Two-Layer Preform Transparency with Recycled Material
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Solution Overview
Problem
Existing two-layer molding methods for plastic bottles result in high haze (turbidity), making it difficult to achieve sufficient transparency, especially when a large proportion of recycled material is used, hindering commercialization.
Innovation Solution
A manufacturing method for a preform and container with a two-layer structure, where the inner layer is made of virgin material and the outer layer of recycled material, with specific weight and thickness ratios, and a controlled cooling process to enhance transparency and production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If a two-layer molding method with recycled material for the outer layer is used, then the recycling ratio is improved, but the haze (turbidity) increases and transparency deteriorates
Solution Approach 1:
The patent applies local quality by creating distinct functional zones within the bottle structure: the inner layer uses virgin material for high transparency and food safety, while the outer layer uses recycled material for cost reduction and environmental benefits. This localized material assignment allows each layer to optimize its properties for specific functions, resolving the contradiction between transparency and recycling ratio.
Solution Approach 2:
The patent employs composite materials by combining virgin PET resin and recycled PET resin in a specific ratio (95:5 to 50:50 by weight) within a two-layer structure. This composite approach enables the bottle to simultaneously achieve high transparency through the virgin material inner layer and high recycling content through the outer layer, resolving the contradiction between these opposing requirements.
2Ease of repair
If a large proportion of recycled material is used, then the environmental benefit is improved, but the haze increases making commercialization difficult
Solution Approach 1:
The patent applies local quality by creating distinct functional zones within the bottle structure: the inner layer uses virgin material for high transparency and food safety, while the outer layer uses recycled material for cost reduction and environmental benefits. This localized material assignment allows each layer to optimize its properties for specific functions, resolving the contradiction between transparency and recycling ratio.
Solution Approach 2:
The patent employs parameter changes by precisely controlling the weight ratio of virgin to recycled material (95:5 to 50:50) and the thickness ratio of inner to outer layer (40:60 to 60:40). By optimizing these parameters, the patent achieves the right balance between transparency and recycling content, making the product commercially viable while maintaining environmental benefits.
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 method enables the formation of transparent resin-made containers with a high recycled material ratio, improving production efficiency and reducing haze to levels comparable to those using 30% recycled material blends.
Implementation Method 1
a cooling process to enhance transparency and production efficiency
Data Source
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AI summary
A preform (10) including: an opening portion (12); a body portion (16); and a bottom portion (18), the preform (10) having a two-layer structure in which the body portion (16) and the bottom portion (18) include an inner layer (22) made of a virgin material and an outer layer (24) made of a recycled material, in which a weight ratio of the recycled material to a total weight of the preform (10) is 50% by weight or more, a ratio of a thickness of the outer layer (24) to a thickness of the inner layer (22) in the body portion (18) is 1.5 or more, and a haze of a body portion (36) of a container (30) molded from the preform (10) is 1.8% or less.