Electrostatic and mechanical properties of extrusion spun PTFE monofilament with integration of microtourmaline particles

Abstract

This study reports on polytetrafluoroethylene (PTFE) monofilaments prepared by extrusion spinning with the integration of tourmaline particles. The resultant PTFE monofilaments have excellent electrostatic properties and contain different amounts and sizes of tourmaline particles. Tensile tests show that the PTFE monofilaments with 7 wt % and 1 wt % of 5 μm particles possessed tensile strengths of 1175 N and 1026 N, which were 12.5% and 23.6% lower than those of the pure PTFE monofilament, respectively. In electrostatic properties, there was 14.3% growth in surface voltage compared with the original PTFE monofilament in the series of monofilaments with varying content of tourmaline particles. When the particle size was 5 μm, the voltage was 14.7% higher than that of pure PTFE monofilament in the series of monofilaments with varying sizes of tourmaline particles. In addition, a model of electric field distribution around the monofilament was proposed based on a static electricity test. Successful research on such an intriguing monofilament might provide a novel application of the PTFE and tourmaline. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46401.

Fabrication and evaluation of aramid fiber/polytetrafluoroethylene emulsion/tourmaline particle composite filter media: Filtration performance, thermal behavior, and mechanical property

“…This was mainly due to the associated movement of fiber and TM particles during the hot-drying of the PTFE emulsion. 17 Smooth inert surface of aramid fiber leads to poor interfacial adhesion between fiber and emulsion, and the rougher surface of fiber can improve the interfacial bonding properties. 30 Therefore, it can be seen that this TM particle was well attached on the aramid fiber through PTFE emulsion.…”

“…The initial pressure drop of AF/PTFE/TM composite filter media is still below 50 Pa even under the highest flow velocity of 3 m/min, and this initial pressure drop is far lower than that of three PTFE membrane filter medias containing the TM particles in previous literatures. 17–19…”

“…This phenomenon can be clearly observed in the partial enlarged drawings (see Figure6(d)) of Figure 6(c) (highlighted in red). According to previous literature, there is no chemical reaction between the PTFE and TM particles during the mixing process, 17,29 and thus the filaments are formed by PTFE emulsion in the fabrication process of the composite filter media. The gravity of adhesive TM particles should play a major role in the formation of the PTFE filaments because this force is imbalanced with respect to PTFE emulsion properties such as surface tension and viscosity.…”

“…14,15 The emission of negative ions is the particular property of TM that is exploited in removing small particles. In the previous literature, TM is invariably used in the electrospinning process to produce functional membrane, [16][17][18] but the electrospinning process is difficult to apply widely because of its high prices and difficulty in preparation. Additionally, the pressure drop through membrane filter media is greatly higher than that of traditional filter material.…”

Double-channel resistance-to-voltage converter for cable teraohmmeters

“…An increase in voltage applied to the cable is limited since the maximum allowable voltage for a given cable is specified in the cable documentation. The voltage level used by the teraohmmeter may provide inaccurate measurement of the insulation resistance [14][15][16][17][18][19]. Interference filtering typically increases the device inertia.…”