Pressure-Sensitive Adhesive Sheet Laser Perforation
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Solution Overview
Problem
Pressure-sensitive adhesive sheets face issues with air entrapment and blistering, particularly when applied to large areas or materials that emit gases, leading to unsightly appearance and potential peeling, and existing methods to prevent these issues either require significant effort, increase costs, or mar the appearance.
Innovation Solution
A method using a CO2 laser to create through-holes in the substrate and pressure-sensitive adhesive layer with specific pulse width, energy, and beam spot diameter settings, ensuring the holes are not visible and effective in preventing air entrapment and blistering, while maintaining the sheet's appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If through-holes are formed in the substrate and adhesive layer to prevent air entrapment and blistering, then air escape function is improved, but the appearance is marred by visible holes
Solution Approach 1:
The patent applies local quality by creating through-holes with specifically controlled small diameters (0.05-0.15mm) that are functionally sufficient for air escape but visually imperceptible. The holes are strategically positioned and sized to provide different properties at different locations: functional at the micro-level for air passage, and aesthetic at the macro-level for appearance.
Solution Approach 2:
The patent creates a porous structure in the substrate and adhesive layer through controlled perforation. This porous configuration allows air to pass through while maintaining the visual integrity of the sheet, as the pore sizes are below the threshold of human visual detection under normal viewing conditions.
2Ease of manufacture
If punching processing with blade die is used to form through-holes, then manufacturing is simplified, but hole diameter becomes too large (0.2-1.0mm) making holes visible
Solution Approach 1:
The patent replaces the mechanical blade die punching system with a hot needle perforation system. This substitution enables precise control of hole diameter through thermal melting rather than mechanical cutting, achieving much smaller hole sizes (0.05-0.15mm) that are invisible while maintaining manufacturing feasibility.
Solution Approach 2:
The patent changes the fundamental processing parameter from mechanical force (blade die) to thermal energy (hot needle). This parameter change enables precise control over hole diameter by adjusting needle temperature and contact time, producing holes small enough to be invisible yet large enough to allow air escape.
3Reliability
If water is applied to adherend or adhesive surface before sticking to prevent air entrapment, then air escape is improved, but time and effort increase significantly
Solution Approach 1:
The patent applies preliminary action by pre-forming through-holes in the adhesive sheet during manufacturing. This eliminates the need for time-consuming water application or other air-removal procedures during application, as the holes are already in place to facilitate air escape during the sticking process.
Solution Approach 2:
The adhesive sheet with pre-formed through-holes is self-service in that it inherently provides its own air escape pathway without requiring external assistance during application. The holes enable air to escape automatically as the sheet is applied, eliminating the need for water application or other auxiliary measures.
4Object-generated harmful factors
If resin material emits gas upon heating or storage, then gas emission occurs, but blistering occurs on the adhesive sheet
Solution Approach 1:
The patent extracts the harmful gas from the system by providing dedicated escape pathways (through-holes) that channel the gas outward. This prevents gas accumulation between the adhesive sheet and substrate that would cause blistering, while the extracted gas is safely vented through the controlled hole structures.
Solution Approach 2:
The patent converts the harmful gas emission into a beneficial controlled venting process. The through-holes transform the potentially damaging gas pressure into a controlled airflow that escapes harmlessly, preventing blistering while maintaining the natural gas-emitting properties of the resin material.
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 effectively prevents air entrapment and blistering without making the holes visible, maintaining the adhesive sheet's appearance and mechanical strength, even under stretching or exposure to liquids.
Implementation Method 1
irradiating with a CO2 laser having a pulse width of from 1 to 140 μsec, a pulse energy at each processing point of from 0.01 to 3.0 mJ, and a beam spot diameter at each processing point of from 30 to 160 μm, so as to form through-holes
Data Source
AI summary
To produce a pressure-sensitive adhesive sheet according to which air entrapment and blistering can be prevented or eliminated through through-holes, and yet the through-holes are not readily visible at a substrate surface, a pressure-sensitive adhesive surface of a pressure-sensitive adhesive layer 12 in a laminate comprising a substrate 11 and the pressure-sensitive adhesive layer 12 is irradiated with a CO2 laser having a pulse width of from 1 to 140 μsec, a pulse energy at each processing point of from 0.01 to 3.0 mJ, and a beam spot diameter at each processing point of from 30 to 160 μm, so as to form through-holes 2 having a diameter at the surface of the substrate 11 of from 0.1 to 42 μm at a hole density of from 30 to 50,000 per 100 cm2.