Hollow needle esp. for injections with polished section with a length of at least ten times the needle tube diameter, for soft transition between needle tube and plastic hose

摘要

The needle consists of a tube (13) with a polished section (12) which extends from a needle tip (18) to an outlet (16). The length of the section is at least ten times the diameter of the needle tube. The polished section increases in size constantly from the distal end (17) of the tip in proximal direction. The needle tip is rounded or wedge-shaped. The polished section extends over more than 30mm, pref. 100mm to 180mm. A synthetic coating (14) extending towards the proximal end is located on the needle tube at a distance to the outlet. Several needles are placed on raised wires of a support and fixed by strips of adhesive, and the polished sections are formed by grinding or wire eroding, e.g. cavity sinking by EDM at intervals of 1-7 sec.