Through-Dry State Tester
Coating Through-Dry State Tester
Paint Through-Dry State Tester
ISO Dryness Tester
Laboratory Dryness Tester
Varnish Through-Dry State Tester
ISO 9117-1

Professional Through Dry State Tester QPI‑SST1800 - Features:

The QPI‑SST1800 Through Dry State Tester is a precision laboratory instrument designed to evaluate the drying condition of liquid coatings, inks, and paint films. It provides a controlled and repeatable way to determine when a coating has reached the “through‑dry” condition — the point at which the film can resist deformation or transfer under defined contact pressure.

Both ASTM and ISO define procedures for assessing drying behavior. The QPI‑SST1800 is engineered to support these procedures with stable mechanics, consistent pressure application, and a clean test geometry that eliminates operator variability.

1. ASTM Through‑Dry Evaluation Method - General Principles

ASTM drying‑state evaluations typically focus on how a coating responds to mechanical contact, pressure, or surface disturbance at defined intervals. While different ASTM standards address specific coating types, the underlying engineering principle is consistent:

ASTM Method Concept

• A coated test panel is prepared using a controlled application method.

• The panel is conditioned under defined environmental parameters (temperature, humidity, airflow).

• A standardized contact element — often a weight, pad, or probe — is applied to the coating surface.

• The response of the coating is observed:

  • Transfer

  • Imprint

  • Surface disruption

  • Elastic recovery

• The coating is considered “through‑dry” when the applied contact no longer causes visible deformation or material transfer.

How the QPI‑SST1800 Supports ASTM Procedures

• Precision vertical loading system ensures repeatable pressure.

• Stable test platform eliminates vibration and lateral movement.

• Controlled contact geometry prevents edge effects.

• Adjustable dwell time allows engineers to match ASTM timing intervals.

• High‑accuracy alignment ensures consistent contact area across multiple tests.

The QPI‑SST1800 provides the mechanical consistency required for ASTM‑aligned drying evaluations, making it suitable for R&D labs, QC departments, and coating development facilities.

2. ISO 9117‑1 Through‑Dry Test Method

ISO 9117‑1 is a widely used international procedure for determining the through‑dry state of organic coatings. Unlike mesh‑based coating tools, ISO 9117‑1 does not use mesh screens. The method relies on gauze (cotton fabric) and controlled contact pressure.

ISO 9117‑1 Method Concept

• A coating is applied to a substrate using a defined application technique.

• After a specified interval, a gauze pad is placed on the coating surface.

• A standardized weight is applied on top of the gauze for a defined time.

• The gauze is removed and inspected for:

  • Adhesion

  • Sticking

  • Transfer of coating material

• The coating is considered “through‑dry” when the gauze lifts cleanly without sticking or leaving marks.

Why Gauze Is Used instead of Mesh

• Gauze provides a soft, absorbent, compliant contact surface.

• It simulates real‑world handling conditions.

• Mesh would create point‑pressure artifacts and is not part of the ISO method.

How the QPI‑SST1800 Supports ISO 9117‑1

• Calibrated weight system matches ISO pressure requirements.

• Perfectly level test bed ensures uniform contact across the gauze.

• Smooth vertical motion prevents premature shear forces.

• Clean removal path allows accurate evaluation of sticking or transfer.

• High‑precision timing control supports ISO dwell periods.

The QPI‑SST1800 is engineered to deliver ISO‑compliant repeatability, making it ideal for laboratories that require traceable and internationally recognized drying‑state verification.

3. Engineering Advantages of the QPI‑SST1800

High‑Stability Construction

The tester uses a rigid stainless‑steel column and a vibration‑free base to ensure consistent pressure application.

Optimized Contact Mechanics

The loading system is designed to apply force vertically without lateral drift, eliminating false readings.

Laboratory‑Grade Materials

All contact surfaces are made from corrosion‑resistant alloys to maintain long‑term dimensional accuracy.

Operator‑Friendly Workflow

• Quick panel placement

• Smooth weight handling

• Clear visual inspection zone

• Easy cleaning and gauze replacement

The Professional Through Dry State Tester QPI‑SST1800 provides engineers with a reliable, repeatable, and standards‑aligned solution for evaluating the drying condition of coatings. Whether following ASTM drying principles or the ISO 9117‑1 gauze‑based through‑dry test, the instrument delivers stable mechanics, precise pressure control, and consistent results that support both research and industrial quality assurance.