Dual-Structure Container With Contraction-Control Grooves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing dual-structure containers, such as the stack preform method, face challenges with irregular contraction of the inner bag container during content liquid discharge, leading to difficulties in stable liquid discharge due to irregular deformation and potential blockage of the discharge passage.
Innovation Solution
The use of an inner bag container preform with contraction-control grooves formed on its surface, which are thinner than the rest of the container, allows for controlled contraction during liquid discharge, preventing irregular deformation and maintaining a stable discharge passage by simultaneous stretch-blow molding using the stack preform method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the inner bag container is made with uniform thickness, then the manufacturing process is simple, but the contraction becomes irregular causing passage blockage
Solution Approach 1:
The inner bag container is designed with non-uniform wall thickness, featuring thinner portions at specific locations (such as the bottom and sides) and thicker portions at other locations. This local variation in thickness allows the thinner areas to contract more easily and regularly during discharge, preventing passage blockage while maintaining manufacturing feasibility through injection molding with varied wall thickness specifications
2Quantity of substance
If the inner bag container contracts irregularly, then the container can accommodate discharged liquid volume, but the discharge passage gets crushed and blockage occurs
Solution Approach 1:
By creating localized thin portions in the inner bag container wall, the design enables these specific areas to serve as contraction zones that maintain the discharge passage open. The thinner walls flex and contract in a controlled manner that accommodates volume changes without crushing the passage, ensuring continuous discharge functionality
3Device complexity
If direct blow-molding is used to produce dual-structure container, then the production steps are integrated, but multi-cavity molding is difficult and productivity is low
Solution Approach 1:
The dual-structure container is divided into two separate preforms (inner bag preform and outer container preform) that are molded independently in multi-cavity molds. These preforms are then assembled by inserting one into the other, allowing simultaneous production of multiple containers while maintaining the integrated structure 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
This approach effectively stabilizes the discharge of the content liquid by controlling the contraction of the inner bag container, preventing passage blockage and ensuring continuous and smooth liquid discharge, while also simplifying the manufacturing process by avoiding complex mold structures and operations.
Implementation Method 1
simultaneous stretch-blow molding
Data Source
Figure 1(a)~2
Figure 3~4
Figure 5(a)~5(b)
AI summary
The present invention provides a dual-structure container to control contraction of an inner bag container so as to effectively solve a problem of difficulty in discharge of a content liquid, which may occur during discharge of the content liquid. The dual-structure container of the present invention includes an inner bag container 31 and an outer container 41 obtained by simultaneous stretch-blow molding according to a stack preform method using an inner bag container preform 1 and an outer container preform 3. On a body 33 of the inner bag container 31, contraction-control thin portions 50 are formed at a plurality of sites at intervals in the circumferential direction such that the thin portions 50 extend like strips in the axial direction.