Multilayer PVC Plastisol Coating to Reduce Heating and Cooling Cycles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of multilayer PVC semi-finished products is extremely energy-intensive due to the need for separate heating and cooling of each layer, as well as frequent heating and cooling cycles, which increases energy consumption and process complexity.
Innovation Solution
The method involves simultaneous or successive coating of the carrier web with multiple PVC plastisols, which are gelled and cooled together, reducing the number of heating and cooling cycles and minimizing energy usage by using a multilayer slot nozzle to apply ungelled plastisols in a wet-on-wet process, with E-PVC plastisols having low intermixing viscosity to maintain desired material properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate coating, gelling and cooling steps are performed for each PVC plastisol layer, then each layer can be formed with controlled properties, but the number of heating and cooling cycles increases, leading to extremely high energy consumption
Solution Approach 1:
The patent merges multiple coating operations into a single simultaneous coating step where multiple PVC plastisols are applied to the carrier web at the same time. This consolidation eliminates the need for separate heating and cooling cycles for each layer, reducing energy consumption while maintaining layer formation control through the use of a doctor blade that meters each plastisol layer thickness independently.
Solution Approach 2:
The patent implements continuous processing by coating multiple plastisols simultaneously and performing a single gelling and cooling cycle that processes all layers together. This continuous approach eliminates repeated heating and cooling cycles, maintaining productive action throughout the process while significantly reducing energy consumption compared to sequential layer processing.
2Use of energy by moving object
If multiple PVC plastisols are coated simultaneously in a wet-on-wet process, then the number of heating and cooling cycles is reduced, but the plastisols may mix and compromise material properties
Solution Approach 1:
The patent applies local quality by giving each PVC plastisol a different viscosity characteristic. This local differentiation in viscosity prevents unwanted mixing between layers while allowing the layers to be applied simultaneously in a wet-on-wet process. The viscosity gradient ensures that each layer maintains its composition integrity despite being coated together.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the viscosity of each PVC plastisol to specific ranges that prevent intermixing. By controlling viscosity as a key parameter, the process enables simultaneous coating of multiple plastisols while maintaining their compositional stability throughout the gelling and cooling process.
3Manufacturing precision
If a doctor blade is used to control layer thickness, then precise thickness control is achieved, but the process requires maintaining a gap between the blade and substrate, increasing device complexity
Solution Approach 1:
The patent segments the coating apparatus into multiple doctor blades, each independently responsible for controlling the thickness of a specific plastisol layer. This segmentation allows precise thickness control for each layer while simplifying the overall device structure, as each blade operates independently without requiring complex coordination mechanisms.
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 approach significantly reduces energy consumption and simplifies the process by minimizing the number of heating and cooling cycles while ensuring the preservation of material properties, allowing for the production of multilayer PVC products with reduced energy expenditure and enhanced efficiency.
Implementation Method 1
Subsequently, the ungelled plastisol layer is gelled, wherein a carrier web coated with a gelled plastisol layer is obtained
Implementation Method 2
Subsequently, the carrier web coated with the gelled plastisol layer is cooled
Data Source
AI summary
A method for manufacturing of a multilayer PVC semi-finished product, in particular a multilayer PVC synthetic leather or a multilayer PVC foam sheet, the method comprising the steps of:a. Coating a coated or uncoated carrier web with a PVC plastisol, whereby a carrier web coated with an ungelled plastisol layer is obtained; thereafterb. Gelling the ungelled plastisol layer, whereby a carrier web coated with a gelled plastisol layer is obtained; and thereafterc. Cooling the carrier web coated with the gelled plastisol layer; characterized in that the coating comprises coating the carrier web with at least two PVC plastisols one above the other, simultaneously or in immediate succession. A corresponding apparatus is further described.