Polyester Film Transparency and Slipping via Particle Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polyester films with incorporated particles exhibit high haze and a whitish appearance, compromising transparency, while those without particles suffer from poor slipping properties and are prone to damage.
Innovation Solution
A polyester film structure is developed with non-heat-resistant particles supported on an unstretched film, which is then stretched, enhancing both transparency and slipping properties by applying or blowing particles onto the film surface before stretching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If particles are incorporated into the polyester film to improve slipping property, then the film exhibits good easy-slipping property, but the film tends to have high haze and whitish appearance, deteriorating transparency
Solution Approach 1:
The patent divides the particle incorporation into two distinct stages: (1) incorporating heat-resistant particles during film formation to provide base slipping property, and (2) supporting non-heat-resistant particles on the stretched film surface to enhance slipping without affecting transparency. This segmentation allows each particle type to serve its specific function without compromising the other property.
Solution Approach 2:
The patent applies different particle types to different locations and stages: heat-resistant particles are incorporated throughout the film bulk during extrusion, while non-heat-resistant particles are applied only on the surface after stretching. This local differentiation ensures that transparency is maintained in the bulk while slipping property is enhanced on the surface.
2Illumination intensity
If no particles are incorporated into the polyester film to maintain transparency, then the film exhibits excellent transparency, but the film has poor slipping property and is readily injured
Solution Approach 1:
The patent segments the slipping function between two particle types: heat-resistant particles provide baseline slipping and injury prevention, while non-heat-resistant particles enhance surface slipping. This segmentation allows the film to maintain transparency while achieving adequate slipping property through coordinated action of different particles.
Solution Approach 2:
The patent creates a composite structure combining heat-resistant particles (incorporated in bulk) and non-heat-resistant particles (applied on surface). This composite approach allows the film to simultaneously achieve transparency (by keeping particle content low and strategically placed) and reliability (through the combined slipping protection of both particle types).
3Ease of operation
If a coating layer comprising particles is formed on the unstretched polyester film to impart slip property, then the film exhibits good slipping property after coating, but the film is unavoidably injured during processing between film formation and coating application due to poor slip property
Solution Approach 1:
The patent performs preliminary action by incorporating heat-resistant particles during the film formation stage, before the coating step. This preliminary particle incorporation provides immediate slipping protection during subsequent processing steps, preventing film injury before the coating layer is applied.
Solution Approach 2:
The patent segments the slipping function across different processing stages: heat-resistant particles are active during film formation and coating application to prevent injury, while non-heat-resistant particles are added after stretching to provide final surface slipping. This temporal segmentation ensures slipping property is available when needed at each stage without compromising film integrity.
Data Source
AI summary
The present invention provides a polyester film that can be suitably used in the applications requiring excellent transparency and slipping property, for example, such as a film member for a transparent electrode used in touch panels, etc., and a member for molding films. The present invention relates to a polyester film comprising non-heat-resistant particles supported thereon, in which after supporting the non-heat-resistant particles on at least one surface of an unstretched polyester film, the unstretched polyester film is stretched in at least one direction thereof, and a process for producing a polyester film comprising the steps of blowing non-heat-resistant particles onto at least one surface of an unstretched polyester film to support the non-heat-resistant particles thereon, or applying a coating solution comprising the non-heat-resistant particles onto at least one surface of the unstretched polyester film to support the non-heat-resistant particles thereon; and then stretching the unstretched polyester film in at least one direction thereof.