Application Note | Flooring Finish Inspection
Surface Finish Inspection of Wood Flooring
Comparing the Roughness and Texture of Hardwood and Laminate Flooring Finishes
Research & Experimental Testing
NANOVEA Laboratory
Visual Design & Editorial
Andrew Shore
Introduction
In various industries, the purpose of a wood finish is to protect the wooden surface from various types of damage such as chemical, mechanical or biological and/or provide a specific visual aesthetic. For manufacturers and buyers alike, quantifying surface characteristics of their wood finishes can be vital to the quality control or optimization of finishing processes for wood. In this application, we will explore the various surface features that can be quantified using a NANOVEA 3D Non-Contact Profilometer.
Why Profiling Wood Finishes Matters
Quantifying the amount of roughness and texture that exists on a wooden surface can be essential to know in order to ensure it can meet the requirements of its application. Refining the finishing process or checking the quality of wooden surfaces based on a quantifiable, repeatable and reliable surface inspection method would allow manufacturers to create controlled surface treatments and buyers the ability to inspect and select wood materials to meet their needs.
ℹ️ Learn more about non-contact profilometry lab services for wood and flooring.
Measurement Objective
In this study, the high-speed NANOVEA HS2000 profilometer equipped with a non-contact profiling line sensor was used to measure and compare the surface finish of three flooring samples: Antique Birch Hardwood, Courtship Grey Oak, and Santos Mahogany flooring. We showcase the capability of the NANOVEA Non-Contact Profilometer in delivering both speed and precision when measuring three types of surface areas and a comprehensive in-depth analysis of the scans.
NANOVEA ST500 Large Area
Optical 3D Profilometer
Test Procedure
| Test parameter | Value |
|---|---|
| Instrument | HS2000 |
| Optical sensor | LS1 |
| Optical sensor height range | 200 µm |
| Scan size | 100 mm × 80 mm |
| Step size | 100 µm × 10 µm |
| Scan time | 00:05:94 (h:m:s) |
Table 1: Test parameters for individual profilometry measurements on Antique Birch Hardwood, Courtship Grey Oak and Santos Mahogany wood samples.
Results and Discussion
Sample description: Courtship Grey Oak and Santos Mahogany flooring are laminate flooring types. Courtship Grey Oak is a low gloss, textured slate gray sample with an EIR finish. Santos Mahogany is a high gloss, dark burgundy sample that was prefinished. Antique Birch Hardwood has a 7-layer aluminum oxide finish, providing everyday wear and tear protection.
Antique Birch Hardwood
Courtship Grey Oak
| Slice parameter | Cracks (blue) | Flatter surface (pink) |
|---|---|---|
| Projected area (%) | 14.70 | 85.30 |
| Volume of void (%) | 2.792 | 67.98 |
| Volume of material (%) | 97.21 | 32.02 |
| Volume of void (µm³/mm²) | 2171270 | 37061813 |
| Volume of material (µm³/mm²) | 75588985 | 17459746 |
| Mean thickness of void (µm) | 2.171 | 37.06 |
| Mean thickness of material (µm) | 75.59 | 17.46 |
Table 2: Slice analysis of the Courtship Grey Oak sample.
Santos Mahogany
| ISO 25178 parameter | Antique Birch Hardwood | Courtship Grey Oak | Santos Mahogany |
|---|---|---|---|
| Sa (µm) | 1.716 | 11.17 | 2.388 |
| Sq (µm) | 2.151 | 15.09 | 3.050 |
| Ssk | −0.07458 | −1.629 | −0.2882 |
| Sku | 3.127 | 5.954 | 3.528 |
| Sz (µm) | 32.79 | 132.3 | 39.50 |
| Sp (µm) | 15.01 | 39.23 | 24.62 |
| Sv (µm) | 17.78 | 93.05 | 14.88 |
| Sdar (mm²) | 2500 | 2558 | 2500 |
| Spar (mm²) | 2499 | 2499 | 2499 |
Table 3: Height parameters of the three flooring samples (Figs. 2, 4 and 8).
Discussion
There is a clear distinction between all the samples’ Sa value. The smoothest was Antique Birch Hardwood with a Sa of 1.716 µm, followed by Santos Mahogany with a Sa of 2.388 µm, and significantly increasing for Courtship Grey Oak with a Sa of 11.17 µm. P-values and R-values are also common roughness values that can be used to assess the roughness of specific profiles along the surface. The Courtship Grey Oak possesses a coarse texture full of crack-like features along the wood’s cellular and fiber direction. Additional analysis was done on the Courtship Grey Oak sample because of its textured surface. On the Courtship Grey Oak sample, slices were used to separate and calculate the depth and volume of the cracks from the flatter uniform surface.
Conclusion
In this application, we have shown how the NANOVEA HS2000 high-speed profilometer can be used to inspect the surface finish of wood samples effectively and efficiently. Surface finish measurements can prove to be important to both manufacturers and consumers of hardwood flooring in understanding how they can improve a manufacturing process or choose the appropriate product that performs best for a specific application.
Frequently Asked Questions About Wood Flooring Surface Inspection
Why measure the surface finish of wood flooring?
A wood finish protects the surface from chemical, mechanical or biological damage and gives a specific look. Quantifying roughness and texture with a repeatable method lets manufacturers control and refine finishing processes and lets buyers select materials that meet their needs.
How were the flooring samples measured?
A NANOVEA HS2000 high-speed profilometer with an LS1 line sensor (200 µm height range) scanned 100 mm × 80 mm of each sample at a 100 µm × 10 µm step.
How rough were the three floor finishes?
Antique Birch Hardwood was smoothest at Sa 1.716 µm, Santos Mahogany laminate measured 2.388 µm, and Courtship Grey Oak laminate, a textured low-gloss finish, was much rougher at 11.17 µm.
What does slice analysis show?
Slices separate the crack-like features of the textured grey oak from its flatter surface: here one region covered 14.70% of the area and the other 85.30%, with void and material volumes and mean thicknesses calculated for each.
Which roughness parameters are useful for flooring?
ISO 25178 area parameters such as Sa, Sq, Sz, Ssk and Sku describe the whole surface, while ISO 4287 profile parameters (P and R values) assess roughness along specific profiles.
Which NANOVEA instrument was used?
The NANOVEA HS2000 high-speed profilometer with a non-contact line sensor, delivering both speed and precision. Its current large-area counterpart is the NANOVEA ST500.
