Embedded Resistance Wire Technique for Epoxy Curing and Self-Healing of PET Thermoplastics

The aim of the present study is to apply an embedded resistance wire technique for curing of thermosetting resins as well as for the self-healing of thermoplastic polymers. The work consists of two parts. In the first part, Kanthal resistance wires embedded in a resin plate acted as heating elements when direct electrical current was flowing through them (Joule heating). During heating, the temperature was continuously monitored using a thermal camera, and accurate temperature times for fixed position diagrams as well as temperature positions for fixed time diagrams were calculated. The effects of curing with this method were evaluated by studying the three-point bending mechanical behavior of the cured resin, comparing it with the corresponding behavior of the same resin when cured using a conventional oven curing method at the same temperature. In the second part of the present work, the possibility of using the same technique for healing existing notches and flaws in a PET thermoplastic is explored. We examined whether providing energy through the resistance wires created the right amount of heat to heal the thermoplastic, or, more specifically, whether it closed the notches and eliminated the abrasions that were artificially created on the specimens. The technique using embedded resistance wires worked equally well, with interesting and promising preliminary results regarding the curing of thermoset resins and the healing of thermoplastics.

Design of one Electrothermal Cutting Machine Used for Producing Packaging Material

Based on the problems of low precision, single-function of the plastic molding machine, a smaller electrothermal cutting machine is developed and designed, which is composed with processing platform, positioning clamp, resistance wire conjoined chuck, cantilever beam, fixed mounts, etc. Regulate the temperature of resistance wire to achieve the cutting of foam model with different melting point by adjusting voltmeter and regulating transformer; adjusting the rotatable positioning cones meshed with the adjusted range of positioning clamp and the adjustable distance between positioning clamp and resistance wire can make model with different requirements. The machine is mainly used in cutting and molding of plastic materials, such as foam and sponge, during the experimental teaching and advertising design. Results of the performance test show that using the machine with auxiliary manual operation is more convenient, efficient and accurate than the traditional making process of plastic model.