Pressure Sensitive Tapes Unwinders

It is interesting here to compare the three techniques which are used in packaging for cases and cartons closing in large plants, as far as the available speeds, strength, costs, ease of application, ease of opening are concerned. In the past, cases were closed and sealed with staplers. This was a fairly slow and manual application, and it is less and less used, and only for small jobs, small production output. For the medium speed production lines upto 5 cases per minute, pressure sensitive tapes, applied by automatic unwinders, are suitable and used. 

Pressure-sensitive tapes consist of a carrier, coated, with adhesive on one side, and wound into a roll. The back side is often coated with a release agent to control the unwind force. 

Release coatings are important components of pressure sensitive tapes as they enable the formulator to adjust the release force according to the application, for example, the unwinding force of tapes and the transfer of double-sided tapes to substrates. 

Release coatings are important components of pressure sensitive adhesive (PSA) products such as tapes and labels [1]. Release materials are coated onto the backside of PSA tape backings (often called low adhesion backsizes or LABs in this form) to provide the desired tape roll unwind force. They are also coated onto various substrates to form release liners for PSA products such as labels and transfer tapes. Typically the thickness of the release coating is less than 1 p,m, and often times less than 0.1 jLm. Release coatings can be thought of as the PSA delivery system, providing a controlled unwind or release force and protecting the adhesive from contamination and unintentional contact until it is applied. 

In transfer tapes, the PSA is coated on the release liner without additional backing. Therefore the release forces on both sides of the liner have to be precisely different and constant over storage time. The adhesives sometimes contain short-cut glass fibers to decrease the elongation during unwinding. Such tapes are used to transfer the PSA to extruded profiles or other parts to endow them with pressure-sensitive adhesion. For use in household and office, special dispensers are available. 

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