Laser welding of thin polymer films to container substrates for aseptic packaging

• Published in: Optics and laser technology Vol. 32; no. 2; pp. 139 - 146
• Main Authors: Brown, N, Kerr, D, Jackson, M.R, Parkin, R.M
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2000; Elsevier Science
• Subjects: Biological and medical applications; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Industrial applications; Laser; Optics; Physics; Polymer; Welding; Welding; Polymer; Laser; Thin films; Multilayers; Laser materials processing; Industrial application; Feasibility; Laser beam applications; Experimental study; Polymers; Laser welding
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/S0030-3992(00)00033-5

Keyhole laser welding of polymers is a subject well covered and researched, but relatively little information exists regarding the welding of thin polymer films, particularly to a heavier substrate. This paper presents the design of a suitable test apparatus for laser welding thin film to a heavier substrate, and shows the results of an investigation into the feasibility of laser welding multi-layer polymer film lids to tubs for the manufacture of aseptic food containers. A consistent weld, free from defects, is the key to process success. Typical welding defects have been synthesised in order to investigate, and consequently remove, their cause. The result is a reliable welding method based on even film clamping. With careful attention to machine design, a seal of high mechanical strength and chemical integrity is possible.