Causes
- Non-uniform matting / roughness of the front or back sides of films
- Inhomogeneous optical properties of foils
- Incorrect roughness for the bonding of the foils
Effects
- Lower product quality
- Visually recognizable inhomogeneities
- Streaking and spots
- Product rejects
- No process reliability
Films used in optical applications, e.g. as screen or cell phone surfaces, only allow inhomogeneities that can no longer be resolved by the human eye.
Technical films that are bonded over the entire surface of consumer electronics devices, for example, require absolutely homogeneous and precisely defined back embossing.
The uniformity of the embossing enables ideal adhesive application and thus homogeneous strong adhesion. Even on the reverse side, only those inhomogeneities that can be resolved by the human eye are impermissible, since the matt structure of the reverse side is formed through to the front side.
