Pulsed Laser Web Cutting for Softer Absorbent Article Edges

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing methods for cutting web structures in personal care absorbent articles using lasers often result in rough edges due to the vaporization of materials, which can be problematic as these articles may come into contact with the wearer's skin.

Innovation Solution

A method involving a laser with a pulse mode operation, where the frequency of the beam radiation is patterned to correspond to the material type and speed of the web structure, allowing for varying profiles of pulses per beam diameter to achieve a softer edge by adjusting the laser's frequency and speed in conjunction with the web structure's movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a laser beam is used to cut the web structure, then the cutting speed and efficiency are improved, but the edge quality deteriorates due to vaporization and melting causing rough edges

Engineering Contradiction:
Improvecutting speedVSAvoidedge quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The laser beam is operated in pulsed mode rather than continuous mode, delivering energy in periodic pulses to the web structure. This allows the material to cool between pulses, preventing excessive melting and vaporization that causes rough edges, while still achieving efficient cutting through repeated thermal cycles.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The laser system dynamically adjusts its operating parameters including pulse frequency, pulse duration, and beam speed to optimize the balance between cutting efficiency and edge quality. The system can vary these parameters based on the specific material being cut and the desired edge finish.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the laser energy is increased to improve cutting efficiency, then the productivity increases, but the thermal damage to the web structure material increases causing rougher edges

Engineering Contradiction:
Improvecutting efficiencyVSAvoidthermal damage
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

By using pulsed laser operation instead of continuous high-power laser, the system delivers intense energy in short bursts followed by cooling periods. This periodic energy delivery achieves efficient cutting through cumulative thermal effect while allowing the material to recover between pulses, reducing excessive melting and vaporization.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The pulsed laser operation maintains continuous cutting action through repeated pulses, ensuring productivity while controlling thermal damage. The high pulse frequency creates a near-continuous cutting effect while the brief intervals between pulses allow heat dissipation.

Inventive Principle:
Principle #20Continuity of useful action

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 a cleaner and softer cut edge in web structures, reducing the risk of skin irritation and improving the quality of absorbent articles by maintaining a consistent number of pulses per beam diameter, even during changes in web structure speed.

Implementation Method 1

employ a laser which can emit a beam of radiation at the web structure

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

The energy output from the beam of radiation can be absorbed by the web structure in the area which is the focus of the beam of radiation

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 3

The absorption of the energy from the beam of radiation can result in the vaporization of the web structure in the area of focus

Methodology Applied
Scientific EffectVaporization: Evaporation

Data Source

PatentUS10994373B2Method of laser cutting a web structure
Publication Date: 2021.05.04 KIMBERLY CLARK WORLDWIDE INC

AI summary

A method of cutting a web structure that is utilized in the manufacture of an absorbent article. The method of cutting the web structure can employ a laser having a pulse mode of operation. In various embodiments, the frequency of the beam of radiation pulsed from the laser can be patterned to correspond to the material of the web structure. In various embodiments, the frequency of the beam of radiation pulsed from the laser can be patterned to correspond to the speed at which the web structure is moving and can change with any change in speed of the web structure movement.