Ultrasonic Bonding Anvil Synchronization for Web Speed Control
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Solution Overview
Problem
The consistency and quality of ultrasonic bonds in disposable hygiene products, such as diapers, are dependent on various factors including web speed, dwell time, and material types, but controlling web speed alone is inadequate to ensure bonds of desired quality.
Innovation Solution
A system and method that synchronizes the velocity of a continuously moving web with the movement of an anvil and ultrasonic horn, using a velocity-changing device and an anvil actuator, to control the dwell time and form stronger bonds, allowing for phasing and synchronization of speeds during the bonding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If web speed is controlled to increase dwell time, then bond quality improves, but production productivity decreases
Solution Approach 1:
The patent applies dynamics by making the anvil roll rotatable at variable speeds rather than fixed. The anvil roll speed can be dynamically adjusted to match different web speeds, allowing the dwell time to be optimized for bond quality while maintaining high production speeds. This resolves the contradiction by enabling both high productivity and high bond quality through dynamic speed matching.
Solution Approach 2:
The patent changes the parameter of anvil roll rotational speed to optimize the bonding process. By adjusting the anvil roll speed parameter to synchronize with web speed, the system achieves optimal dwell time for strong bonds without sacrificing production throughput. This parameter adjustment allows the system to simultaneously achieve high bond quality and high productivity.
2Productivity
If web speed is increased to maintain productivity, then production output improves, but bond consistency deteriorates
Solution Approach 1:
The patent implements feedback control by synchronizing the anvil roll speed with the web speed. The system monitors web speed and adjusts anvil roll rotational speed accordingly to maintain optimal dwell time and bond consistency. This feedback mechanism ensures that bond quality remains consistent even when production output varies, resolving the contradiction between productivity and bond consistency.
Solution Approach 2:
The system dynamically adjusts the anvil roll speed to match web speed variations, ensuring consistent bond quality across different production rates. This dynamic speed matching allows the system to maintain high productivity while preserving bond consistency through real-time parameter optimization.
3Strength
If dwell time is increased to improve bond strength, then bond quality improves, but production efficiency decreases
Solution Approach 1:
The patent uses dynamics by making the anvil roll rotatable at variable speeds. By adjusting the anvil roll speed to match the web speed, the system optimizes dwell time to achieve strong bonds without requiring excessive slowing of the web, thus maintaining production efficiency. This dynamic adjustment resolves the contradiction between bond strength and productivity.
Solution Approach 2:
The system changes the operational parameters by synchronizing anvil roll speed with web speed. This parameter optimization allows the dwell time to be sufficient for strong bonding while keeping the overall production rate high, thereby achieving both bond strength and production efficiency simultaneously.
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 the formation of bonds with improved consistency and quality, enabling the production of stronger and more reliable disposable hygiene products by optimizing the dwell time and bond length based on product type and material.
Implementation Method 1
the web layers are exposed to an ultrasonic emission from the horn that increases the vibration of the particles in the web layers
Implementation Method 2
The ultrasonic emission or energy is concentrated at specific bond points where frictional heat fuses the web layers together
Data Source
AI summary
A system and method for controlling the speed of both a continuous web and a bonding apparatus is provided in order to effectuate stronger bonds in the web. The bonding system includes a velocity changing device for increasing and decreasing a velocity of the web in a machine direction, an anvil and a corresponding ultrasonic horn that interact to form ultrasonic bonds on the web, and an anvil actuator configured to control a movement of the anvil. A control system is also included in the bonding system for controlling operation of the anvil actuator the velocity changing device, with the control system programmed to decrease a moving velocity of the web from a feed velocity to a bonding velocity as the web passes between the anvil and the ultrasonic horn and control movement of the anvil to synchronize the movement of the anvil with the moving velocity of the web.