Non-contact Laser Sealing for Tamper-Evident Packaging
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Solution Overview
Problem
Existing heat sealing technologies for tamper evident packaging are bulky, inefficient, and prone to errors, requiring significant space, long cycle times, and frequent maintenance, especially when sealing thin films like plastic bags.
Innovation Solution
A non-contact sealing method using a laser to create a series of spaced spot welds on a bag without physical contact, employing a system with feed belts, a centrifugal blower, and a laser to fuse opposing sides of the bag together, assisted by air flow and sensors for detection and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat sealing machines are used to seal plastic bags, then the bag can be sealed, but the machinery becomes large and bulky requiring significant space
Solution Approach 1:
The patent replaces the mechanical contact-based heat sealing system with a non-contact laser sealing system. The laser beam delivers thermal energy without requiring physical contact or large mechanical pressing components, thereby dramatically reducing the space required for the sealing machine while maintaining effective sealing capability on plastic bags
Solution Approach 2:
The patent extracts the essential sealing function from the bulky mechanical heat sealing machine and isolates it into a compact laser sealing device. By removing the need for large mechanical pressing plates and contact-based heating elements, the core sealing capability is preserved while the overall machine footprint is minimized
2Reliability
If contact heat sealing is used, then the bag can be sealed, but the cycle time increases and manufacturing output decreases
Solution Approach 1:
The patent replaces the slow mechanical contact heat sealing process with a rapid non-contact laser sealing process. The laser can deliver concentrated energy instantaneously without the delay associated with mechanical pressing and heating, thereby reducing cycle time and increasing manufacturing output while maintaining seal integrity
Solution Approach 2:
The patent enables continuous laser sealing operation where the laser beam can continuously seal bags as they pass through without the intermittent stopping and starting required by mechanical contact systems. This continuous operation eliminates idle time between cycles and maximizes manufacturing throughput
3Reliability
If heated plates contact the packaging to produce seals, then sealing is achieved, but errors such as overheating, melting, or breaking occur
Solution Approach 1:
The patent replaces contact-based heated plates with a non-contact laser beam for sealing. This eliminates the harmful effects of excessive mechanical pressure and localized overheating that occur with contact heating, as the laser energy can be precisely controlled and delivered without physical contact that causes melting or breaking of thin plastic films
Solution Approach 2:
The patent incorporates feedback control mechanisms where sensors detect the sealing process parameters and adjust the laser power in real-time. This feedback system prevents overheating and damage by automatically reducing laser intensity if the sealing temperature exceeds optimal levels, thereby eliminating the harmful effects of uncontrolled heating
4Reliability
If heating machines physically contact the packaging, then seals are produced, but substantial cleaning and maintenance are required
Solution Approach 1:
The patent replaces contact-based heating machines with a non-contact laser sealing system. Since the laser beam does not physically touch the packaging or require large mechanical pressing surfaces, there are no contact surfaces to accumulate residue, grease, or debris that would require frequent cleaning and maintenance
Solution Approach 2:
The patent extracts the sealing function from the maintenance-intensive mechanical contact system and transfers it to a clean, contactless laser system. This removes the source of contamination and wear that necessitates regular cleaning and repair, thereby significantly reducing maintenance requirements
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 and system provide a compact, efficient, and reliable tamper evident seal on plastic bags, reducing the risk of damage and maintenance needs while maintaining manufacturing output.
Implementation Method 1
sealing opposing sides of a bag together proximate a neck of the bag with a laser of a non-contact sealing device
Implementation Method 2
repeatedly emitting intermittent laser light pulses to fuse the two opposing sides of the bag together at the spot welds
Implementation Method 3
holding opposing sides of the bag in proximity to each other with moving air directed from an outlet positioned in the space between the first and second pairs of belts
Data Source
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AI summary
A system for manufacturing tamper evident packaging, for example a bag with a tamper evident seal, includes a non-contact sealing device, a manufacturing conveyor, and in some implementations, a tensioning device and a closure device. The manufacturing conveyor conveys the bag to opposing pairs of in-feed belts of the non-contact sealing device, wherein the belts hold opposing sides of the bag together and a laser with an outlet positioned between a first pair of the belts spot welds the bag along a specified line to fuse the opposing sides of the bag together proximate an opening of the bag. In implementations including the tensioning device and the closure device, the tensioning device draws the opposing sides of the bag together prior to the bag entering the non-contact sealing device, and the closure device applies a removably coupleable closure to the bag after the bag exits the non-contact sealing device.