Separate the substrate families
Paper and foam raise penetration questions. ABS and many rigid plastics raise cleaning and release-agent questions. Flexible PVC adds plasticizer migration. PP and PE often need activation or primer review.
Metal parts need oil and oxide control, while automotive interior parts also need actual-part coverage, abrasion, odor and aging checks.
Compare routes with the same flocking process
Keep flock fiber, adhesive film thickness, open time, voltage and drying condition consistent when two adhesive routes are compared.
Use actual parts where corners, recesses or texture may affect coverage. Flat coupons can hide geometry-related failure.
Substrate gradeCleaning and pretreatmentFlock specificationFilm thicknessDrying and aging test