Bi-material Packaging with Polygonal Gutter and Clearances
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bi-material packaging with a cardboard exterior and plastic interior faces manufacturing challenges due to the need to combine materials with different properties, particularly when the cardboard is not glued to the plastic, making separation and recycling difficult, and complicating the manufacturing process, especially in polygonal configurations where thermoforming deformations apply forces that must be maintained during the molding process.
Innovation Solution
The packaging features a polygonal rod and gutter with clearances at the corners to prevent collision and allow for elastic interlocking, and bulges in the gutter to resist folding, along with a specific thermoforming mold design that includes teeth to maintain the cardboard's shape, allowing for a reduced thickness of cardboard and eliminating the need for adhesives, enabling efficient manufacturing and recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the cardboard covering is pre-positioned in the mold during thermoforming, then the cardboard can be mechanically connected to the plastic container without adhesives, but the thermoforming deformations generate forces that may cause the cardboard to fold or lose its intended shape
Solution Approach 1:
The cardboard covering is pre-positioned in the mold before thermoforming, and its position is secured by preliminary actions (mold clamping, support structures) to prevent folding during the subsequent thermoforming process, enabling adhesive-free mechanical connection while maintaining shape precision
Solution Approach 2:
The mold design incorporates beforehand cushioning measures such as support structures and clamping mechanisms that protect the pre-positioned cardboard from deformation forces during thermoforming, preventing folding before it can occur
2Ease of operation
If clearances are made at the angular regions of the rod to prevent collision with the gutter, then the lid can close properly, but the elastic interlocking mechanism may be weakened
Solution Approach 1:
The rod is designed with local quality variations: clearances at angular regions for easy lid closure, and elastic deformation zones in the straight sections for maintaining interlocking strength, allowing different functional requirements to be met in different locations
3Quantity of substance
If the plastic wall thickness is reduced to minimize plastic usage, then the quantity of plastic is minimized, but the structural strength and rigidity of the container may be compromised
Solution Approach 1:
The container uses composite material construction with a thin plastic container body reinforced by an external cardboard covering, achieving minimal plastic usage while maintaining structural strength through the combined properties of both materials
4Quantity of substance
If the cardboard covering is used to reinforce rigidity and thin the plastic walls, then plastic quantity is minimized, but the manufacturing complexity increases due to combining two materials with very different properties
Solution Approach 1:
The manufacturing process merges the positioning of cardboard covering and the thermoforming of plastic in a single integrated operation, where the pre-positioned cardboard serves as both a reinforcement element and a mold feature, simplifying the overall process despite using two different materials
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 design ensures proper lid closure without obstacles, reduces plastic usage, and allows for the use of thinner cardboard while maintaining structural integrity, simplifying the manufacturing process and facilitating recycling by avoiding the need for adhesives and ensuring effective mechanical support around the container's periphery.
Implementation Method 1
a thermoforming mold making it possible to obtain these bi-material packaging
Implementation Method 2
elastic interlocking by friction contact of at least a fraction of their walls
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Packaging particularly suitable for containing food, comprising on the one hand a container (1) made of plastic-type material having a polygonal base (4) and a continuous peripheral wall comprising a plurality of flat faces (5), the upper edge (6) of said peripheral wall delimiting an opening and being provided with a polygonal peripheral rim (7) extending radially outwards having a gutter (8) suitable for cooperating with a peripheral bead (21) of a lid (2) by fitting the bead (21) into said gutter (8), and on the other hand an outer covering (40) made of cardboard-type material or other bio-based material fitting at least to the contact of the faces (5) of the container (1) and fixed between the gutter (8) and the part of said faces (5) adjacent to the rim (6).The polygonal ring (21) and the gutter (8) have a matching shape for elastic interlocking by friction contact of at least a fraction of their walls, except at the corners of the ring (21) of the cover (2) which have a clearance (22) in their inner wall, eliminating contact with the inner wall of the gutter (8) in each angular region.