Pre-folding Pack Sleeves Without Thermal Damage
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Solution Overview
Problem
Existing pre-folding devices for packaging casings often require high energy for heating, risk damage to the packaging material, and make it difficult to pull out the folding block without damaging the inside surfaces, leading to hygiene issues and potential contamination of food products.
Innovation Solution
A device with folding bars and a folding block that allows for gentle pre-folding of gable and triangular surfaces without contact, using a fold-back mechanism to facilitate easy removal of the block and reduce material stress, featuring a narrow web width and inclined supporting surfaces to minimize material contact and prevent cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heating is used to reduce folding stresses, then the material layers become more elastic and less prone to cracking, but very high energy input is required and excessive heat can lead to discoloration or damage
Solution Approach 1:
The patent replaces the thermal field (heating) with a mechanical field (folding device). The folding device mechanically breaks the crease lines through controlled folding action, eliminating the need for thermal energy input while achieving the same effect of preventing cracks in the packaging material layers.
2Productivity
If the folding block is pulled out after pre-folding, then the pre-folding process is complete, but the folding block may collide with the inwardly folded gable ends and damage the inside of the packaging
Solution Approach 1:
The patent applies preliminary action by performing the unfolding of triangular surfaces before removing the folding block. The back-folder unfolds the triangular surfaces that were folded inward during pre-folding, creating clearance space between the gable ends and the folding block, thus preventing collision and damage during block removal.
3Manufacturing precision
If folding tools firmly clamp the packaging sleeve to fix position during folding, then precise fold lines are achieved, but cracks can occur in some layers particularly where several crease lines intersect
Solution Approach 1:
The patent applies local quality by making the contact surfaces of the folding strips smooth and by designing the back-folder to gently unfold triangular surfaces. This localized adjustment of surface properties and folding action prevents excessive stress concentration at critical points where multiple crease lines intersect, thereby preventing cracks while maintaining fold line precision.
4Manufacturing precision
If the folding strips are rigid to provide stable folding action, then consistent pre-folding is achieved, but the device complexity increases and adaptability to different packaging sizes is reduced
Solution Approach 1:
The patent applies dynamics by making the folding strips pivotably mounted rather than rigidly fixed. This allows the folding strips to adapt their angle and position dynamically during the folding process, accommodating different packaging sizes and shapes while maintaining consistent pre-folding quality through the pivotable mechanism.
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A
AI summary
The invention illustrates and describes an apparatus (15) for the pre-folding of pack sleeves (12), comprising: at least two folding bars (18A, 18B) for the pre-folding of the gable surfaces (9) and of the triangular surfaces (10) of the pack sleeves (12), and at least one folding block (23), which can be introduced into the pack sleeves (12), wherein the folding bars (18A, 18B) each have at least one contact surface (19) for the pre-folding of the gable surfaces (9). The invention also illustrates and describes a method and a system for the pre-folding of pack sleeves (12). In order to achieve particularly careful and damage-free pre-folding of the pack sleeves (12), it is proposed to provide at least one folding-back means (20) for folding back the triangular surfaces (10).