PA66 Also called nylon sixty-six ； Polyhexamethylene diamine adipate; nylon 66 , Abbreviation NY66 。 chemical formula: [-NH （ CH2 ） six － NHCO(CH2)4CO]n - Appearance: white package or granular density with color（ g/cm3 ） one ． 10-1 ． fourteen tensile strength (MPa) 60. 0-80 ． zero Rockwell hardness one hundred and eighteen Impact strength（ kJ/m2 ） 60-100 Static bending strength (MPa) 1 00-120 Martin heat resistance ( ℃ ) 50-60 Modulus of elasticity in bending (MPa) 2000 ～ three thousand Volume resistivity（ Ω cm ） one point eight three × one thousand and fifteen Dielectric constant one ． sixty-three
PA66 character
Translucent or opaque milky white crystalline polymer with plasticity. density one ． 15g ／ cm3 。 melting point two hundred and fifty-two ℃ 。 Embrittlement temperature -30 ℃ 。 Thermal decomposition temperature greater than three hundred and fifty ℃ 。 Continuous heat resistance 80-120 ℃ , Equilibrium water absorption two ． five ％。 It can resist the corrosion of acid, alkali, most inorganic brine solutions, haloalkanes, hydrocarbons, esters, ketones, etc., but it is easily soluble in benzene Phenol, formic acid and other comparative solvents. It has excellent wear resistance, self lubrication and high mechanical strength. But the water absorption is large, so the dimensional stability is poor.
PA66 Application
Widely used to manufacture parts of machinery, automobiles, chemical and electrical devices, such as gears, rollers pulley , roll shaft pump Impeller, fan blade, high-pressure sealing ring, valve seat, gasket, bushing, various handles, support frame, wire cladding, etc. It can also be made into film as packaging material. In addition, it can also be used to make health equipment, sporting goods Daily Necessities Etc.
Process conditions of injection mould
Drying: If the material is sealed before processing, drying is not necessary. However, if the storage container is opened, it is recommended that eighty-five ℃ Dry in hot air. If the humidity is greater than 0.2% , still need to one hundred and five ℃ ， twelve Hours of vacuum drying. Melting temperature: 260~290 ℃ 。 The products of glass additives are 275~280 ℃ 。 The melting temperature should not be higher than three hundred ℃ 。 Mold temperature: recommended eighty ℃ 。 The mold temperature will affect the crystallinity, which will affect the physical properties of the product. For thin-walled plastic parts, if less than forty ℃ In order to maintain the geometric stability of the plastic part, annealing treatment is required. Injection pressure: usually at 750~1250bar , depending on materials and product design. Injection speed: high speed (lower for reinforced materials). Runners and gates : because PA66 The setting time of is very short, so the position of the gate is very important. Gate diameter shall not be less than 0.5*t (Here t Is the thickness of the plastic part). If hot runners are used, the gate size should be smaller than that of conventional runners, because hot runners can help prevent premature solidification of the material. If a submerged gate is used, the smaller diameter of the gate should be 0.75mm 。
Chemical and physical properties
PA66 It has a high melting point in polyamide materials. It is a semi crystal - Crystal materials. PA66 It can also maintain strong strength and stiffness at higher temperatures. PA66 It still has hygroscopicity after forming, and its degree mainly depends on the composition of materials, wall thickness and environmental conditions. In product design, the influence of moisture absorption on geometric stability must be considered. To improve PA66 Due to its mechanical properties, various modifiers are often added. Glass is a common additive. Sometimes synthetic rubber is added to improve impact resistance, such as EPDM and SBR Etc. PA66 The viscosity of is lower, so the liquidity is very good (but not as good as PA6 ）。 This property can be used to process very thin components. Its viscosity is very sensitive to temperature changes. PA66 Shrinkage of 1%~2% The addition of glass fiber additive can reduce the shrinkage to 0.2%~1% 。 The shrinkage rate differs greatly in the flow direction and the direction perpendicular to the flow direction. PA66 It is resistant to many solvents, but weak to acids and other chlorinating agents.
