Water Vapor Permeable Laminar Sheet Production via Merged Extrusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing water vapor permeable laminar sheets require multiple production steps, resulting in increased costs and limitations on achieving thin breathable layers due to minimum thickness requirements, which affect breathability and handling.
Innovation Solution
A method involving the application of a hot melt adhesive onto a carrier sheet followed by a molten water vapor permeable material in a single rolling gap, allowing for improved bonding and reduced layer thickness, with the option of incorporating an open grid for enhanced strength, all within a single process step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a two-step production process is used (producing functional layer separately then laminating), then the carrier sheet provides support for handling, but additional production steps and costs result
Solution Approach 1:
The patent combines the functional layer production and lamination processes into a single integrated extrusion process. The functional layer is extruded directly onto the carrier sheet in molten state and bonded immediately, eliminating the separate production and lamination steps while maintaining handling support through the carrier sheet
2Manufacturing precision
If the functional layer is made thinner to improve breathability, then breathability increases, but the layer cannot be handled without support
Solution Approach 1:
The functional layer is extruded in molten state directly onto the carrier sheet and bonded immediately in the same process step. This allows the layer to be made thinner for improved breathability while the carrier sheet provides continuous support during the entire process, eliminating the need for minimum thickness for handling
3Strength
If hotmelt adhesive is used for lamination, then bonding occurs in heated rollers, but the adhesive must be applied in a separate step before laminating
Solution Approach 1:
The adhesive application and lamination processes are merged into a single step. The adhesive is applied to the carrier sheet and the functional layer is extruded onto it in molten state within the same process window, allowing immediate bonding without separate application and lamination steps
Solution Approach 2:
The adhesive is applied in advance to the carrier sheet before the functional layer is extruded onto it. This preliminary adhesive application ensures bonding readiness when the functional layer arrives in molten state, enabling immediate bonding in the extrusion process
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 enables the cost-effective production of thinner, more breathable laminar sheets with improved mechanical properties by combining previously separate processes into a single step, reducing production costs and enhancing the connection between carrier and water vapor permeable materials.
Implementation Method 1
application of an adhesive onto one side of the side of the carrier sheet at a first location in conveying direction of the carrier sheet, wherein the adhesive is a hot melt adhesive and is applied onto the carrier sheet in a molten state
Implementation Method 2
Cooling of the pressed composite of carrier sheet, adhesive and water vapor permeable material in conveying direction downstream the rolling gap
Implementation Method 3
Application of a water vapor permeable molten material onto that side of the carrier sheet which is provided with the adhesive
Implementation Method 4
Pressing of the composite of carrier sheet, adhesive and water vapor permeable material in a rolling gap which is formed by the first roll and a second roll which cooperates with the first roll
Data Source
AI summary
A method and device for producing a water vapor permeable laminar sheet, including the steps of: a) feeding a laminar carrier sheet to a first roll and applying an adhesive onto one side of the carrier sheet at a first location in conveying direction of the carrier sheet, wherein the adhesive is a hot melt adhesive applied in a molten state; b) applying a water vapor permeable molten material onto that side of the carrier sheet provided with the adhesive at a second location in conveying direction located downstream from the first location; c) pressing the composite of carrier sheet, adhesive and water vapor permeable material in a rolling gap formed by the first roll and a second roll which cooperates with the first roll; d) cooling the pressed composite in conveying direction downstream the rolling gap and hauling the composite from the roll arrangement.