Comprehensive Analysis of PP Yarn (Polypropylene Yarn)!

I. Main Classifications of PP Yarn

According to the spinning process, raw material type and functional requirements, PP yarn can be classified into multiple categories, and the performance and application of different categories vary significantly:

1. Classification by spinning process (the most core classification method

This is the key to distinguishing the structure and performance of PP Yarn. Different processes determine the "fluffiness, strength and hand feel" of the yarn.

PP FDY yarn (Fully stretched filament yarn) :

The one-step process of "spinning - stretching - winding" is adopted. The yarn molecules are neatly arranged and have a high degree of crystallinity. It features high strength, low elongation and good luster, and is suitable for making knitted fabrics (such as sportswear), sewing threads and decorative belts.

PP POY yarn (Pre-oriented filament yarn) :

After spinning, only low-fold stretching is carried out. The yarn has a certain orientation but is not fully set. It has a high elongation and good elasticity. It needs to be made into PP DTY yarn (false twist deformable yarn) through the subsequent "texturing" process, and then used for weaving elastic fabrics (such as casual pants and socks).

PP OE yarn (air-jet spun yarn) :

The air-jet spinning process is adopted. The yarn structure is fluffy, with few fuzz, uniform dryness, good wear resistance and soft hand feel. The cost is lower than that of ring-spun PP yarn. It is mainly used for woven fabrics (such as workwear fabric, canvas) and carpet base fabric.

PP staple fiber yarn

First, polypropylene is made into short fibers (38-51mm in length), and then spun into yarn through processes such as ring spinning and rotary cup spinning. The yarn feels close to cotton, has poor moisture absorption but good air permeability, and can be blended with cotton and polyester to make labor protection clothing and home textile fabrics (such as bed sheets).

2. Classify by raw material type

Virgin PP yarn: Made from brand-new polypropylene chips, it features stable performance and few impurities, making it suitable for scenarios with high quality requirements (such as packaging ropes for food contact and high-end sports fabrics).

Recycled PP yarn: It is made from recycled polypropylene products (such as used plastic bottles, PP films, and used PP yarns) through crushing, granulation, and spinning. It has low cost and good environmental protection performance, but its strength and uniformity are slightly lower than those of virgin yarn. It is mainly used in non-high-end scenarios such as making eco-friendly bags, carpets, geotextiles, and inner linings of trash cans.

3. Classify by function

Functional PP yarn: By adding functional masterbatches or modification processes, special properties are endowed to the yarn, such as:

Anti-uv PP yarn (with anti-ultraviolet masterbatch added, used for outdoor sunshade nets and tents);

Antibacterial PP yarn (with antibacterial agents added, used for socks and medical protective fabrics);

Flame-retardant PP yarn (with flame-retardant masterbatch added, used for fire suits and automotive interior fabrics);

Conductive PP yarn (mixed with conductive fibers or carbon black, used for anti-static packaging and work clothes in electronics factories).

Ii. Production Process Flow of PP Yarn

The production of PP yarn involves four major steps: "raw material pretreatment - spinning - post-treatment - molding". Taking the mainstream "virgin PP FDY yarn" as an example, the process is as follows:

Raw material preparation: Add polypropylene chips (purity ≥99%) to the dryer to remove moisture (moisture content should be ≤0.05%, otherwise bubbles are likely to form during spinning).

Melt spinning: After drying, PP chips are sent into a screw extruder and melted into a melt at 230-260℃. The melt is then extruded through the spinneret (with a pore size of 0.2-0.5mm) inside the spinning box to form continuous filaments.

Cooling and stretching: The filament is rapidly cooled and shaped by cold air (at a temperature of 20-25℃), and then stretched 3-5 times through the stretching roller to make the molecular arrangement more regular and enhance the strength.

Winding and forming: After stretching, the filament is oiled (to reduce friction and prevent fuzz), and then wound into a yarn barrel by the winding machine, thus obtaining the original PP FDY filament.

Subsequent processing (as required) : If it is necessary to produce PP short fiber yarn, the original filament needs to be cut into short fibers and then spun into yarn. If dyeing is required, disperse dyes should be used for high-temperature dyeing at 120-130℃ (PP yarn has poor moisture absorption and requires pressure dyeing).

Dongguan Donghong New Materials Co., Ltd. was founded in 1991 and is located in the 冚 lower industrial zone, Wentang brick kiln, Dongcheng district, dongguan City, guangdong Province. It is a medium-sized enterprise specializing in the production of various types of polypropylene yarn. Currently, the company has over 100 employees. Our company now has more than 20 polypropylene filament production lines, forming an annual production capacity of 10,000 tons of polypropylene yarn. The market share ranks among the top in the same industry.