Realization of high-accuracy positioning at low cost
Sewing industry
A fiber manufacturer known for high quality in the domestic production of apparel fabrics.
A representative of the knit production department inquired us about the sensor used for "positioning" of the bobbin of the automated knitting machine.
Table of Contents
Client’s Issues
The client has used "proximity sensor" for positioning of the bobbin of the automated knitting machine used to produce knit fabrics, however, the repeatability is low (50 μm), which caused unevenness in the fabric quality.
To evenly feed yarns from the bobbin, precise "positioning" of the bobbin is a decisive factor, however, 100 bobbins or more are used per automated knitting machine, so an expensive sensor is not an feasible option.
The client has found our product as a high-accuracy sensor at a price equivalent to that of "proximity sensor" and contacted us.
The main focus of the issues
A proximity sensor that has low accuracy causes unevenness in the product quality.
Because there are many points of detection, expensive sensors cannot be adopted.
Metrol’s suggestions
The conventional "proximity sensor" has a dead zone between ON and OFF called "movement differential", the typical repeatability is about 50 μm which is not suitable for precision positioning.
Although Metrol's "precision positioning switch" is at the same price as "proximity sensor" (2,800 JPY and above), it demonstrates 5 μm repeatability which is 10 times or more as precise as the proximity sensors.
The switch is a mechanical type composed only of precision parts, there is no "movement differential", and the minute actions of the bobbin can be securely detected.
Improvements
The 5 μm repeatability detects the bobbin position steadily.
Low cost has been realized in the same price range as proximity sensors.
Comment from Metrol representative
As stated already, in the sewing industry, the switch also have been adopted for applications such as "detection of the remaining amount of cotton" and "cloth winding inspection" that are difficult for proximity sensors / photo sensors.
Because the switch contacts and detects objects, the readjustment of sensors and frequent conformity to the master are not necessary for any materials.
If you are looking for low-cost and high-accuracy sensors, do not hesitate to contact Metrol.
For further information about the products used in this application
Positioning Contact Switches [CS]
Realization of high-accuracy positioning at low cost!
