Syringe with Integrated Closure Element via Multi-Tool Injection Molding
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Solution Overview
Problem
The production of prefilled plastic syringes with integrated closure elements is costly and prone to contamination due to the need for separate manufacturing steps and subsequent mounting of closures, which increases cycle times and requires sophisticated automation.
Innovation Solution
An injection molding process that integrates a closure element directly onto the syringe body using a multi-tool system, where two plastic materials form a form-locking connection without a cohesive bond, allowing for a detachable and tamper-evident closure element to be formed in a single production step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a closure element is mounted on the syringe during production, then the syringe is sealed, but the production cost increases and cycle time extends
Solution Approach 1:
The closure element is integrated directly into the syringe body through a single injection molding process, combining two separate manufacturing steps (syringe production and closure mounting) into one continuous operation, thereby eliminating the need for separate closure mounting equipment and reducing cycle time
2Reliability
If a closure element is mounted on the syringe during production, then the syringe is sealed, but the equipment complexity increases
Solution Approach 1:
The injection molding tool is designed with multiple cavities that simultaneously form both the syringe body and the closure element in one operation, eliminating the need for separate closure mounting equipment and reducing overall system complexity
Solution Approach 2:
The closure element is pre-formed within the injection molding tool along with the syringe body, so that when the syringe is ejected, the closure element is already attached and ready for use, eliminating the need for subsequent mounting operations
3Ease of manufacture
If the syringe is open at the start of processing, then filling is enabled, but contamination risk increases
Solution Approach 1:
The closure element is integrated into the syringe body during the injection molding process, sealing the syringe immediately upon ejection from the mold, thereby preventing contamination before the syringe is transported to the filling station where it is subsequently opened
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 simplifies and cost-reduces the production of syringes by eliminating the need for separate closure manufacturing, reduces contamination risks, and provides a tamper-evident feature, enhancing safety and efficiency.
Implementation Method 1
a) providing an injection moulding tool which comprises a first, a second and a third tool portion, wherein the first tool portion has a mould cavity open at both sides
Implementation Method 2
c) injecting a first plastic material into the first cavity, as a result of which a hollow cylindrical syringe body is formed
Implementation Method 3
d) cooling the tool portions, as a result of which the syringe body cools and hardens
Implementation Method 4
wherein the first and the second plastic material do not enter into a cohesive connection
Data Source
AI summary
The invention relates to a method for producing a syringe with an integrated closure element, which method comprises the following method steps:a) making available an injection moulding tool which comprises a first, a second and a third tool portion, wherein the first tool portion has a mould cavity open at both sides and extending along an axial direction (X), and wherein the second tool portion has a first injection moulding core and the third tool portion has a second injection moulding core;b) closing the injection moulding tool such that the first tool portion contacts the second and third tool portion, and the first and second injection moulding core each enter the mould cavity of the first tool portion through an opening and finally contact each other, as a result of which these tool portions form a first structural cavity;c) injecting a first plastic material into the first structural cavity, as a result of which a hollow cylindrical syringe body is formed with an end region at its distal end, wherein the end region has an attachment element, provided with an inner thread, and a hollow cylindrical endpiece which is at least partially bounded by the attachment element;d) cooling the tool portions, as a result of which the syringe body cools and hardens;e) bringing the first tool portion into contact with a fourth tool portion provided with a mould cavity closed at one end, as a result of which a second structural cavity is formed at the distal end of the syringe body;f) injecting a second plastic material into the second structural cavity, as a result of which the closure element is integrally formed on the attachment element, wherein the first and the second plastic material do not enter into a cohesive connection.