Hollow-body Molding Device Floating Core Thin-Walled Tube Separation
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Solution Overview
Problem
Conventional hollow body molding devices face challenges in easily separating unnecessary portions from the molded body, often introducing foreign matter or forming resin burrs during the separation process.
Innovation Solution
A hollow body molding device is designed to form a thin-walled tube on the inner surface of the floating core accommodating portion, allowing for easier separation of unnecessary portions by hand, while preventing backflow and maintaining resin quality through a core receiving portion with a smaller diameter than the floating core, thus stabilizing the wall thickness and reducing resin burrs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cutting means such as a saw is used to separate the unnecessary portion from the hollow molded body, then the separation can be achieved, but foreign matter is introduced into the hollow molded body or resin burrs are formed
Solution Approach 1:
The mold cavity is segmented into a main cavity for the hollow molded body and a waste cavity for the unnecessary portion, with a communication passage connecting them. The floating core is segmented into a core body and a core tip, where the core tip forms a thin-walled tube structure that facilitates clean separation without introducing foreign matter or burrs.
Solution Approach 2:
The unnecessary portion is extracted into a separate waste cavity through the communication passage during the molding process itself. The thin-walled tube structure formed by the core tip allows the unnecessary portion to be easily removed from the hollow molded body without requiring cutting operations that would introduce foreign matter or burrs.
2Manufacturing precision
If the floating core is received by the core receiving portion, then backflow of molten resin is prevented and wall thickness is stabilized, but the core receiving portion must have a smaller diameter than the floating core
Solution Approach 1:
The core receiving portion is designed with a specific local geometry where its diameter is smaller than the floating core's diameter. This local dimensional difference creates a interference fit that prevents backflow of molten resin and stabilizes wall thickness, while the overall device structure remains relatively simple.
Solution Approach 2:
The core receiving portion is designed in advance with a smaller diameter to preemptively prevent backflow of molten resin from the waste cavity to the main cavity. This preliminary design feature eliminates the need for additional active control mechanisms, maintaining device simplicity while ensuring manufacturing precision.
3Object-affected harmful factors
If the unnecessary portion is separated by hand, then foreign matter and resin burrs are avoided, but the separation process becomes more time-consuming
Solution Approach 1:
The thin-walled tube structure is formed during the molding process itself by the core tip, preliminarily preparing the separation interface. This preliminary action creates a natural separation plane that allows manual removal to be quick and easy, eliminating the need for time-consuming cutting operations while avoiding foreign matter and burrs.
Solution Approach 2:
The molding process itself creates the thin-walled tube structure that facilitates easy separation. The process serves itself by forming the separation feature during manufacturing, eliminating the need for separate cutting operations and enabling rapid manual removal without compromising product quality.
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 solution enables more efficient separation of unnecessary portions from the hollow molded body, improving the appearance by eliminating gate marks and minimizing resin burrs, with the ability to visually confirm the floating core's passage through the main cavity.
Implementation Method 1
the floating core moves through the molten resin injected into the main cavity so as to extrude the molten resin
Implementation Method 2
the floating core cuts off communication between the floating core accommodating portion and the communication passage when the floating core is received by the core receiving portion so that backflow of the molten resin is prevented
Data Source
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AI summary
Provided is a hollow-body molding device whereby unnecessary portions connected to a hollow molded article after molding can be more easily cut away than by the conventional technique. When a floating core 18 pushes out a molten resin 14 and is accommodated in a floating-core accommodating section D, a tube-shaped molten resin 14, i.e., a thin-walled section 10a, having a wall thickness less than the thickness T1 of a hollow molded article 10 is formed by the floating core 18 on an inside wall surface of the floating-core accommodating section D. After molding, the thin-walled section 10a which is a thin-walled tubular portion integrally connected to the hollow molded article 10 molded in a main cavity A and an unnecessary portion molded in a communicating path C is therefore formed in the floating-core accommodating section D, and the unnecessary portion connected to the hollow molded article 10 via the thin-walled section 10a can therefore be more easily cut away by a manual operation or the like than by the conventional technique.