What is Polyester Fiber and its characteristics?

Polyester is one type of polymer that has the ester functional group in its main chain. The term “polyester” as a specific material most commonly refers to polyethylene terephthalate (PET). Polyesters include natural chemicals as well as synthetics through step-growth polymerization in high temperatures. Polyesters as thermoplastics may change shape after the application of heat. While combustible at high temperatures, polyesters tend to shrink away from flames and self-extinguish upon ignition. Polyester fibers have high tenacity and E-modulus as well as low water absorption and minimal shrinkage in comparison with other industrial fibers.

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Polyester Fiber or Poly Fiber is a man-made fiber, with a high length to width ratio and with suitable characteristics for being processed into fabric.

Polyester fiber is a common textile material, which has the advantages of high strength, good elasticity, heat resistance, abrasion resistance, and light resistance, but also has the disadvantages of poor solvent resistance, dyeability, and poor hygroscopicity.

We offer polyester staple fiber with deniers from 0.9D to 25D, cutting length from 25 mm to 76mm. Our polyester staple fiber are in white and black colors, recycled grade, hollow conjugated, hollow non conjugated, hollow siliconized, hollow slick, solid fiber, spinning fiber, etc…

Our sales volume annually increases and we can guarantee :

• excellent product quality, due to the equipment of production with new high-tech equipment, the involvement of well-trained highly qualified specialists and the control of technological parameters at all stages of production;
• fast delivery due to an extensive partnership with many forwarders, suppliers and factories located across Viet Nam;
• delivery with mandatory compliance with the established deadlines of any volume of products;
• optimal prices and favorable terms of cooperation.

Since established in 2017, we have been motivated by the principles of long-term cooperation with our partners, mutually beneficial and to achieve win win situations.

Preferential characteristics and properties of polyester fiber

The manufacturing technology of these fibers consists in melting and forming polyesters, followed by pressing through a plate with many microscopic holes.

The formed threads retain the properties of the raw material and are distinguished by the following advantages:

• high temperature resistance and fire resistance;
• longitudinal and transverse tensile strength;
• resistance to shock loads, abrasion, multiple bends;
• resistance to ultraviolet light, high/low temperatures, sudden
• temperature changes, aggressive environments, bacteria, fungi, mold, etc.;
• good elasticity and thermal insulation;
• small specific gravity;
• low level of water absorption.

The poly fiber has several technical specifications below:

A) Physical Tech spec:

1. Length
2. Fineness
3. Crimp
4. Maturity
5. Luster
6. Softness
7. Resiliency
8. Work of rupture
9. Density
10. Appearance
11. Flexibility
12. Toughness
13. Elongation

B) Mechanical Tech spec:

1. Strength
2. Elasticity
3. Extensibility
4. Rigidity

C) Chemical Tech spec:

1. Solubility in aqueous salt
2. Solubility in organic salt

Other classification:

1. Primary properties:

• High length to width ratio
• Tenacity
• Flexibility
• Spinning quality (Cohesiveness)
• Uniformity

2. Secondary properties:

• Physical shape
• Elastic recovery and elongation
• Resiliency
• Flammability and other thermal reactions
• Density
• Luster
• Colour
• Moisture regain

Characteristics of polyester fiber

1. High strength

The short fiber strength is 2.6-5.7cN/dtex, and the high-strength fiber is 5.6-8.0cN/dtex. Due to its low hygroscopicity, its wet strength is essentially the same as its dry strength. The impact strength is 4 times higher than that of nylon and 20 times higher than that of viscose fiber.

2. Good elasticity

The elasticity is close to that of wool, and when it is stretched by 5% to 6%, it can be almost completely recovered. The wrinkle resistance exceeds other fibers, that is, the fabric does not wrinkle and has good dimensional stability. The modulus of elasticity is 22-141cN/dtex, which is 2-3 times higher than nylon. .Polyester fabric has high strength and elastic recovery ability, so it is durable, wrinkle-resistant and non-ironing.

3. Strong heat resistance

Polyester is made by melt-spinning method, and the formed fiber can be heated and melted again, which belongs to thermoplastic fiber. The melting point of polyester is relatively high, and the specific heat capacity and thermal conductivity are small, so the heat resistance and heat insulation of polyester fiber are higher. It is the best among synthetic fibers.

4. Good thermoplasticity, poor melting resistance

Due to its smooth surface and tight internal molecular arrangement, polyester is the most heat-resistant fabric among synthetic fabrics. It is thermoplastic and can be made into pleated skirts with long-lasting pleats. At the same time, polyester fabric has poor melting resistance, and it is easy to form holes when encountering soot and sparks. Therefore, try to avoid contact with cigarette butts, sparks, etc. when wearing.

5. Good wear resistance

Abrasion resistance is second only to nylon with the best abrasion resistance, better than other natural fibers and synthetic fibers.

6. Good light fastness

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Lightfastness is second only to acrylic. The light fastness of polyester fabric is better, except that it is worse than acrylic fiber, and its light fastness is better than natural fiber fabric. Especially behind glass the light fastness is very good, almost on par with acrylic.

7. Corrosion resistance

Resistant to bleaches, oxidants, hydrocarbons, ketones, petroleum products and inorganic acids. Dilute alkali resistance, not afraid of mildew, but hot alkali can make it decompose. It also has strong acid and alkali resistance and UV resistance.

8. Poor dyeability, but good color fastness, not easy to fade

Because there is no specific dyeing group on the polyester molecular chain, and the polarity is small, it is difficult to dye, the dyeability is poor, and the dye molecules are not easy to enter the fiber.

9. Poor hygroscopicity

It feels stuffy when worn, and polyester fiber is easy to be charged with static electricity and stained with dust, which affects the appearance and comfort. However, it is very easy to dry after washing, and the wet strength hardly decreases, does not deform, and has good washability and wearability.

Polyester Fiber Types:

A. High/Low shrink fibers:

The high shrink fiber shrinks up to 50% at 100 C while that of low shrinkage is 1%. The high shrink fiber enables fabrics with high density to be produced and is particularly used in artificial leather and high density felt. Low shrinkage fiber is recommended for air filters used in hot air, furniture, shoes, etc.

B. Micro Denier:

Micro denier is available in 0.5/0.7/0.8 deniers in cut lengths 32/38 mm. Ideal for high-class shirts, suiting, ladies’ dress material because of its exceptionally soft feel. It is also available in silicone finish for pillows. To get the best results, it is suggested that the blend be polyester rich and reed/pick of the fabric be heavy.

C. Flame Retardant:

Flame retardant has to be used by law in furnishings/curtains, etc where a large number of people gather like in cinema theatres, buses, cars, etc Europe, Asia, and the USA. It is recommended for curtains, seat covers, car mats, automotive interior, aircrafts interior, etc.

D. Cationic Dyeable:

Gives very brilliant shades with acid dyes in dyeing/printing. Ideal for ladies’ wear.

E. Easy Dyeable:

The easy dye able can be dyed with dispersing Dyes@98 degree C without the need for HTHP equipment. Ideal for village handicrafts etc.

F. Low Pill :

Low pill in 2 and 3 deniers, for suiting end-use and knitwear fiber with low tenacity of 3 to 3.5 gm/denier, So that pills which form during use fall away easily.

G. Antibacterial:

It is antibacterial throughout the wear life of the garment inside repeated washing. Suggested uses are underwear, socks, sports, blankets, and air conditioning filters.

H. Super High Tenacity:

It is above 7 g/denier and it is mainly used for sewing threads. Low dry heat shrinkage is also recommended for this purpose. Standard denier recommended is 1.2 and today 0.8 is also available.

I. Modified Cross-section:

In this, there are TRILOBAL, TRIANGULAR, FLAT, DOG BONE, and HOLLOW FIBRES with single and multiple hollows. Trilobal fiber gives a good feel. Triangle fiber gives excellent luster. Flat and dog bone fibers are recommended for furnishing, while hollow fibers are used as filling fibers in the pillows, quilts, bedding, and padding. For pillows, siliconized fibers are required. Some fiber producers offer hollow fiber with built-in perfumes.

J. Conducting Fibre:

This fiber has a fine powder of stainless steel in it to make fiber conductive. Recommended as carpets for computer rooms.

K. Low Melt Fibre:

It is a bi-component fiber with a modified polyester on the surface which softens at low temperatures like 110 C while the core is a standard polyester polymer. This fiber is used for binding non-woven webs.

There are four common types of polyester, with PET (Polyethylene Terephthalate) being by far the most commonly used. The different types of polyesters are listed below:

• PET (Polyethylene Terephthalate): This is the most commonly used grade of polyester and is known by the following trade names: Mylar, Rynite, and Impet
• PBT (Polybutylene Terephthalate): When compared to PET, PBT has a lower melting temperature
• PEN (Polyethylene Naphthalate): PEN is used in packaging applications as oxygen does not easily permeate through the packaging
• PTT (Polytrimethylene Terephthalate): Has good stain resistance and durability – as such it is typically used in the textile industry

To learn more, see our guide on What is Polyester.

Which Type of Polyester Has a Wide Range of Applications?

Polyester finds the most use as a fabric or textile. This application includes fishing nets, carpets, ropes, clothing, sportswear, and air filters. Polyester accounts for over half the total fiber use globally. 

Where Is Polyester Most Commonly Used?

Due to the prevalence of polyester fabric, polyester is used almost everywhere that fabrics are utilized. This means the consumer, via industries such as clothing, automobiles, and medicine, makes heavy use of polyesters.

Who Is the Most Common User of Polyester?

The largest consumer of polyester fibers is China. This is no surprise as China also leads in terms of global polyester production. The Asia Pacific region is set to account for over 85% of the global polyester market share.

How Much Does Polyester Cost?

In 2021, the average cost per ton of staple fiber polyester was approximately $1,053. This was an increase of over 20% when compared to 2020. The chart below indicates the movement of the polyester price over the last three years.

Are you interested in learning more about pp staple fiber? Contact us today to secure an expert consultation!