Gel pen
A gel roller is a special form of the pen, which is an aqueous gel is used instead of an oily paste as ink.
Design
The gel roller consists of an ink containing polypropylene tube, which opens into a metal tip and is usually taken in a shaft. To prevent drying of the ink, the ink column is closed at the rear by a plug made of silicone. With a cap sealed pins have been in this a seal for the writing tip, while gel roller with push-button mechanism included a coil spring in its writing tip, the ball seals against the wording of the writing tip when not in use.
Function and use
The specificity of the gel is its viscosity from about 200 Pa · s, which dramatically decreases upon application of a shear stress. The rotation of the writing ball created at the interface with the ink column such high shear stresses that the ink is liquefied locally and can be written similarly to an ink roller. The thereby occurring ink flow is five to ten times its a pen, making the writing ball is very well lubricated. This effect causes a very light, smooth writing feeling, but is also responsible for the short length of the write Gelrollers. Side effects are the building of ink residues at the gap between the ball and socket, which can be delivered all of a sudden change in the direction of writing and lead to the blots, and the occurrence of double lines, since the ball given the ink left and right piles up their alley. Gels have the advantage to create opaque compromising on light and dark paper substrates. Since the ink is thickened (usually by a polysaccharide such as xanthan gum), large pigments in the ink can be kept without settling, allowing glitter ink or pigment ink for writing on dark paper.
Writing tips
Gelspitzen are constructed analogously to the ball tips in the pen. The mount is usually made of stainless steel and the writing ball of hard metal or ceramic. The ball diameter is usually between 0.3 and 1.2 mm, and East Asian products to 0.2 mm are available.
Countries of origin
The country with the largest production is Japan, where this type of pen was developed in the 1980s ( the major vendors are Pilot, Uniball and Pentel ). In recent years, China has established itself as an essential next Country cheaper gel pens.