Application Note | Texture Consistency

Surface Texture Consistency Using 3D Profilometry

Quantifying a Repeating Floor Texture for Production Quality Control

Optical pen scanning textured linoleum flooring

Research & Experimental Testing

Craig Leising

Visual Design & Editorial

Andrew Shore

Introduction

Throughout many industries, surface texture is an important aspect of product design. Surface texture not only refines the physical appearance of a product but also serves applications requiring a controlled level of friction or grip, such as flooring. For this reason, machined and molded surface texture production environments are increasingly seeking ways to improve and enhance the control of the intended surface texture.

Importance of 3D Non-Contact Profilometry for Texture Consistency

Unlike other techniques such as touch probes or interferometry, the 3D Non-Contact Profilometer, using axial chromatism, can measure nearly any surface; sample sizes can vary widely due to open staging and there is no sample preparation needed. Nano through macro range is obtained during surface profile measurement with zero influence from sample reflectivity or absorption, with advanced ability to measure high surface angles and no software manipulation of results. It easily measures any material: transparent, opaque, specular, diffusive, polished, rough, etc. The technique of the non-contact profilometer provides an ideal, broad and user friendly capability to maximize surface studies when surface texture analysis is needed, along with the benefits of combined 2D and 3D capability.

ℹ️ Learn more about surface profiling lab services.

Measurement Objective

In this application, the NANOVEA ST400 Profilometer is used to measure the surface texture of linoleum flooring. The intended surface texture should be a repetitive structure with the same relative size. Measuring a small area shows how consistently this texture is being produced.

NANOVEA ST400 Standard

Optical 3D Profilometer

NANOVEA ST400 modular optical profilometer for non-contact 3D surface measurement
Optical pen of the profilometer above textured linoleum flooring
Fig. 1: Optical pen scanning the linoleum flooring.

Results

The topography of a 10 mm × 10 mm surface and each individual depression with its deepest point are shown in Fig. 2. From these, the mean data for the depressions are calculated, as listed in Table 1.

False-color topography of a 10 mm square of flooring and the same area segmented into depressions with their deepest points
Fig. 2: Topography of a 10 mm × 10 mm area (left) and each individual depression with its deepest point (right).
Depression statisticValue
Mean area0.394016 mm²
Mean volume0.000408109 mm³
Mean of mean diameters0.683262 mm
Mean form factor0.638741
Mean aspect ratio1.67253
Mean roundness0.636164

Table 1: Mean data for the depressions.

The power spectrum density shows dominant wavelengths around 0.68 mm and 0.74 mm, with minor peaks up to 1.72 mm.

Power spectrum density versus wavelength with a dominant peak
Fig. 3: Power spectrum density.

The density of depressions shows a fairly even distribution, with a peak around 2.3 per mm².

Density of depressions distribution with a single peak
Fig. 4: Density of depressions.

Surface roughness and surface area are calculated from the 3D measured area (Fig. 5 and Table 2).

3D view of the textured flooring with its ISO 25178 roughness and surface area panel
Fig. 5: 3D view with surface roughness and surface area.
ISO 25178 parameterValue
Sa4.67062 µm
Sq5.34149 µm
Sz27.4532 µm
Sp14.2310 µm
Sv13.2221 µm
Sku1.82375
Ssk0.0363592
Sdar, developed area110.278 mm²
Spar, projected area100.000 mm²

Table 2: Surface roughness and surface area (from Fig. 5).

Conclusion

In this application, we have shown how the NANOVEA 3D Non-Contact Profilometer can precisely characterize the surface texture of linoleum flooring. To check consistency, it would be helpful to measure a batch of samples and compare the parameters shown here. The values of average area occupied, wavelength and density of depressions should be particularly helpful when creating a quantitative quality control process. Surface roughness and surface area are particularly useful when considering the average height of the peaks and valleys (Sa), the maximum peak height and pit depth (Sp and Sv), and the increased surface area created by the texture (Sdar).

Frequently Asked Questions About Surface Texture Consistency

Why measure texture consistency?

Surface texture refines appearance and controls friction or grip, as on flooring, so machined and molded texture production needs a way to confirm the intended texture is being reproduced.

How was the flooring texture analyzed?

A 10 × 10 mm area was scanned, each depression was segmented with its deepest point, and statistics, power spectrum and roughness were calculated.

How large were the depressions?

Mean area 0.394016 mm², mean diameter 0.683262 mm, mean form factor 0.638741, aspect ratio 1.67253 and roundness 0.636164.

What is the texture wavelength?

The power spectrum shows dominant wavelengths around 0.68 mm and 0.74 mm, with minor peaks up to 1.72 mm.

How rough is the texture?

Sa 4.67062 µm, Sz 27.4532 µm, with a developed area of 110.278 mm² over 100 mm² projected (ISO 25178).

How would this be used in production?

Measure a batch of samples and compare these parameters; depression area, wavelength and density are especially useful for a quantitative quality control process.

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