Polyamide 6
Structure of PA6
-[ HN (CH2)5 CO ]-n
Polyamide 6 is prepared from  caprolactam in the
presence of water (which acts as a catalysts) and acetic
acid as a molecular weight regulator.
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Polyamide 6,6
Structure of PA 6,6
-[ HN (CH2)6 NH-CO (CH2)4 CO]-n
The Polyamide 66 is prepared from Polyamide salt, which is
prepared by reacting the hexamethylene diamine and adipic
acid in boiling methanol.
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POLYAMIDE 6
Monomer Structure
 caprolactam
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POLYAMIDE 6,6
Monomer Structure
Nylon Salt
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Monomer Preparation:
1. caprolactam
Cyclohexanone
2. Nylon Salt
Adipic Acid & Hexamethylenediamine
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Preparation of Polyamide 6
 Polyamide 6 is prepared from  caprolactam in the presence of water
(which acts as a catalysts) and acetic acid as a molecular weight regulator.
 The typical combination is charged into the vessel and reacted under a
nitrogen blanket at 250°C for about 12 hours.
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Manufacturing of
Polyamide 6
 The schematic diagrams of the continuous polymerization of  caprolactam
to produce Polyamide 6
Flow diagram of continuous production of Polyamide 6
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Manufacturing of
Polyamide6

The VK tube is used in the polyamide process.

A lactam melt with a relatively high water content (~15%) is fed to the
top of the VK tube equipped with a stirrer and heating coil.
The water vaporises at the top, when viscosity is still low, to give a
residue of the desired composition.
In the lower part of the tube, the equilibrium degree of polymerisation



is reached with an increasing viscosity of the melt.
The polymer is drawn off at the bottom and granulated. Its equilibrium
content of caprolactam and oligomers is about 10% at a final
temperature of 270°C.

The monomer and oligomers are extracted from the chips with hot water,
and the polymer is subsequently dried with hot gas in a ventricle cylinder hot dryer.
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Preparation of Polyamide 6,6
The Polyamide 66 is prepared from Polyamide salt,
which is prepared by reacting the hexamethylene
diamine and adipic acid in boiling methanol.
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Manufacturing of Polyamide 6,6
The polymerization of Polyamide 66 is carried out in several
different reactors connected in series
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Manufacturing of Polyamide 6,6
The starting material is an aqueous solution of polyamide salt containing equivalent
quantities of hexamethylene diamine and adipic acid
 The solution with about 60% solid content is fed into the first horizontal cylindrical
reactor then divided into several components where the water is drawn off as vapor
and precondensate of low mol. wt. is formed.
 This is pumped into the second reactor, which is a heated tube reactor with a
gradually increasing diameter.
 The Polycondensation proceeds here and vapor forms at falling pressure.
 The next step is the removal of water in a steam separator followed by feeding the
polymer melt by means of a screw conveyor into the last reactor, which consists of a
heated screw conveyor where water vapor is again withdrawn and the final polycondensation equilibrium is attained.
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Relations of Structure and properties of
Polyamide 6

The following structural variables affect the properties.
 The distance between the repeating –CONH- group
 The number of methylene groups in the intermediates
 The molecular weight
 N- substitution
 Co-polymerization
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Characteristics of Polyamide 6 & 6,6
(For identification)
The material is semicrystalline and having high water absorption capacity.
 It is milky white - yellow colour
 It is identified by the smell of burnt horn when burned,
yellow
flame with a blue halo, can be formed into a filament.
 Its melting point is 215°C (PA6) & 264°C(PA66)
 Its short term and long term service temperature are respectively
140 - 160°C(For PA6,6 10°C more) and 80 - 100°C.
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Characteristics of Polyamide 6
& 6,6
 The general characteristics of Polyamide 6 & 6,6 is summarized below
Hard and tough thermoplastic
Good abrasion resistance
Low co-efficient of friction
High tensile strength
Good dimensional stability
Low tendency to work
Smooth appearance of surface
Average to high surface gloss
Resistance to lubricants, engine fuels, grease etc.
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Characteristics of
Polyamide 6 & 6,6
Good resistance to coolants, refrigerants, paints, solvent
cements.
Resistant to aqueous solution of many inorganic
chemicals.
Posses high HDT
Attached by strong acids, phenols, cresol at devoted
temperature
High temperature resistance
Low co-efficient of linear thermal expansion
High water absorption
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Comparison between different polyamides
Polyamide 6
Polyamide 66
processing
easy
easy
Strength
good
better
Abrasion resistance
Low
High
Toughness
Low
higher
Water absorption
high
high
cost
less
Little High
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Comparison Performance
Properties
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Grades of Polyamide 6
The Polyamide 6 is available in various grades
 Injection molding grade
 Extrusion grade
 Rotational Molding grade
 Fluidized bed coating grade
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Processing considerations for
Polyamide 6
 The material has to be predried at 80°C for 2 - 4 hours
 While molding Polyamide attention on the following points is
essential.
 High Injection speed of the molding machine
 Control of shot or size
 Minimizing drooling by nozzle of reverse tapper type.
 Shrinkage of the part
 Annealing at 130° to 149°C for 10 - 20 hrs.
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Processing considerations
Polyamide 66
for
 The Polyamide 66 is also processed with much precautions as like
Polyamide 6.
 The annealing temperature of Polyamide 66 part is 149 – 177°C.
 The Polyamide 66 is processed in the temperature range of 260-
320°C.
 The material has to be predried at 80°C for 2 - 4 hours
 Injection moulding, Extrusion techniques, Compression moulding,
Foam moulding and Rotomoulding techniques are used for
processing the materials.
 While moulding Polyamide 66, the precautions what are taken for
Polyamides 6 the some should be taken for Polyamide 66.
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Applications of Polyamide 6(Areas of
Applications)
 Appliances
 Automotive
 Business equipment
 Consumer products
 Electrical
 Hardware
 Machinery
 Packaging
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Applications of Polyamide 6
Appliances
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Laundry equipment
Cooking equipment
Dishwashers and disposers
Cooling equipment
Consumer electronics
Housecleaning equipment
Small kitchen appliances
Sewing machine
Personal care and grooming
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Applications of Polyamide 6
Automotive

Chassis parts

Power plant

Decorative body parts

Functional body parts

Electrical parts

Fuel system

Instrumentation

Heating, ventilating, air-conditioning

Accessories
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Applications of Polyamide 6
Business equipment

Business machines

Vending machines

Office equipment
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Applications of Polyamide 6
Consumer products
Kitchen utensils
Toys
Sporting goods
Apparel fitments
Personal accessories
Photographic equipment
Football face guards are made of Nylon 6
because of its great toughness
Musical instruments
Brush bristles
Packaging
Film for cooking
Fishing line
Tennis racquet
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Applications of Polyamide 6
Electrical
Industrial controls
Wiring and associated devices
Industrial connectors
Batteries
Telephone parts
Switches
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Applications of Polyamide 6
Hardware
Furniture fittings
Door and window fittings
Tools
Lawn and garden implements
Boat fittings
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Applications of Polyamide 6
Machinery
Agricultural
Mining and oil drilling
Food processing
Printing
Textile processing
Engine parts
Pumps, valves, meters, filters
Air blowers
Material handling equipment
Standard components
Gears
Cams
Sprockets
Bearings
Gaskets
Pulleys
Brushes CORPORATE TRAINING AND PLANNING
Caster Wheels
Spur and Pinion gears
Bushing and Bearing
Applications of Polyamide 6
Packaging
Film and coated substrates
Polyamide 6 film for meat
packaging
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Applications of Polyamide 66
Areas of applications are very similar to Polyamide 6.

Appliances

Automotive

Business equipment

Consumer Products

Electrical

Hardware

Machinery and packaging
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Applications of Polyamide 66
Hammer handles of glass reinforced Polyamide are
superior to wood they replaced (Application related to
hardware)
Hammer Handles
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List of Manufacturers/ Suppliers
of Polyamide 6
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