Physical performance indicators: length, fineness, specific gravity, gloss, moisture absorption, thermal properties, electrical properties
Stability index: stability at high and low temperatures, stability to light-atmosphere, stability of chemical reagents, stability of microbial action
Mechanical properties (mechanical properties): breaking strength, initial modulus, resilience, elongation at break, resistance to multiple deformation
Processing performance indicators: cohesive, electrostatic, dyeing
Additional quality indicators for staple fibers: fiber length, crimp, fiber defects
First, the linear density (denier)
- Turks (special) symbol: tex
Definition: The number of grams of 1000m long fiber weight.
Such as 78dtex/24F
- Dtex symbol: dtex
Definition: grams of 10,000m long fiber weight.
- Denier symbol: D
Definition: grams of 9000m long fiber weight.
Fineness is the degree of fiber thickness. There are two types of direct indicators and indirect indicators. The direct index is generally expressed by the diameter and cross-sectional area of ​​the fiber. Since the cross-sectional area of ​​the fiber is irregular and difficult to measure, it is usually not indicated by the direct index, so it is often indicated by an indirect index. The indirect indicator is determined by the fiber mass or length, that is, the quality (fixed length) or length (fixed weight) of the fiber at a fixed length or a fixed weight. In the chemical fiber industry, the fiber mass per unit length is usually used. Density (formerly called denier) indicates that there are three commonly used representation methods.
(1) Representation method
Special or special is the International System of Units (legal measurement unit). The weight in grams of 1000 meters of fiber is called special; one tenth of it is decitex. Since the fineness of the fiber is fine, and the value is small when the fineness is expressed by a special number, the fineness of the fiber is usually expressed in decitex.
For the same fiber (that is, when the specific gravity of the fiber is constant), the smaller the specific number, the finer the single fiber, the softer the hand feeling, the softer the gloss and the easier deformation processing.
2. Denier
The weight in grams of 9000 meters of fiber is called denier. For the same fiber (that is, when the specific gravity of the fiber is constant), the smaller the denier, the finer the single fiber. Once the illegal measurement unit of linear density has been discontinued, it has been changed to the International System of Units.
3. Metric count
The metric count is referred to as the male branch and refers to the length (m) of the fiber of unit mass (g). For the same fiber, the higher the count, the finer the fiber. The metric system is a non-statutory unit of measure for linear density, which has been discontinued and replaced by the International System of Units.
The values ​​of special or decitex, denier and count can be converted to each other as follows:
Denier × count = 9000
Special number × count = 1000
Fractal number × count = 10000
Denier = 9 × special number
Fractal number = 10 × special number
(two) measurement method
There are two methods for determining the fineness of chemical fibers: direct and indirect methods. The most widely used direct method is the mid-section cutting method. The indirect method uses a vibrometer or an air flow meter to measure the fineness of the fiber. The vibration method is recommended internationally to measure the linear density of a single chemical fiber. Since the vibration method measures the linear density of a single fiber by applying a predetermined tension to straighten it, the measurement result is relatively accurate, especially when the fiber having a large curl and the relative strength of the single fiber are required to be used. More superior.
In the production of chemical fiber, the fluctuation of raw materials, equipment operating conditions and process conditions will make the undrawn yarn and the drawn yarn uneven. Therefore, determining the uniformity of the strand along the length of the fiber is an important indicator for measuring the change in fiber quality, which affects the physical-mechanical properties and dyeing properties of the fiber, as well as the textile processing properties of the fiber and the appearance of the fabric. The measurement is generally carried out using a Uster strip uniformity meter, and the measurement results are expressed by an average difference coefficient U%, a mean square error coefficient CV%, and a range coefficient R.
- Metric count (Nm) - a multiple of 1 gram of yarn length at a specified moisture regain, that is, 1 gram of weight is exactly 1 meter long, 1 (male) yarn, 1 gram weight yarn length It is 200 meters long and the fineness of the yarn is 200 pieces. The metric count is also a fixed weight system, so the larger the count, the finer the yarn. Cotton textile wool textile industry has been used.
- Inch Count - means that the unit weight (1 lb) of yarn is a multiple of 840 yards at a given moisture regain. A few 840 yards are a few yarns in the UK. (often expressed in Ne).
Fixed length calculation formula:
(1) Denier (D): D = g / L * 9000 where g is the weight of the wire (grams) and L is the length of the wire (meters)
(2) Tex (number) [tex(H)]: tex=g/L*1000 where g is the weight (gram) of the yarn (or wire) and L is the length of the yarn (or wire) (m)
(3) Dtex: dtex=g/L*9000 where g is the weight of the wire (grams) and L is the length of the wire (meters)
Constant weight calculation formula:
(1) Metric count (N): N=L/G where G is the weight (gram) of the yarn (or silk) and L is the length of the yarn (or silk) (m)
(2) Inch count (S): S=L/(G*840) where G is the weight of the thread (in pounds) and L is the length of the thread (code)
2. Conversion formula:
(1) Conversion formula of metric count (N) and denier (D): D=9000/N
(2) Conversion formula for inch count (S) and denier (D): D=5315/S
(3) Conversion formula for dtex and tex: 1tex=10dtex
(4) Conversion formula for tex and denier (D): tex=D/9
(5) Conversion formula of tex and inch count (S): tex=K/SK value: pure cotton yarn K=583.1 purified fiber K=590.5 polyester yarn K=587.6 cotton yarn (75:25) ) K=584.8 Victorian cotton yarn (50:50) K=587.0
(6) Conversion formula for tex and metric (N): tex=1000/N
(7) Conversion formula for dtex and denier (D): dtex=10D/9
(8) Conversion formula of dtex and imperial count (S): dtex=10K/SK value: pure cotton yarn K=583.1 purified fiber K=590.5 polyester yarn K=587.6 cotton yarn (75: 25) K=584.8 Victorian cotton yarn (50:50) K=587.0
(9) Conversion formula for dtex and metric count (N): dtex=10000/N
(10) Conversion formula for metric centimeter (cm) and inch inch (inch): 1inch=2.54cm
(11) Conversion formula of metric meter (M) and inch code (yd): 1 yard = 0.9144 m
(12) Conversion formula for satin square gram weight (g/m2) and mmi (m/m): 1m/m=4.3056g/m2
(13) Conversion formula for the actual weight and weight of satin: pound weight (lb) = weight per metre (g/m) * 0.9144 (m / yd) * 50 (yd) / 453.6 (g / yd)
Second, the breaking strength
The specimen was stretched by a tensile tester under specified conditions until breaking, and the breaking strength and elongation value were obtained, and the breaking strength was calculated from the breaking strength and the linear density.
Unit: cN/dtex (relative strength)
Absolute strength and relative strength
Wet strength and dry strength
The strength of a fiber refers to the ability of the fiber to resist external damage, which largely determines the durability of the textile product.
The strength of the fiber can be expressed by the absolute strength of the fiber, which is the maximum load that the fiber can withstand under continuous load increase until it breaks. Its legal calculation unit is Newton (N) or Newton (cN). In the past, it used to be expressed in grams or kilograms.
Since the fiber strength is related to the thickness of the fiber, the absolute strength is incomparable for fibers of different thicknesses. Therefore, the relative strength is often used to indicate the strength of the fiber. Relative strength is the maximum tensile force a fiber can withstand per unit linear density (per tex or per denier). The legal unit of measurement is cattle/special (N/tex) or centigram/tex (cN/tex). In the past, it used to be expressed in gram/den.
Third, the elongation at break
The percentage of elongation that occurs when the fiber is stretched is the elongation. The elongation at which the fiber is stretched to break is called the elongation at break, which indicates the ability of the fiber to withstand tensile deformation.
The fiber with large elongation at break is softer in hand. During the textile processing, the force received can be buffered, and the filaments and broken ends are less; however, the elongation at break should not be too large, otherwise the fabric is easily deformed. The elongation at break of ordinary textile fibers is suitably in the range of 10% to 30%. However, for industrial strong yarns, it is generally required to have high breaking strength and low elongation at break, so that the product is not easily deformed.
Fourth, the initial modulus
The elastic modulus of a fiber is also called the "initial modulus", which is the stress-strain ratio at the beginning of a straight line on the fiber tensile curve. In the actual calculation, the elastic modulus of the fiber can be generally obtained by taking a point at which the elongation at the load elongation curve is 1%.
The size of the fiber's elastic modulus indicates how easy the fiber is under a small load. It reflects the rigidity of the fiber and is closely related to the properties of the fabric. When the other conditions are the same, the elastic modulus of the fiber is large, the fabric is stiff and not easily deformed (such as polyester); on the contrary, when the modulus of elasticity is small, the fabric is soft and easily deformed (such as nylon).
Five, combustion performance
The chemical composition and structure of various textile fibers are different, so their combustion properties are also different. The burning property of a fiber refers to the ease with which the fiber burns in the air. In order to determine and characterize the combustion properties of fibers and their products, the International Regulations use the Limiting Oxygen Index (LOI) method. The so-called limiting oxygen index is the lowest percentage of oxygen contained in the mixture of nitrogen and oxygen in the environment when the fibers of the fire leave the fire source and the fibers continue to burn.
The textile fibers can be classified into flammable fibers, combustible fibers, flame retardant fibers, and incombustible fibers according to the characteristics of the ease of ignition of the fibers during combustion, the burning speed, and the flammability after leaving the flame.
Classification of fiber flammability
6. Hygroscopicity
Hygroscopicity is one of the physical properties of fibers. The ability to absorb water from a gaseous environment is often referred to as hygroscopicity.
1. Moisture regain and moisture content
The moisture content of the fibrous material, that is, the amount of adsorbed water, is usually expressed by moisture regain or moisture content. The former refers to the percentage of the mass of the fiber and the mass of the dried fiber, and the latter refers to the percentage of the mass of the fiber and the actual mass of the fiber. The chemical fiber industry generally uses the moisture regain rate to indicate the moisture absorption of the material.
2. Regain rate and standard moisture regain rate under standard conditions
The actual moisture regain of various fibers varies with the temperature and humidity of the environment. In order to compare the moisture absorption capacity of various fiber materials, they are placed under uniform standard atmospheric conditions (20 ° C, 65% relative humidity) for a certain period of time to make them The moisture regain rate reaches a steady state value in the "hygroscopic process", and the regain rate at this time is the regain rate under the standard state.
(2) Detection method of hygroscopicity
According to the test characteristics of hygroscopicity, it can be roughly divided into two categories: direct measurement method and indirect measurement method.
The direct measurement method is a method for directly obtaining the moisture weight in the fiber, thereby calculating the water content or the moisture regain. Such as oven method, infrared radiation method, moisture absorbent drying method, vacuum drying method and the like. Among them, the oven method is the most widely used.
The indirect method is based on the principle that the water content in the fiber material is closely related to certain physical properties (such as resistance, capacitance, vibration absorption properties of water molecules, etc.), and the water content or moisture regain is estimated by measuring these properties, such as the resistance test method. , capacitance test method. Such methods measure quickly, do not damage the fibers, and can be measured online, but there are many interference factors, and the stability and accuracy of the results are affected.
Seven, dyeing
Dyeing is an important property of textile fiber. It contains: suitable dyes that can be used, whether the dyeable chromatograms are complete and shallow, the difficulty of dyeing process, dyeing uniformity and various dyeing Color fastness, etc.
- The dyeability of the fiber is related to three factors: dye affinity, dye speed and fiber-colorant properties.
- The combination of dye and fiber can be through the interaction of ionic bonds, hydrogen bonds, dipoles, and dyes for reactive dyes. The molecular structure and supramolecular structure of the fiber have a great influence on the affinity of the fiber and the dye. The appropriate copolymerization, blending and other modification methods are effective for improving the dyeability, that is, increasing the degree of disorder and And, there are groups which can introduce a pro-dye.
- Dyeing speed is also an important indicator. The entry of the dye from the solution into the fiber is a diffusion process which depends on the diffusion of the dye from the dye bath onto the surface of the fiber, the adsorption of the dye by the surface of the fiber, and the diffusion of the dye from the surface of the fiber to the interior of the fiber.
- The stability of the fiber-dye composite is a structural factor that determines the fastness of dyeing. The various dye fastnesses are mainly related to the properties of the fiber-dye complex, not just the nature of the dye itself.
- The uniformity of dyeing reflects the uniformity of the fiber structure, which is closely related to the process conditions of fiber production. Dyeing uniformity is one of the important quality indicators of chemical fiber filaments.
Eight, curl
- The purpose of curling: the surface of ordinary synthetic fibers is relatively straight and smooth, and the cohesion between fibers is small, which is not conducive to textile processing. Chemical, physical or mechanical crimping of the fibers and imparting a certain curl to the fibers can effectively improve the cohesiveness of the fibers, while increasing the bulkiness and elasticity of the fibers, so that the fabric has a good appearance and warmth.
- The deformed yarn is produced by a deformation technique to impart a permanent curl to the smooth and straightened filaments, so that the tow is curled, and has a certain bulkiness and elasticity.
The crimping characteristics of the textured yarn are generally evaluated by the measurement of the crimp shrinkage ratio to clarify the crimp processing characteristics of each machine and to assess the suitability of the textured yarn for various uses. Differences in crimp performance indicate changes in process conditions or changes in material usage.
- There are many test methods for the deformed filament crimping performance, but they all have the same feature. They measure the length of the filament strand under different loads, and calculate the characteristic value of the crimping characteristic according to the length value.
Fibers and their products undergo external forces during processing and use, and produce corresponding deformations. When the action of the external force is removed, a part of the deformation of the fiber can be recovered, and the other part of the deformation does not recover. According to this characteristic of the fiber, the deformation of the fiber can be made into three parts, that is, the part of the deformation which can be recovered immediately after the external force is removed is called the elastic deformation; when the external force is removed, the part which can be slowly recovered is called the deformation. Elastic deformation; when the external force is removed, this part of the deformation that cannot be recovered is called plastic deformation.
The elasticity of a fiber refers to the ability to recover from fiber deformation. A commonly used indicator for the size of the fiber elasticity is the elastic recovery rate or rebound rate of the fiber. It refers to the percentage of total elastic deformation due to rapid elastic deformation and a certain period of slow elastic deformation.
When the elastic recovery rate of the fiber is high, the elasticity of the fiber is good, and the ability to recover deformation is strong. The textile made of the elastic fiber has good dimensional stability, is not easy to wrinkle during the taking process, and is relatively wear-resistant. For example, polyester has excellent elasticity, and its garments have the characteristics of crispness and wear resistance.
1. Curl shrinkage ratio After the crimped yarn is crimped, the ratio of the difference between the length of the straightened straight length and the length of the straightened elastic state after straightening and the length after straightening is measured under a predetermined load. It reflects the shrinkage produced by the re-recovery of the crimped three-dimensional structure after the textured yarn is straightened.
2. Curl Modulus After the textured yarn is crimped, the ratio of the difference between the straight length and the elastic length in the elastic range and the straight length is measured under a predetermined load. It reflects the stretchability of the textured filament in the elastic stretch range.
Curl stability The deformed yarn is crimped and the ratio of the crimp shrinkage after the load is increased to the weight before the load is applied. It reflects the amount of crimp shrinkage that the textured yarn can retain after being subjected to heavy loads.
4. Curl appearance During the winding process, the deformed filament causes partial curl to disappear, causing the potential curl to reappear, and the curl appears.
5. Curl-forming medium The substance that can be tested to form a temporarily curled and permanently deformed material. Such as dry hot air, water vapor and hot water.
Nine, boiling water shrinkage rate
Definition: The percentage difference between the length of the synthetic fiber sample before and after boiling water shrinkage treatment versus the length before treatment.
Ten, fiber wear resistance (supplement)
Fibers and their products cause wear during continuous processing due to friction during processing and actual use. The wear resistance of the fiber refers to the performance of the fiber to withstand external wear.
The abrasion resistance of the fiber is closely related to the fastness of the textile product. The pros and cons of wear resistance is an important indicator of the performance of clothing for clothing. The wear resistance of the fiber is related to the macromolecular structure, supramolecular structure, elongation at break and elasticity of the fiber.
The order of common fiber wear resistance is as follows:
Nylon>Polypropylene>Vinyl®>Ethylene>Polyester>Acrylic>Polyfluoride>Maeve>Silk>Cotton>Ma>Fuqiang Fiber>Copper Ammonia Fiber>Viscose Fiber>Acetate Fiber>Glass Fiber.
XI. Stability of chemical reagents and microorganisms (supplement)
Stability to chemistry is one of the material's stability properties, also known as chemical resistance. It is a measure of the ability of a fiber to resist the action of a chemical agent. Stability to the action of microorganisms refers to the ability of fibers to resist the action of aphids and molds, also known as microbial resistance.
The stability of chemical fibers to chemical agents is primarily determined by the structure of their polymers. Generally, the carbon chain chemical fiber has better stability to acid and alkali than the heterocyclic chemical fiber, but also has a relationship with the side group. For example, the acrylic fiber has a cyano group on the macromolecular chain, and thus is not resistant to a strong base.
The chemical stability of polyester fibers depends mainly on the molecular structure. In addition to poor alkali resistance, polyester fiber is superior to other chemical agents. Polyester fiber is resistant to microorganisms and is not affected by aphids or molds.
Nylon fiber has good alkali resistance and resistance to reducing agents, but its acid resistance and oxidant resistance are relatively poor. The nylon fiber has a good ability to resist microbial action. In sludge water or alkali, the ability to resist microbial action is second only to that of chlorinated fiber, but the nylon fiber with oil or sizing agent has a reduced ability to resist microbial action.
The acrylic fiber is resistant to acid and alkali, and 35% hydrochloric acid, 65% sulfuric acid, and 45% nitric acid have no effect on the strength, and the strength is hardly decreased in 50% caustic soda and 28% ammonia water. Acrylic fiber is resistant to insects and has good mold resistance.
The vinylon fiber has poor acid resistance and swells and decomposes in concentrated hydrochloric acid, nitric acid and sulfuric acid. Good alkali resistance. There is almost no decrease in the strength in the 50% caustic soda solution and in the concentrated ammonia water. The vinylon fiber is resistant to insects and mold.
Twelve, light resistance and stability to the atmosphere (supplement)
The stability of the action of sunlight and the atmosphere is one of the indicators of fiber stability, also known as weather resistance. It is a measure of the ability of a fiber to resist performance changes caused by climatic conditions.
Lightfastness refers to the property of the fiber to maintain its mechanical properties after being exposed to light. The stability to the atmosphere refers to the performance of the fiber after being exposed to light, oxygen in the air, heat and moisture for a long time without degradation or photooxidation, and no color change.
The chemical fiber light resistance is related to the composition of the fiber molecular chain, the formation of the main chain bond and the crosslink bond; it is related to the vibration energy and conversion of the molecular gene, and is related to the aggregate structure of the fiber; and the intensity of the light radiation, the irradiation time and the wavelength related.
The climatic conditions cause changes in fiber properties, mainly due to oxygen in sunlight and air, so improving the light fastness of the fiber and the stability to the atmosphere are to improve its light stability and oxygen stability.
Thirteen, density (supplement)
The density of the fiber refers to the mass (weight) of the fiber per unit volume, and the usual unit is g/cm3. The density of various fibers is different due to the composition of matter, the arrangement of macromolecules, and the structure of fibers. Among the main chemical fiber varieties, the density of polypropylene is the smallest, and the density of viscose fiber is the largest. There are many methods for determining the fiber density, such as a liquid buoyancy method, a pycnometer method, a gas volume method, a liquid temperature rise suspension method, and a density gradient method. The density gradient method has higher accuracy and is simpler.
Physical performance indicators: length, fineness, specific gravity, gloss, moisture absorption, thermal properties, electrical properties
Stability index: stability at high and low temperatures, stability to light-atmosphere, stability of chemical reagents, stability of microbial action
Mechanical properties (mechanical properties): breaking strength, initial modulus, resilience, elongation at break, resistance to multiple deformation
Processing performance indicators: cohesive, electrostatic, dyeing
Additional quality indicators for staple fibers: fiber length, crimp, fiber defects
First, the linear density (denier)
- Turks (special) symbol: tex
Definition: The number of grams of 1000m long fiber weight.
Such as 78dtex/24F
- Dtex symbol: dtex
Definition: grams of 10,000m long fiber weight.
- Denier symbol: D
Definition: grams of 9000m long fiber weight.
Fineness is the degree of fiber thickness. There are two types of direct indicators and indirect indicators. The direct index is generally expressed by the diameter and cross-sectional area of ​​the fiber. Since the cross-sectional area of ​​the fiber is irregular and difficult to measure, it is usually not indicated by the direct index, so it is often indicated by an indirect index. The indirect indicator is determined by the fiber mass or length, that is, the quality (fixed length) or length (fixed weight) of the fiber at a fixed length or a fixed weight. In the chemical fiber industry, the fiber mass per unit length is usually used. Density (formerly called denier) indicates that there are three commonly used representation methods.
(1) Representation method
Special or special is the International System of Units (legal measurement unit). The weight in grams of 1000 meters of fiber is called special; one tenth of it is decitex. Since the fineness of the fiber is fine, and the value is small when the fineness is expressed by a special number, the fineness of the fiber is usually expressed in decitex.
For the same fiber (that is, when the specific gravity of the fiber is constant), the smaller the specific number, the finer the single fiber, the softer the hand feeling, the softer the gloss and the easier deformation processing.
2. Denier
The weight in grams of 9000 meters of fiber is called denier. For the same fiber (that is, when the specific gravity of the fiber is constant), the smaller the denier, the finer the single fiber. Once the illegal measurement unit of linear density has been discontinued, it has been changed to the International System of Units.
@=================@###page###@==================3. Metric count
The metric count is referred to as the male branch and refers to the length (m) of the fiber of unit mass (g). For the same fiber, the higher the count, the finer the fiber. The metric system is a non-statutory unit of measure for linear density, which has been discontinued and replaced by the International System of Units.
The values ​​of special or decitex, denier and count can be converted to each other as follows:
Denier × count = 9000
Special number × count = 1000
Fractal number × count = 10000
Denier = 9 × special number
Fractal number = 10 × special number
(two) measurement method
There are two methods for determining the fineness of chemical fibers: direct and indirect methods. The most widely used direct method is the mid-section cutting method. The indirect method uses a vibrometer or an air flow meter to measure the fineness of the fiber. The vibration method is recommended internationally to measure the linear density of a single chemical fiber. Since the vibration method measures the linear density of a single fiber by applying a predetermined tension to straighten it, the measurement result is relatively accurate, especially when the fiber having a large curl and the relative strength of the single fiber are required to be used. More superior.
In the production of chemical fiber, the fluctuation of raw materials, equipment operating conditions and process conditions will make the undrawn yarn and the drawn yarn uneven. Therefore, determining the uniformity of the strand along the length of the fiber is an important indicator for measuring the change in fiber quality, which affects the physical-mechanical properties and dyeing properties of the fiber, as well as the textile processing properties of the fiber and the appearance of the fabric. The measurement is generally carried out using a Uster strip uniformity meter, and the measurement results are expressed by an average difference coefficient U%, a mean square error coefficient CV%, and a range coefficient R.
- Metric count (Nm) - a multiple of 1 gram of yarn length at a specified moisture regain, that is, 1 gram of weight is exactly 1 meter long, 1 (male) yarn, 1 gram weight yarn length It is 200 meters long and the fineness of the yarn is 200 pieces. The metric count is also a fixed weight system, so the larger the count, the finer the yarn. Cotton textile wool textile industry has been used.
- Inch Count - means that the unit weight (1 lb) of yarn is a multiple of 840 yards at a given moisture regain. A few 840 yards are a few yarns in the UK. (often expressed in Ne).
Fixed length calculation formula:
(1) Denier (D): D = g / L * 9000 where g is the weight of the wire (grams) and L is the length of the wire (meters)
(2) Tex (number) [tex(H)]: tex=g/L*1000 where g is the weight (gram) of the yarn (or wire) and L is the length of the yarn (or wire) (m)
(3) Dtex: dtex=g/L*9000 where g is the weight of the wire (grams) and L is the length of the wire (meters)
Constant weight calculation formula:
(1) Metric count (N): N=L/G where G is the weight (gram) of the yarn (or silk) and L is the length of the yarn (or silk) (m)
(2) Inch count (S): S=L/(G*840) where G is the weight of the thread (in pounds) and L is the length of the thread (code)
2. Conversion formula:
(1) Conversion formula of metric count (N) and denier (D): D=9000/N
(2) Conversion formula for inch count (S) and denier (D): D=5315/S
(3) Conversion formula for dtex and tex: 1tex=10dtex
(4) Conversion formula for tex and denier (D): tex=D/9
(5) Conversion formula of tex and inch count (S): tex=K/SK value: pure cotton yarn K=583.1 purified fiber K=590.5 polyester yarn K=587.6 cotton yarn (75:25) ) K=584.8 Victorian cotton yarn (50:50) K=587.0
(6) Conversion formula for tex and metric (N): tex=1000/N
(7) Conversion formula for dtex and denier (D): dtex=10D/9
(8) Conversion formula of dtex and imperial count (S): dtex=10K/SK value: pure cotton yarn K=583.1 purified fiber K=590.5 polyester yarn K=587.6 cotton yarn (75: 25) K=584.8 Victorian cotton yarn (50:50) K=587.0
(9) Conversion formula for dtex and metric count (N): dtex=10000/N
(10) Conversion formula for metric centimeter (cm) and inch inch (inch): 1inch=2.54cm
(11) Conversion formula of metric meter (M) and inch code (yd): 1 yard = 0.9144 m
(12) Conversion formula for satin square gram weight (g/m2) and mmi (m/m): 1m/m=4.3056g/m2
(13) Conversion formula for the actual weight and weight of satin: pound weight (lb) = weight per metre (g/m) * 0.9144 (m / yd) * 50 (yd) / 453.6 (g / yd)
Second, the breaking strength
The specimen was stretched by a tensile tester under specified conditions until breaking, and the breaking strength and elongation value were obtained, and the breaking strength was calculated from the breaking strength and the linear density.
Unit: cN/dtex (relative strength)
Absolute strength and relative strength
Wet strength and dry strength
The strength of a fiber refers to the ability of the fiber to resist external damage, which largely determines the durability of the textile product.
The strength of the fiber can be expressed by the absolute strength of the fiber, which is the maximum load that the fiber can withstand under continuous load increase until it breaks. Its legal calculation unit is Newton (N) or Newton (cN). In the past, it used to be expressed in grams or kilograms.
Since the fiber strength is related to the thickness of the fiber, the absolute strength is incomparable for fibers of different thicknesses. Therefore, the relative strength is often used to indicate the strength of the fiber. Relative strength is the maximum tensile force a fiber can withstand per unit linear density (per tex or per denier). The legal unit of measurement is cattle/special (N/tex) or centigram/tex (cN/tex). In the past, it used to be expressed in gram/den.
Third, the elongation at break
The percentage of elongation that occurs when the fiber is stretched is the elongation. The elongation at which the fiber is stretched to break is called the elongation at break, which indicates the ability of the fiber to withstand tensile deformation.
The fiber with large elongation at break is softer in hand. During the textile processing, the force received can be buffered, and the filaments and broken ends are less; however, the elongation at break should not be too large, otherwise the fabric is easily deformed. The elongation at break of ordinary textile fibers is suitably in the range of 10% to 30%. However, for industrial strong yarns, it is generally required to have high breaking strength and low elongation at break, so that the product is not easily deformed.
@=================@###page###@==================Fourth, the initial modulus
The elastic modulus of a fiber is also called the "initial modulus", which is the stress-strain ratio at the beginning of a straight line on the fiber tensile curve. In the actual calculation, the elastic modulus of the fiber can be generally obtained by taking a point at which the elongation at the load elongation curve is 1%.
The size of the fiber's elastic modulus indicates how easy the fiber is under a small load. It reflects the rigidity of the fiber and is closely related to the properties of the fabric. When the other conditions are the same, the elastic modulus of the fiber is large, the fabric is stiff and not easily deformed (such as polyester); on the contrary, when the modulus of elasticity is small, the fabric is soft and easily deformed (such as nylon).
Five, combustion performance
The chemical composition and structure of various textile fibers are different, so their combustion properties are also different. The burning property of a fiber refers to the ease with which the fiber burns in the air. In order to determine and characterize the combustion properties of fibers and their products, the International Regulations use the Limiting Oxygen Index (LOI) method. The so-called limiting oxygen index is the lowest percentage of oxygen contained in the mixture of nitrogen and oxygen in the environment when the fibers of the fire leave the fire source and the fibers continue to burn.
The textile fibers can be classified into flammable fibers, combustible fibers, flame retardant fibers, and incombustible fibers according to the characteristics of the ease of ignition of the fibers during combustion, the burning speed, and the flammability after leaving the flame.
Classification of fiber flammability
6. Hygroscopicity
Hygroscopicity is one of the physical properties of fibers. The ability to absorb water from a gaseous environment is often referred to as hygroscopicity.
1. Moisture regain and moisture content
The moisture content of the fibrous material, that is, the amount of adsorbed water, is usually expressed by moisture regain or moisture content. The former refers to the percentage of the mass of the fiber and the mass of the dried fiber, and the latter refers to the percentage of the mass of the fiber and the actual mass of the fiber. The chemical fiber industry generally uses the moisture regain rate to indicate the moisture absorption of the material.
2. Regain rate and standard moisture regain rate under standard conditions
The actual moisture regain of various fibers varies with the temperature and humidity of the environment. In order to compare the moisture absorption capacity of various fiber materials, they are placed under uniform standard atmospheric conditions (20 ° C, 65% relative humidity) for a certain period of time to make them The moisture regain rate reaches a steady state value in the "hygroscopic process", and the regain rate at this time is the regain rate under the standard state.
(2) Detection method of hygroscopicity
According to the test characteristics of hygroscopicity, it can be roughly divided into two categories: direct measurement method and indirect measurement method.
The direct measurement method is a method for directly obtaining the moisture weight in the fiber, thereby calculating the water content or the moisture regain. Such as oven method, infrared radiation method, moisture absorbent drying method, vacuum drying method and the like. Among them, the oven method is the most widely used.
The indirect method is based on the principle that the water content in the fiber material is closely related to certain physical properties (such as resistance, capacitance, vibration absorption properties of water molecules, etc.), and the water content or moisture regain is estimated by measuring these properties, such as the resistance test method. , capacitance test method. Such methods measure quickly, do not damage the fibers, and can be measured online, but there are many interference factors, and the stability and accuracy of the results are affected.
@=================@###page###@==================Seven, dyeing
Dyeing is an important property of textile fiber. It contains: suitable dyes that can be used, whether the dyeable chromatograms are complete and shallow, the difficulty of dyeing process, dyeing uniformity and various dyeing Color fastness, etc.
- The dyeability of the fiber is related to three factors: dye affinity, dye speed and fiber-colorant properties.
- The combination of dye and fiber can be through the interaction of ionic bonds, hydrogen bonds, dipoles, and dyes for reactive dyes. The molecular structure and supramolecular structure of the fiber have a great influence on the affinity of the fiber and the dye. The appropriate copolymerization, blending and other modification methods are effective for improving the dyeability, that is, increasing the degree of disorder and And, there are groups which can introduce a pro-dye.
- Dyeing speed is also an important indicator. The entry of the dye from the solution into the fiber is a diffusion process which depends on the diffusion of the dye from the dye bath onto the surface of the fiber, the adsorption of the dye by the surface of the fiber, and the diffusion of the dye from the surface of the fiber to the interior of the fiber.
- The stability of the fiber-dye composite is a structural factor that determines the fastness of dyeing. The various dye fastnesses are mainly related to the properties of the fiber-dye complex, not just the nature of the dye itself.
- The uniformity of dyeing reflects the uniformity of the fiber structure, which is closely related to the process conditions of fiber production. Dyeing uniformity is one of the important quality indicators of chemical fiber filaments.
Eight, curl
- The purpose of curling: the surface of ordinary synthetic fibers is relatively straight and smooth, and the cohesion between fibers is small, which is not conducive to textile processing. Chemical, physical or mechanical crimping of the fibers and imparting a certain curl to the fibers can effectively improve the cohesiveness of the fibers, while increasing the bulkiness and elasticity of the fibers, so that the fabric has a good appearance and warmth.
- The deformed yarn is produced by a deformation technique to impart a permanent curl to the smooth and straightened filaments, so that the tow is curled, and has a certain bulkiness and elasticity.
The crimping characteristics of the textured yarn are generally evaluated by the measurement of the crimp shrinkage ratio to clarify the crimp processing characteristics of each machine and to assess the suitability of the textured yarn for various uses. Differences in crimp performance indicate changes in process conditions or changes in material usage.
- There are many test methods for the deformed filament crimping performance, but they all have the same feature. They measure the length of the filament strand under different loads, and calculate the characteristic value of the crimping characteristic according to the length value.
Fibers and their products undergo external forces during processing and use, and produce corresponding deformations. When the action of the external force is removed, a part of the deformation of the fiber can be recovered, and the other part of the deformation does not recover. According to this characteristic of the fiber, the deformation of the fiber can be made into three parts, that is, the part of the deformation which can be recovered immediately after the external force is removed is called the elastic deformation; when the external force is removed, the part which can be slowly recovered is called the deformation. Elastic deformation; when the external force is removed, this part of the deformation that cannot be recovered is called plastic deformation.
@=================@###page###@==================The elasticity of a fiber refers to the ability to recover from fiber deformation. A commonly used indicator for the size of the fiber elasticity is the elastic recovery rate or rebound rate of the fiber. It refers to the percentage of total elastic deformation due to rapid elastic deformation and a certain period of slow elastic deformation.
纤维的弹性回å¤çŽ‡é«˜ï¼Œåˆ™çº¤ç»´çš„弹性好，å˜å½¢æ¢å¤çš„能力强。用弹性好的纤维制æˆçš„纺织å“尺寸稳定性好，æœç”¨è¿‡ç¨‹ä¸ä¸æ˜“起皱，并且较为è€ç£¨ã€‚如：涤纶具有优良的弹性，其制æˆçš„æœè£…具有挺括ã€è€ç£¨ç‰ç‰¹æ€§ã€‚
1ã€å·æ›²æ”¶ç¼©çŽ‡ å˜å½¢ä¸ç»è¿‡å·ç¼©æ˜¾çŽ°åŽï¼Œåœ¨è§„定负è·ä¸‹æµ‹å¾—拉直长度与拉直åŽåˆæ¢å¤å·æ›²çŠ¶æ€æ—¶çš„长度之差与拉直åŽçš„长度的比值。它åæ˜ çš„æ˜¯å˜å½¢ä¸è¢«æ‹‰ç›´åŽå…¶å·æ›²ç«‹ä½“结构é‡æ–°æ¢å¤æ‰€äº§ç”Ÿçš„收缩率。
2ã€å·æ›²æ¨¡é‡ å˜å½¢ä¸ç»è¿‡å·ç¼©æ˜¾çŽ°åŽï¼Œåœ¨è§„定负è·ä¸‹æµ‹å¾—拉直长度与在弹性范围内的弹性长度之差与拉直长度的比值。它åæ˜ çš„æ˜¯å˜å½¢ä¸çš„å·æ›²åœ¨å¼¹æ€§ä¼¸ç¼©èŒƒå›´å†…的伸缩性能。
ã€å·æ›²ç¨³å®šåº¦ å˜å½¢ä¸ç»è¿‡å·ç¼©æ˜¾çŽ°ï¼ŒåŠ é‡è´Ÿè·åŽä¸ŽåŠ é‡è´Ÿè·å‰çš„å·æ›²æ”¶ç¼©çŽ‡çš„比值。它åæ˜ çš„æ˜¯å˜å½¢ä¸åœ¨æ‰¿å—é‡è´Ÿè·ä¹‹åŽä»å¯ä¿ç•™çš„å·æ›²æ”¶ç¼©é‡ã€‚
4ã€å·æ›²æ˜¾çŽ° å˜å½¢ä¸åœ¨å·ç»•è¿‡ç¨‹ä¸ï¼Œå¼•èµ·éƒ¨åˆ†å·æ›²çš„消失，使潜在的å·æ›²é‡æ–°æ˜¾çŽ°ï¼Œç§°å·æ›²æ˜¾çŽ°ã€‚
5ã€å·æ›²æ˜¾çŽ°ä»‹è´¨ 能使被测试的å˜å½¢ä¸å½¢æˆæš‚æ—¶å·æ›²å’Œæ°¸ä¹…å˜å½¢çš„物质。如干çƒç©ºæ°”ã€æ°´è’¸æ°”åŠçƒæ°´ç‰ã€‚
ä¹ã€æ²¸æ°´æ”¶ç¼©çŽ‡
定义：åˆæˆçº¤ç»´è¯•æ ·ç»æ²¸æ°´æ”¶ç¼©å¤„ç†å‰åŽé•¿åº¦çš„差数对处ç†å‰é•¿åº¦çš„百分率。
åã€çº¤ç»´çš„è€ç£¨æ€§ï¼ˆè¡¥å……）
纤维åŠå…¶åˆ¶å“åœ¨åŠ å·¥å’Œå®žé™…ä½¿ç”¨è¿‡ç¨‹ä¸ï¼Œç”±äºŽä¸æ–ç»å—摩擦而引起磨æŸã€‚而纤维的è€ç£¨æ€§å°±æ˜¯æŒ‡çº¤ç»´è€å—外力磨æŸçš„性能。
纤维的è€ç£¨æ€§ä¸Žå…¶çººç»‡åˆ¶å“çš„åšç‰¢åº¦å¯†åˆ‡ç›¸å…³ã€‚è€ç£¨æ€§çš„优劣是衣ç€ç”¨ç»‡ç‰©æœç”¨æ€§èƒ½çš„一项é‡è¦æŒ‡æ ‡ã€‚纤维的è€ç£¨æ€§ä¸Žçº¤ç»´çš„大分å结构ã€è¶…分å结构ã€æ–裂伸长率ã€å¼¹æ€§ç‰å› ç´ æœ‰å…³ã€‚
常è§çº¤ç»´è€ç£¨æ€§é«˜ä½Žçš„顺åºå¦‚下：
锦纶>丙纶>维纶>乙纶>涤纶>腈纶>氯纶>毛>ä¸>棉>麻>富强纤维>铜氨纤维>粘胶纤维>醋酯纤维>玻璃纤维。
å一ã€å¯¹åŒ–å¦è¯•å‰‚åŠå¾®ç”Ÿç‰©ä½œç”¨çš„稳定性（补充）
对化å¦ä½œç”¨çš„稳定性是æ料的稳定性能之一，亦称è€åŒ–å¦æ€§ã€‚它是纤维抵抗化å¦è¯•å‰‚作用的能力的é‡åº¦ã€‚对微生物作用的稳定性是指纤维抵抗蛀虫ã€éœ‰èŒä½œç”¨çš„能力，亦称è€å¾®ç”Ÿç‰©æ€§ã€‚
化å¦çº¤ç»´å¯¹åŒ–å¦è¯•å‰‚作用的稳定性主è¦å†³å®šäºŽå…¶èšåˆç‰©çš„结构。一般碳链化å¦çº¤ç»´æ¯”æ‚链化å¦çº¤ç»´å¯¹é…¸ç¢±çš„稳定性好，但与侧基也有关系，例如：腈纶纤维的大分åé“¾ä¸Šæœ‰æ°°åŸºï¼Œå› æ¤ä¸è€å¼ºç¢±ã€‚
@=================@###page###@=================@涤纶纤维化å¦ç¨³å®šæ€§ä¸»è¦å–决于分å结构。涤纶纤维除è€ç¢±æ€§å·®ä»¥å¤–，è€å…¶å®ƒåŒ–å¦è¯•å‰‚性能å‡æ¯”较优良。涤纶纤维è€å¾®ç”Ÿç‰©ä½œç”¨ï¼Œä¸å—蛀虫ã€éœ‰èŒç‰ä½œç”¨ã€‚
锦纶纤维è€ç¢±æ€§ã€è€è¿˜åŽŸå‰‚作用的能力很好，但è€é…¸æ€§å’Œè€æ°§åŒ–剂作用性能比较差。锦纶纤维è€å¾®ç”Ÿç‰©ä½œç”¨çš„能力较好，在淤泥水或碱ä¸ï¼Œè€å¾®ç”Ÿç‰©ä½œç”¨çš„能力仅次于氯纶纤维，但有油剂或上浆剂的锦纶纤维，è€å¾®ç”Ÿç‰©ä½œç”¨çš„能力é™ä½Žã€‚
腈纶纤维è€é…¸ã€ç¢±æ€§å¥½ï¼Œ35%ç›é…¸ã€65%ç¡«é…¸ã€45%ç¡é…¸å¯¹å…¶å¼ºåº¦æ— å½±å“，在50%è‹›æ€§é’ å’Œ28%氨水ä¸å¼ºåº¦å‡ 乎ä¸ä¸‹é™ã€‚腈纶纤维è€è™«è›€ï¼Œè€éœ‰èŒæ€§èƒ½å¥½ã€‚
维纶纤维è€é…¸æ€§è¾ƒå·®ï¼Œåœ¨æµ“çš„ç›é…¸ã€ç¡é…¸å’Œç¡«é…¸ä¸å‘生溶胀和分解。è€ç¢±æ€§è‰¯å¥½ã€‚在50%è‹›æ€§é’ æº¶æ¶²ä¸å’Œæµ“氨水ä¸å¼ºåº¦å‡ 乎没有é™ä½Žã€‚维纶纤维è€è™«è›€ã€éœ‰èŒæ€§è‰¯å¥½ã€‚
å二ã€è€å…‰æ€§å’Œå¯¹å¤§æ°”作用的稳定性（补充）
å¯¹æ—¥å…‰å’Œå¤§æ°”ä½œç”¨çš„ç¨³å®šæ€§æ˜¯çº¤ç»´çš„ç¨³å®šæ€§æŒ‡æ ‡ä¹‹ä¸€ï¼Œäº¦ç§°è€å€™æ€§ã€‚是纤维抵抗气候æ¡ä»¶å¼•èµ·çš„性能å˜åŒ–能力的é‡åº¦ã€‚
è€å…‰æ€§æ˜¯æŒ‡çº¤ç»´å—光照åŽå…¶åŠ›å¦æ€§èƒ½ä¿æŒä¸å˜çš„性能。对大气作用的稳定性是指纤维å—光照射ã€ç©ºæ°”ä¸çš„氧气ã€çƒå’Œæ°´åˆ†çš„长时间作用åŽï¼Œä¸å‘生é™è§£æˆ–光氧化，ä¸äº§ç”Ÿè‰²æ³½å˜åŒ–的性能。
化å¦çº¤ç»´è€å…‰æ€§ä¸Žçº¤ç»´åˆ†å链节的组æˆã€ä¸»é“¾é”®å’Œäº¤è”键的形æˆæœ‰å…³ï¼›ä¸Žåˆ†ååŸºå› çš„æŒ¯åŠ¨èƒ½é‡å’Œè½¬æ¢æœ‰å…³ï¼Œä¸Žçº¤ç»´çš„èšé›†æ€ç»“构有关；与光è¾å°„强度ã€ç…§å°„时间和波长有关。
气候æ¡ä»¶å¼•èµ·çº¤ç»´æ€§èƒ½çš„å˜åŒ–，主è¦æ˜¯ç”±äºŽæ—¥å…‰å’Œç©ºæ°”ä¸çš„æ°§å¼•èµ·çš„ï¼Œå› æ¤æ高纤维的è€å…‰æ€§å’Œå¯¹å¤§æ°”作用的稳定性是æ高其光稳定性和氧稳定性。
å三ã€å¯†åº¦ï¼ˆè¡¥å……）
纤维的密度，是指å•ä½ä½“积纤维的质（é‡ï¼‰é‡ï¼Œå¸¸ç”¨å•ä½ä¸ºg/cm3 。由于物质组æˆã€å¤§åˆ†åæŽ’åˆ—å †ç Œä»¥åŠçº¤ç»´å½¢æ€ç»“æž„ä¸åŒï¼Œå„ç§çº¤ç»´çš„密度是ä¸åŒçš„。主è¦åŒ–å¦çº¤ç»´å“ç§ä¸ï¼Œä¸™çº¶çš„密度最å°ï¼Œç²˜èƒ¶çº¤ç»´çš„密度最大。测定纤维密度的方法很多，有液体浮力法ã€æ¯”é‡ç“¶æ³•ã€æ°”体容积法ã€æ¶²ä½“温å‡æ‚¬æµ®æ³•å’Œå¯†åº¦æ¢¯åº¦æ³•ç‰ã€‚å…¶ä¸å¯†åº¦æ¢¯åº¦æ³•ç²¾ç¡®åº¦è¾ƒé«˜ï¼Œä¹Ÿè¾ƒç®€å•ã€‚
Fm200 Fire Extinguishing System,Fm200 Fire Extinguisher,Fire Extinguisher,Fire Extinguisher
Fire Extinguisher Accessories,Emergency Light & Exit Light Co., Ltd. , http://www.nbfireextinguisher.com