It may sound odd to discuss the topic of “How to make a consistent hot melt pressure sensitive adhesive” if one has a good formulation in hand. Although products may look the same - they are not identical in size, shape, and weight. Molecular weight (MW), molecular weight distribution (MWD), branching, networking, etc. of each polymerized batch are not always the same. Although HMPSA production does not involve any chemical reaction during mixing, it is simply a blending of several different but compatible ingredients.
Typical HMPSAs are composed of a SBC (Styrenic Block Copolymer), tackifiers, mineral oil, and antioxidants. If formulators and producers carefully read the COA (Certificate of Analysis) of each received ingredient, they may be surprised at the significant deviations between batches or lots received. For example, the specification of MFR (Melt Flow Rate) at 190C for a typical SIS (Styrene-Isoprene-Styrene block copolymer) is 8.0. But the range of this specific…. Read Article >>
How to Make Consistent Hot Melt Pressure Sensitive Adhesives (HMPSA) - by Pierce Covert, Glue Machinery Corporation
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