A medical device customer called us in August. They had just received FDA 510(k) clearance for their new blood glucose monitor, and they needed 500,000 silicone buttons per month, starting in November. We told them we could do 300,000 per month in our current cleanroom. They said they needed 500,000, and if we could not do it, they would go to another supplier.
We started the cleanroom expansion the next week. We added 500 square meters of Class 8 cleanroom space, installed new air handling units, and bought 6 new compression molding presses. The expansion was completed in 6 weeks, and we passed the ISO 13485 audit in October. We can now produce 1 million medical silicone buttons per month, which is double our previous capacity.
This expansion was not just about more space. It was about meeting the stricter requirements of medical device manufacturing. Medical silicone buttons must be produced in a cleanroom, because any contamination on the button can cause an infection in the patient. The cleanroom must meet ISO 13485 standards, which require continuous monitoring of temperature, humidity, and particle count.
What the new cleanroom looks like
The new cleanroom is 500 square meters, and it is Class 8, which means there are no more than 3,520,000 particles per cubic meter of air, for particles 0.5um and larger. The air is filtered through HEPA filters, which remove 99.97% of particles 0.3um and larger. The air changes 20 times per hour, which keeps the particle count low.
The temperature is controlled at 22C ±2C, and the humidity is controlled at 45% ±10%. These parameters are monitored continuously, and the data is logged on a computer, so we can show the customer the history for every batch. If the temperature or humidity goes outside the range, the system alarms, and the production line stops.
The new Class 8 cleanroom, with HEPA-filtered air and continuous environmental monitoring.
The cleanroom has 6 compression molding presses, each with a 100-ton clamping force. The presses are computer-controlled, so the curing time, temperature, and pressure are set automatically. This ensures that every button is cured the same way, every time. We also have a deflashing station, where the excess flash is trimmed off the buttons, and a packaging station, where the buttons are sealed in sterile bags.
What we produce in the cleanroom
We produce medical silicone buttons for a range of devices: blood glucose monitors, infusion pumps, patient monitors, and surgical instruments. The buttons are made from medical-grade silicone, which is FDA-approved and biocompatible. The silicone is cured with platinum, not peroxide, which means there is no residual byproduct that can leach into the patient's body.
The buttons can be color-matched to the device housing, and they can have logos or symbols molded into the surface. We also add metal domes underneath the buttons, so the user gets tactile feedback when they press. The domes are stainless steel, plated with gold, to prevent corrosion in a hospital environment.
Four-legged stainless steel domes, gold-plated for medical applications, mounted inside a silicone button.
What the expansion means for our customers
We can now accept larger orders for medical silicone buttons, with shorter lead times. Our standard lead time for medical buttons is 4 weeks, down from 6 weeks before the expansion. We can also do smaller prototype runs, starting at 500 pieces, because the new presses are smaller and faster to set up.
If you are a medical device manufacturer looking for a custom silicone button supplier, we can help. We have the cleanroom, the certifications, and the experience to produce buttons that meet FDA and ISO 13485 requirements. We can also produce the FPC circuits and membrane switch panels that go with the buttons, so you can source the complete keypad assembly from one supplier.
We are currently running at 60% capacity in the new cleanroom, which means we have room for 400,000 more buttons per month. If you need medical silicone buttons, talk to our sales team. We will send you a sample kit, with our most popular button designs, so you can test them in your application.
- John Smith, Senior Application Engineer, Shanyo
