Curtain-coating development at KCL follows a structured workflow that moves efficiently from laboratory validation to pilot coating trials mimicking industrial processes. This approach ensures reliable scale-up, reduces development risks, and accelerates time-to-market for new coating formulations.
Our process begins with laboratory-scale curtain flow testing. At this stage, we prepare a single coating colour, deaerate it, and evaluate the key parameters that define coating rheology and curtain stability. These include surface tension, pH, viscosity, and solids content. By carefully adjusting surfactant levels, we can fine-tune flow behaviour and optimise the coating’s ability to form a uniform, defect-free curtain and minimize use of chemical additives.
Once the coating shows promising behaviour in the lab, development progresses to our industrial pilot-scale curtain coating line for process-level verification. A one-day pilot trial provides ample time to prepare and deaerate two different coating colour formulations, inspect their curtain flow behaviour, and make small formulation adjustments – such as surfactant level optimisation – based on real-time observations. Surface tension, viscosity, and solids content are measured throughout the day to ensure consistency. Specialty measurements such as extensional viscosity are available on-site.
Within a single trial day, it is typically possible to coat up to three different paper or paperboard substrates at multiple coat weights. This allows customers to evaluate performance across various product families, end uses and specifications as well as obtain representative samples for downstream testing, such as printing and packaging line tests.
By combining lab-scale flow testing with pilot-scale coating runs, KCL offers an efficient and systematic development route. This structured process saves both time and resources while significantly reducing formulation iteration cycles – ultimately enabling faster and more confident market entry for new curtain-coated products.