Crosslinked Textured Polyethylene Sheet for Food Packaging
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Solution Overview
Problem
Conventional multilayer resin sheets used for packaging food products, such as yogurt, face issues with food adhesion, particularly at the top edge portions, leading to splattering when opened, due to lack of water repellence.
Innovation Solution
A thermoplastic resin sheet with a textured surface and a water repellent agent, where the surface is crosslinked to maintain microscopic texture even after heated drawing, combined with a laminated structure including a styrenic resin layer and an oxygen barrier layer, providing excellent adhesion resistance and oxygen barrier properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional multilayer resin sheet is used for packaging food products, then the sheet provides basic packaging functionality, but food products adhere to the packaging material causing sticking and splattering
Solution Approach 1:
The invention applies local quality by creating a textured layer with specific microscopic surface structures (protrusions and recesses) on the inner surface of the packaging material. This localized surface modification provides water repellency precisely where food contact occurs, preventing adhesion without affecting the overall packaging structure or other layers.
Solution Approach 2:
The invention uses composite materials by combining multiple resin layers with different properties: an outer styrenic resin layer for rigidity and thermoforming capability, an inner textured layer with water repellent properties for food adhesion prevention, and intermediate adhesive layers for bonding. This composite structure integrates functions that no single material could provide alone.
2Adaptability or versatility
If the resin sheet is heated and drawn to form molded articles, then the sheet can be shaped into containers, but the microscopic texture may be lost compromising water repellence
Solution Approach 1:
The invention applies preliminary action by pre-texturing the resin sheet surface before thermoforming. The textured layer is prepared in advance with the required microscopic structures, and the crosslinking is performed before or during the forming process. This ensures the texture is already in place and will survive the subsequent heating and drawing operations.
Solution Approach 2:
The invention uses parameter changes by controlling the crosslinking degree and heat treatment parameters to preserve the textured structure during thermoforming. By adjusting processing temperature, time, and crosslinking conditions, the microscopic texture maintains its integrity while still allowing the sheet to be formed into the desired molded article shape.
3Object-affected harmful factors
If a textured layer with water repellent agent is applied to prevent food adhesion, then food product adhesion is prevented, but the structure becomes more complex
Solution Approach 1:
The invention merges the water repellent function with the structural layer by integrating the textured layer directly into the resin sheet composition. The textured layer is formed from resin composition containing water repellent agents, combining surface treatment functionality with the structural layer rather than adding a separate coating or treatment step.
Solution Approach 2:
The invention changes the resin composition parameters by incorporating water repellent agents (such as silicone-based or fluorine-based compounds) into the resin mixture before extrusion. This chemical modification of the base resin provides water repellency as an inherent property rather than requiring separate surface treatment, simplifying the overall structure.
4Reliability
If multiple layers are laminated to enhance oxygen barrier and adhesion resistance, then food protection is improved, but manufacturing complexity increases
Solution Approach 1:
The invention applies multi-functionality by designing each layer to serve multiple purposes: the outer styrenic resin layer provides structural integrity and oxygen barrier, the intermediate adhesive layers provide both bonding and oxygen barrier, and the inner textured layer provides water repellency and food adhesion prevention. This reduces the total number of layers needed while maintaining comprehensive protection.
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 effectively prevents food adhesion and maintains water repellence, ensuring the integrity of the packaged food and extending the shelf life by using a thermoplastic resin sheet with a textured surface and a water repellent agent, which is crosslinked to maintain microscopic texture even after heated drawing, combined with a laminated structure including a styrenic resin layer and an oxygen barrier layer.
Implementation Method 1
at least a surface portion of the texture is a crosslinked material that maintains the microscopic texture even after heated drawing
Implementation Method 2
a textured layer formed from a polyethylene resin composition comprising a water repellent agent, having a microscopic texture on one surface side
Data Source
AI summary
Provided is a water-repellent, thermoplastic resin sheet including a textured layer which is formed from a polyethylene resin composition comprising a water repellent agent and which has a microscopic texture on one surface side, wherein at least the surface region of the textured layer is a cross-linked material which maintains the microscopic texture even after heated drawing. Also provided is a molded article, such as a molded container, formed by thermoforming the thermoplastic resin sheet.