Two-Component Molding for Adhesive-Bonded Injection Device Housings
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Solution Overview
Problem
Existing methods for manufacturing parts and assemblies for drug delivery devices are cumbersome and expensive, particularly in applying adhesives using printing or masking techniques, and struggle with producing semi-finished goods that can be stored and assembled at different locations.
Innovation Solution
A method using two-component injection molding to selectively apply adhesive materials onto specific regions of housing parts, which are then activated using heat or other means to create a strong, irreversible bond between parts without excess adhesive material being expelled, allowing for efficient and reliable assembly of drug delivery device components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If adhesive material is applied using printing or masking techniques, then adhesive can be deposited on specific areas, but the process becomes cumbersome and expensive
Solution Approach 1:
The patent combines the adhesive application process with the injection molding process by integrating an adhesive reservoir and delivery system directly into the mold. This eliminates the need for separate printing or masking steps, reducing process complexity while maintaining precise adhesive deposition on specific areas of the part.
Solution Approach 2:
The adhesive is pre-loaded into reservoirs that are integrated into the mold before the injection molding process begins. This preliminary preparation allows the adhesive to be automatically dispensed in precise amounts during molding, eliminating the need for complex post-processing adhesive application steps.
2Manufacturing precision
If adhesive is applied on first part using printing devices or masking techniques, then adhesive can be placed in selected areas, but production cost increases
Solution Approach 1:
The patent merges adhesive application with injection molding by integrating adhesive reservoirs and delivery channels into the mold structure. This combination eliminates expensive separate adhesive application equipment and reduces overall manufacturing costs while maintaining precise adhesive placement in selected areas.
Solution Approach 2:
The mold structure itself provides the adhesive application function through integrated reservoirs and delivery systems. The mold automatically dispenses adhesive to the correct locations during the injection process without requiring external printing devices or masking materials, reducing manufacturing costs.
3Productivity
If adhesive layer is applied and parts are assembled immediately, then assembly is efficient, but parts cannot be stored as semi-finished goods
Solution Approach 1:
The adhesive is applied in a dormant or pre-positioned state during injection molding, allowing parts to be produced as semi-finished goods and stored for later assembly. The adhesive remains in the molded part ready for activation when needed, enabling both storage capability and efficient final assembly.
Solution Approach 2:
The manufacturing process is segmented into separate stages: adhesive-containing part production, storage of semi-finished parts, and final assembly with adhesive activation. This segmentation allows parts to be stored as semi-finished goods while maintaining the option for efficient assembly when required.
4Strength
If excess adhesive material is present during bonding, then strong bond is achieved, but adhesive is expelled and causes mechanical interference
Solution Approach 1:
The patent uses localized adhesive reservoirs positioned at specific bonding interfaces rather than applying adhesive broadly. This local quality approach ensures adhesive is present only where needed for bonding, providing sufficient bond strength while preventing excess adhesive from being expelled and causing mechanical interference.
Solution Approach 2:
The injection molding process acts as an intermediary that precisely controls adhesive placement and distribution. The mold structure mediates between the adhesive material and the bonding surfaces, ensuring optimal adhesive quantity and distribution for strong bonds without excess that would cause interference.
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 enables efficient, reliable, and cost-effective assembly of drug delivery device components by ensuring no adhesive material is expelled during bonding, preventing mechanical interference and allowing for storage and assembly of semi-finished parts at different locations, meeting production and economic requirements.
Implementation Method 1
The adhesive material is then activated by any suitable means such as heat, induction, ultrasonic vibration, irradiation or the like
Implementation Method 2
The adhesive material is then activated by any suitable means such as heat, induction, ultrasonic vibration, irradiation or the like
Data Source
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AI summary
A method for injection molding at least one first part for an injection device comprising the steps of: A) Injecting a first molding material into a first injection mold to shape the first part whereby the first molding material preferably is a plastic material having non-adhesive properties, B) Providing a second molding material having adhesive properties upon activation, C) Injecting the second molding material into the first injection mold containing the first part or into a second injection mold after the first part has been transferred from the first mold to the second mold, whereby the second molding material is injected onto or around the first part at a location which is intended for adhesive connection between the first part and a second part, whereby the location is in the overlap area between the first part and the second part once the first part and second part have been joined together.