MATERIAL AND SURFACE ANALYTICS

Topics like the adhesion of paint on metal surfaces belong to the scope of material and surface analytics.

The area of material and surface analytics is divided as followed in our lab:

  • Paint
  • Varnish
  • Plastics
  • Metals

We perform the following analytical methods in our lab:

Analytical methods

Flow out time of paint and varnish

ASTM D1200; DIN EN ISO 2431 (formerly DIN 53211)

The liquid is placed in a special cup with a defined hole in the bottom. The viscosity is determined by measuring the time the liquid needs to run out. This method is suitable e.g. for the quality control of paint batches.

Radiation resistance

ASTM D3424; ASTM D5071; ASTM D6695; ASTM G151; ASTM G155; DIN EN ISO 11431; DIN EN ISO 11979-5; DIN EN ISO 7491; DIN EN ISO 4049; DIN EN ISO 4892-2

Materials like plastics, print media and paints can be sensitive to solar radiation. For this purpose specimens can be tested in a light chamber. In this chamber the intensity of radiation can be regulated. Additional it is possible to simulate rain. All parameters are continuously monitored and stored. General questions to be answered with this test are: Gets the material brittle? Does the hue change?

Pencil hardness

ASTM D3363; DIN EN ISO 15184

The surface of painted parts is scratched with a pencil in a defined angle and contact pressure. After scratching the pencil is exchanged against a pencil with a harder pencil lead until the surface is damaged. This test can be used e.g. to check the quality of different batches of painted parts.

Burning behavior

DIN 75200

This method is suitablefor testing the burning behavior of automobile interior materials. A specimen is placed horizontal in a special chamber and lighted on one edge for 15 seconds with a Bunsen burner. Afterwards the Bunsen burner is turned off and the burning behavior of the test specimen is monitored.

Chemical resistance

ISO 2812-1; ISO 2812-4

To check the influence of chemicals like oil or fertilizer to painted or coated parts, the specimens are placed in the test solution or the solution is spotted on their surface. After a distinct period of incubation the specimens are checked for changes in gloss, adhesion of the coating or color changes.

Density of plastics

ASTM D792; DIN EN ISO 1183-1

The density of all plastics excluded foamed once can be determined according to the standard. The specimen is weighed at air and submerged in water or oil. The density is calculated from the results. This method e.g. is useful to check the behavior of plastics and rubber against chemicals like oils.

Elongation

DIN EN ISO 1519

A painted test panel is bended over a standardized cone. The force affecting the paint is the biggest on the tip of the cone. This method is used to check the durability and adhesion of the paint on the substrate.

Color (instrumental)

ASTM D2244

According to „ color (visual) “ the color is measured with a color measuring instrument. By using this device it is possible to determine exactly the color discrepancies between two samples.

Color (visual)

ISO 10526; ASTM D1729

Colors appear different in different light sources e.g. two red painted plates can look the same in artificial light but appear different in daylight. This effect is called metamerism. It depends on the emitted light of the light source and the reflected light of the paint. The test is performed by lab personnel with emmetropia. Different light sources are used (e.g. daylight D65, F2 (CWF) and F11 (TI84).

Cross cut adhesion

DIN EN ISO 2409 and ASTM D3359 Method B

The adhesion of paints to substrates, primings or other paint layers can be checked by using a multi-cut tool. This tool contains six parallel razor blades. For testing two cuts are placed on each other (90° shifted). The resulting squares are examined for spallings and other errors.

Gloss measurement

DIN 67530

The method is based on the reflection of light according to specific angles. The reflection of a polished black glass plate is used as standard and determine as 100 GU (gloss units). For measuring the gloss of painted surfaces we are using a “TriGloss” device which is capable of measuring 20° (high gloss), 60° (medium gloss) and 85° (low gloss).

Residue of ignition

DIN EN ISO 1172

Mineral fibers and talcum are non-burning materials. To determine their content in plastics, samples are burned at 625°C. The difference between the non-burnable residue and the initial weight shows the percentage of filler.

Condensed water test

DIN EN ISO6270-2 (formerly DIN 50017)

Equal to the salt spray test this method is used to find damages or weaknesses of coatings. The specimens can be tested with constant (KK) or alternating climate (KTW). In general the specimen is placed in a test chamber at 40°C and 100% humidity. For KTW experiments the temperature is alternated.

Condensed water test with SO2 (Kesternichtest) enr

DIN 50018; DIN EN ISO 6988; ISO 3231

To check the integrity of galvanic surfaces and coatings in the presence of aggressive gas specimens are placed in a condensed water chamber. A defined amount of sulfur dioxide is added to the chamber. Afterwards the samples are treated according to the corresponding standard. Finally the specimens are checked for defects.

Impact (direkt and indirect) resistance

ASTM D2794

A defined mass is dropped from a defined height on a painted plate. By increasing the height the force impacting the plate gets bigger. As mentioned above (Elongation method) this method is used to check the durability and adhesion of the paint on the substrate.

Orange peel

Ford Standards

Orange peel is an irregularity in the top surface coating that causes distortions in the manner in which a surface reflects the light. By using authorized Ford standards we can perform a categorization of test specimens or production parts.

Salt spray test

DIN EN ISO 9227 (formerly DIN 50021); ASTM B117; GMW 14458

To check the integrity of galvanic surfaces and the properties of coatings on substrates the specimens are placed in a saltwater mist chamber. This method allows finding weak points in short time. It is not an accelerated weathering so there is no possibility to compare the test time with a normal life span.

Dry film thickness

DIN 2360

There are two possibilities to measure the thickness of non-conductive coatings non-destructive.

Magnetic substrates: Inductive method

This method uses two magnetic coils which change their magnetic field in the presence of magnetic substrates. The change depends on the distance of the magnetic coil to the substrate and therefore on the DFT.

Non-magnetic substrates: Eddy current method

In the proximity of a non-magnetic substrate and a magnetic coil alternating currents are produced and affect the magnetic field of the coil. This influence depends on the distance between the substrate and the measuring probe and therefore on the DFT.

Dry film thickness

ISO 2808 Method 6B

To determine the film thickness of coatings on none metallic substrates, we use a special cutter with a defined cutting angle. For this purpose the specimen is marked with felt-tip pen in a contrasting color in the measurement area. After cutting the film thickness is calculated from the projected half-width of the cut and the known angle of the blade.

Shore hardness

Shore-A and Shore-D hardness

ASTM D2240; ASTM D2000; DIN EN ISO 868; DIN 53505 (-A/-D)

The hardness test is used to measure the deformability of rubber (Shore-A) and plastics (Shore-D). The harder the test specimen the higher the value for Shore-A or Shore-D. To measure the hardness a metal rod with a spherical tip is pressed into the specimen. This method is a fast procedure to check or to monitor production batches.

Multi grit tester

ASTM D3170; SAE J400

For testing the behavior of painted or coated surfaces towards rock chip, specimens are placed in a testing chamber. The angle, pressure and rocks are chosen according to the ASTM standard. Afterwards the rock chip pattern is interpreted.

Cupping test

DIN EN ISO 1520

Unlike the impact method in this case a half-spherical ball is pressed with constant force against a painted plate. The test is terminated when the occurring bulge is showing flaws. This test is used like the impact and elongation method to check the durability and adhesion of the paint on the substrate.

Cyclic corrosion

SAE J2334; DIN EN ISO 11997-1; DIN EN ISO 6270-2, VW P1210 und VDA 621415

The cyclic corrosion is a kind of combination of the salt spray and condensed water test. The test starts with a condensed water test followed by a short salt spray test (the salt concentration and composition of the saline solution differs from the classical salt spray solution). Then the specimens are dried at 60°C and 50% relative humidity. Afterwards a new cycle starts. Finally the specimens are examined.

Technical Cleanliness

Technical Cleanliness

VDA 19 Part 2; ISO 16232; Illig value (Illig number)

For the determination of technical cleanliness metallic and non-metallic particles which are transported by the air like fibres, sand, corundum and so on are analyzed. For this reason special particle traps are used. These traps have a sticky surface which binds the dirt. After exposure for a determined amount of time the traps are evaluated by microscope. For the evaluation according to Illig (Illig number) the amount of counted particles is extrapolated to 1000cm2 and standardized to 1h of exposure time. The particle size distribution is multiplied with a factor for each particle size class and the final particle numbers are summarized.

The standard VDA 19 part 1 consists of a CCC-code (Component Cleanliness Code). The class and the amount of particles are presented in the CCC-code after determination.