Accurate quantitative supply of PTFE fine powder

Abstract

PTFE is often used in various fields because of its excellent properties such as low coefficient of friction, heat resistance, and chemical resistance. On the other hand, non-granulated fine powder of PTFE agglomerates easily and tends to fibrillate, therefore, it is difficult to supply it continuously with high accuracy. The purpose of the research is to develop a device that can continuously and accurately supply fine PTFE powder. The authors propose a new method in which combinations of three motions, i.e. vibration, stirring motion and crushing motion, are adopted. The powder in a straight hopper is stirred by a slowly rotating tool while the hopper is vibrated in the horizontal direction. The hopper has stainless steel mesh at its bottom. The powder is dropped through the mesh and supplied into a container. In order to avoid for the powder agglomeration in the hopper, two crushing tools also rotate fast in the hopper. Powder and supply situations are investigated for the supplies by each motion or combination of the motions. Target values and accuracies of one supply are set to 10g±0.1g or 0.8g ±0.02g, respectively. In addition, the target continuity of the supply and target time in one supply are set more than 100 times and less than 40 seconds, respectively. As a result, the target accuracy has been achieved at 95 % or more possibility for both target values. The target conditions of both of the continuity and time have also been cleared.

Keywords

• fine powder
• ptfe
• automation of supply
• powder handling
• accurate supply