PA – Polyamide (nylon)
PA – polyamide (trade name: nylon) Polyamide
PA use: Tenant, gears, links, wireruller, cable ties, electronic cabinets, switches and relays.
Amorphous PA used for water level glass, etc.. which include. required high chemical resistance.
Emballagefilm, (barrieremateriale)
Carpets, brushes.
clothing. As tøjfibre, including reinforcement of natural fibers. polyamide – is the syntetfiber which have the greatest wear resistance. The wear resistance and elasticity makes polyamide unique as binding wire in the yarn are prone to rupture. Polyamide increases both the yarn strength and elasticity.
Fire: Ignite at about. 420°C. It is difficult to ignite and self-extinguishing.
Bending: Varmbukning possible, can possibly. place under nitrogen coverage as the material is oxidized.
Electrical properties: Used for electrical components. Have good insulating properties, However, much affected by moisture.
Colors: PA6 can have a white-yellowish color, the cast is usually most yellow. PA6 is also available in the color black.
May be dyed with water-soluble dyes.
Physiological properties: Polyamide type is excellent for use in contact with food, as packaging and machine parts. See set for this at BGA (Germany) and FDA (USA).
Often used as bearings in food production, virtually eliminating lubrication and thus pollution.
Moisture absorption: Polyamide is not dimensionally stable; Water content is determined by the ambient humidity. The addition of carbon fibers or glass fibers can remedy this. When shooting ca. 2-3% moisture has polyamide high strength and toughness. The water absorbency will not exceed 9%.
Trade names: Nylon®, Ertalon®, Nylatron®
History: Carothers was director of DuPont’s development of organic chemistry in 1928, where he first worked with polymerisation of acetylene, etc.. This led to the discovery of the substance neoprene, and the subsequent discovery of nylon. Dupont starter i 1938 the first commercial production of polymer fibers / synthetic fibers. The 15 May 1940 launches Dupont,the nylon stockings; within a few days, they have sold 5 milion couple to a then great price $1.15 – $1.35 .
Wallace Hume Carothers
born. 27 april, 1896, Burlington, Iowa, U.S.A.
death d. 29 april1937, Philadelphia, however,.
Identification fire test: Burns with a yellowish, blue bound and sooting flame. Melts and forms foamy drops . Smells sharply, “formic acid” or burnt hair (self-extinguishing).
Category: Partly crystalline milky white material (light diffusing).
Chemical resistance: Resistant to many chemicals and solvents. Can not tolerate acids and stronger bases.
Resistant to petroleum products, petrol, the fatty alcohols and ketones, ester, ether and chlorinated hydrocarbons
PA6 and PA6.6 dissolved formic acid, PA11 of phenol.
There is very little tendency for stress corrosion cracking, zinc chloride solutions may cause problems.
No decomposition of hot water and is oxidized at high temperatures.
Chemical structure: Polyamide is a synthetic polymer, consisting of many short kulbrintedele linked by amide bond .
Polyamide occurs in several main types, with the main PA6, PA6,6, PA6,10 og PA11. The numbers indicate the number of carbon atoms, included in molekylelementerne.
delivery semi: Folie, plates rods , hollow bars, welding wire .
Bonding: The pretreatment consisting of degreasing and grinding of the surfaces. For bonding PA at PA chips used in a solvent.
For bonding Polyamide against steel can be used a two component epoxy adhesive.
Polishing:
Mechanical properties: (delkrystallinske types) PA has high rigidity, especially with the addition of glass fibers. Good mechanical properties, over and Bredt temperaturinterval.
Good strength and wear characteristics, and chemical resistance.
Polyamide has no high strength tensile and pressure , particularly at elevated humidity and temperature,. PETP and POM have higher values.
Very tough material, with good damping properties, where it is exposed to dynamic oscillations. Impact strength is high, particularly at elevated humidity.
PA6 and PA6.6 has good abrasion resistance, also against a rough surface, including operation at dirty conditions. The friction is not particularly low without smøring.Ved heavily loaded bearings can be lubricated, or used self-lubricating types PA.
Environment:
Energy is used / raw materials corresponding to 3 kg of oil for the preparation of 1 kg PA.
Optical properties: Klare, amorphous types (Og PA11 PA12) som har en PC code lysgennemgang. Amorphous PA used for water level glass, etc..
Surface treatment: One can without pretreatment touch with silkscreen and intaglio on PA-topics. Topics can be painted with two-component polyurethane.
Metallization is possible, under vacuum, on subjects primed with special paint.
By boiling in water with tøjfarvepulver, Polyamide can be dyed.
Cleaning:
Assembly (mechanical): There are big differences in thermal expansion of polyamide and possibly steel. There are self-tapping screws and threaded inserts, which gives a very high strength, calcd for use in Polyamide.
Injection molding: Widely used.
Cutting: Excellent to work on common værtøjsmaskiner. The steels should be sharp and in correct angles. Use high cutting speeds, and low feed. There can be cooled with air. Length, cool chips requires caution.
Noise control: Good noise-canceling effect
Welding: Extrusion welding units – Heat Mirror 230-270 ° C. Friction welding 60-80 m/min.
Varmluftsvejsning with nitrogen. The polyamide is water-absorbent and should be welded immediately after the casting. may be. dried. Welding Wire should be dried in the oven.
Thermal Properties. Dry out and become brittle at approximately. 100°C . PA4.6 withstands high temperature – around 150 ° C. PA6 anvendes in the temperature range
-40 to 80°C. Above this temperature, required fiber-reinforced, heat-reinforced types, are often added to about 200 ° C.
Crystalline melting point of PA11: 190°C, PA6: 223°C, PA6.6: 265° C and PA4.6: 295°C.
UV- Stability: Attacked by sunlight. This is more a problem when thin-walled items.
Thermoforming: Thermoforming is possible, but should be under nitrogen coverage, as the material is oxygenated.
Density: 1,04 – 1,15