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Polyester Rope The Physical Structure

Laizhou Lutong Plastics Co.,Ltd | Updated: Oct 12, 2017

Dacron is a staple of synthetic fiber and is the name of the polyester fiber in China. Pure terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) as raw material through esterification and ester exchange and polycondensation reaction of fiber forming polymer, polyethylene terephthalate (PET), the spinning and aftertreatment fibers.

The chemical structure

Polyester is the basic material of polyethylene terephthalate, molecular formula/OC - Ph - COOCH2CH2O - n, because there are many molecular chain ester base the said polyester (PET), its chemical structural formula of long-chain molecules for H (OCH2CCOCO) NOCH2CH2OH, used for fiber polyester relative molecular weight is in commonly 18000 ~ 25000, wool-like polyester with low molecular weight, high molecular weight polyester industry. In fact, there is a small amount of monomer and low polymer. These low polymers have a low degree of polymerization and are in a circular form. Polyethylene terephthalate can be reduced by direct esterification by direct esterification of terephthalic acid (PTA) and ethylene glycol (EG).

From the composition of polyester molecule, it is composed of short fat hydrocarbon chain, ester base, benzene ring and end alcohol. In addition to the presence of two endol-hydroxyl groups, the polyester fibers have no other polar groups, so dacron fibers are extremely hydrophilic. Polyester molecule contains about 46% of the ester, ester base in more than 200 ℃ when the hydrolysis, thermal cracking can happen, in strong alkali soap solution, lower the degree of polymerization, ordinary dosage of detergent washing powder under 100 ℃ had no effect on polyester; Polyester contains aliphatic hydrocarbon chain in the molecule, it can make polyester molecular has some soft music, but due to the rotation of benzene ring in polyester molecular and cannot, therefore, polyester macromolecular basic for rigid molecules, molecular chain easily kept linear. Therefore, polyester macromolecules are easy to crystallize under this condition, so the crystallinity and orientation of dacron are high.

The physical structure

The morphological structures observed in the microscope are of circular section and no special longitudinal structure. The filamentous fibrillar tissue can be observed under an electron microscope.

The fibers can change the elasticity of the fiber, make the fiber have special gloss and bulk, and improve the ability of the fiber to be combined with the ability of covering, anti-pilling and static. As triangular fibers have a flash effect; Five-leaf fiber has a fat gloss, good feel and anti-pilling. Hollow fiber because of internal cavity, low density, good heat preservation.

Aggregation structure

Application of electron diffraction measured the thickness of the polyester chain folded wafer is about 10 NM or so, and the length of the polyester single-base is 1.075 NM, therefore, can think wafer thickness of 9 polyester molecular single-base length. However, the length of the chain of polyester macromolecule is about 1.075*130 (mean polymerization degree) =140NM, thus the chain of dacron chips must be folded. The fold is likely to occur in the ch2-ch2-ch2 segment, which is due to the soft flexbility of the chain and easy to fold.

In addition, the polyester macromolecules can also form a straight chain crystallization (fibrillation crystallization). It can be seen that the crystal of the inside of dacron is coexisted with the original fiber crystal. The ratio of these two crystals varies with the tensile and heat setting conditions.


1. High strength. Short fiber strength is 2.6 ~ 5.7 cN/dtex, high strength fiber is 5.6 ~ 8.0 cN/dtex. Due to its low hygroscopicity, its wet strength is basically the same as that of dry state. The impact strength is four times higher than nylon and 20 times higher than viscose fiber.

2. Good elasticity. The elastic approach to wool is almost completely restored when it is 5 to 6 percent elongated. Wrinkling resistance is more than other fiber, that is, the fabric is not creased, the dimensional stability is good. Elastic modulus is 22 ~ 141cN/dtex, 2 ~ 3 times higher than nylon. Polyester fabric has a high strength and elastic resilience. Therefore, it is fast and durable.

3. Heat resistance dacron is made from melt spinning, and the formed fiber can be heated and melted again, which belongs to thermoplastic fiber. The melting point of dacron is relatively high, and the specific heat capacity and thermal conductivity are small, so the heat resistance and adiabatic of polyester fiber are higher. It's the best synthetic fiber.

4. Good thermal plasticity and poor fusibility. Because the polyester surface is smooth and the internal molecules are closely aligned, polyester is the best material for heat resistance in synthetic fiber fabric. It has thermoplastic, can make pleated skirt, and pleating is durable. At the same time, the anti - melt property of polyester fabric is poor, and it is easy to form holes such as soot and Mars. Therefore, should try to avoid contact with cigarette end, spark, etc.

5. Good wear resistance. Wear resistance second only to the best nylon, better than other natural fibers and synthetic fibers.

6. Good light resistance. Light resistance is second only to acrylic. The light resistance of polyester fabric is better than that of acrylic. It is superior to natural fiber fabric. Especially behind the glass, the suntan ability is good, almost equal to the acrylic.

7. Corrosion resistance. Bleaching agent, oxidizer, hydrocarbon, ketone, petroleum products and inorganic acid. The alkali is not afraid of mold, but it can be decomposed. It also has strong anti-acid and alkaline resistance to uv radiation

8. The dyeing sex is poor, but the color fastness is good, not easy to fade. Because there is no specific dye group on the polyester molecular chain, and the polarity is small, the dyeing is more difficult, the stain is poor, and the dye molecules are not easy to get into the fiber.

9. The moisture absorption is poor, the clothes have a sultry feeling, and easy to bring static, dirt and dirt, affect the beauty and comfort. However, it is easy to dry after washing, and the wet strength is hardly reduced, not deformed, and has good washing ability.


Woven from ordinary polyester filament fabric, the garment with performance had good strength, smooth crisp, easy to wash the advantages of fast drying, but there are hard, soft tactility, poor luster, and poor permeability, hygroscopicity, shortcomings. If compared with the silk fabric, the gap is larger, so the silk thread structure is the first thing to imitate silk, to eliminate the disadvantage of the poor performance.