POY yarn is a type of yarn that, in terms of the type of polymer structure, is a partially oriented molecular chain (Partially Oriented Yarn) that is used as a raw material for texturing factories to produce DTY, FDY, ATY textured yarns.  Due to the high consumption of polyester yarn in the textile industry, especially filament yarn is of particular importance.

POY or semi-arranged yarn is produced during the spinning process by using raw materials called semi-matte and glossy polyester chips (PET) in white and also by using masterbatch (colored beads) in self-colored.

Polyester POY yarn is produced with regulating speeds in the range of 2800 to 4200 meters per minute, and with this characteristic, it still does not have a high degree of crystallization, and the general order in them is such that they can be stored for several months without brittleness.  It is possible for the coil to become brittle as well as deform.

This yarn is used in combination with other so-called ITY yarns or is converted into stretch yarn and textured yarn (DTY) in texturing factories, which is one of its most important uses.  These yarns are used to produce the following products.

  Rumble and curtain fabric

  Winter sports clothes

  The underware clothes

  Socks

  Integrated knitted fabric

Sports clothes

This type of yarn is used as a base yarn in the manufacture of various types of textured yarns DTY, ITY, ATY and other types of stretched yarns (FDY).

The production process of POY yarn – stretched polyester is divided into two general parts.

Crystallization and drying stage

Polymerization stage and extruder and yarn spinning

A) The stage of crystallization and drying of chips

At this stage, which is actually the starting point of the product line, first the raw materials, which are the same as polyester chips, with 5% moisture are poured into a feed silo and from there by air flow and through special pipes into the inside.  The secondary tank or silo, which is located on top of the upper part of the production line and is located on the chips drying and crystallizing system, is transferred.  The material is then fed from the secondary silo into a continuous drying system where the chips are heated by hot air and stirred vigorously at the same time to prevent the chips from sticking together to form any lumps or lumps of material.  Avoid heating in the physical phase (amorphous – crystal) during the process.  The design of the dryer and stirrer is such that it ensures that the chips are dried and crystallized in the shortest possible time and without sticking to each other.  Whenever the amount of material entering the system changes due to a change in the spinning and yarn production program, the bus resets the airflow heater to remove the fine particles that are always present in the design feed (polyester chips) and  Collects in a cyclone.  Then, to prevent heat loss, the exhaust gases from the dryer system will be used to preheat the inlet air from the dehumidifier system.  After that, the dried chips in the dryer with a moisture content of less than PPm 3 are poured into the extruder due to their weight.  A dehumidifier system consisting of two tanks containing a desiccant (silica gel) is used to absorb the moisture required by the air drying system.  Ambient air enters one of these two tanks through a set of fans and filters to absorb its moisture.

Then, after a certain period of time, the air flow is transferred from one tank to another by a series of conversion valves controlled by an automatic control system, and at the same time hot air is sent from another separate path into the first tank to regenerate the silica gel in it.  .

B) extruder, polymerization and yarn spinning stage:

The starting point of this stage is the extruder, which consists of a spiral and a tubular chamber that is heated by an electric element.  In the spinning process, the extruder melts the granules, uniforms the melt and provides the required temperature until it is fed under pressure to the spinning pump.  Spinning pump is a gear pump that supplies the same amount of spinning mass (melt or solution) to each position in equal amounts and in uniform amounts.