Systems and methods for high humidity curing within tablet coating system
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tablet coating systems face challenges in maintaining high humidity conditions required for certain polymer materials, leading to defects like picking, sticking, erosion, and frosting, and require additional curing steps that increase production time and cost due to the need for separate chambers.
Innovation Solution
A recirculating air handler is integrated into the pan coater system to supply high humidity air flows, maintaining relative humidity up to 90% and temperatures between 50° C to 80° C, while preventing condensation and maintaining sub-atmospheric pressure to ensure efficient curing within the existing equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high humidity conditions are maintained for curing certain polymer materials, then coating quality is improved, but coating defects such as picking, sticking, erosion, and frosting occur
Solution Approach 1:
The system dynamically adjusts humidity levels during the coating process. High humidity (up to 90% RH) is provided during the curing phase to improve coating quality, while the system transitions to low humidity conditions during the drying phase to prevent defects. This temporal dynamic control resolves the contradiction between needing high humidity for quality and avoiding humidity-related defects.
Solution Approach 2:
The coating process uses periodic alternation between high humidity curing cycles and low humidity drying cycles. The recirculating air handler periodically adjusts humidity levels to match process requirements, allowing the coating to cure properly during high humidity periods while preventing defects during low humidity periods.
2Manufacturing precision
If coated tablets are transferred to a separate curing chamber for high humidity curing, then desired coating properties are achieved, but production time increases and additional costs are incurred
Solution Approach 1:
The patent merges the curing function into the existing pan coater by equipping it with a recirculating air handler capable of providing high humidity conditions. This integration eliminates the need for a separate curing chamber, allowing curing to be performed in the same equipment used for coating, thereby reducing production time and eliminating transfer steps.
Solution Approach 2:
The pan coater is designed with multi-functionality, serving both as a coating applicator and as a curing chamber. The recirculating air handler enables the pan coater to provide high humidity conditions required for curing, making the equipment universal and eliminating the need for dedicated separate curing equipment.
3Manufacturing precision
If transferred to a separate curing chamber, then high humidity curing is achieved, but tablet quality may be impacted by undesired temperature, humidity and mechanical damage during transfer
Solution Approach 1:
By combining the curing function within the pan coater, the system eliminates the transfer step that exposes tablets to mechanical damage and undesired environmental conditions. Tablets remain in the pan throughout the entire process from coating to curing, maintaining quality and avoiding transfer-related risks.
4Productivity
If low humidity conditions are used for rapid solvent evaporation, then drying efficiency is improved, but high humidity curing requirements cannot be met
Solution Approach 1:
The system employs periodic alternation between low humidity drying phases and high humidity curing phases. During drying, low humidity conditions maximize solvent evaporation efficiency. During curing, high humidity conditions are provided by the recirculating air handler to meet the requirements of certain polymer materials. This periodic switching resolves the contradiction between drying efficiency and curing requirements.
Solution Approach 2:
The humidity level is dynamically adjusted based on process requirements. The recirculating air handler transitions the system from low humidity during drying to high humidity during curing, allowing both drying efficiency and curing requirements to be optimized at different times in the process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for high temperature and high humidity curing of tablets within the existing pan coater, enhancing coating quality, reducing production time, and minimizing additional costs associated with separate curing chambers.
Implementation Method 1
a humidifier to introduce moisture into the air flow in an amount resulting in a relative humidity in the air flow of up to about 90%
Implementation Method 2
The vent valve may be opened as needed to maintain the pressure within the pan coater to at least 0.15 inches of water column below atmospheric pressure
Implementation Method 3
maintaining relative humidity up to 90% and temperatures between 50° C to 80° C
Data Source
AI summary
The disclosure encompasses systems and methods for performing high temperature and high humidity curing of tablets using air flow delivered from a recirculating air handler to a pan coater of a tablet coating device. The recirculating air handler may be integrated into a preexisting tablet coating device so that the air flow may be delivered by the preexisting air handler or by the recirculating air handler as desired.