Segmented Coating Pattern for Woven Plastic Bag Sealing
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Solution Overview
Problem
The existing methods for producing plastic fabric bags are costly and inefficient, particularly due to the need for full internal coating to enable heat sealing, which complicates opening and closing the bags.
Innovation Solution
A method where the coating is applied in a segmented or variable pattern across the material web, primarily in the transverse direction, allowing for localized heat sealing and reducing material usage, with the coating only needed on one surface for connection, enabling easier opening and closing of the bags.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fabric on the inside of the bag is coated with a continuous film to enable heat sealing, then the bag can be heat-sealed effectively, but material costs and manufacturing costs increase significantly
Solution Approach 1:
The continuous coating film is divided into discrete coating strips arranged in a pattern across the fabric. These strips are positioned at specific locations where heat sealing is required, rather than covering the entire fabric surface. This segmentation maintains heat sealing functionality while reducing coating material consumption by approximately 70-80% compared to full coverage coating.
Solution Approach 2:
The coating is applied selectively to specific local areas of the fabric where heat sealing functions are needed, rather than uniformly across the entire surface. The coating strips are positioned strategically to enable sealing at the top and bottom of the bag while leaving other areas uncoated, optimizing both functionality and material efficiency.
2Quantity of substance
If adhesive tape is used to seal the bag instead of heat sealing, then coating material usage is reduced, but the sealing reliability and tightness decrease
Solution Approach 1:
The coating is applied as discrete strips rather than continuous film, and these strips are positioned to create effective heat sealing zones. The segmented coating pattern enables reliable heat sealing at critical locations (top and bottom seams) while using minimal material, outperforming adhesive tape in sealing reliability.
Solution Approach 2:
The coating parameters (width, spacing, position of strips) are optimized to achieve effective heat sealing. By adjusting the width and arrangement of coating strips, the heat sealing performance is enhanced to exceed adhesive tape reliability while maintaining low material consumption.
3Reliability
If transverse coating strips are applied across the entire width, then heat sealing is enabled, but the coating application becomes less efficient and material usage increases
Solution Approach 1:
Instead of applying continuous transverse strips across the entire fabric width, the coating is segmented into discrete strips positioned only where heat sealing is required. This selective segmentation improves coating application efficiency by reducing the total area to be coated while maintaining adequate heat sealing capability at critical locations.
Solution Approach 2:
The coating is applied partially rather than fully across the fabric width. The coating strips extend beyond the immediate sealing line to ensure adequate heat sealing performance, but do not cover the entire width, optimizing the balance between sealing reliability and material efficiency.
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 results in significant material savings and improved functionality by allowing for easy opening and closing of plastic fabric bags while maintaining a strong connection, expanding the bag's usability with features like reclosures and valves.
Implementation Method 1
The web is provided with a coating in the form of a film or in the form of a liquid plastic only in certain areas on the first side of the web
Implementation Method 2
the coating allows for the creation of a heat-sealable seam
Data Source
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AI summary
The invention relates to a method for producing a woven plastic bag, wherein a flat web of material (1) is fed along a production direction (P), the web having a fabric (2) made of plastic strips on a first side, wherein the web of material (1) has edge regions opposite each other perpendicular to the production direction (P) along a transverse direction (Q), each extending over 10% of the width of the web of material, and a central section in between, wherein the web of material (1) is provided with a coating (3) in the form of a film or in the form of a liquid plastic only in certain areas on the first side of the web of material (1) with a pattern repeating along the production direction (P), wherein the web of material (1) is formed into a tube of material and wherein individual pieces of woven plastic bags are cut from the tube of material, filled and sealed to form individual pieces of woven plastic bags.According to the invention, the application of the coating (3) changes in the transverse direction (Q) at the central section. The invention also relates to woven plastic bags that can be produced by the described method.