The EPLF and IHD in Dresden has conducted research to improve laminate flooring testing standards.
Laminate flooring continues to be installed in millions of homes and public buildings around the world, however, the laminates of 2016 demonstrate different characteristics from those of their predecessors ten or twenty years ago. Innovations such as deep in register embossing and decorate print marks in reproduced wood flooring mark the ultimate in current laminate production. Matt surfaces are also becoming increasingly popular.
According to the Association of European Producers of Laminate Flooring (EPLF), while technical challenges have been overcome, it has become apparent that the test procedures complying with the laminate flooring standard cannot cater for these new surfaces.
Quality standards that apply to laminate flooring hinge around EN 13329, and the updated version EN 13329:2016. However, while standardised testing for abrasion resistance using sandpaper in line with the Taber abraser method produces significantly lower results for the popular deep textures than for flat ones, this does not relate in any way to the positive experiences that these floors create in real-life applications. Selected matt textures trafficked heavily on a daily basis literally display “pathways” worn by of foot traffic.
The standards do not include a procedure for forecasting this polishing effect, so the EPLF decided that new test procedures had to be developed or the existing test procedures needed to be changed. This resulted in the EPLF proposing a publicly funded research project by the German Federal Ministry of Economic Affairs and Energy. The project was carried out between June 2013 and November 2015 by the Institute of Wood Technology in Dresden (IHD), under the leadership of Dr Rico Emmler. An ad-hoc group from within the EPLF’s Technical Working Group was actively involved in the research and the technical report is now available.
The EPLF compared laboratory and field tests of “deep textures” and the results showed that when using the test procedure as defined in the standard, these structures achieved significantly lower abrasion classes than their “cousins” with smoother structures with an identical overlay, i.e. the transparent wear layer on the surface. On the other hand, the experience gained from the several million square metres of flooring already installed was that this does not apply in real life.
The first part of the project was therefore focused on suitably modifying the test method in order to attain corresponding results in both field and laboratory conditions. This necessitated a systematic examination of the wear processes for deep-textured flooring in both locations. The working group concluded that the two-year field tests did not mirror the clear differences (depending on texture) in the results of abrasion tests carried out according to the current standard.
Microscopic examinations were conducted and profile measurements carried out to explore the cause of the differences. Several inter-laboratory tests and continuous comparisons between field and laboratory showed, however, that variations in evaluation parameters achieved the goal more readily (dividing the specimen and size of area abraded).
The working group was able to develop an alternative solution for evaluating the impact resistance of laminate flooring with deep surface textures. Following the principle of a falling mass, tests were carried out with 14 types of laminate across all impact classes and product types (DPL, EPL, PDL and HPL). Using this newly designed device, the best correlation between results for the impact classes to date were produced using a ram weight of 150 g and a ball diameter of 10 mm. The results of the process developed by the IHD in Dresden were successfully verified in the inter-laboratory tests involving members of the ad-hoc group.
A proposal is being put forward with a view to developing a classification system for the test results similar to micro-scratch resistance according to EN 16094 and the intention is to incorporate into EN 16094 a third procedure, namely the test procedure on polishing behaviour, that was developed during the project.