A world's first 112 pressure sensors in a single mold

Kistler integrates online quality assurance into a 96-cavity mold for medical technology

Kistler Instrumente AG is currently fitting two 96-cavity molds for the production of insulin pen components with pressure sensors for quality assurance. Each of the 96 cavities and each of the 16 manifolds will be equipped with a sensor, such that each mold will come with a total of 112 sensors. The objective of using mold cavity pressure sensors in injection molding these polypropylene components is to establish automatic 100 % quality assurance and thus to ensure zero-defect production.

With a front diameter of only 1 mm, the Type 6183A… sensors are the smallest so far used for cavity pressure measurement. The mold maker adapts the front ends of the sensors to the contours of the cavity wall, using erosion technology to fit both the sensors and the mold inserts.

It is only due to Kistler's single-wire technology that 112 sensors can be integrated into such a compact and complex mold. The cut-and-grip technique permits the sensor cables to be fitted and removed quickly and easily without any additional tooling.

Specially developed high channel charge amplifiers transmit the measurement data digitally to the Dataflow process analysis system, which offers functions for the visualization, monitoring and documentation of injection molding processes based on the cavity pressure curve. As with other Kistler systems, Dataflow monitors changes in cavity pressure in all cavities cycle by cycle. Parts that are identified as defective or non conforming are removed through activation of reject diverters or robots.

Background: the cavity pressure curve

In injection molding, the cavity pressure curve serves as the fingerprint for the forming of molded parts and is the most significant value for the assessment of part quality.

As the supplier of the world's largest and widest range of sensors for all injection molding techniques, a simple connection technology and networkable systems that are intuitively easy to operate, Kistler is the only manufacturer offering a one-stop shop for tools for integrated monitoring in the field of injection molding. Kistler is the world's leading manufacturer of pressure and temperature sensors for use in the plastics processing industry.

Kistler Group

Kistler’s core competence is the development, production and use of sensors for measuring pressure, force, torque and acceleration. Kistler’s know-how and electronic systems can be used to prepare measuring signals for use in analyzing physical processes, controlling and optimizing industrial processes, improving product quality in manufacturing and improving performance in sports and rehabilitation.

Kistler offers a comprehensive range of sensors and systems for engine development, automotive engineering, plastics and metal processing, installation technology and biomechanics.

A worldwide sales presence in the form of 23 group companies and 30 distributors ensures customer proximity, application support on an individual level and short lead times.

With a staff of 820, the Kistler Group is one of the world’s leading providers of dynamic measuring instrumentation. The Kistler Group achieved turnover of 195 million Swiss Francs in the 2007 financial year.