Complex fluids, such as gels, shampoos, and creams, are ubiquitous in the consumer product industry. However, little information is available on their discharge from consumer packaging, often resulting in a considerable heel, i.e., the residual waste material after the discharge process is complete. Here, we used rheological analysis and particle image velocimetry (PIV) to investigate the discharge of rheologically different fluids from a dispensing bottle provided with a modified hand pump. The fluids were described in terms of rheological parameters established by fitting rheometric data with the Carreau equation. The effect of operational parameters was also studied, which included the dip tube diameter, suction pressure, and volumetric flow rate. The data were also analyzed in terms of the dimensionless region of interest (ROI), which captures the relative “high-velocity” region in the fluid during the discharge process and is measured directly using PIV. Both rheological and operational parameters affect the heel at the end of the discharge process. The results presented here enable predicting the heel either by measuring ROI as in the case of transparent fluids and packages or by making use of the heel correlation with operational and rheological parameters also established in this work.

中文翻译：

---

使用流变学和流动可视化分析消费者分配瓶中的复杂流体排放

复杂的液体，如凝胶、洗发水和面霜，在消费品行业中无处不在。然而，关于它们从消费品包装中排放的信息很少，通常会导致相当大的残留物，即排放过程完成后的残留废料。在这里，我们使用流变分析和粒子图像测速仪 (PIV) 来研究流变学不同的流体从配备改进的手动泵的分配瓶中的排放。这些流体被描述为流变参数通过用 Carreau 方程拟合流变数据建立。的效果操作参数还进行了研究，其中包括汲取管直径、吸入压力和体积流量。还根据无量纲感兴趣区域 (ROI) 对数据进行了分析，该区域捕获了排放过程中流体中的相对“高速”区域，并使用 PIV 直接测量。流变学和操作参数都会影响放电过程结束时的脚跟。此处显示的结果可以通过测量 ROI（如在透明流体和包装的情况下）或通过使用与本工作中同样建立的操作和流变参数的鞋跟相关性来预测鞋跟。