This latest session of the Adhesive Academy series explains why going with the flow is not suitable for all applications. High viscosity and non-drip adhesive formulations are often selected for vertical substrates when sagging and flow are not desirable. Non-drip systems also feature superior gap filling capabilities while maintaining outstanding bond strength to a variety of similar and dissimilar substrates.
Dr. B: Hi Sam, what’s your next inquiry about?
Sam: The next question was from an electrical equipment manufacturer. They are bonding two vertical surfaces so it would make sense to use a non-drip compound.
Dr. B: We can recommend a two component epoxy paste adhesive. These can be applied on vertical surfaces without dripping or sagging. They also bond well to both similar and dissimilar substrates.
Sam: But what if they require performance properties that are more common for heat cure adhesives? How will that affect the non-drip compound?
Dr. B: There are certain compounds that will not run, drip or sag even upon curing at elevated temperatures. Most high viscosity products, including thixotropic pastes, will start flowing when heated.
Sam: What’s the difference between thixotropic and non-drip?
Dr. B: Thixotropic systems are non-Newtonian fluids which are gel-like at rest but tend to flow when agitated or stressed. Most systems will also flow when heat is added. However, there are systems which do not flow whatsoever, even with the addition of heat. These are truly non-drip type systems.
Thank you Dr. B. I’ll need to find out more about the customer’s requirements and production process before recommending a suitable compound. Let me give them a call now.