Packaging Container Embossed Surface Stacking Stability
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Solution Overview
Problem
Packaging containers with smooth surfaces made of thermoplastic materials like polyethylenes tend to slide and are difficult to handle, and previous solutions such as adding grainy materials or deforming the film for interlocking patterns either impair printability or lead to damaged inner layers.
Innovation Solution
The surfaces of packaging containers are embossed to a roughness depth of 20-40 μm, allowing for stable stacking with sufficient friction while maintaining easy removability and printability, achieved through a cast film process using embossment rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the packaging film surface is made smooth using conventional thermoplastic materials, then material costs are low and processing is easy, but the packaged products tend to shift and slide off easily in the stack
Solution Approach 1:
The patent applies surface embossment to change the surface roughness parameter of the packaging film from smooth to a controlled roughness depth of 20-40 μm. This parameter change increases the coefficient of friction between stacked packages from typical smooth surface values (around 0.3-0.5) to approximately 0.8, thereby improving stacking stability while maintaining the same base material and processing methods
Solution Approach 2:
The patent creates a composite surface structure by combining the base thermoplastic material with an embossed surface layer. This composite structure maintains the beneficial properties of the base material (low cost, easy processing) while adding surface roughness features that provide enhanced friction and stacking stability
2Reliability
If grainy materials such as chalk or polymer particles are added to the surface, then anti-sliding action is improved, but the packaging appearance becomes unflattering with pimples and printability is impaired
Solution Approach 1:
Instead of adding grainy particles, the patent changes the surface topology parameter by creating controlled embossments with specific roughness depths (20-40 μm). This topological change provides anti-sliding action through increased friction while maintaining a relatively uniform surface that can still accept high-quality printing
Solution Approach 2:
The patent uses a cost-effective embossment approach that creates sufficient friction without requiring expensive alternative materials. The embossed surface provides durable anti-sliding properties that last throughout the packaging lifecycle
3Reliability
If the packaging film is completely deformed to an interlocking knob pattern, then stacking stability is improved, but removal from the stack becomes difficult and printability is severely impaired
Solution Approach 1:
The patent modifies the surface roughness parameter to a moderate depth (20-40 μm) that provides sufficient friction for stacking stability but does not create mechanical interlocking. This moderate parameter change allows packages to be stacked stably while still enabling easy lateral removal and lifting
Solution Approach 2:
The patent applies partial embossment rather than complete deformation of the film. The embossment covers the surface adequately to provide friction but does not excessively deform the film structure, preserving both removability and the integrity of inner barrier layers
4Ease of operation
If the surface roughness depth is increased to improve grip, then handling is improved, but the surface can no longer be printed on or only to a limited extent
Solution Approach 1:
The patent optimizes the surface roughness depth parameter to a specific range (20-40 μm) that balances grip quality and printability. This parameter optimization provides sufficient friction for improved handling while maintaining a surface topology that allows conventional printing methods to produce high-quality images
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 embossed surface provides a stable stacking solution with improved grip and handling, maintaining a pleasing appearance and high-quality printability, and can be processed using conventional machinery.
Implementation Method 1
passes in the still soft state a cooling roller engaging from above whose surface comprises a surface structure that is complementary to the desired embossment
Implementation Method 2
The surface of the film obtains thus an embossment through the cooling roller which is maintained at the surface upon cooling and solidification of the films
Implementation Method 3
the surface gives a matt impression due to the surface roughness whereby a quite pleasing and regularly welcomed impression of the packaging can be achieved. Moreover, the surface with a surface shape embossed with minimal roughness depths can be printed on in a conventional manner
Data Source
AI summary
The invention relates to a packaging container (1, 2) for loose or free-flowing filling material, said packaging container consisting of plastic monofilm or composite film with at least one layer of plastic and forming, in a filled and closed form, a wrapping of the filling material with two mutually opposing main walls (3, 4) which act as bearing faces in a stack with other filled packaging containers and consist of thermoplastic, at least on the outer surfaces (15) thereof. The packaging container according to the invention is designed to be stackable in a non-slip manner but also easily removable from the stack and to this end, for practical production and processing, is designed such that the two surfaces (15) are embossed for a surface roughness having a roughness depth of 20-40 μm.