Professional Knowledge: Softening Agents Classification And Performance And Performance Testing Methods

Classification of softeners

Softener is a kind of auxiliaries in the dyeing and finishing auxiliaries with the largest variety and the largest dosage. According to reports, 920 samples of domestic and overseas samples collected from the Shanghai printing and dyeing technology institute in the past 1990-1999 years have 350 softeners, accounting for 38%. According to its chemical structure, so many kinds of softeners are basically two kinds of long chain fatty groups or polymers.

The long chain chains of long chain fatty family softeners exhibit irregular curling States, forming the flexibility of molecules. The molecular adsorption of flexible molecules plays a lubricating role on the surface of fibers, reducing the dynamic and static friction coefficients of fibers and fibers. Therefore, the structure of long chain fatty acids generally has good softening effect. In softeners, there are not only many varieties but also large dosage. These softeners can be divided into anionic, cationic, non-ionic and amphoteric types according to their ionic properties.

In addition, natural oils and paraffin softeners can also be used as natural lubricants, but they can be classified into different ionic categories according to their ionic properties.

Polymer softeners are mainly polyethylene and silicone two main categories. Polyethylene softeners are relatively simple in variety, less in dosage and less in consumption. Silicone oil softener is used mostly.

Since the main chain of polysiloxane is a flexible helical structure, it can rotate freely at 360 degrees, and the energy required for rotation is almost zero.

Therefore, the molecular structure of polysiloxane is consistent with the softness mechanism of textiles. It can not only reduce the static and dynamic friction coefficient of fibers, but also reduce the intermolecular force and reduce the surface tension of fibers, which is an ideal material for textile softeners.

Silicone softeners, especially amino modified silicone softeners, are the fastest growing softeners in recent years.

Introduction of main softener properties

Because softeners can give fabric a soft and comfortable handle, it can improve the fabric's quality and added value. This is in line with the current trend of high-end and comfortable clothing. The amount of softener is increasing, which promotes the rapid development of softener varieties. There are hundreds of softeners in China.

1, anionic softeners: anionic softeners, in addition to soap and sulfonated oil, are mainly anti - ionic compounds such as sodium succinate, eighteen alkyl ester sulfonate, eighteen alcohol ester sulfates and other anionic compounds and anionic and nonionic compounds with long alkanes. Generally, it has good wettability and thermal stability. It can be used in the same bath with fluorescent whitening agent, and can be used as softener for special white fabric. It is also suitable for cellulose fiber, which can give fabric good water absorption, but its adsorption to fiber is similar to that of direct dyes. It is relatively weak, so its softness is poor and easy to wash away. In addition, because of its softness in bath, it can be used for silk scouring to prevent abrasions.

2, non-ionic softeners: non ionic softeners are generally ten fatty acids (or alcohol) polyoxyethylene esters (or ethers), pentaerythritol or ester of sorbitol. Since the non ionic softener is less absorbent than the ionic softener, it can only play a smooth role. But it can be combined with ionic softeners, other compatible, good electrolyte stability, and does not make the fabric yellowing. It can be used as a non durable softener and can also be an important part of synthetic fiber spinning agent. Some of its products can be used as silk like finishing agents for silk fabrics.

3, cationic softeners: this kind of softener has more varieties and is the most commonly used softener at present. The main reason is that most fibers have negative charge in water. Cationic softeners are easy to adsorb on the surface of the fibers. They have strong binding ability, high temperature resistance and washing resistance. After finishing, the fabric is full and smooth, which can improve the wearability and tear strength of the fabrics, and also has certain antistatic effect on synthetic fibers. Therefore, it is widely used in cotton, nylon, acrylic and other fabrics, and this variety is suitable for silk. However, some cationic softeners are susceptible to yellowing at high temperatures and are accompanied by a decrease in fastness to light. Cationic softeners are generally eighteen amine or two methyl eighteen amine derivatives or stearic acid and polyvinyl polyamine condensation. According to its structure, it can be divided into tertiary amine softener, quaternary ammonium salt softener, imidazoline quaternary ammonium salt softener, dialkyl two methyl quaternary ammonium salt softener and so on.

4, amphoteric softeners: amphoteric softeners are a class of softeners developed to improve cationic softeners. It has strong affinity for synthetic fibers, no yellowing and dyestuff discoloration. It can also be used in silk retraining process to make silk feel better. Amphoteric softeners can also be used together with cationic softeners for synergistic effects. These softeners are generally alkyl amine lactone structures.

5. Silicone softeners: these softeners are latex or microemulsion of polysiloxane and its derivatives, which can make the fabric feel soft and smooth. Products have emulsion polymerization, polymer silicone oil emulsification and modification, blending and other production workers, have basically formed a system, the supply of variety brands are also more. But the application effect and performance are still very different.

(1) two methyl silicone non emulsion: This product is the first used in silicone softeners, and the relative molecular mass of silicone oil used as softener is generally 60 thousand -7 million. After finishing, it can give the fabric a smooth, smooth and cool feel, reduce the friction coefficient of the fabric, and improve the wearability and stitching property of the fabric. However, because there is no reactive group on the molecular chain, it can not react with fibers or cross itself, but only molecules are attracted and attached to the fiber surface. Therefore, the washability is poor and the elasticity is limited.

Silicone silicone emulsion (hydroxyl silicone oil emulsion): This is the most widely used silicone softener in China in 1980s. The relative molecular mass is generally 60 thousand -8. The greater the molecular weight, the better the softness and smoothness. Because of the end of its molecular chain and the sealing of the red base, it can form a flexible polymer film with the reactive backbone of the fiber under the action of the crosslinking agent and catalyst. Therefore, it has washability and can improve the elasticity of the fabric. Organosilicon hydroxy emulsion is divided into cationic organosilicon hydroxy emulsion and anionic organosilicon hydroxy emulsion according to the ionic nature of the emulsifier used. Although organosilicon hydroxy emulsion has hydroxyl at the end of the molecular chain, it is helpful to improve its hydrophilicity and emulsion stability. However, because the emulsion particles of organosilicon hydroxy emulsion are difficult to control fine and homogeneous, the stability of emulsion is also difficult to master. Therefore, the emulsion stability of silicone hydroxy emulsion softener is also an important index to evaluate its quality.

(3) hydrophilic soluble silicone (polyether type hydrophilic organosilicon): these silicone softeners are polysiloxane and polyether modified polysiloxane. They are colorless, spanparent and thick liquid. They can give fabrics good moisture absorption, permeability and antistatic properties. Because they are non-ionic, they can be mixed with various auxiliaries. When used together with resin, it can reduce the chlorine absorption and release of formaldehyde. Besides the resin finishing and softening finishing, it is also widely used in pigment dyeing process. It can not only improve the feel of the fabric due to adhesives, but also improve the shortcomings of the adhesive roller.

Amino modified organosilicon: the introduction of amino groups on macromolecular chains of polysiloxane can greatly improve the properties of silicone. The introduction of amino groups can not only form a strong orientation and adsorption with fibers, but also reduce the friction coefficient between fibers, and react with epoxy, carboxyl and hydroxyl groups. So it can be applied to various kinds of fiber and its blended fabrics such as cotton, wool, silk, viscose fiber, polyester, nylon, acrylic fiber and so on. After finishing, the fabric can obtain excellent softness and resilience, and its handle is soft and plump, smooth and delicate. Generally speaking, the higher the amino content is, the better the softness is. But higher amino content also means greater yellowing. This is mainly the side chain of - (CH2) NH (CH2) 2NH2 has two amino groups (primary amine and Zhong Anji), a total of three active hydrogen atoms, easy to oxidize to form chromophores, and the structure of the diamines has accelerated oxidation synergy. Therefore, there must be an optimal balance between the amino content and yellowing.

The preparation of microemulsion with amino modified organosilicon has been developing rapidly in the past ten years. Due to the introduction of amino groups on the siloxane molecules and their hydrophilicity, the appropriate emulsifier and preparation process can be used as a microemulsion with a particle size below 0.15 m. Because its particle size is smaller than the wavelength of visible light, it has no impedance to visible light, so it can make the emulsion spanparent. The particle size is only 1/10 of the particle size in the ordinary emulsion, which increases the number of effective particles in the microemulsion by 103 times. (if the concentration is the same), the contact between microemulsion and fabric will increase greatly, and it will spread well on the surface of the fabric and easily penetrate into the fiber. Therefore, this product can give the fabric good internal softness, and this softness is more durable. The water solubility, storage stability, heat stability and shear stability of microemulsion products are generally better.

Although the commonly used double amino silicone softeners have good softness, their whiteness, water absorbency and easy detergency are poor, and become serious with the increase of amino functional groups in polymers. In order to improve these shortcomings, it can be achieved by changing the type and quantity of amino functional groups. The change of amino functional groups is mainly the conversion of primary amine to secondary amine group or tertiary amine group, such as N- propyl cyclohexanamine (secondary amine) and N propyl piperazine (tertiary amine) modified silicone softener has been developed for fabric finishing. This softening agent can reduce yellowing during baking, and Bibb amine functional silicone softener has less hydrophobic property, but it makes the texture of the fabric feel dull. It is mainly used for soft finishing of bleached and light colored fabrics.

In addition, in order to obtain a super smooth feel, the ends of two methylsiloxane are modified by amino groups, which can form a very neat directional arrangement on the fabric, thus obtaining excellent smooth handle. If the side chain bases and the two ends of polysiloxane are replaced by amino groups, they can be used as fabric finishing agents, so that the fabric can obtain better softness.

Now silicone softeners have developed rapidly, more and more varieties and prices have declined. The number of applications of silicone softeners has increased considerably. In addition to the above silicone softeners, silicone softeners such as epoxy, amide and carboxyl groups are also available. Because there should be less, there is no introduction here.

6. Low molecular polyethylene emulsion: the softener is the product of low molecular polyethylene after oxidation and emulsification. It has a certain affinity for fibers, which makes the products smooth, and can be applied in one bath with resin, and can improve the tear strength and wear resistance due to resin finishing. It is a cheap fabric softening and slippery assistant before the popularization of silicone softener. At present, these softeners are not commonly used alone, they can be used as a compounding component of various softeners, and can also be used as stabilizer in hydroxyl silicone emulsion.

Testing methods of softeners properties

1. assessment of hand feeling

Generally speaking, a few skilled operators evaluate the feel of the fabric in terms of softness, smoothness and fullness according to the actual touch feeling of the soft finishing fabric.

2. heat discoloration and heat resistance yellowing test

(1) test method: soften finishing fabric (heat discolouration as colored fabric, heat resistant yellowing for bleached fabric), baking (or pressing) 3min at (185 + 2) centigrade, cooling down according to the method.

Heat resistance is evaluated by comparing the color difference between heated and unheated fabrics.

The yellowing resistance of heat is judged by the degree of yellowing of the heating fabric relative to the unheated fabric, and the grade is evaluated by the gray card. The whiteness of heated and unheated fabrics can also be determined, and the yellowing performance is evaluated according to the decrease of whiteness.

2.

Fabric heat treatment can be used in hot air dryer, oven, sublimation fastness tester, scorching tester and other equipment.

According to different fiber types, heat treatment temperature and time should be different, depending on circumstances.

3. scalability test

Test method: cut the sample into a strip of radial 24cm and zonal 2cm, then in the relaxation state, two marking lines with fixed length 20cm in the middle of the fabric are clamped onto the fixed clamp on the upper part of the fabric, the load at the lower end is added to 5g, the distance between the marking lines is L2 (CM) after 1min, then the load of 5g is still kept on the heavy hammer of 200g, and the distance between the marks is L3 (1min) after 1min. The elongation and recovery rate were calculated according to the measured L1, L2 and L3.

2. Calculation:

Elongation = (L2 - L1) * L1 * 100%

The recovery rate is (L2 - L3) x (L2 - L1) x 100%

Description: when the distance of L2 is measured, the loading quality is 100g.

4. wear resistance test of fabric

Instruments and materials:

Instrument: the instrument can be used for testing flat grinding, torturing and grinding. It can be imported from Japan with three wear-resistant instrument. The earliest domestic Y521 three grinding instrument has been used less. The Y522 disc fabric wearer is mainly used for leveling mill.

Others: abrasive; round knife sampler (11.3cm); ruler and so on.

2. Test methods:

Flat grinding: with circular cutter, 5 pieces of circular specimen with straight 11.3cm are placed on the rubber membrane, and the friction speed is adjusted (125 + 5) times /min, the mass of the pressing block is 0.45kg, the air pump pressure is 28kPa, and the multi-directional friction is carried out with emery paper (400# water sand paper) until the sample is worn out, the instrument stops automatically, and the friction times are recorded, and the average value is calculated.

2. Qu Mo: take 20cm x 3cm on the cloth sample (if the yarn density is 20 /cm below, take 20cm * 4cm) 5 pieces of warp (through weft), weft (weft), and draw the same number of side yarns on both sides, so that the width of the specimen is retained 2.5cm. Plus the tensile weight and the briquetting selected according to the square meter mass of the fabric (see table below). The sample and blade are loaded, the switch is shifted to the crankshaft and the instrument is started. The friction speed is (125 + 5) times /min. The fabric is repeatedly bent and rubbed repeatedly on the metal blade until the sample is broken. Record the number of friction, the average value of the meridian and the zonal direction (integer).

The quality of the selected blocks or blocks is based on test data.

Torture: take 5 pieces of 7.6cm / 2.5cm warp and weft sample respectively, and install the specimen on the torture fixture. The quality of the pressing block is 0.227kg or 0.454kg (according to the square meter quality of the fabric). Use 400# sandpaper as abrasive to rub in the same direction until the specimen is broken. The number of friction is recorded, and the mean value is obtained from the zonal and zonal directions.

5. determination of softness - heart-shaped loop method

1. Sample preparation: 10 pieces of warp and weft samples of 2.5cm * 25cm are respectively cut from the fabric to be tested.

2. Test procedure: tape the ends of the sample (1.25cm * 7.6cm) on a flat strip (318mm * 19mm * 3mm), and the installation is shown in the diagram. The effective length of the specimen is 20.0cm, and the shape of the heart-shaped ring is perpendicular to the flat strip of the suspended fabric. After 1min, the distance from the top of the horizontal flat top to the bottom of the heart-shaped ring was measured L (mm). The warp and weft directions of the specimen are measured 5 times, both on the positive and negative sides, and expressed in the zonal and zonal mean values. The measured value of L is large, indicating that the fabric is softer and vice versa. In addition, the measured value L can also indicate the inverse value of fabric directional (warp and zonal) flexural hardness.

Explanation: softness can also be tested by stiffness test. But the bending stiffness and softness are reciprocal relations, that is, the shorter the bending length is, the better the softness is; the opposite is relatively poor.

6. draping test

Sample preparation: take a circular sample of 2 24cm in diameter without a crease, and cut (or punch) a circular hole with a diameter of 0.4cm at the center of each circular specimen. A special device for testing: drape tester

Test steps: cut out the same drawing of the same size as the sample and holding plate, weigh it on the balance (accurate to 0.001g). Adjust the fabric drape tester to the tracing state, place the sample on the clamping plate, so that the fabric is directed to the operator, then put the plexiglass pattern, the blueprint and the upper cover in sequence, gently press 3 times down, rest 3min, and according to the projection projection of the hanging fabric, then cut the pattern and weigh again.

Calculation:

F= (M3 - m2) x (M1 - m3) x 100%

Formula: F - draping coefficient

M1 - the quality of paper with sample size, G;

M2 - the quality of the paper with the size of the holding plate, G;

M3 - the quality of paper after drape projection, G;

Results: the smaller the draping coefficient is, the softer the specimen is.

7. fastness to stitch - sewing test

Test machine: high-speed sewing machine, rotating speed 4000r/min; sewing needle 9# ~ 14#, needle tip should be kept smooth, not hair.

2. Test method: place the sample above 24h in standard condition (temperature 20 C, relative humidity 65%), take the rectangular fabric to 60cm, weft to 15cm, fold into 4 layers and form a 15cm * 15cm square. The distance between rows and rows is 1.3cm, and the zonal and zonal seams are two rows (well shaped). The stitching density is 11 stitches per 2.5cm (11 + 1). When the sewing is finished, the specimen is spread out, and the side of the sample is examined by 5 times magnifying glass, and the number of needles broken by the needle is recorded, and the percentage of the total number of needles is calculated.

Calculation: broken needle rate = broken yarn pinhole number, total pinhole number x 100%

Explanation:

If there is no high-speed sewing machine, the household sewing machine can be used to test with the highest speed.

There is no need to wear sewing thread on sewing needles.

If the above method fails to see the fracture of the fiber, the sample can be immersed in 10min at 40 C and 0.5% soaping lotion, washed for 10 times along the warp and weft direction, washed in cold water, dried at low temperature and inspected with a magnifying glass.

8. test of slipping resistance of woven fabrics

Test instrument: fabric strength tester, stretching speed (100 + 10) mm/min.

Preparation: sample preparation, weft sample (finishing and unfinished fabric) 35cm * 10cm each, and longitudinal direction parallel to the weft yarn. Fold a line at 10cm at one end of the sample. Fold the specimen along the folding line and use the sewing machine [Nm90] (14#) along the width of the crease 10mm. The stitch density is 5 to 5.5 /cm. A sewing thread is made to sew a straight seam. The seam must be parallel to the spanverse yarn, and the stitched specimen can not wrinkle. Then cut along the crease.

(3) the specimen is clamped on the test instrument (powerful machine), the clamping center point is located on the longitudinal center line of the sample, the tension is not more than 2N, then the tensile load is applied to the sample, and the length of (80N) slippage of the center of the fabric suture is measured when the 120N (depending on the amount of fabric slip) is applied. A comparison of the amount of warp (or weft) yarn spanferred at a certain load between the finishing and unfinished fabric stitches is made.

Description: if the GB/T 13772.1 - 1992 test is required for the anti slip test of woven fabrics, the requirement for the strength machine is higher (drawing load elongation curve), and the calculation of slip volume is also more troublesome. Therefore, the yarn slippage of fabric sewn at certain load is measured here.

9. surface friction test

The test device consists of two wood boards (wood blocks), which are lined with test fabrics. The next one is a wooden board with a test fabric on the top and one end fixed and the other side can adjust the inclination angle freely. The upper block is a block of wood with test fabric fixed below. In order to make the two layers of fabric tightly contacted, a heavy object can be placed on the upper wood block. During the test, Shiki Ira was placed on the test table, and the wood blocks were placed in the middle of the lower board. Then, with the fixed point (or contact point with the table) as the fulcrum, the lower plank will slowly lift the other end of the lower plank until the wood block starts to slide down, and measure the angle of the lower plank (theta).

Fabric static friction factor (MU) =tg theta

10. fabric style testing

The feel of the fabric is reflected by the touch, squeezing, pressing and kneading of the hand, and the mechanical properties of the fabric are reflected to the brain. The fabric style instrument is the instrument that decomposes the physical effect of the hand on the fabric into some basic mechanical functions, such as stretching, bending, compression, shearing, friction, etc. The fabric style instrument can make the sensory measurement of fabric feel into an objective quantitative measurement. The measurement of single mechanical properties has been introduced in some of the above methods, while the fabric style instrument combines these individual properties in one instrument.

The mechanical properties of different types of fabric stylus are different. For example, the domestic SYG style tester can be used to determine the 15 mechanical properties of fabric, such as bending, compression, friction, arched deformation and weaving resistance.

Fabric mechanical performance indicators tested by SYG style tester