Laser Marking Vibrating Plastic Bottles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing laser marking methods for plastic bottles, such as PET bottles, face challenges in maintaining image quality due to vibrations during processing, leading to uneven image density and decreased resolution, as the relative position between the bottle and the laser beam changes, causing periodic displacement and density variations.
Innovation Solution
A laser processing apparatus and method that control the frequency of vibration of the container body to be v/L or less, where v is the conveying speed and L is the processing region length, ensuring a stable image formation even with vibrating containers, using a conveyor and light emitter to emit laser light while managing the vibration amplitude and resonance frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser marking is performed on moving plastic bottles, then productivity is improved, but image quality deteriorates due to vibrations causing uneven density and poor resolution
Solution Approach 1:
The invention utilizes controlled mechanical vibration of the bottle in the vertical direction during laser marking. By applying vibration at specific frequencies (natural frequency or its multiples), the bottle surface moves periodically, preventing the laser beam from consistently hitting the same position and thereby reducing vibration-induced marking defects while maintaining high-speed continuous marking
Solution Approach 2:
The invention changes the vibration frequency parameter to match the natural frequency or its multiples, and adjusts the vibration amplitude to an appropriate range. This parameter optimization ensures that the vibration effectively counteracts the harmful effects of bottle movement during marking without causing excessive displacement that would degrade image quality
2Manufacturing precision
If vibration frequency is increased to improve marking uniformity, then image density uniformity improves, but bottle deformation increases
Solution Approach 1:
The invention applies vibration at the bottle's natural frequency or its multiples, which resonates with the bottle's structural characteristics. This resonant vibration distributes stress uniformly throughout the bottle structure, preventing localized deformation while achieving uniform image density through controlled surface movement during marking
3Speed
If laser marking is performed on vibrating bottles, then processing speed is improved, but relative position between bottle and laser beam changes causing periodic displacement
Solution Approach 1:
The invention applies vertical vibration to the bottle during high-speed marking, causing the bottle surface to move up and down periodically. This vibration compensates for the relative position changes between the moving bottle and laser beam, preventing periodic displacement marks by ensuring the laser interacts with different surface positions during each vibration cycle
Solution Approach 2:
The invention employs periodic vibration at specific frequencies (natural frequency or multiples) to create a rhythmic motion pattern. This periodic action synchronizes with the marking process, ensuring that displacement occurs in a controlled, repeating manner that prevents the formation of periodic displacement marks on the final marking
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 formation of high-resolution images on vibrating container bodies by minimizing image density variations, making the image quality more consistent and visually appealing, even when the container is subjected to deformation and rigid body motion vibrations.
Implementation Method 1
a light emitter to emit laser light to a predetermined processing region in the container body conveyed in the conveying direction by the conveyor
Data Source
AI summary
A laser processing apparatus includes: a conveyor to convey a container containing a content in a container body in a conveying direction at a predetermined conveying speed; and a light emitter to emit laser light to a predetermined processing region in the container body conveyed in the conveying direction by the conveyor. A frequency of a vibration of the container body conveyed, in which an amplitude of the vibration of the container body is maximized, is v/L or less, where v is the predetermined conveying speed, and L is a length of the predetermined processing region in the conveying direction.