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PA6 Nylon Material Properties & Injection Molding Process Conditions

  Time: 2017-12-26   Pageviews:247

PA6 Material Properties

PA6 is a kind of milk-white or yellowish keratoid crystalline polymers, and it can be coloured easily and freely. PA6 has good self lubrication, small rigidity, resistance to low temperature and bacteria, slow burning, slow quenching and dropping, foaming and excellent forming processing properties. And the processes for PA6 is also very easy, such as: injection, blow molding, casting, spraying, powder molding, machining, welding, and bolding, etc. Our PA6 nylon pipe can be customized according to your own specific requirements.

shredded pa6 polyamide

PA6 has the highest water absorption rate among all kinds of nylon. But it has poor dimensional stability and affects electrical performance and breaks down voltage. The maximum usage temperature that PA6 can reach is 180 DEG C. The temperature reduces to 160 DEG C with impact modifier and its thermal deformation temperature increases to 199 ℃ by adding 15% -50% glass fiber.

Chemical & Physical Properties of PA6

The chemical and physical properties of PA6 and PA66 are very similar. However, PA6’s melting point is very low, and its processing temperature range is very wide. Its impact strength and solvent resistance are better than PA66, and moisture absorption is also stronger. Because many plastic’s properties are affected by moisture absorption, various modifiers are often added when PA6 is used to increase its mechanical properties. And glass is the most common additive. Sometimes, synthetic rubber such as EPDM and SBR is added to improve impact resistance. For products without additive, shrinkage rate ranges from 1% to 1.5%. The addition of glass fiber additive can reduce the shrinkage rate to 0.3% ℃, but it is a little higher perpendicular to the process. The shrinkage rate of the forming assembly is mainly influenced by the crystallinity and the hygroscopicity of the material. The actual shrinkage rate is also related to the plastic part design, wall thickness and other process parameters.

Typical Application Of PA6: PA6 is widely used in structural components of machinery because of its good mechanical strength and stiffness. And it is also widely used to manufacture bearings as it has strong wear resistance.

Injection Molding Process Conditions

  • Drying: Special attention should be paid to PA6 before processing because PA6 absorbs moisture easily. If PA6 product is packaged and supplied with waterproof material, its container should be kept closed.  If humidity is greater than 0.2%, it is recommended that the PA6 product be dried in hot air for 16 hours. If the PA6 material has been exposed to air for more than 8 hours, it is recommended to dry for more than 8 hours in vacuum with temperature higher than 105℃.
  • The melting temperature for PA6 ranges from 230℃ to 280℃, and reinforced PA6 from 250℃ to 280℃.
  • The temperature of the mould is from 80℃ to 90℃. The temperature of the mould affects the crystallinity of the mould, which affects the mechanical properties of plastic part. The crystallinity degree is important for structural parts, therefore, it is suggested that the temperature of mould should be from 80℃ to 90℃. For longer process and thin-walled plastic, higher mould temperature is recommended. Increasing mould temperature could increase the plastic’s strength and rigidity but reduces its toughness. Low temperature ( 20℃ to 40℃ ) mould is recommended for wall thickness larger than 3mm. For glass reinforcement material, the mold temperature should be greater than 80℃.
  • Injection pressure generally varies between 750 and 1250 bar depending on the design of material and product.
  • The speed of injection should be slightly reduced for the reinforced material.
  • Runner and gate: Because of the very short solidification time of PA6 the gate location is important. The gate’s aperture should be no less than 0.5t ( t refers to thickness of plastic parts ). If a hot runner is used, the size of the gate should be smaller than that of the conventional runner because the hot runner can help prevent the material from solidifying prematurely. If a submersible gate is used, the minimum diameter of the gate shall be 0.75 mm.

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