Deformation Resistance

Physical properties of paint and coatings play an important role in the quality control. Depending on the application a coating is supposed to be extremely hard and rigid such as for example the coating on the hull of an ice-breaker. Automotive coatings however require a certain flexibility since the thin sheet metal of a car body is not fully rigid and a slamming hood should not cause the paint to break. Coil coated steel that is to be formed into products such as white goods or cladding should have excellent forming properties....
Physical properties of paint and coatings play an important role in the quality control. Depending on the application a coating is supposed to be extremely hard and rigid such as for example the coating on the hull of an ice-breaker. Automotive coatings however require a certain flexibility since the thin sheet metal of a car body is not fully rigid and a slamming hood should not cause the paint to break. Coil coated steel that is to be formed into products such as white goods or cladding should have excellent forming properties.

Several empirical tests
There are a number of different empirical tests that are used to deform test panels and so assess the deformation resistance or flexibility. Coatings that fail such a test will crack and/or detach from the substrate. Also there is quite some overlap between different test systems and their results. Many tests provide information about similar parameters such as elasticity / forming resistance, adhesion, hardness, brittleness, stress resistance etc..

Although some tests overlap there is no cross-reference for their results.

More information can be found in the section hardness/scratch resistance

Commonly used tests
Common tests used in the paint and coatings industry are:
  • Bend test
    With this system a coated test panel or lacquered sheet metal is bent over a defined mandrel. Cylindrical mandrels in different diameters or conical mandrels are used.

    The smaller the diameter the sharper the forming of the test panel which leads to elongation of the panel including the coating. A sharper deforming causes more stress to the coating which may lead to cracks or adhesion failure.

    Cylindrical bend test are recognised to be more precise in comparison to conical bend tests which have the advantage that a range of mandrel diameters can be checked on just one panel.


  • Impact Test, or tubular impact test
    With an impact test a rapid deformation of a painted test panel is generated. A specified weight with a specified punch is dropped on a test panel from different heights. The damage on the sample is observed after the test and provides information about physical properties of the coating such as elasticity, hardness and adhesion.

    For the paint industry there are different tests according ISO 6272 , ASTM D2794 and others. Each standard has its own specifics such as weight, punch shape, direct or indirect impact etc..


  • Cupping test
    Cupping testers generate, in contradiction to impact testers, a gradual deformation of the sample. An indenter with a specified shape is slowly forced through the test panel under standardised conditions. During the deformation the panel is visually observed. The cupping value of a coating is the deformation point at which the coating starts to crack.
    To perform this test correctly it is of utmost importance that the deformation is made gradually without any interruptions.

Standards News FAQ Links

Automatic cupping tester

The TQC Automatic Cupping Tester allows to perform a cupping (Erichsen / Dent) test on coated steel panels to define the resistance of paint, varnish or related products to cracking and/or detachment from a metal substrate when subj...

BEND TEST CONICAL MANDREL BASIC

The TQC Conical Bend Test “Basic” is a simplified version of the TQC Conical Bend Test “Pro” (SP1830) It is a laboratory apparatus to bend coated test panels over a conical shaped mandrel in order to assess t...

BEND TEST CONICAL MANDREL PRO

The TQC Bend Test Conical Mandrel "Pro" is a laboratory apparatus to bend coated test panels over a conical shaped mandrel in order to assess the elasticity or resistance of a coating-, paint or varnish to cracking, elongation and/o...

CYLINDRICAL BEND TEST 100MM INCL MANDREL SET (IMPERIAL)

The TQC Cylindrical Bend Test is a very robust yet elegant testing instrument to indicate the elasticity, elongation and adhesion of a paint film at bending stress. The TQC Cylindrical Bend Test is designed to perform tests accordin...

CYLINDRICAL BEND TEST 100MM INCL MANDREL SET (METRIC)

The TQC Cylindrical Bend Test is used to determine the elasticity adhesion and elongation of paint on sheet metal in accordance with ISO 1519. A test panel (max. size 150 x 100 mm) is bent over a cylindrical mandrel. The smaller the...

DIGITAL USB MICROSCOPE WITH LCD SCREEN

Small, portable, inexpensive and easy microscope with LCD display that can be connected directly to a PC. Supplied with software for immediate inspection and measuring. The unique optical design combines the advantages of a USB-micr...

IMPACT TEST

The TQC Impact Test is used to determine the impact resistivity and flexibility of coatings. The dual scale instrument is equipped with a special guidance which assures that the distance between each impact is always according to th...

KNOCK-OUT TESTPANELS

Our new TQC Knock-out testpanels are designed to minimize the build-up of paint on the panel edges because of de knock-out frames. Also because of the 4 mm holes in the knock-out frames it is easy to hang the panels horizontally or ...

Manual Cupping Test

Revolutionary apparatus for testing the resistivity of coatings at various stages of deformation in accordance with ISO 1520. The built in gear-box minimizes the manual force which is required to deform the test panel, allowing to p...

Refurbishing set for Cupping test SP4200 model

Depending on the frequency of use and sample material the indenter of a cupping test may wear over time. A worn indenter may lead to incorrect test results. In order to bring back the cupping test in original condition a refurbish-k...

SET OF 14 MANDRELS FOR TQC CYL BEND TEST 100MM (METRIC)

The TQC Bend Test Cylindrical Mandrels consists of 14 mandrels for the TQC Bend Test Cylindrical, a bend test for determining the elasticity of coatings in accordance with ISO 1519. A test panel (max. size 150x100mm) is bent over a ...

SET OF 7 MANDRELS FOR TQC CYL BEND TEST 100MM (IMPERIAL)

The TQC Bend Test Cylindrical Mandrels consists of 7 mandrels (Imperial) for the TQC Bend Test Cylindrical, a bend test for determining the elasticity of coatings in accordance with ASTM D522. A test panel (max. size 150x100mm) is b...

USB measuring microscope - Model 2012

Small, portable, inexpensive and easy microscope that can be connected directly to a PC. Supplied with software for immediate inspection and measuring. The unique optical design combines the advantages of a USB-microscope digital ...