Adhesion Test Apparatus Model 525

Description

The Adhesion Tester, Model 525, measures adhesion using the adhesion test acc. to ASTM D 4541. All coating materials to which a test cylinder can be stuck with existing adhesives can be examined.

The apparatus is entirely mechanical and requires no electrical supply, which makes it particularly suitable for applications in the field requiring mobile equipment.

Model 525 is of robust construction and easy to operate making it ideal for applications under severe operating conditions.

Principle of Test

A test cylinder (dolly) is stuck to the coating with an adhesive quality and tensile strength and the coating is then pulled off under defined conditions. The tensile stress required for this and a visual examination of the surface that have been separated provide the required information of the adhesive quality of the coating.

It is to be noted that this method of measuring adhesion will give results which are not generally directly comparable with the results from other methods: the cross cutting test procedure mainly shear forces on the coating whereas the force exerted by Model 525 acts perpendicular to the surface.

Design and Function

The Adhesion Tester, Model 525 is made up of a circular housing with three legs containing a concentrically positioned compressing spring. The housing is closed up by means of a cylinder which has scales for reading off the tensile stress and is fitted into the housing from the top.

The three components are coupled by a threaded spindle at the top end of which is fitted either a hand wheel or hexagonal nut and that carries at its bottom end the dolly grip. A pin prevents the dolly from turning relative to the housing . When the parts are screwed together the spring generates a force which is transmitted from the dolly grip to the dolly itself. Simultaneously the cylinder is pressed into the housing taking a maximum reading pointer with it. The pointer holds the maximum force that was reached after the spring has been released.

The cylinder carries two scales for reading off the tensile stress in N/mm² and Ib/sq in. The tensile force is applied to an area of 314 mm² or 1964 mm² corresponding to the dolly diameter of 20 mm and 50 mm, respectively.

Reference Class:

All versions of Models 525 are supplied with a Manufacturer’s Certificate M in accordance with DIN 55 350-18 that includes among others the following information:

• Actual and setting values of the tensile stress
• Product identification
• Test equipments used with calibration status
• Date
• Name of inspector.

At 5 values evenly spread over the measuring range the accuracy of the tensile stress scale is determined (maximum permissible tolerance 3%).

Scope of delivery

• Adhesion Tester Model 525-5: Measuring range 0 - 5 N/mm² / 0 - 700 lb/in² with dolly Ø 20 mm
• 20 Dollies
• Dolly holder
• Base ring
• 2 Tubes universal adhesive*
• Cutting tool
• Carrying case
• Operating instructions
• Manufacturers Test Certificate M

* Note: 2-component epoxy resin adhesive has been successfully used for many years for a variety of materials. However, the best possible suitability for bonding any surface cannot be guaranteed across the board. Even if experience has shown for the clear majority of the common application and requirements and has already confirmed a corresponding suitability for many years, the almost unlimited variety of possibly involved materials may also result a different suitability.