1.Name of the Technology : partial hot air drying process

Year of recommendation : 1992

Background : Stifling- killing of pupae with the cocoon shell is the first process in silk reeling process. Stifling can be done by many methods of which steam stifling and hot air drying are suitable for cocoons. In Indian reeling industry, steam stifling method is commonly adopted. This process is suitable for low quality cocoons produced earlier. With the introduction of new silkworm races, the quality and yield of the cocoon improved. However, silk reeling industry continued to process cocoon with the conventional methods for yarn production.

In other sericulture countries hot air drying is adopted for increasing the quality of raw silk and to store cocoons for longer period. Even though long period storage was not the requirement for the local industry, it was necessary for improving the quality and yield of the yarn.Comparative studies of the stifling methods were conducted and it was found that by steam stifling the cocoons, increases silk waste generation and quality of yarn produced was low compared to hot air dried cocoons. It was necessary to evolve suitable drying method for the local industry.

Technology details : Experiments were conducted by Hot air drying cocoons for three different levels of drayage (low, medium and full drayage). The experiments indicated that medium level drayage of 20-25% will increase the reeling performance and improve raw silk yield and quality.

For achieving low drayage of 25%, cocoons were dried for one hour with temperature of 100 degree C and reducing the temperature for the next 30 minutes.

Advantages of partial drying of cocoons:

  • Reduction in silk waste.
  • Saving in stifling cost.
  • Improves working hygiene.
  • Decrease in yarn cleanness defects.
  • Improves pupa utility value.
  • Longer cocoon storage period.

Field relevance: Steaming of cocoons being less productive as proven in the field trials, adoption partial hot air drying technology for stifling is essential for improving productivity, work hygiene and raw silk quality.

Cost economics:

Method

Quantity/batch

Stifling cost/batch (approx)

Stifling cost /kg cocoon

Steam stifling

10Kgs.

Rs.10.00

Re.1.00

Hot air drying

(electrical)

50 Kgs.

Rs.40.00

Re.0.80

Hot air drying

(wood fired)

50 Kgs.

Rs.25.00

Re.0.50



2.Name of the Technology : cocoon conditioning

Year of recommendation : 1992

Background : Moisture in the cocoon is eliminated due to drying of cocoon, if the cocoons are fully dried there is no moisture remaining in the cocoons immediately after removing from the drier. However it absorbs the ambient moisture and attains equilibrium. When the cocoons are partially dried, there is moisture remaining in the pupae which is constantly eliminated by the dead pupae. When partially dried cocoons are taken for reeling immediately, the thin end of the shells rupture at the boiling process leading to cocoon waste and the silk yield and some of the yarn quality is reduced.

Technology details : In order to bring the equilibrium moisture level in the cocoons, it was established that by storing the cocoons for a period of 48 hours the reelability increased and cocoon wastage was minimum.

Based on these experiments, it was recommended that partial dried cocoons have to be conditioned for 48 hours for increasing the reeling performance of the cocoons as well as reduce silk wastage.

It is recommended to store partially dried cocoons thinly spread in trays with wire mesh bottom.

Field relevance

  • Reduction in cocoon waste
  • Reduction in silk waste
  • Improvement in yarn quality.


3.Name of the Technology : cocoon sorting

Year of recommendation : 1988

Background : The various types of defective cocoons present in the lot obstruct the reeling efficiency, quality of raw silk and also the yield of raw silk. In the experiments conducted with various percent of defective cocoons in reeling lot, it was observed that the as the percent of defective cocoons, especially the stained and melted cocoons, increases silk yield and yarn quality decreases.

Technology details : Development of cocoon sorting table

In order to separate the melted cocoons with the stain not visible externally, a simple cocoon sorting table was developed with provision for light to pass through the cocoon. The table was made of wood with a cocoon bin and sorting area where a semi-transparent glass was fixed, beneath the glass, two fluorescents lights were fixed. When the cocoons were placed on the glass, the light passed through them the stains within the cocoon was easily visible. With this arrangement it is possible to separate all types of defective cocoons.

Field relevance : Reeling with the defective cocoons reduces reelability and silk yield and increase silk wastage. Separation of defective cocoons from the lot increases the quality of raw silk yarn.



4. Name of the Technology : vacuum cocoon boiling equipment

Year of recommendation : 1999

Background : The open pan method of boiling cocoons for softening the sericinwas found to be defective as there was no control in the level of softening of the partially dried cocoons.After partial ho air drying it was observed that when cocoon are cooked in the open pan method, resulted in patchy soaking of shell layer reducing silk yield and increase in pelade layer wastage, due to variation on the softening of sericin on the filament in the inner layers. This lead to filament breakages and resulting in reduced reelability. It was found necessary that partially dried cocoon has to be boiled by different boiling technique.

Preliminary experiments were conducted by comparing the open pan, three pan and simulated conveyor cocoon boiling machine conditions. It was observed that the three pan method and the simulated conditions of conveyer boiling methods produced better results when compared to open pan method, both in reeling performance and raw silk quality. However the two technologies were not adopted in the field due to inconvenience of three pan method and high investment of conveyor boiling machine.

Information of cocoon boiling of Japanese and Chinese cocoon boiling methods were studied. During the conveyor method of boiling, the partial vacuum created during low temperature treatment helped in soaking the layers of the cocoon shell. This principle was used to design experiments to achieve uniform soaking and softening of cocoon layers.

Technology details : Based on the preliminary experiments, it was observed that when cocoons were vacuumed in a water media, air inside the cocoons was drawn out of the shell and was replaced with water. When hot water media is used during vacuuming, as water permeated into the shell it soaked and softened the sericin by which it was easy to unwind the filament. A simple vacuum cocoon boiling equipment was designed and fabricated. Experiments with various pressure levels and water temperature were conducted and the optimum level of temperature and vacuum pressure for crossbreed and bi-voltine cocoons was established. The model of the equipment was suitable for cottage basin reeling units.

Recommendations

  • Partial hot air dried cocoons has to be processed is vacuum boiling method.
  • Permeation bath temperature and vacuum pressure to be as follows,
  • Cocoon

    Water temperature

    Vacuum pressure

    Crossbred cocoons (Avg. Shell%18-20%)

    50º C.

    300-350 Hg mm

    Bi-voltine cocoon (Avg.Shell %18-22%)

    60º C.

    400-450 Hg mm

  • Vacuum pump capacity to have air displacement and attain vacuum pressure of 550 mm in 3 min.
  • Air release value to be controlled in 40 – 45 sec.
  • Cooked cocoon to be directly brushed in 85 degree C hot water bath for about 45 sec.

Field relevance : Presently, steam stifled cocoons are boiled in open pan cooking method in the reeling industry. The survey conducted indicates silk waste generated to the extent of 35 % (on raw silk weight.) and renditta ranging between 8.0 to 10.0, for cross breed cocoon. This technology was demonstrated in different clusters of silk reeling. By adopting partial hot air drying method for stifling and vacuum cocoon boiling technique, it is possible to reduce the silk waste by 8 % - 10 % and decrease the renditta by 0.5 on an average. The fuel requirement of the filature is reduced by 25-30%, by which, it can be said that the technology is environment friendly. As the reelability is increased the workload of the operator is reduced which helped in maintaining uniformity of the yarn denier.

Economics : Based on field trails and data collected during the Institute’s “Transfer of Technology” programme, the following results were obtained.

By savings in cost
(For a reeling unit with a capacity of 10 kgs raw silk production per day)

I. Reduction in cocoon cost :

Cocoon consumption per day @ 8.0 renditta

80 kgs

Decrease in avg. renditta due to adoption of

technology

0.5

Cocoon consumption per day @ 7.5 renditta

75 kgs

Quantity of cocoon saved per day

5 kgs

Cost savings @ Rs. 300/- per Kg.

Rs 300 x 5kgs = Rs. 1500 /day

or Rs 37500 / month (25

days)

II. Reduction in fuel cost :

Fuel expenditure per kg raw silk production

Rs.60/-

Savings in fuel @ 25 %

Rs. 15/kg raw silk

Fuel savings for 10 kgs raw silk production

per day

15 x 10 = Rs.150/-

Or 15 x 25 =3750/- per month

Total cost reduction ( I + II ) per day

Rs 1500+150=1650

Total cost reduction ( I + II ) per month

Rs 37500+3750=41250/-



5. Name of the Technology : metal buttons

Year of recommendation : 2000

Background : The buttons are used in reeling machine to gather the filaments from cocoon and obstruct lumps or slugs of filaments enter in to the yarn. The porcelain buttons are commonly used in the industry because of low cost. The size of the hole is an important factor in reducing the cleanness defects and also the reeling efficiency. Worker could easily tamper the porcelain buttons and increase the occurrence of slugs in the yarn. During the process of development of the denier sensor, need for developing improved button was felt. Hence the metallic buttons were designed and fabricated to improve the cleanness of yarn but also to protect the denier sensor from cleanness defects.

Technology Details : In order to provide a suitable button with having proper hole size which is tamper proof and serves for a long period, various material were used to construct buttons and found that the stainless steel buttons served the objectives.

The design of the steel buttons were such that at the diameter widens forming a conical shape at the bottom of orifice. The conical shape helps in threading the yarn. The depth of the hole was fixed at 0.5 mm. The size of hole of the button is 2 to 3 times more than the average thickness of the raw silk yarn being reeled and in accordance to the standard formula. The stainless steel buttons gave desired results in reeling.

Advantages

  • Proper size of hole
  • Long life
  • Tamper proof and rust proof
  • Conical shape in provide at one side of the hole for easy threading and the buttons can be placed in the machine with convex portion fining upwards for preventing water removed from yarn being re-absorbed by the filaments.

Field relevance : Porcelain buttons available in the industry does not have holes as per the requirement. Further, even though the cost is low, the life of these buttons are very short. Indian raw silk yarn quality suffers because of cleanness defects. By using metal buttons, reelers can be benefited with improvement in the yarn cleanness and long life, which is cost effective.

Economics

Cost of porcelain buttons for 10 basin unit

Re.120.00

Approximate life of each button

15 days.

Expenditure on buttons in the unit per year

Rs. 1520/-

Cost of metallic button (approx)

Rs.100/-

Total investment on metallic buttons (for the same unit

Rs.6000/-

Approximate life of metallic buttons

> 5 years.



6. Name of the Technology : length of croissure

Year of recommendation : 1993

Background : Croissure play an important role for the increase in tenacity, cohesion of the yarn which is necessary when it is used as warp in power loom weaving. Higher tenacity and cohesion reduces yarn breakage rate and fraying out of filaments due to rubbing at the pre-processes of twisting and weaving. Hence binding the filaments is important during the reeling operation.

Technology details : Experiments were conducted by imparting different length of croissure and its effect on tenacity and cohesion were studied.Three different level croissure length levels were studied ie. 4 cms, 6cm, 8cm and 10cm. It was observed that the yarn quality with a croissure twist measuring 8 cms increased the tenacity and cohesion characteristic of the yarn. The coils inserted in the croissure was also measured and was found that the no. of coils inserted in the croissure with 8cm. length was about 65 coils i.e., 8 coils/cm.

Field relevance : Yarn produced with long croissure will have higher tenacity and cohesive properties which is essential for weaving the yarn on power looms.

Economics : Reelers will have to increase the length of croissure during reeling, which does not cost anything. However in order to obtain long croissure, the pulley alignment should be as per the specifications and new polypropylene pulleys has to be fixed. Yarn with higher tenacity and cohesion is the requirement of the weavers and pay higher price.



7. Name of the Technology : reeling speed

Year of recommendation : 1990

Background : Winding speed at reeling play an important role in the production and quality of raw silk. It was evident that, in the reeling industry, in order to increase the raw silk production per unit labour, basin and time, the reelers fixed driving pulleys which rotates the reels at a very high speed. As per the observation made in many reeling units the reel speed ranged from 300 to 400 rpm. Such high speed was not suitable for quality of cocoon available and the process parameters, being adopted.

Experiments were conducted to optimise reeling speed for improving the quality of the yarn. Three different reel speed levels and its effect on yarn quality were studied. For manual reeling systems, as the speed increases, the denier of the yarn becomes finer. The size deviation is also effected, as the speed increases from the lower speeds to higher speeds.

Technology development : Based on the analysis of the experimental results, it was concluded that by maintaining the reeling speed at about 200 –220 rpm would help in improving the quality of raw silk yarn in terms of uniformity in yarn denier and improvement in reeling efficiency thereby in creasing raw silk production.

Field relevance : In order to improve the yarn uniformity of yarn and efficiency of the unit, it is essential to reduce the speed of reeling. At lower speeds, the workers will be able to maintain the required number of cocoons per reeling end through the reeling process thus reducing the variation in yarn denier. Size deviation and max size deviation can also be reduced significantly. Entrepreneurs will utilize the inputs to the maximum level, thus improving the efficiency by 15%.

By reducing the speed of reeling there is reduction in the production per basin per day, this is compensated by the increase in the reeling efficiency and optimum utilization of inputs and better quality of yarn fetching higher price.



8. Name of the Technology : re-reeling speed

Year of recommendation : 1990

Background : Winding speed of re-reeling play an important role during skein formation. High speed at leads to improper drying of skeins which results in gum spots and winding breaks. With high speed of skein winding, workers will not be able to knot the broken yarn, as it takes longer time to stop the reels, this contributes to the winding breaks.

Technology development : Experiments were conducted to determine the optimum speed to be maintained at re- reeling.It was observed that winding of the yarn at a speed of 150-160 rpm resulted in proper drying of the skeins without loss in production.Skein drying temperature has to be maintained at 40o C

Field relevance
Proper diamond pattern formation
Optimum level silk drying without gum spots.



9. Title of technology : water quality for silk reeling

Year of recommendations : 1992

Background : Silk reeling process requires about 50-150 liters of water for one kilogram of raw silk production. The color, luster, softness and production of the yarn are mainly dependent on the quality of water which is used for reeling. In cocoon cooking, the sericin gum dissolution and absorption of water will relatively depend on the water characteristics. Many times the naturally available water may not conform to the standards. Reelersutilize nearest water sources available irrespective of it quality and unknowingly obtain varied results.

In sericulturally advance countries the importance of water in reeling has been studied extensively and have prescribed standards on the machineries and process parameters and raw material. Similarly, water quality characteristics has been standardized to suit Indian reeling industry to achieve better results in reeling.

Technology details : Water samples were collected from different reeling centers to study reeling performance and quality of raw silk considered along with its quality. These studies were conducted with a view to determine the extent of influence of water in reeling process

Based on the experiments and data analysis, it was found that the following water characteristics play important in reeling process and effect yield and quality of raw silk.
1. pH
2. Electric conductivity in micro mhos / cm
3. Total Hardness ( as CaCO3 in ppm)
4. Total Alkalinity (as CaCO3 in ppm)
5. Chlorides.

Studies were taken up to know the water characteristics season wise and was found that the characteristics are considerably influenced by the seasons.With the aid of various experiments conducted on reeling water, desirable characteristics of water for the process for charaka, cottage/filature, multiend and automatic reeling were determined and there given in Table. Any deviation from these characteristics may require treatment for improvement.

Table: Suitable water characteristics

SL. No

Water characteristics

Concentration

01

PH

6.5-7.5

02

Conductivity(Micro mhos/cm at 25 C)

100-500

03

Total Alkalinity (ppm)

50-150

04

Total Alkalinity - Total Hardness= X.

-30<X<+30

Classification

Suitable water group : Water which has the above mentioned standard characteristics are termed as suitable water. This is further sub-divided into four groups. They are SW, SW-A, SW-C and SW-EC, SW classes water conforms completely to the standards. The concentrations of water characteristics, varies from one to other sources. The water which does not confirm to the standard characteristics is further classified for better understanding of their collective influence in reeling. Water which needs to be treated has been divided in to three main groups viz. water having medium concentration, high concentration and very high concentration of dissolved solids. The reeling water is further sub divided in to A, B and C class in medium concentration group, D, E and F class is high concentration group and G class in very high concentration group.

Water treatment methods: Each characteristic such as pH total hardness total alkalinity is corrected by different treatment methods. Since hardness, alkalinity and pH of water are considered as most important characteristics, various water treatment methods that can be used for treating reeling water has been identified. Water samples from different reeling clusters of Karnataka were tested for their quality parameters as per the KSSRDI standards. About 12,000 samples of water were tested and classified district wise. Software has been developed for creating data base of water quality of different reeling clusters.

Field relevance : As any available water is used for reeling in the industry, usage of suitable water will improve the productivity and yarn quality. Suitability of water for reeling is determined after testing a sample for its characteristics.

Economics

a. Increase in sale price due to improvement in quality on using treated water.
b. Reduced wastage and increase in silk yield.
c. Low consumption of water.
d. Improvement in productivity.



10. Title of Technology: Improvement of raw silk yarn characteristics by sizing

Background : Silk fabrics are of two types yarn degummed variety and fabric degummed variety. Majority of the fabrics produced in the domestic market is of yarn degummed variety. Fabric degummed variety viz. crepe, chiffon & georgette are in great demand both in domestic and international market. To produce these fabrics the quality of the yarn required is high. Indian raw silk suffers from poor tenacity and cohesion properties mainly due to the raw materials and process practices adopted in reeling industry. The post reeling process requires good tenacity and cohesion in the yarn besides other yarn characteristics. Keeping this in view an effort is made to improve the Tenacity and Cohesion properties of the raw silk yarn to make yarn suitable for power loom weaving.

Technology details : Raw silk yarn obtained after reeling is being treated with PVA sizing agent at re-reeling stage to improve the Tenacity and Cohesion properties of the raw silk yarn. Tenacity and Cohesion properties can be improved by the application of sizing agent PVA at 1.5to2.0 gpl similar to cotton woolen and synthetic blends. Yarns treated have better yarn characteristics and have better working performance on loom.

Field Relevance : Improvement in yarn characteristics facilitates use of locally produced silk yarn as warp on power loom this reduces the dependability of imported silk yarn.



11. Title of Technology : optimization of twist levels for the production of crepe georgette and chiffon fabrics.

Background : 40% of the silk fabrics produced in the country are of these varieties produced on power looms. Various manufacturers use different level of twist in the yarn resulting into different effects on the fabrics. Even though fabrics produced from local multi bivoltine silk have good demand in domestic and international market, Power loom weavers prefer to use imported yarn mainly to obtain improved performance on loom and to produce consistent quality fabrics. High twisted yarn fabrics Viz. crepe chiffon and georgette are influenced by the twist in the warp and weft yarns and twist in the yarn has a direct influence on the physical, mechanical and aesthetic properties of fabrics, and on the cost of manufacture. So Optimum levels of twist, construction particulars and other specifications for the process of manufacturing crepe, chiffon and georgette has been evolved using local multi bivoltine yarn

Technology Details :

Light crepe fabrics (1987/1989) : Light crepe fabric is an open textured fabric with crinkled surface on it produced by untwisted warp and highly twisted weft yarn. Twist in the yarn has a direct effect on the physical, mechanical and aesthetic properties of the fabric. Optimum levels of twist and specifications to manufacture light crepe fabrics are evolved.

Recommendation
Warp 20/22De zero twist 2 in heald eye 4/ dent.
Weft 20/22De 2SX2Z 3000TPM, Reed120s, PPI 100.

Medium crepe fabrics (1990/1991) : Crepe silk fabrics are woven with grey untwisted yarn as warp and highly twisted yarn as weft. The properties of the fabric are dependent on the denier, tenacity and elongation properties of the twisted yarn. The texture in the fabric is obtained after degumming and finishing it depends primarily on the degree of twist in the yarn and geometrical construction of the fabric.

Recommendation :
Warp 26/28De zero twist 3 in heald eye 6/ dent.
Weft 26/28De 2SX2Z3000TPM, Reed100s PPI 100.

Chiffon fabrics (1991/1992) : Chiffon fabrics are light weight fabrics made from highly twisted warp and weft yarns these fabrics have wavy ridges along the warp direction. The amount of twist and direction of twist and Ply of the yarn play a significant role on the texture of the fabric.

Recommendation
Warp 20/22De 1800TPM, 1 in heald eye 2/ dent4SX4Z.
Weft 20/22De2Ply2800-3000TPM SorZ Reed100s PPI 100.

Georgette fabrics (1992/1995) : Georgette fabrics are light weight open textured plain woven fabric with pebbled effect and minimum luster and are made entirely from crepe yarns. High twisted yarns are used in both warp and weft way directions there is a substantial shrinkage in both warp and weft directions when the fabric is subjected to degumming and finishing.

Recommendation
Warp 20/22De 2Ply2200TPM 1 in heald eye 2/ dent2SX2Z,.
Weft 20/22De2Ply 2SX2Z 2800-3000TPM Reed120s PPI 90-120.

Advantages : Standardization of twist levels improves the quality of fabric preserves the inherent characteristics of raw silk yarn. Optimum levels of twist in the yarn improve the process efficiency at different stages of fabric manufacture and reduce the variability of the product by reducing the defect in the fabrics.

Field Relevance : Technology for crepe fabrics was developed under joint program with KSIC weaving factory. KSIC is specialized in manufacture of crepe fabric using local multi bivoltine yarn for the manufacture of fabric which is in great demand.

Cost benefit : Saving in twisting and manufacture cost of fabrics by 15to 20%.



12. Title of Technology: Technology for soaking of silk yarns (2006)

Background : Silk fabric manufacturing process involves introduction of twist to singles and plied raw silk yarn. The presence of sericin renders the raw silk yarn hard stiff and brittle offering resistance to twisting. The amount of twist imparted to the raw silk yarns differs depending on the type of the fabric. Soaking of raw silk is an important and primary process of silk fabric manufacture. It is a process of making raw silk soft and supple to facilitate better silk throwing and weaving operations.

Technology details : Soaking is performed by treating the raw silk with an emulsion of soap and oil, selection of soap and oils their concentration in emulsion, temperature and duration of soaking as been worked out. To overcome the tedious method of preparation of soaking emulsion, Mrudula Soaking oil was developed for the purpose. It is a ready mix which overcomes the tedious method of preparation of oil and soap emulsion. It avoids the variation caused by the effect of oil chemicals and soap used in such preparations.

Advantages : Mrudula soaking oil developed for the purpose assists in standardization of soaking method, improves the process performance of the yarns during fabric manufacture by preserving the yarn characteristics such as tenacity and elongation which ultimately determines the fabric properties.

Field Relevance

  • Standardization of soaking method.
  • Improvement in pliability of the yarn by reducing the inter fiber friction.
  • Improvement in process performance and reduction in silk waste.
  • Tenacity and elongation properties in the yarn are preserved.

Cost benefit : Mrudula soaking oil works on par with imported oil and its cost is less (Rs 75to90) and can be produced locally.



13. Title of Technology : Technology for twist setting in silk yarns

Background : Twisted raw silk yarn tends to untwist and revert back to its original state whenever the yarn tension is slackened after twisting resulting in snarls and breakages in further processing. Twist setting forms an integral part of silk throwing operation. Setting of twist in the yarn helps in production of good quality fabrics with desirable fabric properties.

Technology details : In the industry small manufacturers use open steamers, medium scale manufacturers use steam agers and big manufacturers use vacuum steamers. Cost of vacuum steamer is high and un affordable by small manufacturers. Temperature, duration and pressure for different yarns and methods of setting are worked out.

SL.No

Method

Pressure

Temperature

Time

1.

Open steamer

Low twist<1000 Tpm

High twist>1000 Tpm

No pressure

>100 c

45 Min

90 to 120 Min

2.

Improved steamer

Low twist<1000 Tpm

High twist>1000 Tpm

No pressure

>100 c

45 Min

90 to 120 Min

3.

Pressure steamer

Low twist<1000 Tpm

High twist>1000 Tpm

1.2 Kg/cm2

>120 C

35 Min

80 Min

4.

Vacuum steamer

Low twist<1000 Tpm

High twist>1000 Tpm

Vacuum

75 to 90 C

20 Min

40 Min

Advantages : Optimum twist setting conditions prevents harsh treatment of steam and helps to preserve the inherent properties and facilitates better performance of yarns during fabric manufacture.

Field evaluation : Technology developed was transferred to M/s S.R.Textiles, Chanapatana. M/s Sreenivasa Textiles, M/s J.K.Fabrics under T.O.T programmes.



14. Title of Technology: kssrdi improved warping creel for silk industry (2006)

Background : Warping is a process of preparation of yarn sheath with uniform tension wound on a beam. It is one of the important process which decides the performance of the loom and the quality of fabrics produced. In traditional warping machines the tension between the yarns in the warp sheet is not uniform this is attributed to the poor working principle of the creel.

Technology Details : The new creel is developed at KSSRDI with financial assistance from user industry to produce quality warp beams creel works on nose unwinding principle and has a tensioning device that controls the tension between the ends of the warp sheet facilitating incorporation of warp stop motion on looms. The creel is incorporated with electronic yarn detecting device to detect broken ends this facilitates mending of broken ends and increase the efficiency of machines.

Advantages/ Field evaluation : Facilitates production of warp beam with uniform tension between the adjacent ends of the warp sheet this aides power loom weavers to incorporate warp stop motion on power loom to produce quality fabrics. The creel developed was field tested after a suitable modification was handed over to sponsors.



15. Title of Technology: optimum twist levels for the production of taffeta fabrics (2009)

Background : Taffeta fabrics account for 60% of the silk fabrics produced in the country and are manufactured using organzine yarn as warp and tram yarn as weft in degummed and dyed state and are woven on handlooms and power looms. Weavers by the virtue of their experience use their own levels of twist for single and double yarns without considering the concept of balance in twist and effect of twist on fabric quality and cost.

Technology Details : The levels of twist required for bivoltine and multi bivoltine yarn varies. The optimum level of twist for primary and secondary twist for the organzine and tram yarns is determined considering the strength elongation properties, packing fraction of filaments and process performance of the yarns during fabric production twist levels for primary and secondary twist is arrived. Optimum level of twist for 2ply organzine warp yarn 900/800Tpm for local multi bivoltine silk and 800/700Tpm for bivoltine silk and 400Tpm for weft yarns is found suitable combination for weaving fabrics with desirable characteristics.

Advantages/Field Relevance : Optimum level of twist helps in standardization and production of fabrics with desirable properties. Texture of the fabric, dimensional stability, crease recovery, drape ability of the fabric is dependent on the levels of twist in the yarn.



16. Title of Technology: influence of silk yarn characteristics on process performance and fabric quality(2007).

Background : Majority of the silk fabrics produced and exported to European countries from China and Japan are of fabric degummed variety these fabrics are produced using high quality raw silk yarn (grade 2A and above). In our country majority of the fabrics produced is of yarn degummed type mainly due to poor quality of raw silk yarn available for weaving produced from decentralized reeling industry. There is a need to select quality raw silk to produce good quality fabric. As the physical and mechanical properties of the fabric have a significant relationship with the yarn properties.

Technology Details : Comprehensive study of yarns produced from different regions and machineries were evaluated and fabrics were woven and studied for physical, mechanical, and low stress mechanical properties, it is observed that size deviation, tenacity and elongation have a greater influence on the fabric quality.

Advantages/Field Relevance : By knowing the yarn characteristics before processing the weaver will be able to decide upon the fabric quality that could be produced. Yarn uniformity, tenacity and elongation properties have a significant effect on the low stress mechanical properties and on the processing performance of the yarn at different stages of fabric manufacture.