Assembly in Action: Laser Welds Ensure Durable Seals
December 18, 2008
SmarTire Systems Inc. (Richmond, British Columbia) manufactures tire pressure and temperature monitoring systems (TPMS) for aftermarket and OEM applications. The systems ensure that car or truck tires are correctly inflated, promoting long tire life and fuel efficiency.
Recently, the company developed what it calls its SmartWave product, an external, stem-mounted TPMS that is easily retrofitted onto older trucks. By tapping into a vehicle’s existing communications network, the system relays tire data directly to a driver or a company’s central routing depot.
To be successful, the product needed to be robust enough to withstand harsh weather and harsh usage. A typical commercial vehicle travels about a million miles in 5 years.
With this in mind, SmarTire encases the electronics comprising each SmartWave monitor in a housing made of Zytel HTN PPA and Zytel HTN PPA SuperStructural resins from Dupont (Wilmington, DE). SmartTire then uses a laser welder and Dupont-specified welding protocol to join the two parts, creating an impermeable seal between the two materials.
The application represents the first time a customer has successfully used lasers to join the two dissimilar materials. The result is an assembly that can withstand pressure spikes up to 200 psi and temperatures as high as 200 C.
SmarTire is also using lasers to etch a bar code and numeric tracking information on each SmartWave system. By doing so, it ensures that the data will be readable even after prolonged use, in spite of the units’ small marking area.
For more on plastics and laser welding, visit www.dupont.com.