History
of DYLARK Engineering Resins
DYLARK styrene Maleic Anhydride (S/MA) copolymers were developed in late
sixties. The resins exhibited high heat resistance compared to polystyrene,
high-impact polystyrene (HIPS), Acrylonitrile Butadiene Styrene (ABS)
and Styrene Acrylonitrile copolymer (SAN). In the early seventies, elastomer-modified
reactor and fiberglass reinforced DYLARK grades provided enhanced heat
resistance, impact, tensile and flexural strength and flexural modulus
properties. These performance characteristics were adapted into a new
and growing automotive application - substrates for soft instrument panels
(IP’s).
Soft IP’s with injection-molded thermoplastic substrates replaced
formed steel substrates. Thermoplastic substrates reduced vehicle weight
to meet C.A.F.E. standards, provided overall cost savings and permitted
greater flexibility in interior designs and esthetics. In addition, the
automobile industry and customers perceived soft IP’s to provide
greater passenger safety.
DYLARK resins were evaluated as 20% dry blends, physical mixtures of resin
and chopped fiberglass strands. These resins exhibited higher heat and
impact resistance and improved cross-car stability compared to existing
commercial resins. During this time, vehicle designs increased the windshield
slope, which increased the temperature on the IP’s exposed top surface.
Due to cross-car thermal expansion, IP’s using competitive substrates
buckled and warped along the windshield edge. The thermal stability of
DYLARK glass-reinforced resins demonstrated the physical properties required
to withstand thermal expansion in the new designs. Glass-reinforced DYLARK
also fulfilled U.S. government regulations for improved safety and head
impact through greater energy management over a range of temperatures
and speeds.
Soft IP’s progressed beyond carriers for polyurethane foam to include
more intricate designs for one and two-piece IP constructions. The new
designs were more functional, improved cross-car structure and contained
additional packaging compartments for radio, heater and speedometer openings.
Additional DYLARK grades were created with increased impact and handling
ease to meet expanding industry performance standards. Pre-compounds,
pellets with encapsulated glass, replaced dry blends for increased handleablity
and processability. S/MA glass reinforced precompound eliminated most
in-plant handling and molding problems associated with fiberglass fuzz
balls, while providing more consistent and reliable molding operations.
At the same time, part weight control and dimensional stability were enhanced.
Impact grades provided improved handleablity and enhanced performance,
including heat resistance, head impact, chemical resistance, superior
urethane foam adhesion and noise, vibration and harshness performance.
Today, several engineering resins designed specifically for IP substrate
applications are available, but many designers and suppliers continue
to specify DYLARK resins because of the outstanding balance of properties
and proven performance. During the past three decades, DYLARK substrates
were installed in more than 200 million soft instrument panels worldwide.
Numerous automobile manufacturers specify DYLARK worldwide and new applications
continue to develop as NOVA Chemicals’ customers expand throughout
North America, Europe and Asia.
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