An analysis of the extrusion welding process

Abstract

A mathematical model has been developed for the heating phase of extrusion welding. It is shown that weld quality is mainly determined by melting a layer of the base material. All the parameters relevant to the heating phase are shown to affect weld quality through their effect on the thickness of the molten layer in the base material. It is shown that these parameters can be well controlled.

Effects of welding procedures on mechanical and morphological properties of hot gas butt welded PE, PP, and PVC sheets

“…Atkinson and Turner [22] insisted on the necessity to apply sufficient pressure on a hot gas weld to obtain satisfactory weld strength, and reported that weld strength and interfacial bonding improved if a heated roller was used immediately following the welding torch to compress the molten polymer. Michel [42,43] mentioned the importance of extrusion V-welds on HDPE. Good quality welds can be obtained when the welding pressure is set in such a way that full root fusion is guaranteed.…”

“…The molten zone must not be necessarily large in volume but must exist in order for the polymer chains to fuse across the interface. Michel [42,43] developed a mathematical model for the heating phase of extrusion welding and showed that weld quality was affected by heating phase and molten layer thickness in the base material. For extrusion V-welded HDPE sheets, high creep strength was attained at a molten layer thickness of about 0.25 mm.…”

Hot‐tool and vibration welding of poly(vinyl chloride)

“…In some applications creep rupture may be more important, for which the time to rupture at different stress levels may be the appropriate measure of weld quality (49). Process conditions can have a large effect on the morphology of the weld zone, which in turn can affect impact performance (50).…”

Fabrication Techniques For Fluoropolymers

“…Both the hot air nozzle and the welding shoe are attached to a weld head, which moves along the joint line at a particular welding velocity. [95] [96] In extrusion welding polypropylene, extruded material crept under the surface of the welding shoe when the angle β (Fig. [95] [96] The process is similar for a lap-seam (Fig.…”