Polyethylene Laminate for Moisture Control
Solution Overview
Problem
Existing protective materials for objects during transportation and storage fail to adequately address moisture and condensation issues, leading to corrosion and mold growth, especially in high humidity environments, and often allow water vapor to re-enter the protected space.
Innovation Solution
A laminate structure comprising a high water vapor permeable shrink-stretch film and a hydro-entangled nonwoven fabric, both made from ethylene-based polymers, with a controlled water vapor transmission rate to prevent moisture ingress and promote vapor exit, ensuring a dry environment and reducing corrosion risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional protective materials are used during transportation and storage, then objects are protected from environmental damage, but moisture and condensation accumulate leading to corrosion and mold growth
Solution Approach 1:
The patent employs micro-perforated polyethylene film with controlled pore sizes and distributions to enable selective moisture vapor transmission. The porous structure allows water vapor to escape while maintaining overall protective barriers, directly addressing the condensation accumulation problem in conventional protective materials.
Solution Approach 2:
The invention combines multiple materials with different properties: polyethylene film for water resistance, micro-perforations for vapor transmission, and hydrophilic coatings for moisture management. This composite approach creates a multi-functional protective system that simultaneously provides barrier protection and moisture escape pathways.
2Object-affected harmful factors
If micro-perforated films are used to address moisture issues, then water vapor can escape, but the physical properties of the film decrease and become weaker
Solution Approach 1:
The patent applies micro-perforations selectively in specific zones of the film rather than uniformly across the entire surface. The perforation density, size, and distribution are locally optimized to provide sufficient vapor escape pathways while maintaining film strength in critical load-bearing areas.
Solution Approach 2:
The invention carefully controls multiple parameters of the micro-perforations including pore size (micrometer scale), pore density, depth, and distribution patterns. By optimizing these parameters, the film achieves the right balance between vapor permeability and mechanical strength, preventing film degradation.
3Reliability
If conventional wrapping materials are used, then objects are covered for protection, but condensation forms on surfaces increasing corrosion rates
Solution Approach 1:
The micro-perforated film acts as an intermediary layer between the protected object and the external environment. It provides a controlled interface that allows moisture vapor to pass through while maintaining protective barriers, preventing the direct contact between condensation and the wrapped object surface that causes corrosion.
Solution Approach 2:
The protective system enables self-regulation of moisture levels by allowing water vapor to automatically escape through the micro-perforations when condensation occurs. The film passively manages moisture without requiring external intervention, maintaining a drier environment around the protected object.
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 laminate effectively maintains a dry environment around protected objects, reducing corrosion and mold growth by allowing water vapor to escape while preventing re-entry, thus enhancing the longevity and condition of transported or stored items.
Implementation Method 1
nanoclay, which is coated with titanate, or zirconate coupling agents
Implementation Method 2
a first side for contacting an object to be packaged and a second side opposite the first side that is exposed in use
Implementation Method 3
a hydrophilic nonwoven fabric in contact with the film along an interface
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Polyethylene fibers of 1 to 3 denier having a heat distortion temperature higher than 70°C as measured by ASTM D 648 at a load of 455 kPa can comprise 1 to 6 wt.% nanoclay, which can be coated with a titanate, zirconate or silane coupling agent. The fibres can be used in soft wipes and nonwoven fabrics. The nonwoven fabrics preferably have a multilayer structure where the fibers of one layer have a different denier or hydrophilicity than the fibers of the other layer. This structure allows for water vapor permeability in one direction (inside-to-outside) and not in the opposite direction to allow wrapped article to dry or to keep wrapped articles dry and prevent corrosion related damage. The preferred polyethylene is LLDPE.