Pull-Off Yapışma Testi

In order to perform satisfactorily, coatings must adhere to the substrates on which they are applied. In practice, three different test procedures are used to assess the resistance of paints and coatings to separation from substrates:

Cross-Cut Test

This test method specifies a procedure for assessing the resistance of paints and coatings to separation from substrates when a right angle lattice pattern iscut into the coating, penetrating through to the substrate.

The method may be used for a quick pass/fail test. When applied to a multi-coat system, assessment of the resistance to separation of individual layers of thecoating from each other may be made.

Scrape Adhesion

This test method covers the determination of the adhesion of organic coatings such aspaint, varnish, and lacquer when applied to smooth, flat(planar)panel surface.It has been found useful in providing relative ratings for a series of coated panels exhibiting significant difference in adhesion.

The materials under test are applied at uniform thickness to flat panels, usually sheet metal of uniform surface texture. After drying, the adhesion is determined by pushing the panels beneath a rounded stylus or loop that is loaded with increasing amount of weight until the coating is removed from the substrate surface.

Pull-off Test

Adhesion of asingle coating or a multi-coat system of paint, varnish or related products is assessed by measuring the minimum tensile stress necessary to detach or rupture the coating in a direction perpendicular to the substrate. This method maximizes tensile stress as compared to the shear stress applied by other methods such as scratch adhesion and results may not be comparable. The test is performed by securing a loading fixture (dolly) perpendicular to the surface of the coating with an adhesive. After the adhesive is cured, a testing apparatus is attached to the loading fixture and aligned to apply tension perpendicular to the testsurface. The force applied is gradually increased and monitored until either a plug of coating material is detached, or a specified value is reached.

BGD 500 digital pull-off adhesion tester is a portable, hand-operated instrument which is used to measure the force required to pull a specified test diameter of coating away from its substrate using hydraulic pressure. The pressure is displayed on a digital LCD and represents the coating’s strength of adhesion to the substrate.

It evaluates the adhesion (pull-offstrength) of a coating by determining the greatest tensile pull-off force that it can bear before detaching. Breaking points, demonstrated by fractured surfaces,occur along the weakest plane within the system consisting of dolly, adhesive,coating layers and substrate.

Test Principle

Coating or a multi-coat system of paint is applied/distributed to substrate uniformly witha certain thickness.

After coating has been dried or cured, adhere dolly to surface of coating directly with special adhesive.

After the adhesive is cured, use BGD 500 digital pull-off adhesion tester to attach the loading fixture and aligned to apply tension perpendicular to the test surface. Tester pull off the dolly at a speed of 1MPa/s by hydraulic pump, and measures the force required to pull a specified test diameter of coating away from its substrate using hydraulic pressure, this force is shown through the LCD oftester.

Easy to use

Characters

CONVENIENT

◆ Portable design, can be used anywhere.

◆ Built-in rechargeable lithium battery, no need any external power source.

◆ Selectable directly four different sizes dolly for different resolution and testing range

◆ Get the testing results from LCD directly.

◆ Includes all tools needed for testing

PRECISE

◆ Each PsiaTester’s pressure system is calibrated towithin 1% accuracy by NIST traceable load cells

◆ High-precise professional sensor ensures 0.01MPa resolution

◆ Self-aligning dollies ensure to get a reliable testing results for smooth or uneven surfaces.

INTELLIGENT

◆ Store all test results （includes Max.pull-off power,pull-off rate, dolly size and time）automatically

◆ Two units （MPa and psi）for selection and can be converted automatically.

◆ No need any software, PsiaTester is also a U disk,when connecting the computer, operator can read all data directly which is recorded during testing.

◆ Showing pull-off rate allows users monitor and adjust pull speed according to different test requirements.

DURABLE

◆ Waterproof, dustproof and shockproof design meets any harshest operating environment

◆ Strong plastic carrying case

◆ Two year warranty

Structure