Process Control in the Production of Artificial Leather Skins
The exact transfer of the leather pattern to the artificial leather skin should be ensured for the process control during the production of artificial leather skins. The forming tools have metal surfaces; artificial leather skins are soft and very soft silicone imprints should also be collected.
Leather imitation in car interior
Image Credit: FRT
The rough leather structure and the microstructure on the nubs and in the scars should all be measured and all measurements should be performed using the same sensor.
Conventional stylus tools are able to scan the surface mechanically, but they are too slow to take 3D measurements, and they cannot measure the soft surfaces without interaction.
A lens in the sensor follows the height of the object being measured in non-contact autofocus systems. The highly structured artificial leather surfaces can only be measured extremely slowly.
Artificial leather surfaces for car interiors should not be reflected in the windshield of the car because they absorb incident light to a high degree. An optical sensor has to be extremely sensitive in order to be able to establish the topography from the small amount of light scattered on a black artificial leather surface reliably.
The MicroProf® utilizes a confocal, chromatic distance sensor that focuses white light on the measuring object and establishes the height of the measuring object in the measuring spot from the spectral distribution of the light scattered on the surface.
For different measuring tasks, there are different measuring heads with measuring ranges of up to 10 mm and a height resolution from 3 nm.
The system can be employed to measure the entire spectrum of materials utilized, for example, silicone, leather, metal and plastic. The full resolution (2 μm lateral, 3 nm in height) is available for every possible measuring field size for measurements with the MicroProf®.
The SLS is an optical line sensor that can be used for very quick measurements. It also works according to the principle of chromatic distance measurement. Instead of a single measuring spot, this sensor produces 192 measuring spots, which are lined up equidistantly along a line.
For each measuring point, a distance value with a resolution in the nm range is produced. It is possible to generate a 3D measurement immediately while scanning along a measurement direction perpendicular to it because of the line arrangement of the measuring points.
3D view of leather-like structure
Image Credit: FRT
By using measurement rates of up to 2 kHz, the scanning of a measurement object is possible in a fraction of the time needed for point sensors.
Utilized in MicroProf® to evaluate the measured data, the Mark III software determines the slope of the flanks, the height of the nubs, and the width of the scars. The roughness of the surface is determined in small areas between the scars.
The Automotive Industry Wishes
The high quality demands of the automotive industry are met with regard to gloss and color embossing. They also create a range of design possibilities, as small radii, but also complex geometries with large undercuts, can be produced with high precision.
Authentic Haptics for Modern Imitation Leather Cover in Cars
The haptic in cars is important; the appearance and touch of the matt black imitation leather cover are both key factors.
The automotive industry is always developing new materials that look great, are durable and feel good. Most of these are leather-like surfaces, known as slush skins, which exact contour images of leather structures and real-looking decorative seams. They do not fade or become brittle like real leather.
Slush Skin Determines the Function of the Airbag
Slush skins must have a certain thickness since they also cover the areas under which the airbag is located. It must not be so thin that it collapses and the perforation of the underlying material becomes visible and also so thin that the cover of the airbag tears open in an emergency.
Example: Imitation of the Leather Structure
The topography measurement of slush skin for automotive interiors is one specific example. In this instance, the height and diameter of the grains are measured in large surface areas and the high resolution micro-roughness of the individual grains is established.
In this case, it is crucial to be able to dynamically adjust the measuring range from the millimeter range to the micrometer range. These measurements are vital for the manufacture of tools, the design of structures, production monitoring and quality control.
The aim is to optimize the structures to attain the best possible imitation of the leather structure through synthetic surfaces. The result must have the desired characteristics when touched, but it must also be as resistant as possible to dirt and effects like heat or humidity.
This information has been sourced, reviewed and adapted from materials provided by FRT Metrology.
For more information on this source, please visit FRT Metrology.