Study On The Lubrication System Of Gel Ink And Its Writing Performance

As one of the core raw materials of gel ink pen,the performance of the gel ink has a crucial impact on the writing performance of the gel pen.There are many factors affecting the performance of gel ink,such as thixotropy,pseudoplasticity,lubrication,moisture retention,viscosity and surface tension.Based on the analysis of factors affecting ink performance,this paper found that the lubrication of ink,especially a key index,is conducive to smooth and even ink output and smooth and full lines,while poor lubrication will lead to failure in writing due to wear problems.The good lubrication of ink itself and the optimal matching between ink and pen tip play a decisive role on the performance of the gel pen.Therefore,the basic formulation system of gel ink was studied firstly.The compatibility of raw materials with different properties was selected,and the key components such as thickener and moisturizer were mainly selected,and a gel ink basic formulation suitable for writing was constructed.On this basis,the influence of lubricant on the writing performance of gel ink formulation was studied from two aspects of lubricant type and its amount.Finally,a gel ink formulation with good lubrication performance,comfortable and long-term stability was obtained.In addition,this paper innovatively studied the friction and wear problems in the start-stop phase before filling ink with a gel pen.It is found that there was a layer of writing lubrication film about 500 nm thick on,the surface of ball socket of pen tip,which also had some effect on the writing performance of the gel pen,and the lubrication film is adsorbed on the surface of-the ball.socket through chemical adsorption effect,when the cutting oil is used for processing the free-cutting stainless steel metal tip.The lubrication film is mainly composed of a hydrophilic substance such as a h,ydrocarbon-based acid or a hydrocarbon-based alcohol.The lubrication condition between the ball and the ball socket is boundary lubrication.The writing lubrication film can reduce the friction and wear of the pen tip.Compared with the results without the lubrication film,the average friction coefficient of the tip is decreased by 32%,the wear rate is decreased by 77%.The mark of the refills without lubrication film on the pen tip presents regular light color and continuous decrease of ink output.When the pen tip slides for 600 m,it will be completely invalidated due to greater wear.The mark of the refills with lubrication film is full and clear,and the change in ink output is slight.The hydrophilic substance in the lubrication film can improve the wettability of the ball socket on ink,which can continuously improve the lubrication performance of pen tip and achieve long-term service for gel pen.