From the perspective of China’s polyester filament yarn development, it developed from conventional spinning to high-speed spinning, which started from chip spinning. As the stable development of PET melts spinning polyester filament and rapidly increased numbers of chip spinning manufacturers, the profit of regular chip spinning filaments is going down sharply. Therefore, the chip spinning enterprises, which are not superior in cost, are forced to seek reform in order to compete with melt direct spinning ones.

Our country started the research and development of chip spinning polyester filament through the study about the development progress of overseas countries and analysis about fiber structure of high value-added imported polyester fabrics at that time. At first, the various profiled filament was introduced to the market, and then came colored filament, cationic modification filament, different contraction mixed fiber, flame retardant polyester filament, polyester silk brocade composite fiber, sea-island composite fiber, high shrinkage, total extinction fiber, superfine fiber (dpf 0.3 or less), composite fiber, conductive composite fiber, civil and industrial polyester monofilament, etc.

With the continuous emergence of various differentiated polyester filaments, the profit margin of chip-spinning polyester filament has not been enlarged by melt spinning one but has gradually gone up. In recent years, the profit margin of related enterprises has even exceeded that of melt direct spinning filament enterprises. With the newly opened track of differentiation, chip spinning enterprises can better meet the needs of users, forcing melt direct spinning enterprises to explore and produce differentiated polyester filament as well.

“Filament Differentiation is the only way for chip spinning mills to gain profit from the fierce market competition with melts spinning enterprises.”

1 More Obvious Advantage in Small-scale Chip Spinning Mills

Slice chip spinning takes polyester chip as raw material, which needs to increase the chip storage tank and mixing equipment, so it has no advantages compared with melt direct spinning in the aspect of conventional mass products. However, the advantage of chip spinning lies in its flexible production and rapid market response, especially in the development of differentiated, functional, and other high value-added products.

Chip Spinning Process

The technology of chip spinning has the advantages of convenient production conversion, low conversion cost, and convenient product development, especially in the development and production of super simulation fiber, multi-component composite fiber, and other complex products with structure and function. Compared with melt spinning enterprises, the production capacity and output scale of polyester filament enterprises using chip spinning technology are relatively small, but the product features are more obvious and added value of the products is high.
Chip-spinning enterprises take differentiation as their main development strategy. In terms of development strategy and trends, outstanding chip-spinning companies are devoted to the development of specialty products and continuously improve added-value in products to meet the demands from downstream fabric and terminal apparel, home textile, etc. For example, they have been researching and developing “five imitations” fibers (imitation cotton, imitation linen, imitation silk, wool-like, imitation leather), especially high simulation animal fur. What also included are functional fiber (new super or superfine fiber and elastic fiber, etc.) and eco-friendly fiber, which uses biomass feedstocks or recycles materials for mass production. Under the background of consumption upgrading in China, chip spinning technology meets the personalized needs of the public and guides the trend of the downstream market through continuous development and production of differentiated fibers.

2 Difficult to Achieve Differentiation for Melt-spinning Enterprises

Melt spinning takes polymer melt as raw material and is fed into spinning without the process of granulation and re-melting. Its biggest advantages are large yield and relatively low cost. With the localization of the polyester industry, the melt spinning equipment with large capacity and low input is developing rapidly and the scale of the equipment is expanding continuously. Melt spinning enterprises increase their cost advantage by expanding production scale.

Melt Spinning Process

Melt spinning has the characteristics of a large single yarn scale and a long process. The polymerization and spinning conditions affect each other in the production process. And the process regulation influences a wide range. As a result, it has the disadvantages of difficult product quality control and product development.
Melt spinning can only produce conventional products and common differentiated products. It is difficult to produce differentiated products with higher technical content, more functional requirements, and more complex multi-components and structures.
For example, they can not manufacture products with high technical content, like super simulation, two-component, multi-component, new polyester (PTT). Moreover, because of the high expense of conversion cost in melt spinning production lines and poor production flexibility, the development of specialty products is very risky and costly. Based on the above characteristics, melt spinning manufacturers mainly produce conventional products and simple differential products (such as fine denier and ultra-fine denier).

Process Route Chip Spinning Melt Spinning
Raw Materials PET chip, PTT chip, PBT chip, etc.
Two or more types are used together according to production demands.		 PTA and MEG
Products All the products can be produced by melt spinning. All kinds of functional, composite, and differentiated products. common products and general differentiated products
Advantages convenient product development, convenient product conversion, and low conversion cost, especially in the development of products such as super-simulated fibers with multi-functions and multi-component composite fibers large-scale production, high production capacity, and relatively low cost
Disadvantage relatively high unite production cost
less competitive in conventional products compared with melt direct spinning		 limited differentiated product development, poor production flexibility, high demand for technology and function, the lack of production capacity of multicomponent and complex products.