Drop test: A new method to measure the particle adhesion force
Drop test: A new method to measure the particle adhesion force
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DOI：
10.1016/j.powtec.2014.04.022
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发表时间：
2014-09-01
影响因子：
5.2
通讯作者：
Ghadiri, M.
中科院分区：
文献类型：
--
作者：
Zafar, U.;Hare, C.;Ghadiri, M.
附着力的测量在大量应用中具有很大的意义，例如粉末涂覆和粘性粉末的加工。已建立的测量方法，如原子力显微镜（AFM）和离心法是昂贵和耗时的。对于工程应用，需要开发一种快速测试方法。跌落试验方法是为此目的而设计和开发的。在本试验方法中，将粘附在基材上的颗粒安装在止动环上，并通过将其从设定高度跌落，使其撞击止动环，从而使其受到拉力。从临界颗粒尺寸的分离力和粘附力的平衡，计算出界面比能，在临界颗粒尺寸以上颗粒分离，在临界颗粒尺寸以下颗粒保留在基底上。需要一个粘附模型来估计颗粒与表面之间的粘附力，在这项工作中，我们使用JKR理论。根据牛顿第二运动定律，使用基于其尺寸和密度的估计颗粒质量以及计算的颗粒加速度来估计分离力。已经测试了许多材料，例如硅烷化玻璃珠、Avicel、α-乳糖一水合物和淀粉，并且已经量化了颗粒和基底表面之间的粘附力和能量。一致的界面能与一个狭窄的误差带的值，独立的冲击速度。由于后者是不同的，不同的颗粒尺寸分离;然而，获得了类似的界面能值，这表明该技术是稳健的，因为它实际上是基于许多颗粒的显微镜观察。用跌落试验方法获得的结果的趋势与其他研究人员使用AFM和离心法等已建立的方法进行的研究中所示的趋势相似。(C)2014作者由爱思唯尔公司出版
Measurement of the adhesive force is of great interest in a large number of applications, such as powder coating and processing of cohesive powders. Established measurement methods such as Atomic Force Microscopy (AFM) and the centrifugal method are costly and time consuming. For engineering applications there is a need to develop a quick test method. The drop test method has been designed and developed for this purpose. In this test method particles that are adhered to a substrate are mounted on and are subjected to a tensile force by impacting the stub against a stopper ring by dropping it from a set height. From the balance of the detachment force and adhesive force for a critical particles size, above which particles are detached and below which they remain on the substrate, the interfacial specific energy is calculated. A model of adhesion is required to estimate the adhesive force between the particles and the surface, and in this work we use the JKR theory. The detachment force is estimated by Newton's second law of motion, using an estimated particle mass, based on its size and density and calculated particle acceleration. A number of materials such as silanised glass beads, Avicel, alpha-lactose monohydrate and starch have been tested and the adhesive force and energy between the particle and the substrate surface have been quantified. Consistent values of the interface energy with a narrow error band are obtained, independent of the impact velocity. As the latter is varied, different particle sizes detach; nevertheless similar values of the interface energy are obtained, an indication that the technique is robust, as it is in fact based on microscopic observations of many particles. The trends of the results obtained with the drop test method are similar to those shown in studies by other researchers using established methods like the AFM and the centrifuge method. (C) 2014 The Authors. Published by Elsevier B.V.