Edge curling types

Cupping- A type of warping that causes boards to curl up at their edges. 

Fiber kink Also called curl yarns, looped yarn, or snarl in a fiber. In fabric, a short length of yarn that has spontaneously doubled back on itself to form a loop. It can be a type of a waviness occurring as interior edges, not to be confused with the more abrupt departures as ridges or surface marks. 

The large effect of bulk doping and Fermi level on surface reactivity is seen when n-type and p-type silicon single crystals are etched. A high Fermi level in the silicon (upward curling band edges) etches with formation of clean crystal planes, while the surface of anodically etched p-type silicon is ramified and highly porous. 

Curling always begins with the tape edges, where the reduced thickness of the tape does not exert as much gravitational force. One of the other stress-relief mechanisms was covered in previous sections the Type II plasticizer. The Type II plasticizer in a tape structure can act as a lubricant, facilitating motion within the tape structure in response to drying stress instead of curling. 

Mascara and eyeliners are also complex formulations, and need to be carefully applied to the eye lashes and edges. Some of the preferred criteria for mascara are good deposition, ease of separation and lash curling. The appearance of the mascara should be as natural as possible. Lash lengthening and thickening are also desirable. The product should also remain for an adequate time and it should also be easily removed. Three types of formulations may be distinguished anhydrous solvent-based suspension, water-in-oil emulsion and oil-in-water emulsion. Water resistance can be achieved by addition of emulsion polymers, e.g. poly(vinyl acetate). 

---