Quality control of medical pipettes

Very high speed dimensional and aspect checks

Medical Industry

The quality control and sorting system for medical pipettes

A qmt measuring station

Pipettes are used in the medical industry to perform small volume assays. To guarantee the precision of this dosage, the pipette tips must have a geometry as well as a perfect surface condition.

The production process by plastic injection of pipettes does not allow total control of quality. 100% automatic control is therefore necessary

qmt has developed the qmtsort-tip measuring station for testing plastic pipettes. This checks the dimensions as well as the surface condition of the products leaving the injection machine at a rate of 20 pipettes per second.

OEM products

Documentation

qmtsort-tip pipette measuring station

qmt has developed and industrializes the qmtsort-tip station for 100% quality control of medical pipettes. To guarantee the precision of this dosage, the pipette tips must have a geometry as well as a perfect surface finish.

The product and controls

qmtsort-tip controls the following 7 parameters for each tip:

Mes04: Surface homogeneity
Mes06: Presence of injection burrs inside the tip
Mes07: Presence of a filter

Typical pipette tip dimensions are 0.5mm inside diameter (+0.050/0 tolerances) and 0.9mm outside diameter (+0.025/-0.025 tolerances).

The measuring station

The pipettes are packaged in racks, a motorized system comprising two servomotors performs the movements in order to allow scanning. In order to guarantee an optimal cycle time, qmtsort-tip includes six optical assemblies which work in parallel and are synchronized with the movement of the two axes (see diagram below). The control of a rack of 120 probes therefore represents the acquisition and processing of 120 images involving 840 results (7 controls per probe).

The system includes standard LED diascopic illumination and 6 incidental illuminations developed specifically for this application in order to guarantee very high power and a small footprint.

The integrated computer system communicates with the entire machine through opto-isolated 24VDC digital lines and an OPC server for reference selection and traceability management.

qmtsort-tip software

The control and supervision software has been developed to be used by operators without specific IT skills. It is multi-language and the user interface is graphical only.

The qmtsort-tip software includes an easy-to-use control (reference) program creation mode so that customers can create custom programs. The control programs are memorized and can therefore be recalled during subsequent productions.

The qmtsort-tip software allows the saving of the results as well as the images in order to allow a follow-up of the production history as well as an understanding of the detected defects.

qmtsort-tip was born from a collaboration with Zubler

qmtsort-tip is a product developed together with Zubler Handling AG within the framework. It is standardized to be installed on Zubler automatic lines. qmtsort-tip is a measurement station , therefore a sub-assembly which is integrated into a complete machine. It includes hardware, software and hardware.

Findings

qmtsort-tip is a product that meets a very strong demand. It has been deployed successfully for more than 10 years with installations in Switzerland, Germany and the United States.