Tehnologija zavarivanja polimetilmetakrilata (PMMA)

Abstract

Polimetilmetakrilat (PMMA), zbog svojih karakteristika, pre svega transparentnosti i relativno male gustine, predstavlja danas vrlo atraktivan materijal u inženjerstvu. Zbog toga, istražuju se nove mogućnosti spajanja ovog materijala u cilju dobijanja kompleksnijih i većih radnih predmeta. U ovom radu su prikazane tehnike zavarivanja i spajanja, koje imaju potencijal za primenu u proizvodnji: ultrazvučno zavarivanje, toplotno spajanje, mikrotalasno zavarivanje i tačkasto zavarivanje trenjem. Takođe, prikazani su i uporedne vrednosti smicajne čvrstoće, jednog od dominantnih pokazatelja kvaliteta zavarenog spoja. Na osnovu prikazanih rezultata, najveću smicajnu čvrstoću ima tačkasto zavarivanje trenjem, sledi mikrotalasno zavarivanje, dok najmanju nosivost zavarenog spoja imaju toplotno spajanje i ultrazvučno zavarivanje. Pored toga, na osnovu specifičnosti pojedinih tehnika zavarivanja, može da se konstatuje da je tačkasto zavarivanje trenjem pogodnije za veće radne predmete, dok je veličina radnog predmeta kod mikrotalasnog zavarivanja ograničena veličinom mikrotalasne komore.

Polymethylmethacrylate (PMMA) has attractive features, primarily its transparency and low density, which make it a very promising engineering material. Therefore, a novel bonding and welding techniques are being developed, to enable obtaining more complex and larger products. In this paper, perspective bonding and welding processes are presented: ultrasound welding, thermal bonding, microwave welding and friction spot welding. Furthermore, shear strengths of joints obtained by different techniques are shown. Shear strength of joints is commonly used to evaluate the quality of joints. The highest shear strength has friction spot welding, followed by microwave welding. The lowest shear strengths were obtained with thermal bonding and ultrasound welding. Specific characteristics of each joining technique determine their usefulness: friction spot welding is more suited to welding large pieces, while the work piece dimensions weldable by microwave welding is limited by microwave chamber size.