Explanation on operating rate of polyester industry

Besides the polyester polymerization rate, the operating rate index of the polyester industry also involves the run rate of polyester filament yarn, polyester staple fiber and PET bottle chip. Confusion may appear during the tracing of the run rate: why does the operating rate of polyester filament yarn, polyester staple fiber and PET bottle chip lower than the polyester polymerization rate sometimes? How do these indicators relate with each other? It is necessary to make explanation here.

The polyester plants we mentioned refer to all units that undergo the polymerization reaction of PTA and MEG. After the polymerization, according to different later products, it can be further divided into (direct-spun) PFY, PSF, PET bottle chip and PET film unit. If there is no later process, directly producing PET fiber chip, it is called chip unit.

However, few domestic polyester units purely produce PET fiber chip now, PFY and PSF unit is more common. In addition to spinning, a portion of the chip is produced, called side chip.

Therefore, we generally discuss the capacity of PFY, PSF and PET bottle chip, but rarely talk about PET fiber chip capacity. PET fiber chip is more as an intermediate good or an alternative product, without the concept of capacity strictly, but will affect the accounting of polyester production.

For example, a polyester plant with annual capacity of 200KT is used to produce PFY, so the corresponding direct-spun PFY capacity is also at 200KT, and the daily capacity is 550 tons.

This unit, if the PFY production is 550mt/day, not producing PET fiber chip, then the corresponding direct-spun PFY run rate and the polyester polymerization rate is both at 100%.

If PFY daily output is 440 mt/day and PET fiber chip daily production is 110 mt/day, the corresponding O/R for PFY is only 80%, but the polymerization rate is still 100%.

If PFY daily output is 440 mt/day and no PET fiber chip is produced, then the corresponding O/R for PFY is 80%, and the polymerization rate is also 80%.