On-line Waterborne Coating for Polyurethane Pultrusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyurethane pultrusion composite materials face issues with insufficient weather resistance and high coating costs due to inefficient off-line spraying processes, which are time-consuming and environmentally harmful, especially when exposed to outdoor conditions.
Innovation Solution
An on-line coating method is developed using waterborne coatings, specifically waterborne polyurethane, fluoro-olefin vinyl ether, or polyvinylidene fluoride coatings applied at temperatures between 30 to 90°C, directly on the polyurethane pultrusion composite material post-molding, allowing for rapid curing and eliminating the need for a basecoat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If off-line spraying process is used for coating polyurethane pultrusion composite materials, then coating protection can be applied, but the coating rate is low, coating steps are numerous, and the process is time-consuming and labor-consuming, leading to high coating cost
Solution Approach 1:
The patent merges the coating process with the pultrusion manufacturing process by implementing on-line coating. The coating die is integrated into the pultrusion line, allowing coating to be applied continuously as the composite material exits the mold, eliminating the need for separate off-line spraying operations and significantly improving coating rate and productivity
Solution Approach 2:
The patent applies coating preliminarily during the pultrusion process itself, before the material completes its manufacturing cycle. By incorporating the coating die within the pultrusion line, the coating is applied while the material is still in the manufacturing flow, reducing total process time and eliminating post-manufacturing coating steps
2Reliability
If off-line spraying process is used for coating polyurethane pultrusion composite materials, then coating protection can be applied, but the process involves too many coating steps and is time-consuming, leading to high coating cost
Solution Approach 1:
The patent combines multiple processes into one continuous operation. The on-line coating die integrates coating application with the pultrusion manufacturing flow, allowing coating to be applied in a single continuous step rather than through multiple separate spraying operations, thereby reducing both the number of steps and total time required
Solution Approach 2:
The patent establishes continuous coating action by integrating the coating die into the pultrusion line. As composite material continuously exits the mold, it passes through the coating die which applies coating continuously without interruption, eliminating the start-stop nature of off-line spraying and reducing total coating time
3Reliability
If solvent-based coatings are used for coating polyurethane pultrusion composite materials, then coating protection can be applied, but new environmental protection problems are caused
Solution Approach 1:
The patent changes the chemical composition parameter of the coating material from solvent-based to water-based formulation. This substitution eliminates harmful organic solvents while maintaining coating protection functionality, addressing environmental concerns without compromising the protective performance of the coating
4Reliability
If high temperature curing is used to cure the coating on polyurethane pultrusion profiles, then the coating can be cured, but the size stability of the profiles is affected
Solution Approach 1:
The patent changes the curing temperature parameter from high temperature to low temperature processing. By formulating the coating and process parameters for low-temperature curing, the profile dimensions remain stable while the coating still achieves proper curing and adhesion
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 method provides a cost-effective, environmentally friendly, and efficient coating process with excellent adhesion, enhancing the weather resistance and appearance of polyurethane pultrusion composite materials without affecting their size stability.
Implementation Method 1
on-line applying at least one waterborne coating to the polyurethane pultrusion composite material at a temperature ranging from 30 to 90° C.
Data Source
AI summary
The present invention relates to a method of coating a polyurethane pultrusion composite material, comprising: a) preparing a polyurethane pultrusion composite material by a polyurethane pultrusion process, the polyurethane pultrusion process comprising: impregnating a fiber reinforcing material with polyurethane resin, and then curing the impregnated fiber reinforcing material in a mold to provide a polyurethane pultrusion composite material; and b) drawing the polyurethane pultrusion composite material to leave the mold, and then on-line applying waterborne coating(s) to the polyurethane pultrusion composite material at a temperature ranging from 30 to 90° C. The method according to the present invention can achieve a good coating to the polyurethane pultrusion composite material.