Polyamide 6 Cast, better known as PA6G, is a beige coloured, firm, homogeneous, stress-relieved cast polyamide, with a high degree of crystallinity.
While PA6 is obtained with an extrusion process, PA6G is obtained from a monomer moulding process, in which semi-finished products (plates, tubes, rods of finished parts) are created by a controlled reaction. Caprolactam is melted separately with activator and catalyst, then mixed and immediately put into a heated mould, that gives shape to semi-finished products. This process is called casting reaction (Polyamide 6 Guss which, translate from German means Polyamide 6 Cast), which could be divided into:
Thank to this production method, a significant improvement is obtained, which reflects in a better performance of the material and also a better physical properties. It is also an appropriate method to produce larger parts.
PA6G offers a high abrasion and wear resistance at low medium speeds compared to cast iron, steel or bronze, especially under harsh conditions, such as contact with sand or dust. Its visco-elasticity complies with a various environmental requirements, in fact it can easily prolong machine lifetime and it is perfectly suitable for parts such as rollers, gear wheels, etc.
With a specific weight of 1,15 g/cm3, PA6G only weight approx.13% of the same volume of bronze, 15% of steel and 43% of aluminium, which means less centrifugal force and imbalance in rotating parts.
Polyamide 6 Cast offers excellent sliding properties, even when running dry, which characterise it as a friction bearing material for machine parts that are subject to a lot wear. Because of the low coefficient of friction, lubrification is often unnecessary or only an initial lubrification is required when the parts are installed.
Unfortunately PA6G is influenced by temperature and moisture. When temperatures increase or water is absorbed, tensile and compressive strength are reduced, modulus of elasticity and hardness are reduced, while impact resistance and expansion increase. Dimensional stability is also affected by these circumstances. However, the high crystallinity of PA6G reduces moisture absorption considerably. Water is only absorbed very slowly. The rate of absorption reduces progressively with the depth of penetration.
Saturation level in standard climate (23°C/50%RH) depending on type: 1,5 – 2%. Linear deformation due to moisture absorption: approx. 0,15 – 0,20% per 1% water absorbed. Linear deformation due to temperature changes: approx. 0,1% per 10°C temperature change.
PA6G offers also a good chemical resistance against weak acids and alkalis as well as all conventional organic and inorganic bases. It is resistant to hydrocarbons (such as Petrol), oils, fats, esters, ketones and ether. It resists to trichlorethylene, carbon tetrachloride, methylene chloride, Fringe and Freon too.
It is suitable to work submerged into sea water, but like water, and also with chloroform, ethanol and methanol, a little swelling could be caused. Alcohols are largely indifferent and it can also resist to mineral acids in low concentrations. There may be slight discoloration on the acetic acid, phenols, cresols, glycols and benzyl alcohol, especially at high temperatures.
Our Polyamide 6 Cast is FDA approved and can also be certified according EC 1935/2004, EC 2023/2006 and EU 10/2011.
Thanks to the incredible improvement of plastic science, Polyamide 6 Cast has been improved a lot in last few years, thanks to a different type of additives, such as:
Polyamide 6 cast, usually available in rods, tubes and plates, also in huge dimensions (up to Ø1500 and tk.500 mm), is produced by different Companies, each one with its own commercial name. Although that, each PA6G has more less the same characteristics and can easily substitute one each other.
Most famous brand names are: