Polymers welding

M < M, disentanglement predominates and Eq. 8.9 applies such that little bond rupture occurs. (3) When M > M, bond rupture y PWgS fStSS t t Afl 4flPU n complete disentanglement cannot occur when M > M, bond rupture occurs randomly in the network and the percolation parameter p becomes dominated by chain ends such that 9. Polymer-polymer welding... [Pg.390]

Flash welding has the following advantages compared with other polymer welding techniques that use... [Pg.245]

Process temperatures are normally below 350°C. LCPs are processable on a variety of conventional equipment. The LCPs generally have low melt viscosity as a result of their ordered melt. They should be dried before use to avoid degradaflon. LCPs can be injection molded on conventional equipment, and regrind may be used. Mold-release agents are generally not required. Part design for LCPs requires careful consideration of the anisotropic nature of the polymer. Weld lines can be very weak if the melt meets in a butt type of weld line. Other types of weld lines show better strengths. [Pg.326]

ESCA can also be used to analyze fracture surfaces, particularly those involving immiscible (asymmetric) interphases. While finely divided polymer blends offer some difficulties, plates of two different polymers welded together provide valuable model materials. Foster and Wool (19) and Willett and Wool (20) studied the polystyrene/poly(methyl methacrylate) interface welded at 125 and 140°C see Figure 12.5 (20). As described above, ESCA makes use of... [Pg.623]

Adhesives may be used to bond two different structures together to form a composite, as in polymer-polymer welding. The problem of adhesion also extends to the bonding of an engineering polymer directly to a nonpolymer substrate. [Pg.667]

SchweiBgerat blowpipe, welding torch schweiBen polym weld SchweiBen po/ym welding... [Pg.222]

SchweiBnaht weld seam polym weld line, weld mark, knit line, flow line... [Pg.223]

Ultrasonic welding can be used to weld parts made from all grades of PVDF including copolymers or alloys, reinforced or not. The standard procedure for crystalline polymer welding by ultrasonic techniques (geometry of weld joint, type of booster, and horn) can be applied for all elements made from PVDF.I" ]... [Pg.493]

In the second section we shall briefly review more recent trends in molecular rheology, including attempts to deepen the understanding of entanglements on a molecular level, and the use of the reptation ideas to describe various practical problems such as polymer/polymer welding, phase separation of polymer mixture, flow behaviour of a polymer melt close to a solid wall... [Pg.399]

To summarize, for autohesion (polymer-polymer welding), there will be rapid (Rouse) interdiffiision, which occurs to distances comparable to the radius of gyration of the entanglement molecular weight. Me, say 3 nm (O Table 2.4). The interface is very weak and could be described in terms of the nail solution, with chain pullout being the dominant fracture mechanism. [Pg.30]

APPLICATION OF POLYMER WELDING THEORY TO INDUSTRIAL PROCESS DESIGN... [Pg.1923]

In the eurrent study, mierostructure of lass -welded joints was investigated and eharacterized for differsit polymers welded at different levels of lass powers. [Pg.2326]

Benatar, A., Recent Advances in IntematioDal Polymer Welding Research and Development, in Proceedings KTP-Jubilaumstagung , 8, 199-209... [Pg.2370]

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