Syringe production is done on high-performance machines at cycle rates up to 600 syringes per minute. At these cycle rates, the purpose of automatic syringe inspection is to check correct assembly, labeling and filling, as well as to ensure traceability. Smart cameras are mainly used for this, and are delivered in a stainless steel design for usage in the isolator. The design is both application-specific and adapted to the practical possibilities for integration in the machine.
Visualization and operation are usually done centrally on the OCTUMISEr user interface, which is installed either on an individual stainless steel computer, or on the customer's HMI system.
Typical examples of inspection in syringe production are:
- Mounting dimensions
- Plunger assembly
- Misalignment of syringe tops
- Spalling on the finger flange
- LLA inspection
- Syringe length
- Position and printing of labels
- Reading codes
- Completeness in the syringe nest
The purpose of these inspections is to detect defects at an early stage in the machine, thereby avoiding error propagation and any further processing of faulty components. This prevents downtimes cause by a defective product, thereby increasing the efficiency of the machine.
1.1 Dimensional Assembly Inspection
One important assembly dimension to be inspected is the position of the syringe top in respect to the syringe body. To measure this dimension reliably we usually use a back-lighting arrangement and bi-telecentric lenses. The highest reproducibility of the measurement values is achieved by the use of a telecentric lighting as well.
The choice of the camera and also the arrangement of the components for best integration into reduced space on the machine is done application specific. The communication integration is also customer specific, industrial standard interfaces like Profibus, Profinet, dig. IO, EIP etc. can be provided.
1.2 Plunger Assembly Inspection.
One important criterion for plunger assembly inspection is the screw in depth of the plunger rod into the plunger stopper. To be able to measure this dimension reliably the different colors of the components, different filling levels and required tolerances need to be considered for application specific selection and setup of the components. Due to reduced space in the assembly & filling machine an incident light setup is usually chosen for this application.
1.3 Straight fit inspection of the needle guard protection
The angle between the needle guard protection and the syringe body needs to be in between tight tolerances for a perfect assembly. To meet high accuracy demands usually telecentric lenses with a backlighting setups is implemented. Sometimes due to space constrains mirrors need to be used to fit into the assembly machines. To measure the correct angle, a setup of at least two cameras needs to be used and of course appropriate mathematics.
1.4 Spalling Inspection on the Finger Flange
Spalling on the finger flange may harm the medical expert staff when handling the syringes and as such need to be detected during assembly before shipment.
For the automated inspection of the finger flange for such defects a special incident lighting setup is implemented to enable good contrasts for the finger flange edges and shapes. The image processing software used, compensates the usual variations in shape, size and appearance of the finger flanges leading to reliable inspection results. Therefore the individual finger flange types need to be trained once. The system is configurable so that different flange types may be inspected with adjustable inspection criteria and tolerances.
1.5 LLA inspection
For a faultless syringe, the Luer Lock Adapter (LLA for short) must not have any breakouts on the "wing". This is also ensured by an automatic inspection.
Depending on the mechanical situation, a transmitted light arrangement is implemented directly or indirectly in order to achieve a picture which is as rich as possible.
The evaluation is carried out in the gray scale by means of pattern comparison and by means of measurement functions. For each LLA format, a specific test procedure is stored, which is called upon format change.
The format can be changed directly from the HMI system of the machine via the implemented interfaces.
1.6 Syringe length
The total length of the syringe with attachment is automatically measured and classified according to customer requirements. Depending on the format and length range, either a high-resolution camera or two normal-resolution cameras with telecentric optics are used.
A telecentric transmitted light illumination is also required for the length measurement since otherwise the repeatability is not sufficient. Depending on the mechanical situation, deflection mirrors can also be necessary for the appropriate machine integration.
1.7 Position and printing of labels
The control of the variable data of the syringe label on readability and correctness on the basis of the production specifications is an essential component for the safe handling of the medicinal products.
The label data are available as both plain text and machine readable code as 1D or 2D code. The label inspection includes both inspections, ie OCR / OCV and code reading.
For a safe reading of the codes and signs, a minimum resolution of the camera system is necessary - this is designed to suit the application. Particularly in the combination of plaintext and codes, a high computing power is necessary in order to carry out the inspections step by step.
Position after application or control during application, a transmitted light or incident light arrangement may be necessary. Depending on customer requirements, the absolute positions or deviations from a format-specific setpoint position are determined and transferred to the controller.
1.8 Reading codes
In addition to the identification of the encodings on the label, an identification of directly-marked codes on e.g. On the injection test or tub for a reliable assignment in the production and / or traceability necessary. As a rule, intelligent cameras with specific lighting are also used in stainless steel construction when mounted in the insulator.
Data validation according to GS1 or SecurPharm is implemented and tested. The standard interfaces can also be used for PLC communication or line integration.
1.9 Completeness in the syringe nest
For the inspection of the complete filling of the injection test, a high-resolution camera with a specific LED incident light is used.
The necessary large-area illumination under the confined space conditions in the machine is a constructive challenge. Here the 3D construction helps to start the project which OCTUM provides as standard.
Depending on the specification, an IO or NIO signal can be output as well as the faulty position in the nest.