Charcoal filters in a respirator will remove the vapors for a period oftime. If you can smell the resin vapor safer placing the mask back on after a break, replacethe filters immediately. Some times ,charcoal filters last less than 4 hours. Store therespirator in a sealed bag when not in use. If working with toxic materials for an extendedperiod of time, a supplied air mask and hood are recommended. Avoid skin contact with thefibers and other particles by wearing long pants and long sleeves along with gloves or barriercreams. The eyes must be protected using leak-proof goggles (no vent holes) when workingwith resins or solvents because chemical damage to the eyes is usually irreversibleAluminium 7075 was also considered for low stress areas. High streesareas required materials such as fiber based composite with either a thermoplastic orthermosettings matrix.the wing of the aircraft needs very high strength components , sovaries of composite is consider for spar are listed below. The skin is made out of HEXCELwith a high temp thermoplastic matrix with honeycomb core. The thermoplasticCELAZOLE(R) POLYBENZIMIDAZOLE OR PBI is used as the matrix material in highheat areas because it can withstand 5800F for over 20000 hrs before degrading. The materialproperties can be seen below.The wing use spectra 1000 as the fiber as it has as higher strength compared to hexel.The matrix material for spectra 1000 parts is RIP3000, A low temp matrix matrial that has amould temperature below the critical temp of 1470C of spectra 1000.The spars also contain a honeycomb core to prevent buckling of the load carrying spectra byincreasing the stiffness of the panel and up to 37 times the stiffness, if the core is 4 times theplate’s thickness. The honeycomb used in aluminium based material because it has higheststrength to weight ratio.
Other areas that are used composite are longerons and control surfaces. The forward fuselagelongerons are the made of spectra fibers and the rear longerons are made of HEXCEL. TheHEXCEL is required for rear longerons as they undergo the heat produced by the engine.The control surface are made of HEXCEL based skin, thermoplastic flanges will be attachedto the bulkheads. The thermoplastic of flange and adjoining piece can then be heated locallyto bond the flange and adjoining piece together.COMPOSITE COMPARISONSMATERIALDENSITYMAX STRENGTHMAX TEMPHEXCEL CARBONFIBER AS4C150.0643 lb/in^3602000psiHONEYWELLSPECTRA 1000140.035 lb/in^34350000psi1470CDUPONT KEVALAR140.052 lb/in^34350000psi1490CTHORNEL T-300PAN140.0636 lb/in^3529000psiSGL SIGRAFIL CS009140.065 lb/in^3522000psiTHERMOPLASTIC USED AND THEIR PROPERTIESMATRIXMATERIALDENSITYMAXSTRENGTHMOLDTEMPMAXTEMPCelazoile(R)PolybenzimidazolePBI140.047 lb/in^323200psi3100CRTP 3000140.0303 lb/in^33500psi93.30C2500CMETALS:METALS such as aluminium are a staple in aircraft structures. Aluminium is a material withstrength to weight ratio better than steel and is a very high strength material and has verygood high temp properties,so it will be used around the engine to shield the compositelongerons from the extreme engine heat . aluminium lithium is lighter than typically 7075