More safety, less waste: Intelligent joining technology for the assembly of injection systems

Injection systems such as insulin pens, auto-injectors, and disposable syringes are now part of everyday medical care. However, their assembly determines whether a product can be used reliably and safely. Conventional joining technologies quickly reach their limits here—especially when it comes to documented quality, reproducible processes, and high flexibility. PROMESS assembly presses offer a modern, process-reliable solution that not only works more precisely but also more intelligently – a real step forward for manufacturers of medical technology systems.

The growing challenges in the assembly of injection systems: High demands on precision and traceability

The assembly of medical technology products – especially injection systems – is a sensitive process. Each component must be positioned precisely and joined with a defined force. Even the slightest deviations can cause a product to malfunction – with potentially serious consequences for the user.

Manufacturers today face several challenges:

• Increasing product complexity: Modern injection systems consist of many components—plastic parts, springs, needles, pistons, etc.—that must be assembled with precision.
• High regulatory requirements: Standards such as ISO 13485 and FDA requirements demand complete traceability and comprehensive process documentation.
• Cost pressure and efficiency requirements: Despite growing quality demands, processes must remain economical.
• Lack of transparency in conventional joining systems: Pneumatic presses or mechanical devices make it almost impossible to monitor or trace individual joining processes. Errors go unnoticed or are only discovered during time-consuming final inspections.

This problem is particularly evident in automated assembly lines, where hundreds of products are manufactured per hour. If the process is not monitored, serial errors can render entire batches unusable – resulting in high economic losses and a risk to patient safety.

The solution: NC assembly presses – precise, intelligent, validatable

PROMESS offers a solution for monitoring and controlling joining processes with its NC joining systems. The modules combine an electric servo drive with integrated force and position measurement. An intelligent control system records all measurement data during the joining process in real time and evaluates it. This allows both the assembly and the quality of the joined component to be monitored.

How does the system work in practice?

A simple example: When assembling an autoinjector, the inner carrier must be inserted into the housing with a spring. The spring must not be damaged and the housing must not be overloaded. PROMESS assembly presses enable:

• Precise positioning of components through controlled movement of the press punch.
• Real-time force monitoring: If the resistance during pressing is too high or too low, the process is stopped.
• Complete documentation of each individual joining process with time stamp, force-displacement curve, and OK/NOK evaluation.
• Integration into existing control and quality assurance systems via interfaces (e.g., OPC UA, Profinet).

Advantages over conventional joining systems

Compared to conventional pneumatic or hydraulic joining systems, PROMESS assembly presses offer a number of technical advantages. A key feature is the high level of process reliability thanks to integrated real-time monitoring. While conventional systems merely execute movements without monitoring the process, the electromechanical assembly presses continuously record force and position parameters. This ensures complete process and result transparency, enabling the early detection of defective or incorrectly positioned components.

In addition, the modules meet the requirements for validatability and traceability, as required in particular in regulated industries such as medical technology. All process data is automatically and completely documented. Each individual joining process is clearly traceable and can be reliably reconstructed if necessary, for example in the context of audits or recall campaigns.

The modular architecture allows different product variants to be manufactured on a single system. Process parameters such as force and position specifications can be adjusted via the software, eliminating the need for mechanical retooling. This significantly reduces setup times, increases productivity, and lowers operating costs.

Finally, the electromechanical joining systems also contribute to increased sustainability and cost-effectiveness. By reducing scrap, rework, and manual inspection, the investment usually pays for itself in a short time. In addition, energy consumption is significantly lower compared to pneumatic solutions, as the electric drive only requires energy when a joining operation is actually being performed.

Practical application examples

Assembly of insulin pens: The cap must fit

When assembling insulin pens, for example, the cap must be positioned precisely and locked into place. Too much force can damage the mechanism, while too little force results in an inadequate hold. With PROMESS, the force-displacement curve can be monitored precisely. Incorrect locking is detected immediately and the affected product is automatically ejected.

Spring tension in autoinjectors: Reliable and reproducible

The correct preload of the spring in the injection mechanism is essential. Too little tension and the active ingredient will not be injected. Too much and the device becomes difficult to control. PROMESS enables precise adjustment and monitoring of the joining parameters during spring integration. The results: consistent quality, less scrap, and maximum safety for the patient.

Integration into modern production lines

PROMESS assembly presses are designed for use in automated production lines. They can be easily integrated into PLC or MES systems via standardized interfaces. The associated software platform allows the user to:

• Configure and save joining profiles
• Define tolerance windows
• Perform quality evaluations in real time
• Generate reports for quality assurance or audit documentation

Conclusion: Joining technology with vision for greater safety in medical technology

The assembly of injection systems is more than just putting components together. It is a highly sensitive, validated process with a direct impact on product quality and thus on patient safety. NC assembly presses from PROMESS offer a future-proof solution that helps manufacturers meet regulatory requirements and produce cost-effectively. Intelligent assembly technology not only secures processes, it also builds trust: in the product, the manufacturer and ultimately in medical care itself.