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How UV Cured Adhesives Enable High Volume, Quick & Efficient Bonding for Manufacturers

Posted on 2/2/2021 9:13:42 AM By Fastener and Fixing
  

The growing demand for adhesives of various sorts in the past few decades has been accelerated by changes in the bonding process which can play a big role in determining which adhesive is considered best for the application. In many instances, UV curing has become the most sought after for high volumes, fast bonds and efficient and effective curing, and for curing a wider range of substrates, as well as enabling the bonding of two totally different substrates.

UV curing has changed considerably since it was first introduced using equipment aimed at producing a broad spectrum of light energy, and adhesives which initially contained one photoinitiator which reacted only to these broad wavelengths. As this broad spectrum UV developed further, a second photoinitiator was added to allow for absorption of more light, reduced curing time, and for curing through transparent substrates which contained UV blockers. UV curable adhesives could and still can polymerize within a matter of seconds under broad spectrum or monochromatic LED UV light, and it’s a system still considered appropriate for all UV curable adhesives, and especially for epoxies.

The later introduction of LED UV curing equipment which cuts out the replacement of UV bulbs used in broad spectrum UV curing and generates considerably less heat during curing has made the curing process easier and more efficient. It also enables the incorporation of small modular units with high intensity in existing automated systems, and adhesives can be cured using several wavelength options.

Different dual curing products have been developed to provide reliable and complete curing processes for adhesive applications which have areas which are not reached by the light. One method involves initially exposing the adhesives to UV/LED light and then post-curing them thermally in a second step and using atmospheric moisture to cure the areas that UV/LED light could not reach. Where the light cannot reach the components being bonded at all, curing with heat from thermosetting epoxies becomes the best option.