Moisture cured, reactive polyurethane adhesives are formulated using an isocyanate and amorphous and crystalline polyols of varying composition which are reacted to form a polyurethane prepolymers that is a solid at room temperature. These compositions contain residual isocyanate functionality that is reactive with moisture that comes from the atmosphere and surface to be bonded.
PU hot melts contain catalysts to promote the moisture cure and also contain other additives to control rheology, open time and strength of the resulting polyurethane polymer. The choice of polyols, based on performance requirements is an important factor in formulating any polyurethane system. Designing hot melts is no different. Understanding how isocyanate and polyol structure affect reactivity and the physical properties of the formulated hot melt is an important aspect of hot melt formulation which this training is intended to provide.
Why you should not miss this training?
This is a highly recommended industry training and must for every formulator looking for noticeable improvements in his/her formulations. Attending this exclusive technical training will give you an upper edge in:
- Chemistry of hot melts, isocyanates and polyols with examples
- Achieving the desired goals with reactive hot melts adhesive
- Designing a hot melt from a structure/property perspective
Our expert will discuss and share his expertise regarding the reactive hot melt formulations and moisture curing and related case studies.
Who should attend this training?
This is a very useful industry recommended training for professionals in chemical industry in particular:
- R&D chemists, adhesives & sealant formulators
- Scientists, product development specialists
Also suitable for students who are interested in better understanding PU hot melt products and formulation needs.
Training Outline
An introduction to hot melt adhesive considerations
Comparison of PUR adhesive systems
The chemistry of isocyanates and polyols
Formulating from a Structure / Property perspective
Some troubleshooting tips
Summary of important concepts
Q&A session to clear doubts
FAQ
- Why do moisture-cured PU hot melt adhesives often fail in real production despite working in lab trials?
Because lab conditions do not capture moisture variability, substrate interactions, and cure kinetics that directly impact bond strength and long-term performance in real applications. - What are the most common hidden mistakes in reactive PU hot melt formulation?
Small formulation decisions related to isocyanate index, polyol selection, or catalyst balance can silently impact open time, curing behavior, and final mechanical properties. - Why is controlling moisture curing more complex than it seems?
Moisture curing is influenced by environmental exposure, adhesive thickness, and formulation chemistry, making it difficult to achieve consistent performance without a structured approach. - How do you balance open time, viscosity, and final strength in reactive hot melts?
These properties are interdependent, and optimizing one without understanding the system can lead to instability, poor bonding, or processing issues. - What causes inconsistency in production batches of PU hot melt adhesives?
Variations in raw materials, processing conditions, and formulation sensitivity can lead to differences in curing, viscosity, and bond performance. - Who should attend this training?
This training is designed for professionals who want to move beyond trial-and-error formulation and build a deeper understanding of reactive PU hot melt systems for consistent industrial performance.
