Functional Tapes – Paul Wu's Blog

Photo elasticity based stress analysis

Mechanic deformation can lead to the optical property change in an optical media, which is called photo elasticity. Therefore, this principle is commonly adopted to investigate the stress distribution in a material.

Keynote Vs vibration frequency

From vibrationdata.com, the following table lists vibration frequency for each piano keynote.

Optical path for reflection/transmission measurement in Perkin Elmer spectrophotometer

The following figure from Perkin Elmer shows the optical path for transmission and reflection measurements using an integrating sphere.

Color and measurement (ASTM E1164)

The color of an object is determined by illuminant (light source), object, and observer (detector, eyes).

Photo elastic modulator

photo elastic modulator

Photo elastic modulator (PEM) is one the critical components in a phase modulated ellipsometer, which modulates phase and amplitude changes in detected signal, based on that Psi and Delta will be measured and n, k, d, and others accordingly in principle.

Transmittance/Haze/Clarity measurement-ASTM D 1003

As a simplified view, light is incident upon a sample, three processes occur: transmission, absorption, and reflection, as schematically shown in the follow figure, including retroflection, diffuse reflection, specular reflection, diffuse transmission, and specular transmission.

OCA for good gap filling

Patent application, WO 2017/058499 Al, teaches a method to formulate OCA with good gap filling property for display applications.

initiators

In optically clear adhesive synthesis, free radical initiators can be photoinitators or thermal initiators. The amount of the free radical initiator is often in a range of 0.05 to 5 weight percent based on a total weight of monomers used. The following are some examples of initiators including both thermal and photo-initiators:

PSA for use on low energy surfaces

US patent 5874143 teaches a method to make PSAs for use on low energy surfaces.

Stretch releasing tape-2

WO1995006691A1 teaches how to make a conformable pressure sensitive adhesive tapes which comprise a layer of polymeric foam in the backing and may be adhered firmly to a substrate and thereafter removed therefrom after only being stretched at an angle no greater than about 35° from the surface of the substrate.