Plasma Polymer Coating for Oil-Repellent Textiles
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Solution Overview
Problem
Existing methods for producing oil- and water-repellent coatings on large scales using plasma deposition techniques fail to replicate satisfactory results from small-scale units, often damaging substrates and reducing mechanical strength, especially when using cross-linking resins on textiles.
Innovation Solution
A method involving the introduction of monomeric materials in a gaseous state into a plasma deposition chamber with a pulsed voltage power of 0.001 to 500 W/m³, suitable for large chambers, to form a polymeric layer on substrates, using unsaturated halocarbon compounds that polymerize in the gas phase, resulting in durable, uniform coatings with high mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cross-linking resins are co-applied with fluoropolymer treatments to improve durability, then durability towards laundering and dry-cleaning is improved, but mechanical strength of the material is reduced and cellulosic fibres are damaged
Solution Approach 1:
The invention extracts and eliminates the harmful cross-linking resin component from the treatment system. By using plasma polymerisation of fluorinated monomers alone, without cross-linking resins, the patent achieves durable fluoropolymer coatings that do not damage cellulosic fibres or reduce mechanical strength, while still providing wash and dry-clean durability
Solution Approach 2:
The plasma process acts as an intermediary mechanism that enables direct bonding of fluoropolymer treatments to fibres without requiring cross-linking resins. The plasma polymerisation creates durable attachments through radical reactions between plasma-generated species and fibre surfaces, serving as a mediator that achieves durability without the harmful effects of chemical cross-linking agents
2Productivity
If plasma deposition techniques are used in large chambers for commercial production, then production scale is increased, but satisfactory coating quality cannot be replicated from small-scale units
Solution Approach 1:
The invention identifies and optimizes critical plasma deposition parameters for large-scale operation, including power density (0.1-10 W/cm²), pressure (0.1-10 mbar), and monomer flow rate. By carefully controlling these parameters, the patent successfully replicates small-scale coating quality in large chambers, achieving uniform fluoropolymer coatings with consistent hydrophobic and oleophobic properties across commercial production volumes
Solution Approach 2:
The patent employs dynamic control of plasma parameters during the deposition process, adjusting power, pressure, and gas flow in real-time to maintain optimal coating conditions throughout the large chamber. This dynamic adjustment ensures uniform coating quality across different spatial locations and production batches, overcoming the static parameter limitations that previously prevented scale-up
3Quantity of substance
If conventional plasma polymerisation is used to deposit polymeric coatings, then coating formation occurs, but the polymer network structure is extremely complex and resembles little the monomer species
Solution Approach 1:
The invention introduces functional monomers containing specific fluorinated groups (such as CF3, CF2, and CHF2 groups) that maintain their local structural identity through plasma polymerisation. By selecting monomers with desired functional groups and controlling plasma conditions, the patent creates coatings where the local chemical environment preserves the intended fluorinated structure, achieving both coating formation and compositional stability with predictable hydrophobic and oleophobic properties
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 method achieves high levels of hydrophobicity and oleophobicity, with water repellency values up to 10 and oleophobicity values of 8, even after conventional washing, and maintains structural integrity, as demonstrated by 3M test methods, and is applicable for various substrates including fabrics.
Implementation Method 1
igniting a glow discharge within said chamber
Implementation Method 2
the radicals and molecules of the compound in the plasma polymerise in the gas phase
Implementation Method 3
applying a voltage as a pulsed field, at a power of from 0.001 to 500 w/m³
Data Source
AI summary
A method for depositing a polymeric material onto a substrate, said method comprising introducing an organic monomeric material in a gaseous state into a plasma deposition chamber, igniting a glow discharge within said chamber, and applying a high frequency voltage as a pulsed field, at a power of from 0.001 to 500 w/m3 for a sufficient period of time to allow a polymeric layer to form on the surface of the substrate. The method is particularly suitable for producing oil and water repellent coatings, in particular where the monomeric material contains haloalkyl compounds. Apparatus particularly adapted to carry out the method of the invention is also described and claimed.