Study Of Nylon Powders Applied In Selective Laser Sintering

Selective laser sintering (SLS) is a rapid prototyping technology in which a three-dimensional object is created layer by layer from heat-fusible powdered materials with LASER. This paper developed several kinds of nylon 12 powder applied in selective laser sintering.In SLS, mechanical property and dimensional stability is greatly affected by property of powder used in SLS. At presents, there are some shortcomings in powder such as thermal-oxidative stability, narrow sintering window temperature and poor powder recycling characteristic, which would induce the poor mechanical properties and low dimensional stability. As the reason above, it will bring a lot of benefits to develop powder with low sintering temperature, wide sintering window temperature, excellent thermal-oxidative stability and good powder recycling characteristic.Sintering property of powder and mechanical property of fabricated parts were improved by preparing nylon powder with addictive and fillers. The plasticizer, heat stabilizer and nucleating agent were used in preparing nylon 12 powders. The sintering property and powder recycling characteristic were greatly improved. The determined ratio of additives was 2wt% N-EBS, 2wt% Zinc Stearate, 30wt%glass filler (GF) and 0.8wt% 1098/168.Sintering parameters of powder was determined, laser power was 15W, laser scanning speed was 2000mm/s, layer thickness was 0.15mm. The density, tensile strength, bend strength, bend modulus and thermal deformation temperature of fabricated part was 0.98g/cm3,44MPa,50.8MPa,1.36GPa and 52℃respectively.Potassium Titanate Whiskers (PTW) reinforced nylon 12 composite were prepared by wrapping PTW in nylon 12 particles via dissolvent-precipitation method. Characterization of powder and fabricated parts induced that PTW improved tensile strength, bend strength and bend modulus of fabricated parts and made the lesser impact strength descend than glass filler did, the best ratio of PTW in composite powder is 20wt%.SEM image of fabricated parts impact fracture indicated that PTW over 20wt% in nylon 12 could not be well dispersed, which will induce descending of mechanical properties of parts.