, and the time it took to compile one ended the conversation befo...
Application Guides
Industry-specific heat seal testing protocols for pharmaceutical, food, film, and battery packaging
Heat Seal Test for Pharmaceutical Blister Packaging: ISO 11607 and ASTM F88 Protocol
Pharmaceutical blister pack seal integrity is a patient safety issue. This guide covers the complete heat seal testing protocol — from equipment setup to acceptance criteria — per ISO 11607 and ASTM F88.
Heat Seal Strength Testing for Food Packaging Films: Preventing Failures Before They Reach Consumers
Food packaging seal failures cause contamination, spoilage, and recalls. ASTM F88 heat seal testing with the KHT STH-3A provides the quantitative data to prevent them.
Lithium Pouch Cell Heat Seal Testing: Ensuring Aluminum Laminate Film Integrity for Battery Safety
Seal failure in a lithium pouch cell allows electrolyte leakage, moisture ingress, and in worst cases, thermal runaway. This guide covers the complete ASTM F88-based testing protocol for aluminum laminate film at the 200°C specification.
Lab Film Heat Seal Testing Procedure: ASTM F2029 Step-by-Step Protocol
ASTM F2029 is the standardized procedure for making laboratory heat seals that are used as input to ASTM F88 strength testing. Following this protocol precisely is the foundation of reproducible, inter-lab-comparable heat seal data.
Technical Standards Explained
Deep dives into ASTM F88, F2029, ISO 11607, hot tack vs heat seal, and 3T process optimization
ASTM F88 Heat Seal Strength Test: The Complete Guide for Flexible Packaging Laboratories
ASTM F88 is the foundation of flexible packaging seal quality control — referenced by ISO 11607, USP <1207>, and virtually every buyer specification. This guide explains the complete method.
ASTM F2029: Standardizing Laboratory Heat Seal Procedures for Flexible Barrier Materials
ASTM F2029 solves the inter-lab repeatability problem in heat seal testing. It defines exactly how to make a laboratory seal so that results from different labs — and different instruments — can be meaningfully compared.
Heat Seal 3T Optimization: Finding the Perfect Temperature, Time, and Pressure Window
Every heat sealing process is defined by three variables: Temperature (T), Time (t), and Pressure (P). Optimal seals require all three to be within their respective optimal ranges. This guide explains how to use the STH-3A gradient tester to efficiently map the 3T design space.
Hot Tack vs Heat Seal Strength: Key Differences Every Packaging Engineer Should Know
Hot tack and heat seal strength both measure how well a seal holds — but they measure it at completely different moments. Confusing the two is one of the most common mistakes in flexible packaging QC specification.
Vacuum Seal Integrity Testing: A Step-by-Step Guide to 3 Core Methods
ASTM F2096 sets the bar for a passing bubble emission test at roughly 81% detection probability for a 250 µm hole, not 100%. A package can clear that bar and still be carrying a leak the test wasn't b...
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