DOD INKJET SYSTEM USING ER FLUID INK

ERF具有电介质油状液体基础，其中微小的固体颗粒与少量表面活性剂一起悬浮，以防止重力沉降。如果流体上没有施加电场，这种电流变液的喷射是通过在高压下迫使墨水产生的。当施加电场时，ERF油墨不会从喷嘴中喷射出来，因为它的粘度增加了。因此，这种油墨的液滴生成可以进行电气控制。此外，由于电流变液的组成与印刷油墨的成分非常相似，因此这种类型的DOD喷墨系统具有较高的打印质量和紫外光适应性。实验表明，液滴的产生是由交流电场控制的，液滴产生速率约为100DPS。然后，使用牛顿力学和特定平行墨道的等效长度计算从喷嘴喷出的液滴体积，该墨道提供与锥形或窄宽度部分相同的粘性流体流动阻力。从喷嘴喷出的液滴体积计算结果与实验观测结果吻合较好。

ERF has a dielectric oily liquid base in which fine solid particles are suspended with small amount of surface active agents to prevent gravitational settling. A jet of this ERF is produced by forcing ink under high pressure if no electric field is applied across the fluid. When the electric field is applied, the ERF ink is not ejected from the nozzle because of its increased viscosity. Therfore, droplet generation of this ink can be controlled electrically. Furthermore, high printing quality and UV light fitness are expected to this type pf DOD inkjet system, since the composition of ERF is very similar to that of printing ink.We showed experimentally that droplets generation was controlled by an AC electric field and droplet generation rate is about 100 dps. Then, the droplet volume ejected from the nozzle is calculated using Newtonian mechanics and the equivalent length of a particular parallel ink channel that gives the same viscous resistance to fluid flow as dose the tapered or narrow width part. The calculated droplet volume ejected from the nozzle agrees well with that of experimentally observed results.