Whether can the substrates with oily surface be bonded?

Generally speaking, the oily surface can not be bonded by adhesives. Because the reservoir molecule would separate the adhesive from substrates without producing a strong adhesive force. Only cleaning the oil and grease on the surface can the substrates be bonded well. However, it is very common that some substrates with oil can not be cleaned during the manufacturing process. So Using special adhesive can bond these oily surface in some special cases. Through the improved epoxy resin adhesive, acrylate adhesive and some pressure-sensitive adhesive , it is easy to bond oily surface with high viscosity. Moreover, the viscosity are different because of the different adhesion principles. In the most cases, it is better to clean the surface before using adhesives.