Microwave welding of high density polyethylene using intrinsically conductive polyaniline

Abstract

The use of intrinsically conductive polymers in welding of plastics and composites offers the possibility of developing new welding methods. Intrinsically conductive polyaniline (PANI) composite gaskets were used to microwave weld high density polyethylene (HDPE) bars. Two composite gaskets were made from a mixture of HDPE and PANI powders in different proportions. Adiabatic heating experiments were used to estimate the internal heat generation and electric field strength in the gasket. During welding, the effects of heating time, heating pressure and welding pressure were evaluated. It was found that increasing the heating time and the welding pressure increased the joint strength. The maximum tensile joint strength was achieved using a 60 wt% PANI gasket with a heating time of 60 sec and a welding pressure of 0.9 MPa; this resulted in a tensile weld strength of 24.79 ± 0.34 MPa, which equals the tensile strength of the bulk HDPE.

Synthesis and processing of biodegradable and bio-based polymers by microwave irradiation

“…Polymer surface modification has been performed by a microwave induced plasma treatment (Leonelli & Mason, 2010): to cite an example, poly(dimethylsiloxane) (PDMS) slabs were irreversibly sealed within 30-60s by means of a 30 W plasma generated in glass bottles containing 2-3 Torr of oxygen (Hui et al, 2005). Similar procedures are reported in papers dealing with modification of PDMS surface hydrophilicity (Ginn & Steinbock, 2003) and polyaniline-aided welding of high density poly(ethylene) (Wu & Benatar, 1997). Welding of thermoplastics such as ultra high molecular weight polyethylene (UHMW PE), polycarbonate and ABS could be achieved by focused microwave irradiation of the specimen joint interface (Yarlagadda & Chai, 1998).…”

Welding methods for joining thermoplastic polymers for the hermetic enclosure of medical devices

“…Few studies have been performed on microwave welding of thermoplastics since it is a relatively new polymer welding technique. Wu and Benatar developed a microwave joining method (butt joint) for HDPE using PANI at the weld line [92]. They found that the thickness of the molten layer influenced strength, with greater thicknesses resulting in stronger bonds.…”

RF/Microwave Applicators and Systems for Joining and Bonding of Materials

“…Figure 8.11 shows a comparison of addition of two different levels of PANI on the heating capability of HDPE [26]. Figure 8.11 shows a comparison of addition of two different levels of PANI on the heating capability of HDPE [26].…”

“…[26]). The change comes mostly from the distance between the electrodes changing due to closing of the jaw to press the softened workpiece.…”