TPi January 2011

for tube making

AK Steel marks 100 years of research and innovation

By integrating the two resins, the PolyMedex composite multi-layer tubing features the best benefits of thermoset polyimide and TPE tubing. PolyMedex Discovery Group serves medical device manufacturers with comprehensive development and manufacturing services for intravascular, minimally invasive, and implantable applications. Its capabilities include polymer distribu- tion, custom compounds, bioresorbable and drug delivery formulations, thermoplastic and thermoset tubing, and custom components. revolutionise the automotive exhaust market in the 1990s with the introduction of specific types of aluminised stainless steels. Today, in addition to several other research projects, AK Steel is developing products that help its automotive customers design lighter, more fuel-efficient vehicles. AK Steel produces flat-rolled carbon, stainless and electrical steels, primarily for automotive, appliance, construction and electrical power generation and distribution markets. AK Tube LLC, a wholly owned subsidiary of AK Steel, produces carbon and stainless electric resistance welded (ERW) tubular steel products. AK Steel – USA www.aksteel.com

AK Steel has reached a new milestone, marking 100 years of innovation at its research facility in Middletown, Ohio. The company’s predecessor, Armco, announced the creation of a research department on 22 September 1910. Since that time, AK Steel has been an industry leader in new product development, customer technical services and steelmaking process improvements. “AK Steel has a proud heritage of research and innovation,” said James L Wainscott, chairman, president and CEO of AK Steel. “Throughout historic PolyMedex Discovery Group has announced the availability of custom multi-layer tubing composed of thermoset polyimide and thermoplastic elastomer (TPE) laminate. Through a manufacturing process developed by PolyMedex, the high strength and tight tolerances of thermoset polyimide are combined with the wide variety of material options and configurations available in thermoplastic elastomers. Polyimide and TPE composite multi- layer tubing is suitable for demanding medical device applications that require a combination of high performance and manufacturability. The primary value of the polyimide and TPE multi-layer tubing is the ability to utilise the benefits of thermoset polyimide, while mitigating its limitations. Thermoset polyimide has a minimum tensile strength of 20,000 psi (138 MPa) which is 30% greater than high performance thermoplastics such as polyetheretherketone (PEEK). Due to its hard and glossy surface, polyimide is suitable for device working channels, improving passability of metallic devices such as implants. Polyimide is also resistant to the harshest chemicals and features a dielectric strength of 10,200 volts. Thermoset polyimide tubing can be produced with ID tolerances in the range of ±0.0002" to ±0.0005" (0.0051 to

eras of technological, regulatory and industrial changes in American history, AK Steel has held, and continues to hold, a leading position in the area of steelmaking research.” Among the products and processes developed by AK Steel throughout its history, the company pioneered the world’s first continuous hot rolling sheet mill in the 1920s. Its research also led to the development of various types of electrical steels used in power transmission and distribution equipment. The company also helped 0.013mm) depending on diameter. This makes the material suitable for small diameter vascular device assemblies where high strength and tolerance stackup are a critical concern. The greatest limitation of thermoset polyimide tubing is that it is available only in a round single lumen configuration and is difficult to bond, colour or thermal form. In contrast, TPEs can be extruded in virtually unlimited configurations, including profiles and multilumen. A wide variety of durometers and stiffnesses allow TPE polymers to solve a broad range of medical device challenges. TPE tubing can also be thermally formed after extrusion to create critical catheter components such as traumatic tips and flares for connector fittings.

Multi-layer polyimide and TPE tubing

PolyMedex Discovery Group – USA www.polymedexgroup.com

Multi-layer composite tubing

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January 2011 Tube Products International