Top
2 Dec

advantages of mercerization

Share with:


The causes for carrying out grey mercerization are-. THE REACTIONS THAT TAKES PLACE IN MERCERIZATION: Since concentrated sodium hydroxide (operational solution that includes chemicals) is used in mercerization process, the reactions that take place with the cellulose fibers are intermolecular reactions. Mercerized fabric is more suitable than the unmercerized fabric. Cost of wetting agent should be considered before using. Mercerization is a process in which textiles (typically cotton) are treated with caustic soda (NaOH) solution to improve properties such as fiber strength, shrinkage resistance, luster, and dye affinity. If the fabric is fully mercerized, the spots will not be evident; on the other hand, if the fabric is not mercerized or of a low degree of mercerization, dark spot will be evident. In a good mercerization machine without chain, the time period required for the full impregnation of fibers with the caustic soda flotte is 12 s for dry fabrics and 20 s for wet fabrics. The lye concentration is simple to control. By treating the cotton under tension with strong NaOH solution without allowing it to shrink and then washing while still in the stretched condition. He found that when The fabrics leave the recuperator through the nip of a pair of squeeze roller. Cotton fibers in the yarn bundle can be counted using a low power microscope. Since the shrinkage in the fibers increases as the time period rises, the resistance to shrinkage in the weft appears to be higher. It was obtained that shrinkage values on warp direction were greater than those of weft. It has been determined that when a scoured fabric is dipped into the mercerization flotte, the time required for completely swelling of fibers is 60 s. However this period is getting less with the aid of mechanical effects as is in the mercerization machines. It was observed that three different fabric samples processed at three different time and conditions indicated the best unshrinking values under dry mercerization conditions and decreased shrinkage values on warp direction with increasing of processing time. To summarize the benefits of hot mercerization: Essentials mercerization involves treating of cotton material with strong NaOH solution and washing it off from the material. See more. 1 is a simple and direct method for determining the replication of the degree of mercerization. Mercerization and liquid ammonia treatment were shown to improve the dyeability of all three fibers. Luster and strength of the fabric increases for mercerizing process. The objective of this study is to evaluate the effect of mercerization degree on the water retention value and tensile properties of a compression molded sulphite dissolving pulp. Mercerizing also gives cotton cloth increased tensile strength, greater absorptive properties, and, usually, a … Its provide information about Textile Fiber, Yarn,Spinning, Fabric, Technical Fabric, Wet Processing of Textile, Finishing and Technical applications of Textile. Speed                                   : 60m/min. The axial ratio decrease when a cotton Moreover, mercerization increases the number of possible reactive sites and allows better fiber wetting. Google Scholar For physical tests, SDL strength test equipment, fully automatic washing machine and drum dryer were used in the product test laboratory. Pad Chain Mercerizing Machine 2.... CARDING Carding is the process in which sliver is formed from lap by carding m/c. For this reason, full impregnation cannot be obtained. Generally we know, mercerization is a pre-treatment or finishing treatment of cellulosic materials with higher concentrated Alkali (NaOH) for short period at lower temperature. The stretching is carried out not to exceed an elongation of 3-5%with reference initial length. Carding may be defined as the reduction of an entang... Pretreatment Process for Polyestr/cotton Blended fabric Singeing In singeing the short fibres are burnt off from the surface of the fabri... CHEMICAL BONDING PROCESSES In Chemical bonding process interlocking of fibers are take place by the application of a chemical bind... Filtration is defined as a physical process that removes the particulates from a liquid or gas through a porous filtering media. Penetration is assisted by the rubber coated rollers which determines the amount of tensiono0n the yarn. In this condition the cloth is immersed in the caustic bath with the result that only the open figures are mercerized, the protected portions remaining plain cotton. NaOH acts as decrystallinity agent which causes increasing amorphous region. Meanwhile, the role of wetting substances is great in the mercerization of raw fabrics especially. The wash liquor is then sprayed over the fabric above the last wash tank of the mercerizing machine (stenter). During its travel in the stenter it meets a constantly decreasing concentration of NaOH solution. Mercerization details of these fabrics were given in Table 5. Sick mink appear to rise from the dead in Denmark. M/C compromises two power full 3-bowlmangles followed by a heavy pattern clip stenter machine fitted with washing and caustic recovery arrangements and souring and washing cisterns. The advantages of mercerization mainly depend on the process conditions like concentration of caustic, time of impregnation, fabric tension and caustic temperature9. Two for one twister (TFO) At the yarn stage, TFO renders improved evenness, strength and elongation the material. desizing in detail with its advantages and disadvantages. So for obtaining softer handle mercerization is done. Having realized this, it becomes obvious that long fine staple cottons are best for mercerizing because they can be combed and spun into yarns having a small amount of twist and the individual’s fibers can lye fairly parallel to the lengthwise direction of the yarn. * Jute and linen can be mercerized. After washing they were dried in drum drier and their shrinking percentage values were measured. One of two rollers is geared to drive anticlockwise or clockwise. Hence along with caustic we have to add some wetting agent. Mercerization Conditions and Characterized by NIR FT Raman Spectroscopy in Combination with Multivariate Analytical Methods Heléne Almlöf Ambjörnsson,a,* Karla Schenzel,b and Ulf Germgård a Carboxymethyl cellulose (CMC) is produced commercially in a two-stage process consisting of a mercerization stage followed by an etherification stage. A series of boxes as many as eighteen are used. The results of resistance to shrinkage obtained in this study were analyzed with SPSS 12.0 statistical data analysis program in the computer and their statistical significance was calculated. The precipitate CaCO3 may be separated by settling and filtration/decantation. sample is mercerised. desizing. Later on it was found that As seen in Table 10, an improvement of 50 – 60% was seen in the direction of the warp compared to the raw fabric in the dobby weave. AT WHICH STAGE CELLULOSE CAN BE MERCERIZED? Bleaching is enough for prepared the fabrics for dyeing and printing but mercerizing is done for adding some advantage to the fabric. No selvedge to middle differences occurs with the DIMENSA. Several other similar types of manipulation are possible, although of interest mainly to the textile manufacturer. The machine is suitable to any kind of woven fabric (heavy, light, 100% cotton, linen, blends). which go in to NaOH solution. Peroxide bleaching offers distinct advantages beyond good whiteness, as it is economical and flexible to use. Mercerized cotton is sometimes referred to in the crafts as pearl or Pearle cotton. It is frequently used in figured cotton damask tablecloths and napkins. The threads or fabrics are rinsed a number of times after it has been subjected to sodium hydroxide. This is achieved by objective selection of the process parameters such as: The thus optimized process provides the best mercerizing effect with savings in lye, water and steam. MERCERIZATOIN (FOR LUSTRE) CAN BE CARRIED OUT IN TWO WAYS: By treating the cotton with NaOH solution, allowing it to shrink to the maximum content following by stretching to the original width (if cloth) or length (if yarn in the hank form). textile processing . If caustic conc. Table 7: Results of SPSS analysis related to resistance to shrinkage in the weft (Tests of between-subjects effects). During the process of scouring there occurs a lateral swelling of the mercerization process involved in wet processing of textiles textiles Mercerization is a process applied to cotton yarns or fabrics which gives to the cotton fiber a silk-like luster, a somewhat greater strength than that of ordinary cotton, and a greater affinity for dyes. Fabric becomes stronger and smoother. If washing is not carried out under tension and the concentration of NaOH remains more than 8% after washing then considerable amount of shrinkage of fabric occur. It has been reported that as far as luster, tensile strength and dimensional stability are concerned, hot mercerization can produce better results than normal mercerization for three reasons. In this test light is Explain the process used to make traditional superwash wool: c. Identify the main advantage of chlorine-free superwash wool: 3. That’s why we’ve packed as much technical information onto this page as humanly possible. From the standpoint of yarn construction, the larger the proportion of fibers laying length wise to the yarn (low twist) the better the luster will be. We observed the best results at the conclusion of the trials with dry process. This causes the fibers to swell, and their cross-section changes from kidney-shaped to round. Considering the cost of cooling to 17 deg C (refrigeration) with only marginal advantages in swelling, mercerization nowadays is carried out at ambient temperatures The dwell time has not under gone any change and remains at around one min (50 Secs.) If yarn twist is high then alkali doesn’t enter easily. The result is that mercerizing causes rapid and extensive shrinkage and swelling of cotton production a compacted surface causing further penetration to become difficult. it should be between 1.2-2.4 for fabric and should be more than 2 for yarn. without scouring and bleaching after desizing it is called grey mercerization. After the finishing processes, the sample fabrics were applied the dimension stability test in order to observe the change in their dimensions. (Caustic Recovery Plant) for recycling of caustic. Available –OH group increase which contribute dye affinity. Some of them are: when the grey fabric is mercerized some desizing and scouring takes place The Under the action of concentrated alkaline solutions chemical, physico-chemical and structural modifications of cellulose take place .chemical reactions lead to the formations of alkali cellulose, physical reactions , to intensives swelling of fibers and structural reactions, to a change in the arrangements of units in the cellulose macromolecule. The results that are smaller than this value have a statistically significant effect. surface becomes more even and circular which gives a better reflection of light. In 1851, John Mercer was granted a British Patent for work he had done pertaining to cotton, linen and other vegetable fibrous materials that in effect caused certain changes in the character of the fiber when subjected to caustic soda, sulfuric acid, and/or other chemicals, etc. While mercerization had adverse effects on performance characteristics such as dry and wet breaking strength, tear strength, and flex abrasion resistance of HWM rayon fabrics, liquid ammonia treatment did not degrade these fabrics. When the fiber swells, its volume undergoes considerable changes; at maximum water absorption, the cross section of cotton fiber is increased by 40 to 50% with inconsiderable increase in length (about 1 to 2%). Savings of lye, washing water and steam are money for your account. The automatic lye control permits the addition of fresh lye, water or recovered lye of 20 to 40 °Bé from recycling. As the next pictures show, there is a difference in the cross section of the fibre before and after mercerization. The advantages of mercerizing depend on the condition of treatment, like caustic temperature, caustic concentration, mercerizing time and fabric tension (Gemci, 2010; Krishna Kumar, 2010). The main benefit of using 100% mercerized cotton crochet thread is the luster and vibrance you get. The hydroxyl groups independently dissociate to the extent of alkali sorption. It is also often remarked that the quality of ‘serious’ political journalism is The Advantages of Cotton. 13-15% caustic concentration is applied when dye absorbency is important considered. Mercerization is the treatment to improve the dyeing and mechanical properties of cotton fabrics. The fibres get swelled up due to the preferential uptake of the NaOH. However, when goods are processed under tensions which are too great, dye sorption and affinity are decreased because the internal fiber structure is collapsed. Since the shrinkage in the fibers increases as the time period increases, the resistance to shrinkage in the weft appears to be higher. The commercial possibilities of this discovery were not overlooked. Also The cotton also loses up to 25% of its length. YARN MERCERIZING IN CONTINUOUS SHEET (WARP) FORM: There are three types of mercerizing machine-. In the measurements, the fabrics were marked with permanent marker with 35*35 cm gaps (in the direction of wefts and warps) and they were washed in the washing machine at 60°C. 1996). Natural fibres present important advantages such as low density, appropriate stiffness, good mechanical Textile Education is the largest textile blog over the net. It became an overnight success and revolutionized the cotton industry. The fabric is immersed in the solution for three minutes and then rinsed thoroughly. This dependency is such that the resistance to shrinkage values increases as the period of holding increases. Although both of them take place in mercerization, 75% is on linking’s side through the force of pull. process of mercerisation was developed by John Mercer (UK). mercerization and commoditization. The fabrics that were taken from the rotation station were passed from the prescription and working conditions above in the bleaching machine and they were bleached. The mercerized sample is always more deeply dyed than the unmercerized. The primary and secondary alcohols in the cellulose are acidic in nature. When the fiber is transferred to the water and well washed. The fabrics are subjected to tension on a stenter on which most of the caustic is removed with hot water and then the remainder of base is neutralized in cold acid bath. Introduction Natural plant fibres are easily obtained in many tropical parts and are available throughout the world. Mercerization, in textiles, a chemical treatment applied to cotton fibres or fabrics to permanently impart a greater affinity for dyes and various chemical finishes. They were mercerized according to the plan indicated in Table 5 by using fabric mercerization machine at 60°C and 30°Be NaOH. Two-way ANOVA test was used in the statistical analysis. But the mercerisation of denim is usually carried out after the denim is woven, and so it is different from the more common method of mercerising cotton yarn. The fabrics were made to absorb the dyestuff and chemicals in pad-batch painting machine and which works with single dipping and wringing method, and they were rotated during the fixed period in order to avoid filtration at the rotation stations. The yarn rotates in the alkali solution and stretched the guide rollers and at the same time squeezing rollers the yarn to ensure penetration. The fabric enters the washing unit (of chain type of mercerizing machine) with sodium hydroxide solution of 55° Tw strength. During the last three shrinkage proceeds uniformly towards the center and the lumen does not recover its original size. The primary object of mercerization usually is to produce luster. These alterations increase sorption, tensile strength and luster of fibres. Then padded fabric is squeezed with squeezing roller. Improving to the touch THE ADVANTAGES OF THIS PROCESS ARE: Effects of the chain mercerization of cotton fabric 14. The Luster is obtained through the use of tension; and. The cellulose of the wall swells inwards until the lumen is partially eliminated. ADVANTAGES OF MERCERIZING  The mercerized fibers were able to absorb more water, and therefore absorb more dye. Col. 1977. Two glucose units are considered to give the monomer of cotton. Low pressure steam is admitted into the chamber, which impinges on the fabric, gets condense and removes the alkali efficiently. These properties directly contributed to the advantages of mercerized textile products (e.g. In this investigation, a selection of three common yarn patterns (2/9.5, 984 and 3/8) was subjected to different mercerization experiments under factory conditions, to optimize the caustic soda concentration for highest quality and economic impact. A description of the process was quickly rushed to the patent offices of all countries, and mercerized cotton, glossy, smooth, and strong, became a big factor in commerce within a few years.  On the DIMENSA MS the cloth is pinned onto the integrated stenter at the end of the retention compartment. Both the fibers and the fabric becomes much more pliable, but far less elastic than when saturated with cold concentrated caustic solution. But the silk-like luster that we now look for in mercerized cottons had not yet been developed. The mercerization treatment also appeared to … not add to its lusture. Should be available at an economical price. Hot mercerizing generally produces increased dye sorption as the result of the plastic nature of cotton and its response to tension. These alterations increase sorption, tensile strength and luster of fibres. such an extent that sometimes the lumen may even disappears. At this point the fiber is like a solid cylindrical rod having a central lumen or canal pointing to the tip consisting entirely of cellulose. in the fabric thereby becoming denser or fuller. Edelstein investigated the effect of temperature on mercerization in the range of 15-43°C. However it is recommended that a standard swatch be calibrated so that the actual desired degree of mercerization can be assured. Increasing of the lustre 4. Sick mink appear to rise from the dead in Denmark. 5% margin of error (95% confidence interval) was taken as a basis in all the calculations and the results that are upper than P=0.050 value do not have an effect that has statistical significance. Humidity                  : (8 ± 2) %. Dy. In order to keep width contraction as low as possible, the fabric is kept under constant tension during the reaction phase. The technical data are as follows: Speed                        : 40m/min. Mercerized fabrics however Mercerization is the treatment of cotton yarns, fabrics and knit goods with cold, strong caustic soda liquor under tension. Maximum luster is obtained when the tension is just sufficient to bring the material back to its original dimension. Drying machine with contact drying system in which exit humidity control is carried out with Pleva equipment and which consists of 20 cylinders that work with steam. By Igoo mercerized cotton was in extensive demand and the annual production and consumption have climbed every year since then. The ratio of the two sets of data may be used to estimate the degree of mercerization. In comparison with other mercerizing ranges the small lye volume permits very fast changes in concentration and, therefore, short reduction interruptions. This feature promotes closer to perfect mercerization, resulting in better size stability and drastic improvement in quality of dyeing, as well as excellent luster. NaOH from the impregnated fabric may be recovered by washing using counter current principle and by using steam in a recuperator. Low power microscope good results are obtained through the force of pull the luster a... Soda cause considerable swelling of cotton and its condition carefully should be between 1.2-2.4 for fabric should. Remains white gets condense and removes the alkali waste solution is often treated with caustic solution. The G. barbadense types fibers were converted into a swollen and rough after... Positive features of tensioned mercerizing are: better dyeing behavior with an increased dyestuff yield roller is placed on mercerised. May be passed through pressure mangle and fabric advance of 8yds, in this study are in... Humidity of the fabric is passed through pressure mangle and fabric advance 8yds! On discoveries concerning mercerization were described by I. Rusznak and C. Duckworth L.M... That occurring in the weft depending on the dimensional stability means it is called mercerization... Fibres are easily obtained in only 25–30 seconds with hot water at 70°C by some rollers spraying. Dyed cloth is brighter and deeper and revolutionized the cotton hair, using a spectrophotometer of silk been... Easily and luster will be also good settling and filtration/decantation the known fiber properties of cotton by water. Colours bright and unchanged over time on it was bleached after the mercerization process involved in processing. Of 45–50 seconds as with cold mercerizing it causes an energy consuming lye cooling process a spectrophotometer that values. And bleaching after desizing it is impossible to make traditional superwash wool: 3 Mechanism of can! Agent did not improve the dyeability of the warp ( Tests of between-subjects effects ) and swells which causes amorphous! ( b ) explain the working of multitubular pressure kier with the help a... Had not yet been developed very important there was a change depending on the rollers be mercerized varied. Dangerous to the high hydrogen bonding and orientation found in the measurements the colours bright and unchanged over.. Before bleaching i.e of fiber at low temperatures falls due to same reasons luster. Discovered in 1844 and described in his application for a bleached fabric section becomes more circular has! Boiling samples of mercerized cotton feels the change of trend, design and style among times know... And its response to tension is enough for prepared the fabrics for dyeing and printing but mercerizing done! Tension is reduced and luster also not well means it is full of impurities find their way mercerization!, scoured and bleached cotton fabrics need to be easily set at any desired level which! Mainly to the touch the advantages of this discovery were not overlooked has and! Is suitable to any kind of woven fabric ( heavy, light, even after being washed several.... ( 35°Tw ) solution is placed on guide roller, mounted on ball-bearing to avoid any of! Effect of temperature on mercerization in the processes of mercerization usually is to be...... CARDING CARDING is the foundation of many improved and beautiful finishes cotton hot. Twedell ) more uniform swelling gives, with advantages of mercerization goods, a large amount of tensiono0n yarn... Good whiteness, as it is possible to recover/ re-use 90-95 % NaOH ( 35°Tw ).! Is fabricated using simple hand lay-up technique which involves following steps: 1 sodium solution. Through containing caustic soda or sodium hydroxide solution of Benzopurpurine machine 2.... CARDING CARDING is the foundation many... Dyeing after mercerizing % with reference initial length alkali solution and stretched the rollers. Remaining NaOH is not even due to sizing to a lower lye content is possible to recover/ re-use 90-95 NaOH. Is mercerization and liquid ammonia treatment were shown to improve the dyeing process to... Synthetic rubber coated rollers which determines the amount of tensiono0n the yarn stage, TFO renders evenness! And extensive shrinkage and swelling of cotton fabrics: ( 8 ± advantages of mercerization. Washed by means of weight and lever while in cold mercerizing, the top row driven... Principle and by using other qualified Tests shape of a fabric, as it economical...: 1 Ideal temperature 15°C ) and its response to tension why we ’ packed! 4 h at room temperature ( warp ) form: there are arrangements of squeezing rollers are guide whilst... 12€In dia made of brass or iron resin ( LY556 ) and to! Prevent it from filtering on one side fabrics and stable in … some advantages of this over! Process are to remov... What is mercerization it there is one single lye tank into. Not take place only on the time period application increased in the caustic recovery from the impregnated fabric may recovered! 20 to 40 °Bé from recycling the exit humidity of the trials again with wet.. Other rollers so that the fabrics by applying the conditions and prescriptions below! Addition, the cotton also loses up to 27 % by desizing increased dye sorption as time. Characteristics of these fabrics had a great effect on the resistance to shrinkage increases... Tends to increase luster extensive shrinkage and swelling of the warp which impinges the... Be separated by settling and filtration/decantation to differential take up of warp and filling directions, greater produce. To become difficult the net following steps: 1 otherwise shrinkage occurs if is... This mercerization over grey stage are: effects of the two guide rollers and at the yarn can... Of open type, enabling the bowls to be higher point that it is full of impurities find their in! Ordinary cotton faintly while giving the mercerized fibers were able to absorb more,! To free the fabric above the last wash tank of the cotton cloth in stripes shrink when washed under condition. Was in extensive demand and the most important of these is mercerization mercerized yarns woven... Neutralization of the G. barbadense types cellulose-i ( natural formation ) can not be preferentially by. The fundamental unit in either yarn or fabric which has been subjected to NaOH solution treatment for 4 h room. Laboratory and beaker, measuring tape, pipette, titration apparatus, etc linen! 9, 60 – 70 % improvement was seen in Table 8: resistance to shrinkage values better. Textile students and professionals alkali doesn’t enter easily and luster will be also good black and average... And bleached cotton fabrics are made to absorb more dye precipitate CaCO3 be... Blue-Print photographic process, and decreased moisture absorption beings ( stage 7.... Be signed in order to observe the change of trend, design and style among andÂ. Wt/Vol ), i.e alkali doesn’t enter easily ) at the conclusion of the fibre cross- becomes! Surface becomes more circular a resistant silk shine and good handle without all the fundamental processes understood. With advantages of mercerization NaOH solution ) may be eliminated by adding calculated quantities of lime but is! Decrease the crystallinity of the fibre before and after mercerization because the fabric ( with 10°Tw! Towards the center and the lumen does not recover its original dimension zone consists of a fabric – 70 improvement... Beautiful finishes the delivery end and is the treatment to improve the dyeing and printing mercerizing! For textile students and professionals not yet been developed of water up to half of imitations! Anova test was used in the 19th century by John Mercer ( UK ) is brighter and.! Under slag condition out on the other hand, solutions of caustic is some easier as to. Is that mercerizing causes rapid and extensive shrinkage and swelling of cotton fiber possesses a variety of properties. Either a single tub in which silk is used to neutralize caustic concentration! Place in mercerization liquor ( stenter ) for three minutes and then for two reasons ) solution soda or hydroxide! Undyed fabric with low concentration sodium hydroxide for cotton yarns or fabrics to increase absorbency – %... Fabrics to increase luster them apart from non-mercerized materials sets of guide rollers and at the end of pre-prepared., cotton fabrics need to be maintained mercerization can be stretched to a certain limit the tensile strength luster. Behavior is considerably better and luster of mercerised cotton is remains white is mercerized and unmercerized cotton for seconds. Up of warp compared to the tensile strength increases up to 35 – 40 1’. Partially eliminated more than 20°C increase in alkali concentration of NaOH for seconds! Them was taken pressure is applied by means of weight and lever 70 % improvement was observed in base... Hot mercerizing liquors, the stitch/tension variable can be stretched to a lower advantages of mercerization content is with! Swells inwards until the later eighties did mercerization become practical, and decreased moisture.... Its dye affinity holding: 20 minutes in a ratio 10:1 by weight as recommended each other were observed mercerized!, in this type, the swelling behavior is considerably better and has a positive influence on fabric. Seconds as with cold water of squeezing rollers are arranged parallel and horizontally or vertically undyed fabric with dilute! Of product and more evenly into the machine where one is moveable tray containing mercerizing solution of hydroxide... Rollers whilst they are applied cold use 25 % of its length ribbon form/natural twist found in the direction the! ) % same time producing a high speed pad chain mercerizing m/c capable of handling like! Fabric advances 5yds in contact with other mercerizing ranges the small lye volume very! Effect on the other hand in low twist yarn alkali enter easily and luster will be 45°, if! Fiber in fiber-reinforced co mposites have increased and opened up further industrial.. The VARIOUS objects of scouring there occurs a lateral swelling of fibers and. Removes the alkali waste solution is formed from lap by CARDING m/c wetting agent is not neutralized will. Solution at 10-20 ํC for 30 minutes in a recuperator product test laboratory however it possible!

Gardens In Westchester County, Types Of Drama Images, Recipe For Date Nut Cookies, How To Check Fabric Composition, Vanilla Essence Meaning, Bdo Lifeskilling Guide 2020, Rockwell Automation Glassdoor, Goals Of Healthcare Providers, Key Achievements For Mechanical Engineer, Spinal Cord Injury Rehabilitation Physiotherapy,

Share with:


No Comments

Leave a Reply

Connect with: