Single-Layer Hollow Container Compression Stretch Blow Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for manufacturing single-layer hollow containers with excellent oxygen and solvent barrier properties are limited by the direct blow method, which restricts productivity and fails to meet strict barrier property conditions, especially when using resin compositions like those disclosed in PTL 1.
Innovation Solution
A compression stretch blow method is employed, involving the formation of a preform by compression-molding a resin composition of polyolefin, meta-xylylene group-containing polyamides, and modified polyolefin, followed by stretching and blow-molding, to achieve a single-layer hollow container with improved barrier properties and increased productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the direct blow method is used to manufacture single-layer hollow containers with barrier properties, then oxygen and solvent barrier properties are improved, but productivity is restricted and manufacturing efficiency decreases
Solution Approach 1:
The patent changes the molding parameters by switching from direct blow molding to compression stretch blow molding. This parameter change enables the resin composition to form a layered structure during the stretching process, achieving excellent barrier properties while significantly improving productivity compared to the direct blow method.
Solution Approach 2:
The patent uses a composite resin composition containing polyolefin, meta-xylylene group-containing polyamide (5-35 mass%), and modified polyolefin. This composite material structure, when processed through compression stretch blow molding, creates a single-layer hollow container with both excellent barrier properties and high productivity.
2Reliability
If the direct blow method is used to manufacture single-layer hollow containers, then oxygen barrier properties are improved, but the ability to meet strict barrier property conditions is insufficient
Solution Approach 1:
The compression stretch blow molding process introduces additional control parameters (stretching ratio, heating temperature, molding pressure) that enable precise control over the final barrier properties. The stretching process creates a specific molecular orientation and layered structure that enhances oxygen barrier performance and allows meeting strict barrier property conditions.
3Ease of manufacture
If polyolefin is used as the base material for hollow containers, then ease of manufacture and processing are improved, but oxygen barrier properties deteriorate
Solution Approach 1:
The patent creates a composite material system where polyolefin (60-90 mass%) provides ease of manufacture and processing, while meta-xylylene group-containing polyamide (5-35 mass%) provides excellent oxygen barrier properties. The modified polyolefin component facilitates compatibility between the two materials. This composite approach maintains the processing advantages of polyolefin while achieving the barrier properties needed for oxygen-sensitive packaging.
4Device complexity
If a single-layer structure is used for hollow containers, then device complexity is reduced and manufacturing is simplified, but achieving both productivity and barrier properties is difficult
Solution Approach 1:
The patent achieves the dual goal of simplicity and productivity by changing the molding parameters to compression stretch blow molding. This single-layer structure with optimized processing parameters eliminates the need for complex multi-layer coextrusion equipment while achieving both high productivity and excellent barrier properties through the stretching-induced molecular orientation and layered morphology.
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 enhances oxygen and solvent barrier properties, allowing for the production of single-layer hollow containers with reduced oxygen permeability and improved solvent resistance, while significantly increasing productivity compared to traditional direct blow methods.
Implementation Method 1
a resin composition obtained by melting and mixing polyolefin, meta-xylylene group-containing polyamides, and modified polyolefin
Implementation Method 2
a step of stretching the preform
Implementation Method 3
a step of blow-molding the stretched preform
Data Source
Figure 1A~1C
Figure 1D~1E
Figure 2A~2B
AI summary
A single-layer hollow container includes: a resin composition that is formed of 60 to 90% by mass of polyolefin, 2 to 35% by mass of meta-xylylene group-containing polyamides, and 5 to 30% by mass of modified polyolefin. The meta-xylylene group-containing polyamides are dispersed insularly in the polyolefin, and in a case where each of a vertical length and a horizontal length of the meta-xylylene group-containing polyamide in an initial state is 1, the vertical length of the meta-xylylene group-containing polyamide in the hollow container ranges from 3.3 to 15.8 and the horizontal length ranges from 0.5 to 2.0.