Vertical Bag Packaging Ultrasonic Sealing Preheating
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Solution Overview
Problem
In vertical-type bag packaging, steam-replacement deaeration leads to nonuniform temperature distribution at the bag mouth, causing incomplete or excessive welding during ultrasonic sealing, as existing technologies lack effective preheat treatment methods to address this issue.
Innovation Solution
A vertical-type bag packaging method and machine that includes a preheating step between steam-replacement deaeration and ultrasonic sealing, where the seal portion is preheated to a uniform temperature above the lowest and below the melting temperature of the bag material using steam from the same supply source or heated pressing members, ensuring consistent heat application during ultrasonic sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If steam-replacement deaeration is performed, then deaeration effect is improved, but temperature distribution at seal portion becomes nonuniform
Solution Approach 1:
The patent applies preliminary action by introducing a preheating step before ultrasonic sealing. The seal portion is preheated to a uniform temperature (e.g., 80-100°C) using heating means such as hot plates or heated air blowing, before the ultrasonic sealing process begins. This preliminary temperature equalization ensures that subsequent ultrasonic heating is uniform across the seal portion, preventing incomplete or excessive welding in different regions.
2Loss of time
If ultrasonic sealing is performed directly after steam-replacement deaeration, then process time is reduced, but sealing quality deteriorates due to nonuniform heat distribution
Solution Approach 1:
The patent introduces a preheating step as preliminary action before ultrasonic sealing. This preheating process equalizes the temperature distribution at the seal portion, ensuring uniform ultrasonic heating and high sealing quality. Although this adds a step to the process, the preheating can be efficiently performed using heating means integrated into the sealing apparatus, and the process continues sequentially without idle time, thus minimizing the additional time required.
3Area of stationary object
If hot plates with wide width are used for heat sealing, then sealing coverage is improved, but temperature control precision deteriorates due to steam-induced temperature variations
Solution Approach 1:
The patent replaces the conventional hot plate heat sealing method with ultrasonic sealing. Instead of relying on external heat conduction from wide hot plates that are affected by steam-induced temperature variations, the system uses ultrasonic vibration to generate heat directly at the seal portion through mechanical energy conversion. This substitution eliminates the temperature control precision problems associated with wide hot plates while maintaining adequate sealing coverage through the focused ultrasonic energy.
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 ensures reliable and stable ultrasonic sealing by uniform preheating of the seal portion, preventing incomplete or excessive welding and improving operational efficiency by eliminating the need for a separate heat source.
Implementation Method 1
steam is blown into the bag to replace the air in the bag with the steam, thereby effecting deaeration... the temperature in the vicinity of the widthwise center of the bag increases to from 95° C. to 100° C., and the temperature in the neighborhood of the laterally opposite side edges of the bag increases to around 60° C.
Implementation Method 2
the horn is ultrasonically vibrated to generate heat in the seal portion of the bag mouth, thereby welding the seal portion
Implementation Method 3
the seal portion is preheated to a temperature not lower than the temperature of the highest temperature region of the seal portion before it is preheated and below the melting temperature of the material constituting the inner side of the bag
Implementation Method 4
a preheating step of preheating a seal portion of the mouth of the bag... using steam from the same supply source or heated pressing members
Data Source
AI summary
A vertical bag packaging machine has a steam nozzle that is inserted into a bag to inject steam thereinto after an article to be packaged has been filled into the bag, thereby replacing the air in the bag with the steam to effect deaeration. After the steam-replacement deaeration, a seal portion to be ultrasonically sealed is preheated by a preheating device, thereby making the temperature of the seal portion uniform throughout it. The preheating temperature is not lower than a temperature of a highest temperature region of said seal portion before it is preheated and below a melting temperature of a material constituting an inner side of said bag Thereafter, the seal portion is ultrasonically sealed by an ultrasonic sealing device. Thus, reliable and stable ultrasonic sealing can be realized.