In order to achieve a sufficient adhesion between the zipper tape and the neoprene or trilaminate, very often a grinding process of the TPU coated tape is carried out. Please consider, that the TPU coating thickness is only a few micrometers. Grinding affects the TPU surface negatively and can lead to microscopic pinholes or cracks. Cleaning liquids and glue might diffuse into the textile leading to TPU material degradation and TPU delamination. If you think grinding cannot be avoided, please ensure that the grained areas are 100% covered by the adhesion glue, so that no water can migrate into the microscopic cracks and pinholes during zipper usage and result hydrolysis and microbiotic degradation, in the long term.
TIZIP always recommends avoiding grinding and to check out alternative glues. Insufficient adhesion of the zipper tape to the fabric can also lead to “water pockets” where water and moisture accumulate and cause material degradation.