Surface Profilometry Method and Apparatus
Technology description
Interferometry is used to measure the three-dimensional surface profiles of materials with micron to sub-micron resolution. Using traditional methods, numerous algorithms have been proposed to determine an interferogram’s peak position and improve detection accuracy.
Such methods fail when measuring diffusely scattered materials such as paper or paperboard due to a lack of visibility in the white-light interferogram. To overcome this lack of visibility, very complex algorithms that demand excessive computing power are required. This results in cumbersome and expensive solutions.
The technology that has been developed is a non-contact method to rapidly measure the surface roughness of paper or paperboard using scanning white-light interferometry (SWLI) and image processing.
This new method uses the interference fringes created from the measuring beam and reference beam to generate a topographical map of the material surface. This allows the surface position to be extracted even if the interferogram strength or contrast is weak.
Surface roughness is a quality measurement that is required for most paper and paperboard products and the surface profile data obtained from this method can be employed to calculate these values.
Advantages
The new non-contact scanning white-light interferometry (SWLI) profilometry method and apparatus has several advantages over traditional surface profiling tools:
- Able to measure root mean square average roughness of more than approximately one micron;
- Does not require excessive amounts of computing power or human input;
- Removes need to analyze low coherent interference fringes;
- Able to profile rough surfaces with low spectral reflected intensity.
These advantages make the new non-contact SWLI method much more beneficial when profiling and measuring surface roughness of materials such as paper.
Stage of development
The proof-of-concept prototype stage is complete.
Lab testing using typical paper materials is complete.
A working prototype is currently being developed and results are being cross validated against traditional instruments.
Intellectual property
US Provisional Patent: 61/737,566 – Method and Apparatus for Surface Profilometry
This technology is available for licensing.
Contact information
Office of Research Services, Industry-Government Services
University of New Brunswick
Phone: (506) 453-4674
partner@unb.ca
