Precision on a Millimeter Scale: How a Tiny Silicone Tube Improves Drug Delivery Safety
A 5 mm silicone tube with a 0.25 mm bore—manufactured via micro injection molding with ± 0.03 mm tolerances. How Hepako helped a U.S. customer go from prototype to qualification in just 6 weeks: a real-world case from the field of medical technology.
In modern infusion and dosing systems, precision is paramount. Even the slightest deviations in flow rate can have serious consequences when administering highly potent medications. At the same time, requirements for miniaturization, biocompatibility, and process reliability are constantly increasing – especially in the field of medical technology.
A recent project illustrates how specialized manufacturing partners like Hepako from Germany can reliably meet these demands – even under time pressure and with complex technical requirements.
The Challenge: A Tiny Silicone Tube with Tight Tolerances
A U.S.-based manufacturer of infusion systems approached Hepako with a demanding task: as part of the development of a new device for microdosing liquid medications, a small silicone component was needed that would serve as a flow restrictor within a control circuit.
The specifications were exceptional:
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Length approx. 5 mm
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Inner bore only 0.25 mm
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Outer diameter in the low millimeter range
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Tolerances of ± 0.03 mm to ± 0.05 mm
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Material: high-purity silicone, 50 ± 5 Shore A
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Biocompatible per ISO 10993, autoclavable, and reliably manufacturable
The customer also faced significant time pressure – initial prototypes were required within just a few weeks to conduct early functional testing.
Why Silicone Was the Right Choice
Silicone offers decisive advantages over thermoplastic materials for drug dosing applications:
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Excellent elasticity and dimensional stability, even at very small wall thicknesses
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High resistance to temperature and aging, ideal for autoclavable components
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Biocompatibility and chemical resistance to the media being conveyed
The challenge was to combine these material advantages with a cost-effective and reproducible manufacturing technology – under tight tolerances and strict deadlines.
Implementation: From Prototype Tooling to Series Production
The customer chose Hepako as a project partner due to its expertise in micro injection molding of elastomer parts. Micro injection molding not only enables precise reproducibility, but also clean processing under controlled conditions – a crucial factor for medical components.
Phase 1: Prototyping with Near-Series Tooling
Within just four weeks, a single-cavity prototype tool was developed, allowing the production of 1,000 near-series prototypes. Thanks to Hepako’s in-house tooling competence and short internal communication paths, the ambitious timeline was met.
Phase 2: Testing and Design Optimization
Following the first round of device-level testing, the customer requested a geometry adjustment to optimize flow characteristics. This was quickly implemented in the prototype tool without disrupting the project timeline.
Phase 3: Transition to Series Production
After successful testing, a multi-cavity tool was developed and manufactured for series production within six weeks. Initial orders for parts from the series tool followed soon after – enabling the customer to begin their qualification and approval processes with the desired production-level parts just weeks after project initiation.
Result: A Tiny Component with a Big Impact
The result is a barely visible, highly precise component that performs a critical function within a medical device. Despite its small size, the silicone tube is key to ensuring safe and reproducible drug delivery – a strong example of how millimeter-scale precision in injection molding contributes to medical safety.
The customer benefited from fast prototype availability, flexible design adjustments, and a smooth transition to series production – a clear advantage in a fast-moving innovation-driven industry.
Result: A Tiny Component with a Big Impact
The result is a barely visible, highly precise component that performs a critical function within a medical device. Despite its small size, the silicone tube is key to ensuring safe and reproducible drug delivery – a strong example of how millimeter-scale precision in injection molding contributes to medical safety.
The customer benefited from fast prototype availability, flexible design adjustments, and a smooth transition to series production – a clear advantage in a fast-moving innovation-driven industry.
Outlook: Miniaturization as a Key Trend
Demand for tiny, functional components made of silicone and rubber is increasing – not only in medical technology but also in diagnostics, sensing, and micromechanics. Developing such parts requires more than just processing know-how:
It calls for partners who combine materials expertise, tooling technology, and process understanding – and who can deliver stable, scalable solutions even under challenging timelines.
Conclusion: Technical Expertise and Partnership-Based Collaboration
This project exemplifies what is possible when a specialized contract manufacturer and an innovative medical technology company work together. For Hepako, realizing this tiny silicone tube was not a standard job but another opportunity to demonstrate its ability to deliver fast, reliable solutions even under demanding conditions.
With nearly 50 years of experience in processing silicone and rubber molded parts, including numerous medical projects, Hepako remains a trusted partner for companies seeking precision, flexibility, and technical depth – whether in the smallest millimeter range or beyond.
Hepako GmbH
Gewerbegebiet 7
82399 Raisting, DE