X-ray transparent, capable of being machined to 0.001 inch, and inherently more flame resistant than PEEK, Solvays PrimoSpire SRP material also boasts a mirror finish.
Almost 150 years ago, Alexander Parkes unveiled the first man-made cellulose-based plastic at the 1862 Great International Exhibition in London. In the years since, more than 60 generic resin families have been created with thousands of different grades, but the development of new chemical backbones has slowed. In the last several months, however, two material companies have introduced what they call new polymers.
Some 13 years after developing new polymerization catalysts and 11 years after creating new monomers from that technology, GE Plastics (Pittsfield, MA) will launch what its calling its first new resin since introducing Ultem polyetherimide (PEI) commercially in 1984, with the development of Extem thermoplastic polyimide (TPI). Brian Herington, general manager high-performance polymers, and Rob Costella, global product manager for high-performance polymers, offered some details on the product, as well as progress on Ultem production expansion in Cartagena, Spain, during a mid-November webcast (see MPW November 2006 First Look for initial report).
Extem will launch in Q1 2007 with two general familiesâUH and XHâand GE is positioning the high-heat amorphous thermoplastic as an alternative to semicrystalline high-heat materials, which can exhibit post-mold shrinkage issues, and imidized thermosets, which can require postmold curing.
Our customers are demanding more in higher performance, Herington said. Theyre asking for materials that bring them extreme part performance with higher temperature resistance and severe chemical performance. They also want improved productivity to meet competitive marketplace challenges.
The officials said GE has secured more than 30 patents for the material, with 33 still pending. Production is currently handled from a pilot plant in the U.S. thats been operational for two years, with production capability in the hundreds of tons. The $250 million Cartagena plant will be able to produce thousands of tons by 2008, and have room to grow with the market, which GE anticipates at potentially $100 million.
GE said it has identified 75 potential products, spanning aerospace, defense, medical, automotive underhood, and lighting, among others. Extem UH will have a glass transition up to 311Â°C, and continuous temperature performance to 230Â°C. XH will have glass transition up to 267Â°C, and exhibits 50% more strength at 170Â°C than Ultem PEI.
Extem will be available this quarter, with target applications including high-heat electrical connectors, aerospace/defense applications, and underhood automotive components.
The other new entrant, PrimoSpire SRP (self-reinforcing polymer), is an amorphous, thermoplastic, rigid-rod polymer, based on substituted 1,4 polyphenylene composed of carbon-carbon-aryl bonds. Solvay Advanced Polymers (SAP; Alpharetta, GA) has placed PrimoSpire at the top of its reorganized SolvaSpire pyramid of ultraperformance polymers. David Thomas, R&D chemist who came to SAP with the acquisition of SRP creator Mississippi Polymer Technology (Bay St. Louis, MS), calls PrimoSpire the worlds stiffest unreinforced thermoplastic.
Originally marketed as Parmax (see November 2003 MPW for initial report), Solvay has expanded the number of available grades and processing methods. Previously there was only one gradeâmarketed for profile extrusion and compression moldingâbut Solvay has launched injection molding and film extrusion products for clear films with ablative properties or net-shape parts with outstanding mechanical properties.
SAP has 52 patents surrounding the materials: PR-120 for extrusion and compression molding, and PR-250 injection molding and film. PR-120 has a tensile strength of 30,000 psi and a tensile modulus of 1.2 million psi. PR-250s tensile strength is 23,000 psi, making it 60%-100% stiffer than unfilled PEEK, according to SAP.
The company says that without flame retardants, PR-250 is ahead of PEEK, polyethersulfone (PES), and polyetherimide (PEI) in fire resistance, and truly ablative, showing a video where a test plaque was subjected to a 4000Â°F acetylene flame for two minutes without failure or off-gassing. In addition, the dimensional tolerance of less than 0.001 inch makes it fully machineable. The material has a mirror finish, attractive for electronics aesthetics, and it is X-ray transparent, as opposed to filled resins, giving it potential entrÃ©e into a number of medical applications. The company is still considering pricing strategies, but anticipates PrimoSpire falling in the $50-$60/lb range. GE Plastics, Fairfield, CT, USA; www.geplastics.com. Solvay Advanced Polymers, Alpharetta, GA, USA; www.solvayadvancedpolymers.com