The Project: A durable material was needed from which to
fabricate protective bumpers for a portable pain management device.
The Solution: A thermoplastic vulcanizate alloy was selected
for its excellent surface quality, easy processability, high tear strength, and
aesthetic benefits.
Biowave Corp. is a medical device manufacturer whose pain
therapy products help patients manage pain and reduce the use of medications,
such as opiates. Its devices deliver a therapeutic electrical signal into deep
tissue in the body, blocking the transmission of pain. In addition to a version
for clinicians, the company offers the BiowavePRO non-invasive neuromodulation
system designed for individual use by athletes to reduce pain and enhance
rehabilitation.
In designing the housing for the BiowavePRO, Biowave had
several objectives. The portable device, targeted at college and professional
sports teams, had to be durable enough to handle a sports environment—travel on
buses and planes, use in locker rooms, and the risk of being bumped or dropped.
The design called for two protective bumpers on the sides of the housing to
provide a non-slip grip for the user. In addition to durability, these bumpers
needed resilience for a comfortable feel and the ability to incorporate
membrane switches.
An important goal was brand distinction, including a sleek,
simple design and signature color. To achieve this, Biowave wanted the bumpers
to give the appearance of being integrated with the front and rear housing and
to be custom colored.
Molding & Material Recommendation
Biowave consulted PTA Corp., its molder, for guidance on materials for the
housing. PTA turned to PolyOne GLS Thermoplastic Elastomers due to a
longstanding relationship and confidence in the company’s ability to provide
the best material in a short timeframe. Polyone recommended its Versalloy XL
9070X-1 thermoplastic vulcanizate (TPV) alloy for excellent surface quality,
easy processing with excellent flow, and high tear strength. It can also be
easily colored for excellent aesthetics.
PolyOne provided custom coloring and rapid delivery of the
material to meet a tight production schedule. The bumpers were molded
separately and then slipped into channels between the upper and lower housing
components instead of overmolding them onto the housing. This approach
maintained the streamlined design while controlling costs.
From a processing standpoint, PTA was very satisfied with
the moldability of the Versalloy TPV, which delivers a high-quality surface
finish and resists striations that can occur with other elastomers.
Delivering a Value-Added Solution
The Versalloy TPE material is helping Biowave win and retain customers among
sports teams, many of which purchase multiple devices for their players. Its
high performance under rugged conditions helps generate recommendations and
repeat orders. Currently, nearly 40 professional teams and 17 college programs
use BiowavePRO
Competitive differentiation: The Biowave device is often
referred to by its blue color, helping the product stand out from competitors.
When the technology was profiled on television, the attractive color caught
audiences’ attention and generated many inquiries.
Usability: Versalloy material makes a major contribution to
the ruggedness and versatility of the device. Its toughness prevents the
bumpers from shredding or marring, even with extensive handling.
Portability: The ability to use the BiowavePRO practically
anywhere is of great value to mobile sports teams. Versalloy TPV contributes
light weight and a sure grip that is important for safety and precision.
Cost savings: Molding the bumpers separately and inserting
them into the housing keeps costs down yet provides the seamless appearance of
overmolding. Creating a two cavity tool for the bumpers saved PTA 70% over the cost
of an overmolding tool and reduced scrap rates typical with overmolded housings
by 80%.
Joe Kutka is the global market development manager,
healthcare for PolyOne GLS Thermoplastic Elastomers. He is responsible for research
and development efforts to support critical new market trends on an
international scale. Kutka can be reached at 815-759-2607 or joseph.kutka@polyone.com.