Greenhouse screen
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional greenhouse screens with anti-fog coatings suffer from low transparency and short-term stability, as the anti-fog additives are easily washed off, leading to reduced mechanical and optical properties over time, and often contain environmentally harmful substances.
Innovation Solution
A greenhouse screen comprising interconnected polyester film strips with a permanent anti-fog coating applied to at least one surface, using a thermoplastic polyester base layer with UV stabilizers and a refractive index lower than the base layer, achieving high transparency and long-term UV stability without significant yellowing or embrittlement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional anti-fog coatings are applied to greenhouse screens, then anti-fogging properties are achieved, but transparency is reduced and the coating is easily washed off
Solution Approach 1:
The patent applies a permanent anti-fog coating with specific refractive index parameters (lower than the base layer) to maintain transparency while achieving durable anti-fogging properties. The coating composition and application parameters are optimized to prevent water droplet formation without significantly reducing light transmission.
Solution Approach 2:
The greenhouse screen uses a composite structure with a thermoplastic polyester base layer and a permanent anti-fog coating layer. This composite material combination provides both the mechanical strength of polyester and the durable anti-fogging properties of the coating, resolving the contradiction between coating effectiveness and transparency.
2Reliability
If anti-fog additives are incorporated into the polymer matrix, then anti-fogging effect is achieved, but the additives are easily washed off and mechanical properties deteriorate
Solution Approach 1:
The permanent anti-fog coating is applied in advance to the base layer during manufacturing, creating a durable bond before the product is put into service. This preliminary application ensures the coating is firmly attached and will not be easily washed off during use, maintaining both anti-fogging effect and stability.
Solution Approach 2:
The patent uses an adhesion promoter or coupling agent as an intermediary between the base layer and the anti-fog coating. This intermediary substance enhances the bonding between the polyester base layer and the coating, preventing the coating from being washed off while maintaining the anti-fogging effect and mechanical properties.
3Duration of action of stationary object
If greenhouse screens are used for long-term UV exposure, then they provide continuous protection, but yellowing and embrittlement occur
Solution Approach 1:
The patent incorporates UV stabilizers into the permanent anti-fog coating and base layer to protect against UV degradation. These stabilizers absorb or block UV radiation, preventing yellowing and embrittlement, thereby extending the service life of the greenhouse screen while maintaining its protective function.
Solution Approach 2:
The patent modifies the chemical composition parameters of the polyester base layer and coating by incorporating UV stabilizers and selecting materials with high UV resistance. These parameter changes enable the material to withstand long-term UV exposure without yellowing or becoming brittle, extending the service life.
4Reliability
If conventional anti-fog substances are used, then anti-fogging properties are achieved, but environmentally harmful substances are present
Solution Approach 1:
The patent replaces conventional anti-fog substances that contain harmful chemicals with a permanent anti-fog coating based on environmentally friendly materials. The coating provides the same anti-fogging functionality through physical surface modification rather than chemical additives, eliminating harmful substance release while maintaining effectiveness.
Solution Approach 2:
The permanent anti-fog coating creates an inert, non-reactive surface that prevents water droplet formation without requiring toxic chemicals. This inert coating layer provides durable anti-fogging properties while being environmentally safe, resolving the contradiction between effectiveness and environmental harm.
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
The solution provides a greenhouse screen with high transparency (>93%) and long-term UV stability, maintaining mechanical and optical properties for at least 5 years, while avoiding the use of harmful substances and ensuring effective anti-fogging properties.
Implementation Method 1
The anti-fog coating has a lower refractive index than the base layer B
Implementation Method 2
a polar hydrophilic region which can interact with water to reduce the surface tension of the water droplets so that a continuous transparent water film
Data Source
AI summary
A greenhouse screen comprising strips of film material that are interconnected by a yarn system of transverse threads and longitudinal threads by means of a knitting, warp-knitting or weaving process to form a continuous product is provided. At least some of the strips comprise a polyester film having a transparency of at least 93%, said polyester film having at least one base layer B comprising a thermoplastic polyester and a UV stabilizer. The polyester film has a first and a second surface, wherein a permanent anti-fog coating is applied to at least one of the first or second surfaces of the polyester film. The anti-fog coating has a lower refractive index than the base layer B.A process for producing said film is also disclosed.