Delamination Container Two-Layer Injection Molding Residual Heat
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Solution Overview
Problem
The existing methods for manufacturing delamination containers face challenges in achieving a successful two-layer structure due to thermal deformation of the inner layer when the outer layer with a higher melting point is injected, leading to difficulties in weldability and potential misalignment between the layers.
Innovation Solution
A manufacturing method involving two-stage injection molding followed by blow molding, where the first layer is injection-molded from a resin with a higher melting point, and the second layer is injection-molded on the inner side of the first layer from a resin with a lower melting point, utilizing residual heat to facilitate the blow molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer layer is injection-molded at high temperature to achieve good weldability, then the weldability between layers is improved, but the inner layer undergoes thermal deformation and melts
Solution Approach 1:
The patent changes the temperature parameter by using residual heat from the first injection molding step instead of additional heating. The outer layer is injection-molded utilizing the heat already present in the preform, thereby achieving weldability without subjecting the inner layer to excessive thermal conditions that would cause deformation or melting
Solution Approach 2:
The inner layer is pre-formed with appropriate thermal properties during the first injection molding step. The preform is designed to have sufficient residual heat that can be utilized in the subsequent outer layer injection, eliminating the need for reheating and preventing thermal damage to the inner layer
2Manufacturing precision
If the inner layer is strongly fixed to the core mold to prevent misalignment, then the positional accuracy is improved, but the weldability between layers deteriorates
Solution Approach 1:
The patent changes the thermal parameter by maintaining appropriate temperature conditions during injection molding. The outer layer is injected while the inner layer retains residual heat, ensuring good weldability without requiring strong mechanical fixation that would compromise positional accuracy
3Stability of the object's composition
If cooling is applied between injection molding and blow molding to prevent deformation, then the shape stability is improved, but the manufacturing cycle time increases
Solution Approach 1:
The patent applies the self-service principle by utilizing the residual heat from injection molding directly for the blow molding step. The preform maintains sufficient heat from the injection process to enable subsequent blow molding without requiring external heating or cooling interventions, thereby maintaining shape stability while minimizing cycle time
Solution Approach 2:
The manufacturing process maintains continuous useful action by transitioning directly from injection molding to blow molding while the preform still retains residual heat. This eliminates idle cooling time and keeps the material in a suitable state for forming throughout the process
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 method allows for the successful production of delamination containers with a two-layer structure, enhancing aesthetic appearance, physical property strength, and reducing the risk of misalignment and thermal deformation, while also shortening the manufacturing cycle compared to cold parison blow molding.
Implementation Method 1
a first injection molding step of injection-molding a first layer of a preform having a bottomed cylindrical shape from a first resin material
Implementation Method 2
a second injection molding step of injecting a second resin material different from the first resin material to form a second layer on an inner peripheral side of the first layer
Implementation Method 3
a blow molding step of blow-molding, in a state of having residual heat from injection molding, the preform obtained in the second injection molding step
Data Source
AI summary
In a manufacturing method for a delamination method, in a second injection molding including forming a second layer on an inner peripheral side of a first layer of a preform having a bottomed cylindrical shape, a second resin material is guided from an opening portion formed in the first layer toward the inner peripheral side of the first layer, and a locking portion protruding from the opening portion toward an outer peripheral side of the first layer is integrally formed with the second layer.