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Fibermaq launches RTM injection machine
forces that increase tensile strength. Gelspinning also increases directional orientation of fibers, which also augments strength. This contrasts with conventional solution spinning where PAN co-polymer solution is directly converted to a solid fiber without the intermediate gel state and can produce less robust material. The gel-spun carbon fiber produced by Kumar’s team was tested at 5.5–5.8 gigapascals (GPa) and had a tensile modulus in the 354–375 GPa range. ‘This is the highest combination of strength and modulus for any continuous fiber reported to-date,’ Kumar claimed. At short gauge length, fiber tensile strength was measured as high as 12.1 GPa, which is the highest tensile-strength value ever reported for a PAN-based carbon fiber.
Fewer imperfections According to Kumar, the internal structure of the gel-spun carbon fibers measured at the nanoscale showed fewer imperfections than commercial carbon fibers, such as IM7. Specifically, the gel-spun fibers display a lower degree of polymer-chain entanglements than those produced by solution spinning. This smaller number of entanglements results from the fact that gel-spinning uses lower concentrations of polymer than solution-spinning methods.
TECHNOLOGY
A high strength and high modulus carbon fiber processed at Georgia Tech. Photo courtesy Gary Meek, Georgia Tech.
Professor Satish Kumar and research engineer M.G. Kamath examine the precursor and carbon fibers processed at Georgia Tech. Photo courtesy Gary Meek, Georgia Tech.
Kumar and his team converted the gel-spun polymer mix into carbon fibers via a selective treatment process called pyrolysis, in which the spun polymer is gradually subjected to both heat and stretching. This technique eliminates large quantities of hydrogen, oxygen, and nitrogen from the polymer, leaving mostly strength-increasing carbon. ‘It’s important to remember that the current performance of solution-spun PAN-
based carbon fibers has been achieved after many years of material and process optimization – yet very limited material and process optimization studies have been carried out to date on the gel-spun PAN fiber,’ Kumar said. ‘In the future, we believe that materials and process optimization, enhanced fiber circularity, and increased solution homogeneity will further increase the strength and modulus of the gel–spinning method.’ The work is part of a four-year, US$9.8 million project sponsored by the Defense Advanced Research Projects Agency (DARPA) to improve the strength of carbon fiber materials. The research was reported recently in the journal Carbon. Georgia Institute of Technology; www.gatech. edu
Fibermaq launches RTM injection machine Fibermaq, a Brazilian supplier of composite molding machinery, has launched an injection machine for the resin transfer molding (RTM) process, a technology used by molders of composite parts for the automotive industry. The RTM Evolution Electronic machine includes a PLC control system that allows the storage of different injection programs. ‘In both the pneumatic and electronic
versions, the volume of material injected will always be that previously defined,’ said Christian de Andrade, director of Fibermaq. ‘In the pneumatic version, the dosing is given by the number of strokes, that is, multiples of 100 ml. In the electronic model, in turn, the volume to be dosed is more flexible.’ The molding machine also features a new pressure gauge configuration, which facilitates the control of the operation, and a
display to indicate the passage of peroxide. There is a more simplified system for hose fitting, and, to increase operator safety, Fibermaq has closed all areas where there are moving components. Fibermaq has also introduced a new gelcoat machine model with a capacity of 4 kg/min, suitable for the manufacture of small parts. Fibermaq; www.fibermaq.com.br
Evonik launches new glass fiber compound Evonik has developed Vestamid HTplus M1035 P1, a glass-fiber reinforced molding compound based on polyphthalamide (PPA). The material is designed for dynamically stressed casing components in the automotive industry. It has high burst pressure strength to withstand alternating stresses
and good chemical resistance against corrosive media, the company says. The new PPA grade also achieves good results as regards to the impact strength. Vestamid HTplus M1035 P1 also has good flow behavior making the surface of the injection-molded parts smoother and defect-free, Evonik states.
The Vestamid HTplus product family was developed to replace classic metal applications. It is a semi-crystalline, polyphthalamide-based material that is resistant to high temperatures and chemicals. Evonik; www.evonik.com
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Reinforced Plastics Volume 59, Number 6 November/December 2015
Fewer imperfections According to Kumar, the internal structure of the gel-spun carbon fibers measured at the nanoscale showed fewer imperfections than commercial carbon fibers, such as IM7. Specifically, the gel-spun fibers display a lower degree of polymer-chain entanglements than those produced by solution spinning. This smaller number of entanglements results from the fact that gel-spinning uses lower concentrations of polymer than solution-spinning methods.
TECHNOLOGY
A high strength and high modulus carbon fiber processed at Georgia Tech. Photo courtesy Gary Meek, Georgia Tech.
Professor Satish Kumar and research engineer M.G. Kamath examine the precursor and carbon fibers processed at Georgia Tech. Photo courtesy Gary Meek, Georgia Tech.
Kumar and his team converted the gel-spun polymer mix into carbon fibers via a selective treatment process called pyrolysis, in which the spun polymer is gradually subjected to both heat and stretching. This technique eliminates large quantities of hydrogen, oxygen, and nitrogen from the polymer, leaving mostly strength-increasing carbon. ‘It’s important to remember that the current performance of solution-spun PAN-
based carbon fibers has been achieved after many years of material and process optimization – yet very limited material and process optimization studies have been carried out to date on the gel-spun PAN fiber,’ Kumar said. ‘In the future, we believe that materials and process optimization, enhanced fiber circularity, and increased solution homogeneity will further increase the strength and modulus of the gel–spinning method.’ The work is part of a four-year, US$9.8 million project sponsored by the Defense Advanced Research Projects Agency (DARPA) to improve the strength of carbon fiber materials. The research was reported recently in the journal Carbon. Georgia Institute of Technology; www.gatech. edu
Fibermaq launches RTM injection machine Fibermaq, a Brazilian supplier of composite molding machinery, has launched an injection machine for the resin transfer molding (RTM) process, a technology used by molders of composite parts for the automotive industry. The RTM Evolution Electronic machine includes a PLC control system that allows the storage of different injection programs. ‘In both the pneumatic and electronic
versions, the volume of material injected will always be that previously defined,’ said Christian de Andrade, director of Fibermaq. ‘In the pneumatic version, the dosing is given by the number of strokes, that is, multiples of 100 ml. In the electronic model, in turn, the volume to be dosed is more flexible.’ The molding machine also features a new pressure gauge configuration, which facilitates the control of the operation, and a
display to indicate the passage of peroxide. There is a more simplified system for hose fitting, and, to increase operator safety, Fibermaq has closed all areas where there are moving components. Fibermaq has also introduced a new gelcoat machine model with a capacity of 4 kg/min, suitable for the manufacture of small parts. Fibermaq; www.fibermaq.com.br
Evonik launches new glass fiber compound Evonik has developed Vestamid HTplus M1035 P1, a glass-fiber reinforced molding compound based on polyphthalamide (PPA). The material is designed for dynamically stressed casing components in the automotive industry. It has high burst pressure strength to withstand alternating stresses
and good chemical resistance against corrosive media, the company says. The new PPA grade also achieves good results as regards to the impact strength. Vestamid HTplus M1035 P1 also has good flow behavior making the surface of the injection-molded parts smoother and defect-free, Evonik states.
The Vestamid HTplus product family was developed to replace classic metal applications. It is a semi-crystalline, polyphthalamide-based material that is resistant to high temperatures and chemicals. Evonik; www.evonik.com
283
TECHNOLOGY
Reinforced Plastics Volume 59, Number 6 November/December 2015