Cross Cut Adhesion Test

Knife incisions were made for cross cut adhesion test through the coating system down to the substrate at three different places. Pressure sensitive adhesive tape was firmly pressed over the inscribed area. Coating removal along the scribed lines was examined and no peeling or removal of paints was found. 

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Figure 15.5 Classification of paint film in cross-cut adhesion test.

The cross-cut adhesion test provides a rating for the adhesion of a surface material to a plastic substrate. The original ASTM standard D3359-02 for the cross-cut adhesion test was developed to measure the adhesion between thin paint films and flat, metal substrates. This test, however, is not well suited for three dimensional plastic parts that are covered with fabric. It will be shown in this study that improper cross-cut testing protocol can result in false failures and artificially low adhesion performance scores. A modified cross-cut adhesion test procedure is documented here that is based on the ASTM method and is applicable to fabric covered parts. 

Plastic parts with fabric attached to the surface must pass a series of durability tests including the cross-cut adhesion test. The cross-cut test is important in order to assess the adhesion strength of the fabric to the snbstrate plastic. This adhesion test provides a rating for the adhesion between all layers from the fabric surface down to the substrate plastic. The original ASTM standard D3 3 59-02 was developed to measme adhesion between thin paint films and flat, metal snbstrates (4). The cross-... 

A modified cross-cut adhesion test procedure is documented here that is based on the ASTM method and is applicable to fabric laminate over molded parts. The goal of this work is to document the learnings for this test method as applied to fabric covered plastic parts. 

Table 1. Rating code for the cross-cut adhesion test...

Key Words Cross-cut adhesion test, fabric, adhesion. 

D-3359-02 cross-cut tape test for adhesion, American Society for Testing and Materials, ASTM, West Conshohocken, PA. 

Figure 12.23 Optical images of (a, d) mild red color were peeled off. (g, h) Cross-steel/epoxy, (b, e) mild steel/phosphate/epoxy, sectional images of mild steel/electrodepos-and (c, f) mild steel/electrodeposited silica/ ited silica/epoxy paint on ITO. (Adapted with epoxy after cross-cut adhesion tape test (a-c) permission from Ref [78].) and Machu test (d-f).The areas marked with...

The procedure detailed here is based on the Standard Test Methods for Measuring Adhesion by Tape Test ASTM designation D3359-02, Test Method B - Cross-Cut Tape Test. The modified procedure presented here adjusts the ASTM procedure for fabric covered parts. 

Specification for electroplated coatings of 65/35 tin/nickel alloy Method for the evaluation of results of accelerated corrosion tests on metallic coatings Methods of test for paints Cross-cut test Pull-off test for adhesion Resistance to artificial weathering (enclosed carbon arc) and Addendum No. 1 Resistance to continuous salt spray Notes for guidance on the conduct of natural weathering test... 

Figure 3 presents results of adhesion for LBG1025/PVDF composites. As one can see, in the particular testing conditions, LBG1025 has a poor adhesion (100% of the coating has been removed by the Scotch tape even without a need to make cross-cut scratches on the surface of current collector). 

Figures 30.17-30.19 depict the durability of the surface treatments examined with ETA-3183, which is the most difficult one to modify the surface effectively among samples employed. Because the water can reach the interface directly through cross-cuts, this accelerated adhesion test was much more severe when cross-cuts were...

Figure 30.17 Tape adhesion test results at various water boiling times for primer on methane-plasma treated ETA-3183 with six cross-cuts made before and after immersion into boiling water 2 3 torches, 2.0 A arc current, 1000 seem argon, 10 seem methane, 270mtorr pressure, and 1.9 s plasma exposure time.

As discussed, the degree of adhesion is critical to the effectiveness of a paint coating. Consequently, the specification of the degree of adhesion must be supplied by each paint manufacturer. Because of this, routine methods for the measurement of the degree of adhesion have been established for the purpose of quality testing. The most popular test used is the cross-cut test, which is quite often complemented with pull-off methods. Both methods have been the subject of standardization. 

Many methods are used to measure adhesion of a coating to a substrate. The most commonly used methods belong to one of the following two groups direct pull-off methods (e.g., ISO 4624) or cross-cut methods (e.g., ISO 2409). The test method must be specified details of pull-stub geometry and adhesive used in direct pull-off methods are important for comparing results and must be reported. 

In the cross-cut test, which is the most commonly used of the lateral stress methods, knife blades scribe the coating down to the metal in a grid pattern. The spacing of the cuts is usually determined by the coating thickness. Standard guidelines are given in Table 8.2. The amount of paint removed from the areas adjacent to, but not touched by, the blades is taken as a measurement of adhesion. A standard scale for evaluation of the amount of flaking is shown in Table 8.3. 

Adhesion Cross-cut test value similar before and after tape test... 

An enhancement to the cross-cut test is to apply adhesive tape to the grid. The tape is then pulled off by hand in a smooth action (preferably at an angle of 90°) and the grid is then assessed as per Table 6.2. In order to maximize the comparability of measurement, the results should always be stated together with the adhesive strength of the adhesive tape used and if possible the angle at which the tape is pulled off. 

Representative samples of the lacquered, metallized, or coated materials are taken and by means of a sharp knife a cross-hatched pattern of squares of dimensions 1 mm by 1 mm is cut into the surface. A strip of transparent adhesive tape of good quality is pressed firmly over the test area, then pulled away in a single continuous movement. Finally the test area is examined and whether squares have been removed (and in what number) noted. 

The metallic layers were examined either by conventional or cross-section TEM in a Jeol 200 Cx microscope. For the cross section preparation a sandwich of two laminates is made, glued face to face with an epoxy, cut in small pieces, mechanically polished, and then ion milled to a final TEM observation thickness. The plane section TEM sample are prepared by dissolving the PET in trifluoroacetic acid for 5 to 10 mn. The area observed, on plane section TEM, for the grain size calculation is close to 0.2 urn. For the adhesion measurements, test pieces consist of aluminum support (1 mm thick) double sided tape (Permacel P-94) PET (12pm) / evaporated aluminum/ ethylene acrylic acid (EAA) copolymer film. These laminates are prepared for the peel test by compression under 1.3 105 N.m2 at 120°C for 10 seconds. The peel test is performed by peeling the EAA copolymer sheet from the laminate in an INSTRON tensile tester at 180° peel angle and 5 cm min peel rate. 

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