Eliminating read through with 2k adhesives for Automotive components

摘要

Automobile assembly applications require the use of specific 2K adhesives for bonding substrates without resulting in read-through.Bond line read-through(BLRT) is the visible distortion(surface waviness) of a bonded substrate caused by stresses that occur during adhesive curing.Adhesives that eliminate BLRT allow for the use of alternative materials,such as plastic,which can help lightweight the entire assembly of a vehicle.These lighter weight materials require an adhesive that can adapt to the thin materials yet provide adhesion with the same unvarnished visual quality.Eliminating BLRT is important since these areas are prominently visible on a vehicle meaning distortions and deformations are unacceptable to end users.and promote automotive lightweighting? In general,pure epoxies are much thicker and increase the potential for defects upon curing.Polyurethanes are often considered but may require surface treatment prior to application.In addition,they contain isocyanates that are becoming less accepted by regional environmental,health and safety(EHS) regulations,especially in Europe.Softer acrylics have many desirable characteristics,yet present challenges such as lower resistance to metal corrosion and lower shear strength.Therefore,the combination of acrylic and epoxy(acrylic modified epoxy) is the best adhesive for no read through on lightweight materials.