Quality Needles — one of the world’s leading medical-needle producers and exporters, specialising in the manufacture
of surgical suture needles — is using a fast high-accuracy CMM with a laser scanner for inspecting its in-house-produced tools.
Based in Noida, India, the company makes more than 2,500 different types and sizes of regular-eye, spring-eye, drilled-end and atraumatic needles in large quantities.
It currently exports 80% of its output to Europe, Asia, the Americas and Africa for use in a wide range of procedures, from ophthalmic to cardiovascular.
Strict quality-assurance procedures are adhered to, as the needles must conform to world-wide standards, such as IS-9165: Bureau of Indian Standards and the German Vornorm DIN-13170.
To meet these standards, Quality Needles tests its products for sharpness, stiffness and ductility — plus other characteristics.
The tools that produce the needles are also monitored closely, and the manufacturer’s success is largely attributed to the in-house development of its own production equipment, tools and technology. External suppliers were either unable to guarantee the levels of quality required, or the parts would have had to be imported and were simply too costly.
The feed wheel has a key role in the manufacturing process, as it is used to transport the needles from station to station. The EN 31 carbon alloy steel component features grooves that vary in size; typically, they are between 0.20mm and 0.90mm wide, and both accuracy and concentricity are very important for their functionality.
Anchan Mago, general manager at Quality Needles, said: “After recently upgrading our production facilities, including the introduction of a new five-axis CNC machining centre, our previous manual measuring methods — using calipers, micrometers and other manual techniques — could not cope with the increased throughput.
“So we set out to find a comprehensive and accurate quality-assurance method that could not only increase measuring productivity but also introduce a higher level of precision and repeatability.”
Accuracy and reliability
Quality Needles needed a metrology solution that was accurate and reliable enough to check the profile, straightness, dimensions and concentricity of components in a high-productivity environment.
A feed wheel was used as a test piece to determine if the various laser scanners being benchmarked were capable of measuring surfaces and features. The company finally selected an Altera CMM with LC15Dx laser scanner from Nikon Metrology (
www.nikonmetrology.com).
Mr Mago said: “The Nikon machine offered a superior insight into the quality of our products, allowing us to manufacture complicated parts much more easily. The angles of the grooves in our feed wheel were too tight for the other laser scanners to measure, and sometimes grooves were not detected at all, but there was no issue for the LC15Dx.”
With Nikon Metrology’s Enhanced Sensor Performance (ESP3) technology and a probing error of just 1.9µm, which the company says is comparable to the accuracy of tactile probing, the LC15Dx offers the best accuracy for a laser scanner.
ESP3 maintains accuracy, speed and data quality by ‘intelligently’ adapting the laser settings for each measured point in real time, which is necessary to cope with shiny surfaces and varying reflections.
Point clouds generated during inspection routines are compared to original CAD models, with coloured deviation plots indicating where errors have occurred.
As well as the LC15Dx scanning head, Nikon supplied the Altera CMM with an SP25 scanning probe, mainly to measure the inner diameters of the wheels.
Mr Mago says the increase in productivity and quality helped the company to recover the capital cost of the metrology solution within one year, adding: “Needle quality has improved, and productivity has increased by 3.1%, which is quite appreciable considering that we work on 110 million cycles per month.”