Cryogenics - an Engineering Tool for Textiles and Apparel
Volume 8, Issue 1, Spring 2013
Cryogenics - An Engineering Tool for Textiles and Apparel
M. Parthiban, M.R. Srikrishnan and S. Viju Department of Fashion, Textile Technology PSG College of Technology
ABSTRACT
Cryogenics is the study of the production of very low temperature (below −150 °C, −238 °F or 123 K) and the behavior of materials at those temperatures. The word cryogenics stems from Greek and means "the production of freezing cold"; however, the term is used today as a synonym for the low-temperature state. A person who studies elements under extremely cold temperature is called a cryogenicist. Rather than the relative temperature scales of Celsius and Fahrenheit, cryogenicists use the absolute temperature scales. These are Kelvin (SI units) or Rankine scale (Imperial & US units). It is not well-defined at what point on the temperature scale refrigeration ends and cryogenics begins, but most scientists assume it starts at or below -150 °C or 123 K (about -240 °F). The National Institute of Standards and Technology at Boulder, Colorado has chosen to consider the field of cryogenics as that involving temperatures below −180 °C (-292 °F or 93.15 K). This is a logical dividing line, since the normal boiling points of the so-called permanent gases (such as helium, hydrogen, neon, nitrogen, oxygen, and normal air) lie below −180 °C while the Freon refrigerants, hydrogen sulfide, and other common refrigerants have boiling points above −180 °C.
Keywords: cryogenics, material freezing, refrigeration
Introduction condition1. Aging, disease, and damage due to cooling low temperature are all Cryogenics is low temperature potentially things that can be repaired by physics: "The branches of physics and nanotechnology and other future molecular engineering that involve the study of very repair technologies. Cryonics will work only low temperatures, how to produce them, and when future medicine has mastered these how materials behave at those repair technologies. It seems inevitable, with temperatures". Cryogenics is important the progress of science, that these repair because rocket fuel (oxygen and hydrogen) technologies will come to exist. Cryonics is must be loaded in as liquids at cryogenic important for people who want to live much temperatures. Cryogenics is also important longer than is possible in the current world for attaining super-conduction and for of medicine. Cryonics is a "lifeboat to the cryogenic tempering of metals for future" from the current "primitive" state of hardening. Even with good preservation of medicine. Cryonics is no so important for body tissues by cooling and vitrification, people who are happy to live to be 70 or 80 future science will be required to cure and want no more of life, even with the presently incurable diseases and to potential of rejuvenation and perfect health. rejuvenate elderly people to a youthful Article Designation: Scholarly 1 JTATM Volume 8, Issue 1, Spring 2013
When people say "cryogenics" what they often really mean is "cryonics", which is "The emerging medical technology of cryopreserving humans and animals with the intention of future revival." Cryonics is important insofar as it can provide a means for people who are living today to live very long lifespans -- perhaps hundreds of thousands of years. DEEP CRYOGENIC Fig 1. Cryogenic valve processing is different from conventional cryogenic processing and requires cooling Cryogenic processing is not a the parts to more than 300° below zero substitute for heat treatment, but rather an compared to about 120° for conventional extension of the heating - quenching - cryogenic processing2. DEEP CRYOGENIC tempering cycle. Normally, when an item is processing is a microprocessor controlled quenched, the final temperature is ambient. dry process, which includes cooling the The only reason for this is that most heat parts at a programmed rate. Soaking the treaters do not have cooling equipment. parts for up to thirty-six hours, and then an There is nothing metallurgically significant additional tempering operation to relieve about ambient temperature. The cryogenic any stress that may remain. During heat process continues this action from ambient treating, steel's micro-structure transforms temperature down to −320 °F (140 °R; 78 K; from austenite to martensite, which makes −196 °C). In most instances the cryogenic the steel much more wear resistant. cycle is followed by a heat tempering However, some small pockets of austenite procedure. As all alloys do not have the may not transform and this does not allow same chemical constituents, the tempering the knives to perform as well as they can. procedure varies according to the material's DEEP CRYOGENIC processing helps chemical composition, thermal history change retained austenite to martensite, and/or a tool's particular service application. completing the transformation process3. The entire process takes 3–4 days.
Cryogenic processing Cryogenic production Cryogens, like liquid nitrogen, are Cryogenic cooling of devices and further used for specialty chilling and material is usually achieved via the use of freezing applications. Some chemical liquid nitrogen, liquid helium, or a reactions, like those used to produce the cryocompressor (which uses high pressure active ingredients for the popular statin helium lines). Newer devices such as pulse drugs, must occur at low temperatures of cryocoolers and Stirling cryocoolers have approximately −100°C (about -148°F)4. been devised. The most recent development Special cryogenic chemical reactors are used in cryogenics is the use of magnets as to remove reaction heat and provide a low regenerators as well as refrigerators. These temperature environment. The freezing of devices work on the principle known as the foods and biotechnology products, like magnetocaloric effect5. Cryogenic vaccines, requires nitrogen in blast freezing temperatures, usually well below 77 K or immersion freezing systems. Certain soft (−196 °C) are required to operate cryogenic or elastic materials become hard and brittle detectors. at very low temperatures, which make cryogenic milling (cryomilling) an option Cryogenic Treatment for some materials that cannot easily be A cryogenic treatment is the process milled at higher temperatures. of treating work pieces to cryogenic
Article Designation: Scholarly 2 JTATM Volume 8, Issue 1, Spring 2013
temperatures (i.e. below −190 °C (−310 °F)) used on LNG piers to transfer liquefied to remove residual stresses and improve natural gas from LNG carriers to LNG wear resistance on steels. The process has a storage tanks, as are cryogenic valves. wide range of applications from industrial tooling to improvement of musical signal Cryogenic application in textile and transmission. Some of the benefits of apparels cryogenic treatment include longer part life, (a) Liquid ammonia mercerization less failure due to cracking, improved Stable shaping process technology thermal properties, better electrical opens the doors to fashion, a transitory properties including less electrical fantasy determining the form, color, design resistance, reduced coefficient of friction, and new effects of textiles and clothing. This less creep and walk, improved flatness, and process, presently, is typical in fashionable easier machining6. cotton industry products and is also one of
the mature technologies developed in textile Cryogenic hardening and fiber industry. The features such as A cryogenic treatment is the process fitness, comfort, easiness to stretch, etc., are of treating work pieces to cryogenic highly desired today. New purified cotton is temperatures (i.e. below −190 °C (−310 °F)) a quality product material made using this to remove residual stresses and improve high technology, that overcomes the wear resistance on steels. The process has a traditional flaws of shrinkage, wrinkled wide range of applications from industrial clothes, and improves dramatically the tooling to improvement of musical signal natural properties of softness, comfort of transmission7. Some of the benefits of cotton. cryogenic treatment include longer part life, Liquid ammonia finishing (or) liquid less failure due to cracking, improved ammonia mercerizing’ refers to the process thermal properties, better electrical that truly revives the cotton through the properties including less electrical expansion of liquid ammonia at an ultra-low resistance, reduced coefficient of friction, temperature inside the fiber. When the less creep and walk, improved flatness, and cotton fiber is treated at -33ø C liquid easier machining. ammonia, ammonia at ultra-low temperature will permeate immediately into the Major Industrial uses crystallographic structure of the fiber. Stress will be released through interior expansion, Liquefied gases, such as liquid which makes the fiber cavity round and nitrogen and liquid helium, are used in many smooth and rearranges the molecular cryogenic applications. Liquid nitrogen is structure, thus the crystallographic structure the most commonly used element in becomes slack and stable. This physical cryogenics and is legally purchasable around change makes the surface of the entire fabric the world. Liquid helium is also commonly smooth and bright, with solid and soft feel, used and allows for the lowest attainable so elasticity and wash-and-wear is fully temperatures to be reached. These liquids achieved. are held in either special containers known The benefits of liquid ammonia as Dewar flasks, which are generally about mercerizing lies in the following effects that six feet tall (1.8 m) and three feet (91.5 cm) can be achieved simultaneously: The superb in diameter, or giant tanks in larger appearance, feel and brilliancy of dyed commercial operations. Dewar flasks are shades, make the buyer select the ammonia named after their inventor, James Dewar, the mercerized garment/fabric rather than the man who first liquefied hydrogen8. regular caustic mercerized one. Museums typically display smaller vacuum Low shrinkage post washing flasks fitted in a protective casing. Increase in wrinkle resistance Cryogenic transfer pumps are the pumps
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Increase in fiber elasticity components. The problem of “Retained Softer to touch and brighter Austenite‟ has been with us from the Enhanced tensile strength beginnings of the development of steel Dimensional stability components. Austenite is a soft allotropic Resistance to abrasion form of iron that forms at high temperature. Dyeing uniformity, dyestuff affinity, During cooling it gets transformed to other color solidity structures of which martensite are the Wash and wear properties desirable harder phase. But rate of cooling plays a major role in the formation of (b) Cryogenic treatment in garment martensite. If martensite is not formed manufacturing during cooling, other softer structures may result or austenite itself may remain The technique starts from the purchase unconverted. This is unstable at lower of cutting knives and sewing needles. temperatures and is likely to transform into Thematerials were given cryogenic martensite spontaneously under certain treatment. Cryogenic treatment is the conditions. However such spontaneously process of converting the austenite state formed martensite tends to be brittle unlike (malleable) of the materials to the martensite the acceptable tempered martensite. The state (tough). Such that the processed cryogenic process can be applied on garment materials have increased wear resistance, cutting knives and sewing needles10. increased toughness, and reduced brittleness, 9 The straight knife cutting machine but are not too much harder This results in consists of a base plate, an upright stand the the extension of the durability of cutting hold the vertical blade, motor, a handle for knives and sewing needles. The estimated moving assembly, a sharpening device and a life extension is measured for cutting knives handle to transfer the whole assembly from and sewing needles by comparing the treated one place to another. Two kinds of power and untreated knives and the treated and are required to operate a straight knife. untreated sewing needles were used in the Motor power drives the reciprocating blade garment industry. and operator power drives the knife through
three ways. Normally, the available blade (c) Cryocooling application in garment vary from 10 cm to 33 cm and normally cutting knives available strokes vary from 2.5 to 4.5 cm. To explain the theory behind the the greater the blade movement the faster improvements found on cryogenic cooling it the blade cuts the fabric and more easily the is necessary to explain the process by which operator can move the machine. tempering produces hardened steel alloy
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Before Use After Use
Fig 2. Cryogenically Treated Garment Cutting Straight Knives
(d) Cryogenic treatment on sewing thickness of the needles; it serves only to needles distinguish one needle from another. These sewing needles are cryogenically treated and Sewing needles are classified by their their ratings are elaborately discussed in length and thickness. The usual types are following data tables. “standard” and “long”. The numbering system is not directly related to the length or
Fig 3. Cryogenically Treated sewing & various types of sewing needles
It has been found during the present With the recently done technique, it scenario that wear resistance of garment has been proven that the life of the cutting cutting knives and sewing needles improve knives and sewing needles has been when they are cryogenically treated11. Two extended around 47 % and 15-25% interpretations of the mechanisms respectively. After the cryogenic process the underlying the cryogenic process emerge cutting knives and sewing needles are used based on the observed results. in the machines for cutting and sewing operations. 1. The transformation of retained austenite to martensite, 2. Precipitation of fine alloying carbides,
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Specific application of cryogenic tool in material shows little or no change in yield or textiles and apparel tensile strength. The treated material becomes less brittle, without a change in Nowadays the developments in the original hardness. The most significant and textile scenario, focuses on the production of consistent change is the increased toughness, a better quality product at lower cost. With stability and wear resistance. Almost any the above theme the industry people kind of tool steel or dynamic part, for compete among themselves for a better whatever application, will exhibit some kind return on their investment. The technique of life increase. As less tools or parts are also demonstrates the savings obtained by needed, there is substantial savings in the industry with the implementation of dollars. Additional savings include less cryogenic treated knives and sewing needles downtime and short runs, less maintenance in garment machinery parts. As regards the and change-over, which allows for lower quality at lower cost concept mentioned production costs. above, we are at the halfway point with regards to this technology. That is, the lower References production cost by the increased life of knives and sewing needles parts has been 1. Alexandru, Ailibeai G. and Baciu C. demonstrated. And the statistical analyses (1990), Influence of Cryogenic about the performance of machinery parts treatment on life of high speed steels, were installed in a garment industry with Materials science and Technology. pp cryogenic treated knives and needles. 203-206. Further our study can move towards the 2. Barron R.F. (1982), Cryogenic treatment application of this process to other textile of metals to improve wear resistance, machinery parts; which can be cryogenically Cryogenics, August. pp 409-413. treated to extend their life and also to enhance their working life. With this in 3. Catherine C.Fay, Diane M. Stoakley, view, sewing machine and metallic parts Anne K. St. Clair, NASA Langley used in the garment industry have been research center (1998), “Molecularly brought into the preview of this treatment as oriented polymeric thin films for space a second part of this technique. applications”. 4. Chrysler (1986), Cryogenic immersion Major End uses in textile field enhances wear resistance, Metal As such it can be implemented in various Progress, Vol.129, pp64. textile fields like, 5. Collins D.N. (1996), Deep cryogenic Spinning (travelers, rings, mote knives, treatment of tool steels, Heat treatment carding wire points, etc.) of Metals, pp 40-42. Weaving (temple rollers, picker, etc.) Garments (other types of cutting knives, 6. Paramasivam S. (2005, Cryogenic others types of needles, etc.) treatment on the extension of life of Knitting (latch, spring beard & textile machine parts, project thesis. compound needles, etc.). 7. Meng, fanju, etal (1994), Role of Eta - carbide precipitations in the wear Conclusion resistance improvements of Fe - 12Cr - Cryogenically treated materials show Mov - 1.4C Tool steel by cryogenic a marked increase in wear resistance without treatment, ISIJ International, Vol 34, any desirable change in dimensional or No. 20 pp 205 - 210. volumetric integrity. Redressing or 8. Ronald C. Lasky (2003), The effects of regrinding treated tools removes less stock cryogenic tempering on tool steels, material resulting in longer tool life. The www.nitrofreeze.com.
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9. S.Y. Fu, L.F. Li, Y.H. Zhang, C.J. 10. Satish kumar. S (2004), Effect of ultra- Huang, Y.F. Xiong (2002),Mechanical cooling on the useful life of rings & properties of SGF reinforced PA66 / PP travelers, project thesis blends at RT and cryogenic temperature, 11. Mr. D. Vasanth Kumar & Mr. C. Proceedings of the 19th cryogenic Sivaraman, “Extension of the durability engineering conference, France. of garment cutting knives and sewing needles”, fibre2fashion.com
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