Screen-printable adhesive helps cut waste

Developers of a new UV-cured screen printable adhesive claim the product will help manufacturers boost productivity by 40% and help cut waste. Dean Palmer reports A new, UV-cured, screen printable adhesive has been developed that should help manufacturers of electronics equipment, membrane switches, nameplates, keypads and automotive dashboards boost productivity levels, improve process control and reduce waste levels. 3M SP-7514, jointly developed by 3M and Nor-cote, is an innovative liquid PU-acrylate based adhesive material that is suitable for both flat bed and rotary screen-printing. The material can be processed faster and more consistently than solvent- or water-based alternatives. The developers say the product has been "optimised to give a balanced combination of peel and shear strength" and is "durable for long term performance in arduous environments". Accurate outlines with thicknesses of less than 25(m can easily be printed and, unlike die-cut adhesive films, no tooling is required and no cutting waste is created during processing. The material is 100% adhesive (ie. No water or solvents are used) so this eliminates shrinkage and improves the processing environment. And, since the adhesive will not dry on the screen, periodic cleaning of equipment is not necessary. 3M claims this and the fact that UV curing is faster, means that manufacturers can improve their productivity levels by as much as 40%. Dr Chris Howitt, technical manager at 3M's UK industrial business, told Eureka: "This new adhesive technology gives manufacturers exactly what they have been looking for in terms of processing speed, control and environmental performance." SP-7514 also gives the user the ability to control the performance characteristics of the adhesive by definitive curing. Altering the intensity of the UV light enables the shear, peel and tack properties to be matched exactly to the application. Curing stops when the UV source is switched off and the adhesive properties remain constant and repeatable, regardless of changes in temperature or humidity. After curing, the material behaves like a typical pressure-sensitive adhesive tape. It can be laminated immediately or protected with a release liner for later use.