Gusset Preheating Assembly for Plastic Bag Thickness Reduction
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Solution Overview
Problem
Gusseted polypropylene bags occupy more space due to uneven thickness across their width, caused by thicker side portions, making them less efficient for stacking and rolling compared to ungusseted bags.
Innovation Solution
A gusset preheating assembly that uses heating gun assemblies to relax gussets by blowing warmed air and applying pressure with rollers, reducing the thickness and stiffness of the bag, allowing for more bags to be packed in a given space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If gussets are formed on the bag to allow it to open wider and hold more materials, then the bag's capacity and functionality are improved, but the thickness of the bag becomes uneven across its width and the sides become thicker and stiffer, causing the bag to occupy more space when stacked or rolled
Solution Approach 1:
The patent applies thermal energy to change the physical state of the gusset material from a stiff, thick state to a relaxed, thinner state. By heating the gusset to its melting point and then allowing it to cool, the material parameters (thickness, stiffness) are temporarily changed to achieve better packing, while the functional parameters (capacity, strength) are preserved
Solution Approach 2:
The patent performs a preliminary heating action on the gusset before the bag is stacked or rolled. This preliminary thermal treatment relaxes the gusset in advance, reducing its thickness and stiffness before the packaging operation, thereby minimizing the space occupied during storage and transport
2Adaptability or versatility
If gussets are formed on the bag, then the bag can open wider to hold more materials, but the side portions become thicker than the central region, making the bag less efficient for stacking and rolling
Solution Approach 1:
The patent changes the thermal parameters of the gusset material by heating it to its melting point and then allowing it to cool. This thermal cycle transforms the gusset from a thick, stiff structure to a thinner, more flexible structure, improving packaging efficiency while maintaining the bag's opening width and capacity
Solution Approach 2:
The patent replaces mechanical compression methods with a thermal field approach. Instead of using mechanical pressure to flatten the gusset, the patent uses thermal energy to melt and relax the material, achieving the same effect of reducing gusset thickness and improving packability
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 solution enables a 40% increase in the number of bags that can be stacked or rolled, as the reduced thickness of gussets allows for a more compact packaging arrangement without compromising the bag's functionality.
Implementation Method 1
heating gun assemblies that blow warmed air into gussets on the bags thereby relaxing those gussets
Implementation Method 2
rollers that apply pressure thereto so that the so-formed gusseted bags take up less room
Implementation Method 3
the gusset is allowed to cool as it passes through press-rollers and this causes gusseted regions of the bag to relax and form a crisper crease
Data Source
AI summary
A gusset preheating assembly and a method of using the same. The assembly includes a heating gun assembly mounted on a frame. Spreader rods open up a gap in a bag's gusset and nozzles blow warmed air into the gap. Orthogonally arranged first and second hydraulic members are operatively engaged with heating gun assembly and are activated to move the heating gun assembly vertically or horizontally. Hot air blowing into the gap from the nozzle relaxes the gusset. Pressure is applied to the relaxed gusset, thereby reducing the thickness of the gusset region of the bag. The reduction in thickness makes it possible to increase the number of gusseted bags that are packaged in a container or on a roll.