Are you bonding to plasticized material with pressure-sensitive tape? Be aware that most pressure-sensitive adhesives do not react well to plasticisers. A plasticiser is a chemical compound that is frequently added to other plastic materials to make the base material softer and more flexible. A plasticiser is defined as “a substance or material incorporated in a material (usually a plastic or elastomer) to increase its flexibility, workability, or distensibility” by the IUPAC (International Union of Pure and Applied Chemistry) council. PVC is an example that we can all relate to. A plasticiser is added to the PVC formulation, increasing its softness and flexibility. Many rubber materials also contain plasticizers.
Many of us in the pressure-sensitive tape industry has dealt with applications that necessitate the use of an adhesive to bond to a plasticized material. These applications can be extremely challenging. Initially, adhesive tapes frequently bond well to PVC and other plasticized materials. The issue is with the adhesive’s long-term performance.
As previously stated, plasticiser adds flexibility and softness to a plastic or rubber; however, that flexibility does not last indefinitely. If you’ve ever noticed how some flexible plastics and rubber become brittle and crack over time, you’re not alone. The plasticiser migrates out of the material, causing the material to lose flexibility.
When a pressure-sensitive adhesive is applied to a plasticized material, the plasticiser in the material migrates into the adhesive. Because plasticiser adds flexibility and softness to the adhesive, it changes the performance characteristics of the adhesive tape. The plasticiser frequently softens the adhesive to the point where it becomes “goo” and loses all properties. This plasticiser migration and loss of adhesive performance are what makes bonding to plasticized materials so difficult.
Although there is no way to prevent plasticiser from migrating into the adhesive, acrylic adhesives can be modified so that there is little or no noticeable difference in performance. To create a cross-linked structure in the adhesive, special monomers are co-polymerized. This helps to reduce or slow down plasticiser migration and keeps the adhesive performing well. If you have a plasticized tape application, contact your adhesive tape supplier and request a plasticiser tolerant adhesive.
For more information see the links below.
http://www.qmed.com/mpmn/article/know-your-plasticizers-new-study-plasticizer-migration
Originally Written By Jay Hirschberg (https://www.linkedin.com/pulse/how-does-plasticizer-affect-adhesive-tape-jay-hirschberg).
