Coated Sheet Manufacturing to Prevent Neck-In With Low-Viscosity Materials
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Solution Overview
Problem
Existing sheet manufacturing methods using extrusion molding dies face issues with 'neck-in' phenomenon, causing the film width to be narrower than the die width due to low viscosity of molten resin, making it difficult to produce sheets with desired shapes.
Innovation Solution
A method and apparatus that adjust the viscosity of the liquid material to 100000 mPa·s or less, apply it as a coating on a base material, solidify the coating, and wind up the sheet, using coaters and solidification regions to maintain desired sheet shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the viscosity of the liquid material is low to improve flowability and ease of coating, then the neck-in phenomenon occurs causing the sheet width to be narrower than the die width
Solution Approach 1:
The invention specifies a viscosity range of 100-100,000 mPa·s for the liquid material, optimizing the viscosity parameter to prevent excessive neck-in while maintaining adequate flowability for coating application. This parameter optimization resolves the contradiction by finding the sweet spot where the material flows sufficiently for coating but maintains enough viscosity to prevent severe width contraction.
Solution Approach 2:
The invention applies a release agent to the cooling roll surface before coating the liquid material. This preliminary action prevents the liquid material from adhering to the cooling roll, allowing the sheet to be easily peeled off after solidification and reducing the severity of neck-in by minimizing friction and adhesion forces during the cooling and peeling process.
2Manufacturing precision
If the viscosity of the liquid material is increased to reduce neck-in phenomenon, then the coating application becomes difficult and manufacturing complexity increases
Solution Approach 1:
The invention defines a specific viscosity range (100-100,000 mPa·s) that balances coating applicability with neck-in prevention. Within this range, the material remains sufficiently fluid for coater application while maintaining enough viscosity to minimize neck-in phenomenon, thus resolving the contradiction between ease of manufacture and manufacturing precision.
Solution Approach 2:
The release agent serves as an intermediary substance applied to the cooling roll surface. It facilitates the coating process by preventing adhesion between the liquid material and the cooling roll, allowing for easier coating application and subsequent peeling while maintaining sheet width accuracy through reduced friction during the process.
3Productivity
If a conventional extrusion molding die is used with low viscosity material, then production speed can be maintained, but the sheet shape cannot be maintained due to neck-in
Solution Approach 1:
The invention extracts and eliminates the neck-in phenomenon by using a coater to apply the liquid material onto a cooling roll instead of using conventional extrusion molding. This fundamental process change allows the material to be deposited in the desired shape directly, preventing neck-in while maintaining continuous production capability through the coating and rapid solidification process.
Solution Approach 2:
The invention utilizes rapid phase transition from liquid to solid state through contact with the cooled roll surface. This rapid solidification occurs immediately after coating, locking in the desired sheet dimensions before neck-in can occur, thus maintaining both production speed and shape consistency.
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
Enables stable production of sheets with desired shapes even with low viscosity materials, reducing limitations on usable raw materials and preventing neck-in issues.
Implementation Method 1
a step (b) of applying the liquid material to have a sheet shape by a coater, thereby forming a coating body
Implementation Method 2
a step (c) of solidifying the coating body, thereby providing a sheet
Data Source
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AI summary
In the present invention, a sheet is stably manufactured even when using a liquid material having a low viscosity. This method for manufacturing a sheet comprises: (a) a step for making adjustment to a liquid material LM containing a raw material so as to have a viscosity of 100000 mPa·s or less; (b) a step for performing, by means of a coating machine 13 and in a sheet-like manner, coating using the liquid material LM to form a coating body; (c) a step for solidifying the coating body to obtain a sheet 50; and (d) a step for winding the sheet 50.