Glass-Filled Polyethylene Dispenser Valve for Moisture Curable Foams
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Solution Overview
Problem
Moisture curable products in aerosol cans, such as polyurethane foams, face issues with moisture migration through dispenser valves, leading to premature curing and valve failure, especially when cans are not stored upright, causing the foam to adhere to the valve and impair its operation.
Innovation Solution
A dispenser valve made from glass-filled polyolefin, specifically high-density polyethylene with a glass content of 2-40%, particularly 10-30%, which is more resistant to moisture infiltration and less adhesive, reducing the likelihood of foam curing interference with the valve's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polypropylene valve members are used in moisture curable foam aerosol cans, then the valve provides adequate structural function, but moisture migrates through the valve causing premature curing and valve failure
Solution Approach 1:
The patent applies composite materials by combining polyethylene base resin with glass fibers (2-40% by weight) to create a valve member that resists moisture migration. The glass fiber reinforcement provides dimensional stability and moisture resistance while the polyethylene matrix provides structural integrity, solving the problem of moisture migration through conventional polypropylene valves.
Solution Approach 2:
The patent changes the material parameters by selecting specific polyethylene resin characteristics (density 0.93-0.97 g/cm³, molecular weight 50,000-500,000) and glass fiber content (2-40% by weight) to optimize moisture resistance. These parameter changes transform the valve material from moisture-permeable polypropylene to moisture-resistant glass-filled polyethylene.
2Reliability
If cans are stored upright, then moisture migration through the valve is reduced, but the contents surround the valve member when stored improperly, shortening the migration path and causing curing interference
Solution Approach 1:
The patent converts the potentially harmful interaction between foam and valve into a beneficial outcome by making the valve surface non-adhesive through glass fiber reinforcement. The glass-filled polyethylene structure prevents foam adhesion even when foam surrounds the valve member during improper storage, transforming the harmful curing interference into a non-adhesive interface that maintains valve operation.
Solution Approach 2:
The patent changes the surface properties of the valve by incorporating glass fibers (2-40% by weight) into the polyethylene matrix, which modifies the surface energy and adhesion characteristics. This parameter change reduces the adhesive interaction between the valve surface and curing foam, preventing valve seizure during improper storage conditions.
3Ease of manufacture
If conventional polypropylene valves are used, then manufacturing is simple and cost-effective, but the valves are adhesive and foam curing inside the container adheres to the valve member interfering with operation
Solution Approach 1:
The patent uses composite materials (glass-filled polyethylene) that maintain ease of manufacture through conventional injection molding processes while adding glass fiber reinforcement (2-40% by weight) to eliminate adhesion problems. The composite structure allows standard manufacturing methods to produce valves with non-adhesive surfaces that resist foam curing interference.
Data Source
AI summary
An improved valve member, aerosol dispenser valve containing the valve member, aerosol container for dispensing moisture curable foams, and moisture curable foam and dispenser, in which the valve member is made of a glass filled polyolefin. The polyolefin is preferably a polyethylene. The glass content is between about 2% and about 40%, more preferably between about 10% and about 30%; and most preferably between about 15% and about 25%.