Shades of jeans

Basic to advanced technology

ABSTRACTStone age denims famous in today’s world

Gaurav Thakur (M.F.Tech-III)

Jeans have always been on everyone’s wish list, especially faded. Because of its toughness, style and less care required. Also, now a days governed by the shades or finishes offered by different buyers. As a result a lot of effort is being put to cater with different shades with less hazardous techniques employed and high productivity.

INTRODUCTION

Garment finishing is one the process applied on garment in order to get a desired look or appearance of the garment, with the introduction of new technologies and equipment it has been fairly easy to obtain desired shades and results. For finishing of denim fabrics, a range of techniques are used. They all are projected at new possible effects of fabric appearance, namely mill wash or rinse wash, moon wash, over dyed-look, stone wash ,

sand wash ,bleach, damaged-look, scrubbed look , sand-blast, PP spray , whisker Effect , 3D effects and etc. Especially, the dry finishing creates many effects on denim fabric, it stimulates the customers to buy and also enhances the market potential of the denim market. We can say that dry finishing has taken jeans to the next level, the next generation jeans.

DRY FINISHING,

The distressed jeans that we see around everywhere undergo a wide variety of wet as well as dry treatments to get the desired effects. Destroying denims is as much an art as it is a technique. The direction in fashion is varied across all areas particularly in denim dry finishing, whether worn or torn to wrinkled or

pressed, these trends can appeal to a wide range of consumers. These can be achieved by variety of denim dry processing technique, which are mainly dependant on physical and on chemical abrasion of the surface dye there by producing different wash-down looks to the denim fabrics

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Basic Level of TechnologyDENIM HAND SCRAPING

Hand scraping is step which is generally being done in rigid form of garments to get distress look. Location can be front thigh & back seat or it can be overall / global application as per standard. Emery paper (silicon) is being used to scrap the garments in particular placement. Emery paper comes in different number generally starts from 40 till 600 and above, higher the number finer the emery paper, lower the coarseness of the paper.

In garment industry from 220, 320 & 400 number papers are most popular & widely used.

Purpose of doing this process is make used worn out look to the garments. The most important factor is to select right number of paper according to the fabric strength & intensity need. Feathering /merging white sanded part to dark blue area in such way that it should look natural & not artificial. Scraping can be done on inflated rubber balloons for better effect (horizontal or vertical it’s up to operator’s convenience), even it can be done on plain wooden board of garment size & hand pressure should be uniform in order to get better results.

Gaurav Thakur Apparel Technology Management

Model and Make of Jeans Holders Features of MachineryHot tek ,Hilson Ck-D Mild steel structure

Regulated Air Filling inflating of BalloonsAutomatic Front & back Turning with Adjustable timer(Plc)220 volt-single phaseSingle & double headSingle Head-Dimensions- 1150x1010x2440(mm)Double head- 1150x2020x2440(mm)

WHISKERS/MOUSTACHES, CHEVRON, KNEE STAR, & HOT SPOT: On denim, Whiskers/moustaches, chevrons are nothing but the worn out lines /impression generated by natural wearing on hip & thigh area. There are many designs &pattern available. This is being done manually with help of sharp edge emery paper roller on fine wood stick or pasted on plastic material. Before starting execution placements & pattern must be marked on

garments, this will help operator to execute the pattern right to match the aesthetics of garment. A whisker effect (worn out lines) on Denim Hot spots are heavy/ intense area on thigh or knee which is made purposely to create used look & on knee area if any whiskers line are there, called knee star. All the above operations are carried out in width direction hence it appears intense than hand sand with less strokes, because hand sand is carried out in length direction.

Gaurav Thakur Apparel Technology Management

Intermediate level of TechnologySandblasting has become the key method for finishing most modern jeans requiring that ‘worn-out’ look. Under the sandblasting process the denim is smoothed, shaped and cleaned by forcing abrasive particles across it at high speeds. The process is fast and cheap and demand for pre-worn denim has led to a massive rise in its use. But this fashion comes at a price: the health and even the lives of sandblasting workers.

SAND BLASTING

Sand blasting is the process of scrubbing off the garment by blowing high speed air mixed with very fine particles of sand. This is a very successful and most widely used process for fashion articles. When the surface area of the garment is blasted, white cotton appears beneath the blasted area and the affect appears is very similar to the worn out jeans. Sand blast provides a very uniform result which cannot be achieved with its alternates. Its specialty is the merging effect that is blended with such a beauty that it has no difference with natural effect. Sand Blasting Effects on Denim High

pressure of air produces a powerful backward thrust to operator so it is always recommended to fix the gun in appropriate stands rather than placing it on shoulders or using it with bare hands. On some fabrics sand blasting is not successful for it covers the characteristics of fabric. Especially in fabrics which are famous for slub patterns it flattens the look. Specified areas for sand blasting are front thigh, back seat, back panel near bottom or front panel around knee. Sometime full body blasting is also done for giving a unique look to fabric. Hot spots may be designed for more real look on front knees or back seat by intense blasting in these areas.

A single worker can produce between 20 and 30 pieces per hour hand-sanding while with manual sandblasting he could make between 35 and 60 pieces.

Model And Make Features of MachineryTesuo ,Bensua BS-PS Max Capacity-200,250,300(kg)

Air consumption- 4cbm/minWorking pressure-0.6 ~ 0.8mpaNozzle orifice-6.3 , 8, 9.5 (mm)

Advance Level of TechnologyLASER TECHNOLOGY (jeans Go Green)

It is a computer controlled process for denim fading. This technique enables patterns to be created such as lines and/or dots, images, text or even pictures. It is water free fading of denim. Being an automatic system, chances of human error are slim. Also called spray painting in denims. This technique has relatively high cost.

Gaurav Thakur Apparel Technology Management

Replacing Traditional Technique for Denim Finishes

The laser technology is the fastest growing technique presented by many companies as a perfect replacement for traditional methods of sandblasting, stone washing, burning, etc. and much more that the industry has yet not seen. The success of the technology is based on the fact that Indigo today is a synthetically produced vat dye that is bound to the fabric by mechanical forces rather than chemical and unlike other vat dyes, Indigo has very little affinity to cotton making it suitable for washed down treatments.

The various laser techniques available in the industry are considered a much safer, environment friendly, economical and superior technology that has advantages that offers not only aesthetic variation but also gives freedom to designers to innovate at quick speed saving critical commercial time in product development and crucial cost during production. According to experts the technologies on offer increase output per workstation by almost 500 % while reducing loss of fabric strength by 50%.

Another advantage that is interesting for users is the significant elimination of environmental problems associated by previous abrasive processes while having the ability to replicate an exact abrasion pattern on all units besides infinite flexibility to create different ‘worn look’ designs otherwise impossible. The health benefits cannot be undermined as processes like hand sanding generate tremendous amount of dust that can be detrimental to workers health. Wastages in processes like stone washing where considerable wear and tear on machine and excessive water is normal are also significantly reduced, as there is no wear and tear and zero water application. In fact the industrial design and in built cooling system allows the machine to run continuously for hours and requires minimal maintenance.

Not only can denim be laser engraved, but pile fabrics as well. The laser burns away the pile in selected areas leaving a permanent design that closely mimics and embossed pattern. 100% cotton corduroy and velvet can be laser engraved to produce an impressive permanent design without the use of resins.

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How much does it cost to operate the laser?

The cost of operating the laser can be easily figured out by plugging your electricity rates into the following formula:

For a 100 watt laser

Typical Max power consumption = 1300 Watts (This assumes full power, constant laser on.) If power costs $0.075/KWH, i.e., Rs 3.37/KWH [Rs 45 x 0.075=Rs 3.37] in your area, it costs $0.1/hour to operate the laser. (1300 x 0.75)/1000 = 0.098. Or, about 10 cents per hour, or 80 cents (Rs 36) per eight hour day. Taking the average cost of power as approx. Rs 5.0 per unit in India, the laser would cost around Rs 53.5 per 8 hr shift.[Rs 36 x 5.0/3.37= Rs 53.5]

Return on Cost: At the 100-watt power level, typical patterns can be created at a feed rate of one square metre per minute. The unprocessed denim has a bulk value of approximately $1 (U.S.) per square metre whereas the engraved denim has a typical value around $15 per square metre. Excluding the cost of consumables (mostly electricity), this translates into a gross profit of $14 per minute, or $840 per hour.

JEANOLOGIA: New technology for jeans finishing, faster and with less energetic consumption

The textile laser and the eco-washing machine G2 was shown at ITMA Barcelona. This new technology makes possible savings of 62% of power, 67% of water and 85% of chemical products and 55% of time in jeans finishing Jeanologia company presented latest innovations for Jeans finishing, under the slogan of 3E (Ecology, Efficiency and Ethics), that allows to get greater energy, water, chemical sand time savings. Jeanologia has long been a pioneer in the development of textile laser which has avoided the use of unhealthy techniques and has reduced the energy consumption and the pollution. This laser can reproduce authentic worn patterns on Jeans reducing production time and assuring reproducibility achieving true authentic look.

As well as laser, Jeanología has G2Technology, an eco-washing machine that works only with active oxygen and ozone, allowing wash jeans and shirts with vintage finishing, without using water or chemicals.

The new laser technology will allow greater production compared with other ways of jean finishing such as manual scraping, spray or sandblasting. Laser offers high levels of productions. With laser technology 100 or 200 of jeans can be produced per hour, while manual scraping produces only 10 units per hour, sandblasting 30 and spray 60. Specifically, the G2 technology allows to save per garment a 62% of Kw/h, a 67% of water (litres), an 85% of chemical, as well as a 55% of production time.

The environmental benefits that this new technology brings are impressive. That is six billions units of Jeans per year are produced in the world, it means that every jean consumes 70 liters of water, 1 kw/h and 150 grams of chemicals, this figure represents per year 420 million m3 of water, 6 billion kw/h and 900,000 tons of chemicals. If everyone in the textile industry starts using this new technology, the equivalent of 2 years of human consumption of water in Paris and 2 years consumption of electricity in Nepal could be saved per year, as well as 720,000.00 tons of chemicals products

Gaurav Thakur Apparel Technology Management

Gaurav Thakur Apparel Technology Management

Pair of denims

 Hand Scraping with Emery paper  CM price of the garment(Rs) 60Sewing cost 40% 0f Rs 50 24SAM value for single operation 0.6Total SAM 20CM price per garment 0.72

 

 Basic Level of Technology

Advanced Level of Technology

Sam value for single operation(min) 5 0.60Production per day (shift of 8 hours) 96 800Working days /month 26 26No. of months /year 12 12Production per annum 29952 249600CM price per denim 6.00 0.72Cost output/annum 179712 179712Production Target( pcs/day) 800 800No of machine required 8 1Cost of one machine (Rs.) 90000 4000000Cost of total machine (Rs.),T 720000 4000000Annual Depreciation(%) 0.15 0.15Depreciated value of m/c aftr oneyear (Z) 626087 3478261Cost of one operator p.m 3000 3000Total operators salary (Y) 288000 36000CM price from total m/c (X) 1437696 179712Cash Inflow (I) 1149696 143712ROI for the first year,(X-Y)/Z 183.63% 4.13%Pay back Period (T/I) 0.63 27.83

REFFERENCE:

http://www.indiantextilejournal.com/articles/FAdetails.asp?id=4330

http://stonevillejeans.com/blog/jeans-go-green-lasers

http://www.alibaba.com/showroom/jeans-scraping.html

http://www.fibre2fashion.com/news/textile-news/newsdetails.aspx?news_id=112168

http://www.alibaba.com/product-gs/329751249/Jeans_Sandblasting_Machine_TS2082.html

http://www.alibaba.com/product-gs/379085607/Jeans_Pants_Jackets_Sandblasting_Machine_Glass.html

Gaurav Thakur Apparel Technology Management