Capillary writing medium reservoir system

Abstract

A capillary writing medium colorant reservoir system for a writing instrument and process for producing the colorant reservoir. The main problem in such colorant reservoirs is the storage time. During this time, the writing capacity of new writing instruments declines since the walls of the writing instruments are, if only slightly, permeable to solvents. In the long run a stored writing instrument thus dries out and loses the major proportion of its original writing capacity. To this end, the invention has a colorant reservoir with an elongated reservoir body made of fibrous material. The reservoir body is surrounded by a sleeve which is permeable to liquids and gases and gives the reservoir body its shape. The reservoir stores colorant to produce liquid writing medium, the colorant being stored between the fibers of the fibrous material of the reservoir body in dry form. A single-part or multipart wick projects from either side of the reservoir body. A process for producing the colorant reservoir is also proposed, according to which the elongated capillary fibrous body is surrounded by a gas and liquid-permeable but liquid-proof film and the fibrous body thus surrounded is soaked in or with a colorant concentrate. The soaked fibrous body is drained off and dried. Then a single-part or multipart rod-like wick is introduced, the wick being longer than the elongated fibrous body.