New method for the evaluation of high-gloss surfaces according to EN 17214

 

 

Until now, there was no uniform definition of a glossy surface. This does not refer to the gloss level, which can be measured and documented easily and comprehensibly. In the new standard EN17214, the surface structure of a high-gloss surface is divided into different quality classes and evaluated.

One could argue excellently about what constitutes a high-gloss surface. A high-gloss surface can have the same degree of gloss with different surface structures. Is the surface as smooth as a mirror, does it have a slight orange peel or even surface irregularities? The punctual gloss level measurement could not help you to make a decision.

 

State of the art

Surface inspections of components are generally used for the Qualitycontrol or quality impression before the delivery of products and, if necessary, to carry out quality assurance within the manufacturing plant without cost-intensive measures for the return of construction elements and products to enable internal reworking.

For the inspection of corresponding surfaces, large industrial companies have correspondingly complex devices in operation, which allow an automatic or perform semi-automatic testing of surface structures. As a rule, such surface monitoring is carried out continuously during the manufacturing process for each produced component.

Since such systems are relatively expensive to purchase and maintain, the purchase is generally not profitable, especially for small and medium-sized companies. Here, a purely visual inspection of the corresponding surfaces is often carried out with the help of experienced employees.

As shiny or highly polished surfaces on furniture fronts have been very successful for a long time, especially in the furniture industry, the corresponding inspection has reached its limits due to employee experience.

 

Aim of the MHanser GlossIn testing device

The aim in the development of the testing device was to provide a cost-effective procedure and a corresponding device with which anyone can carry out a professional and standard-compliant testing of all types of high-gloss surfaces. The testing device should also be able to be used by inexperienced employees, so that the costs for a regular quality inspection of corresponding surface structures are kept in a manageable order of magnitude.

 

Solution of the task

With regard to the procedure for assessing the surface structure of a high-gloss surface, the task is solved by the technical teaching disclosed in EN 17214 and the MHans gloss inspector.

With regard to the device required for the process, the solution to the problem is given by the combination of features described.

 

Many aspects are important for the process of assessing the structure of high-gloss surfaces, which had to be taken into account in the implementation of the task.

- It was necessary to construct a device with a frame on which a housing can be rotated about an axis. This is important to ensure the exact angle of the gloss inspector to the test medium.

- The housing has an internal light source. The light is transmitted through a translucent, standardized reference sample element arranged in front of the outlet opening, which is provided with rectangular overlapping opaque bar-shaped areas arranged to each other.

- The standardized reference pattern is blasted onto a surface to be evaluated, which is arranged at a defined distance from the outlet opening of the housing.

- The visible reflection of the standardised reference sample on the test surface is compared with the reference samples described in EN 17214 and the deviations of the test sample visible on the surface from the reference sample are classified according to a quality scale.

- The procedure described is characterised in particular by easy handling and a simple design of the associated device.

 

It has been clear, that the test sample projected onto the surface to be tested, by the reference sample is distorted or blurred to a lesser or greater extent depending on the quality of the corresponding surface. The degree of blurriness and distortion can be classified in a quality scale according to relevant experience.

This quality scale is described in the standard in a total of five steps, whereby step five is the step which represents the greatest possible correspondence between the test sample projected on the surface to be tested and the reference sample.

In contrast, level 1 is characterized by significant changes in the reference structure or strong dullness.