Delamination Container Preform Molding to Prevent Inner Layer Deformation
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Solution Overview
Problem
The challenge in manufacturing delamination containers is the thermal deformation of the inner layer due to the higher melting point of the outer layer resin material during the injection molding process, preventing the use of a continuous one-stage hot parison type blow molding method.
Innovation Solution
The method involves forming the outer layer with a thin film portion and then injecting the inner layer resin material at a lower temperature through the broken thin film portion, followed by blow molding to create a delamination container using a hot parison type blow molding method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the outer layer resin material with higher melting point is filled after inner layer molding, then the outer layer can be formed, but the inner layer surface melts and thermally deforms
Solution Approach 1:
The inner layer is molded first before the outer layer resin material is filled. This preliminary action allows the inner layer to be formed and cooled to a stable temperature state before exposure to high-temperature outer layer material, preventing thermal deformation while maintaining the desired shape
Solution Approach 2:
The filling of outer layer resin material is performed rapidly after inner layer molding is complete. By rushing through the filling process immediately after inner layer formation, the exposure time of the inner layer to high-temperature material is minimized, preventing heat transfer that would cause melting and deformation
2Manufacturing precision
If extrusion blow method is used for delamination container manufacturing, then the process is established, but appearance, dimensional accuracy, and physical strength are inferior
Solution Approach 1:
The injection molding process and blow molding process are merged into a continuous one-stage hot parison type blow molding process. The preform is injection-molded and then immediately blow-molded without separate intermediate steps, eliminating the need for complex multi-stage manufacturing while achieving superior dimensional accuracy and appearance
Solution Approach 2:
The manufacturing process transitions from extrusion blow method to hot parison type blow molding with injection molding. This parameter change in the manufacturing method enables continuous processing that improves dimensional accuracy and physical strength while maintaining ease of manufacture through process integration
3Strength
If one-stage hot parison type blow molding method is used, then appearance, dimensional accuracy, and physical strength improve, but inner layer thermal deformation occurs due to high temperature filling
Solution Approach 1:
The inner layer is molded first in the sequential injection process before outer layer material is filled. This preliminary action ensures the inner layer is formed and stabilized before exposure to high-temperature outer layer material, maintaining inner layer stability while achieving the strength benefits of continuous processing
Solution Approach 2:
The injection molding and blow molding processes are performed continuously in one stage without interruption. This continuous useful action improves physical strength and appearance while the sequential injection of inner then outer layer maintains thermal stability through controlled timing
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 allows for the production of delamination containers with improved appearance, dimensional accuracy, and physical strength while reducing environmental impact by using a single-stage manufacturing process.
Implementation Method 1
the thin film portion is broken by injection pressure of the inner layer resin material
Implementation Method 2
the inner layer resin material having a temperature lower than the melting point of the outer layer resin material
Data Source
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AI summary
A manufacturing method includes an injection molding process of injection-molding a preform (10) having a two-layer structure including an outer layer preform (60) and an inner layer preform (80), and a blow molding process of blow molding the preform (10) to mold a delamination container made of resin. The injection molding process includes an outer layer molding process of filling an outer layer injection mold (50) with PET (outer layer resin material) to mold the outer layer preform (60) and molding a thin film portion (61) in a part of the outer layer preform (60), and an inner layer molding process of injecting PP (inner layer resin material) toward the thin film portion (61) to break the thin film portion (61) and filling an inner layer injection mold (70) with PP having a temperature lower than a melting point of PET via the broken thin film portion (61) to mold the inner layer preform (80).