Gel roller
A gel roller is a special type of ballpoint pen that uses an aqueous gel as an ink instead of an oily paste .
Design
The gel roller consists of a small tube made of polypropylene containing ink , which ends in a metal tip and is usually held in a shaft. To prevent the ink from drying out, the column of ink is closed at the back with a silicone plug. Pens closed with a cap have a seal for the writing tip in this, while gel pens with a push-button mechanism contain a coil spring in their writing tip, which seals the ball against the holder of the writing tip when not in use.
Function and use
The specialty of the gel is its viscosity of around 200 mPa · s , which decreases dramatically when a shear stress is applied. The rotational movement of the writing ball generated at the interface with the ink column such high shear stresses that the ink is liquefied locally similar to a rollerball pen can be advertised. The resulting ink flow is five to ten times that of a ballpoint pen, which means that the writing ball is very well lubricated. This effect causes a very light, gliding writing feeling, but is also responsible for the short writing length of the gel roller. Side effects are the build-up of ink residues at the gap between the ball and socket, which can suddenly be released when the direction of writing is changed and lead to a blot, and the appearance of double lines, as the ball piles up the released ink to the left and right of its path. Gels have the advantage of producing opaque smears even on light and dark paper substrates. Since the ink is thickened (usually by a polysaccharide such as xanthan gum ), even large pigments can be held in the ink without settling, which enables glitter or pigment ink for writing on dark paper.
Writing tips
Gel nibs are constructed in the same way as ballpoint pens . The frame is usually made of stainless steel and the writing ball is made of hard metal or ceramic . The sphere diameter is usually between 0.3 and 1.2 mm, with East Asian products available from 0.2 mm.
Countries of origin
The country with the largest production is Japan, where this type of pen was developed in the 1980s (major manufacturers are Pilot, Uniball and Pentel). In recent years, China has also established itself as a major manufacturer of cheap gel rollers.
Web links
Individual evidence
- ↑ a b c d ink pens ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 1.1 MB). Staedtler Mars, accessed March 1, 2012.
