Multilayer Blow Bottle with Segmented Blackness for Molding
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Solution Overview
Problem
Existing injection blow molding methods face challenges in stably molding multilayer blow-molded bottles due to difficulties in heat transfer and moldability, particularly when the outer layer has high blackness, leading to inefficient heating control and reduced moldability.
Innovation Solution
A multilayer blow-molded bottle is created using a two-layer preform with an outer layer and an inner layer, where the outer layer is made of materials like polyethylene terephthalate with added pigments to achieve a gray color and high injection blowability, and the inner layer is made of polyolefin resins with higher blackness, allowing for efficient heat transfer and separation, and using near-infrared heaters for uniform heating during the molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the outer layer is made with high blackness materials to improve heat absorption, then heating efficiency is improved, but heat transfer control becomes difficult and moldability deteriorates
Solution Approach 1:
The bottle is divided into two distinct layers: an outer layer with high blackness (carbon black) for efficient heat absorption and an inner layer with low blackness for uniform heat transfer. This segmentation allows each layer to perform its specific function optimally without interfering with the other, resolving the contradiction between heating efficiency and moldability.
Solution Approach 2:
Different regions of the bottle wall are given different optical properties: the outer layer has high blackness concentrated in specific areas to maximize heat absorption where needed, while the inner layer maintains low blackness throughout for consistent heat distribution. This local differentiation of properties enables simultaneous optimization of heating efficiency and heat transfer control.
2Temperature
If carbon black is added to the outer layer to improve heat absorption, then heating performance is improved, but heat transfer uniformity deteriorates
Solution Approach 1:
The multilayer structure segments the heat transfer function across two layers: the outer layer with carbon black handles heat absorption, while the inner layer without carbon black handles uniform heat distribution. This functional segmentation resolves the contradiction between heating performance and heat transfer uniformity.
Solution Approach 2:
The inner layer acts as an intermediary between the outer heat-absorbing layer and the core of the bottle. It receives heat from the outer layer and redistributes it uniformly throughout the bottle wall, preventing localized overheating and ensuring consistent heating performance.
3Use of energy by moving object
If the outer layer has high blackness to improve heat absorption, then energy efficiency is improved, but control precision deteriorates
Solution Approach 1:
By segmenting the bottle into outer and inner layers with different optical properties, the system achieves high energy efficiency through the outer layer's carbon black while maintaining precise heating control through the inner layer's uniform heat distribution capability, which prevents localized thermal hotspots.
Solution Approach 2:
The invention changes the optical parameters (blackness) of different layers to achieve the desired balance: the outer layer has high blackness for energy efficiency, while the inner layer has low blackness for precise temperature control. This parameter differentiation resolves the contradiction between energy efficiency and control precision.
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 enhances the moldability and stability of the blow-molded bottles by optimizing heat transfer and maintaining the desired thickness and rigidity, enabling the production of bottles with improved structural integrity and flexibility.
Implementation Method 1
an infrared absorbing material such as carbon black is added to an inner layer to reduce a temperature difference between inner and outer layers
Implementation Method 2
using near-infrared heaters for uniform heating during the molding process
Implementation Method 3
The preform is then molded into a desired shape by blowing air into the preform which is heated
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
A blow bottle (12) includes an outer layer (13) and an inner layer (14), wherein the inner layer has blackness higher than that of the outer layer, and wherein the outer layer has an L* value of 20 or more and 90 or less in an International Commission on Illumination (CIE) L*a*b* color system.