Coated Polymeric Substrates Two-Stage Curing Adhesion

Solution Overview

Problem

Existing methods for continuous inline production of coated polymeric substrates face issues with low adhesion, surface defects, and environmental concerns, particularly in solvent-free UV-curable coating systems, which result in poor long-term adhesion and optical quality.

Innovation Solution

A method involving at least two curing steps, with the first step being thermal or radiation curing, and a subsequent radiation curing step, along with controlled incipient dissolution time and contact temperature, to achieve a mixed phase between the coating material and substrate polymer, enhancing adhesion and surface quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the substrate temperature is increased to improve adhesion, then adhesion strength improves, but film detachment becomes difficult and line disruptions occur

Engineering Contradiction:

Improveadhesion strengthVSAvoidfilm detachment

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The curing process is divided into two distinct stages: a first curing step performed through the film at elevated temperature (70-120°C) to ensure proper adhesion, and a second curing step performed after film removal at lower temperature to complete the curing without causing film detachment issues. This segmentation allows each curing step to be optimized independently for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first curing step is performed preliminarily through the film before the film is removed. This preliminary curing at controlled temperature establishes proper adhesion between the coating and substrate while the film is still in place, preventing premature film detachment and allowing the coating to set properly before the film is removed for the second curing step.

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If UV curing is performed immediately after lamination to prevent film detachment, then film detachment is prevented, but adhesion deteriorates due to substrate swelling

Engineering Contradiction:

Improvefilm detachment preventionVSAvoidadhesion

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The curing process is divided into two distinct stages: a first curing step performed through the film at elevated temperature (70-120°C) to ensure proper adhesion, and a second curing step performed after film removal at lower temperature to complete the curing without causing film detachment issues. This segmentation allows each curing step to be optimized independently for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The curing process uses different temperature parameters for the two curing steps. The first curing step occurs at elevated temperature (70-120°C) to promote adhesion, while the second curing step occurs at lower temperature after film removal to complete curing without causing excessive substrate swelling or film detachment problems.

Inventive Principle:

Principle #35Parameter changes

3Strength

If elevated substrate temperature is used to accelerate incipient dissolution and improve adhesion, then adhesion improves, but surface quality deteriorates due to clouding

Engineering Contradiction:

ImproveadhesionVSAvoidsurface quality

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The curing process is divided into two distinct stages: a first curing step performed through the film at elevated temperature (70-120°C) to ensure proper adhesion, and a second curing step performed after film removal at lower temperature to complete the curing without causing film detachment issues. This segmentation allows each curing step to be optimized independently for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The curing process uses different temperature parameters for the two curing steps. The first curing step occurs at elevated temperature (70-120°C) to promote adhesion, while the second curing step occurs at lower temperature after film removal to complete curing without causing excessive substrate swelling or film detachment problems.

Inventive Principle:

Principle #35Parameter changes

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 approach results in high long-term adhesion, reduced surface defects, and improved chemical resistance and fire performance, while being energy-efficient and environmentally friendly, allowing for integration into existing extrusion lines with minimal maintenance and staffing.

Implementation Method 1

coating material or adhesive, curable preferably by means of radical polymerization

Methodology Applied

Scientific EffectRadical polymerization: Photopolymerisation

Implementation Method 2

the incipient dissolution time and also, in preferred embodiments, of the contact temperature... a mixed phase of coating material or adhesive and dissolved substrate polymer

Methodology Applied

Scientific EffectIncipient dissolution: Solvation

Data Source

PatentUS9630387B2Process for continuous inline production of coated polymeric substrates or laminates

Publication Date: 2017.04.25 POLYVANTIS GMBH

AI summary

The present invention relates to a method for the continuous inline production of coated polymeric substrates or laminates and also to an apparatus for implementing this method.