TEXTILE RESEARCH AND IMPLEMENTATION

Transcription

1 COTTON INCORPORATED February 19, 1993 TEXTILE RESEARCH AND IMPLEMENTATION SUPPLEMENT TO PAD-BATCH DYE BULLETIN, STEPS FOR CONTROLLING FABRIC QUALITY PRIOR TO PAD-BATCH PREPARATION OR PAD-BATCH DYEING PROCEDURE FOR 100% COTTON JERSEY AND OTHER KNITS Greiee Goods Insoection All holes must be sewn closed. If very large, it should be cut out and pieces sewn together with butt seamer. Seam must be as flat as possible to avoid impression onto fabric when b em ing. Careless greige goods inspection, holes, and bad seams will produce poor quality and excessive seconds. Preparation THIS FIRST STEP IS VERY IMPORTANT! When processing 100% cotton fabrics on beams, becks, jets, or bleach ranges and the holes and seams are not sewn properly, the difficulties will be compounded later during pad-batch dyeing. Dwinrr of Fabric on Relaxed Drver Spread fabric properly before it is laid flat onto the screen. For tubular fabrics, when ring guiders are not used, the fabric has a tendency to develop a fold. As the fabric exits, the inside of the fold is damp. This will result in uneven dyeing. It is essential that the fabric is cooled off when plaited into the truck or rolled up. If the fabric has hot spots, uneven dyeing will be the result CREEDMOOR ROAD RALEIGH, NORTH CAROLINA *TELEPHONE (919) FAX (919) NEW YORK LOS ANGELES DALLAS ATLANTA BASEL OSAKA SINGAPORE MEXICO CITY Cotton. The fabric of Our Lives:.

2 Fabric must again be inspected to detect holes which may have occurred during bleaching. Also, correct bad seams, if any. All pieces sewn together to complete a dye lot must have loops pointed in the same direction. This can easily be controlled by making arrows at the end of a knitted roll when doffing. If pieces are reversed and are not run in the same direction, slight color changes can occur from piece to piece within the same dye lot. When the dye lot is ready for dyeing, the truck or roll should be covered with plastic and stored in an area free from draft, excessive moisture, steam, etc. It is essential to make accurate calculations and weighing of dyes and chemicals. A print out scale is highly recommended. Mixing of reactive dyes should be done at temperatures recommended by the d$stuff manufacturers. Check the following before padding the dye solution onto the fabric. Fabric style and accurate weight of dye lot. All dispensing lines must be clean. Pad trough must be rinsed out well. Check function of mixing pump blending ratio of alkali and fiber-reactive dye. Check pad pressure side to side and center. Check wet pickup. Calculate volume of formula based on wet pickup to have sufficient dye liquor for the entire lot. Check all functions on operating panel. Have sufficient leader cloth, approximately 10 yards of 100% cotton interlock fabric, wrapped onto beam overlapping perforations by approximately 8-9 inches on each side (reusable). Center fabric using ring guiders at entry (tubular fabrics). Fabric after padding should overlap 3-4 inches on each side of beam perforation. To wind a good flat tubular fabric onto the beam, it is essential that the fabric balloons when it exits the dye trough before padding. This does not pertain to open-width fabrics. After the dye lot is padded, it should be wrapped immediately with plastic, air tight, and moved to a conditioned storage area. The beam is now rotated while the fiber-reactive dyes react with the cotton fabric. Equilibrium will vary depending upon dyestuff selection. When reaction is complete, move beam to wash-off station and rinse with cold water first. When ph is 8.5-9, wash with hot water. Do Not Recirculate. When clear, proceed and dry fabric. 2

3 NOTE: When formulating a dye formula, be assured that all dyes used in a formula have very similar substantivity values. If not, tailing may occur. This condition will be very evident in light and medium shades. Checks should be made in the laboratory first. Also check foaming. Some chemicals in the formula or dispersing agent foam excessively. This condition will result in light spots and too much ballooning during the padding operation. Open-width fabrics will not balloon. All of the above are vital quality control checks for a pad-batch dye operation and must be adhered to in order to take advantage of better fabric quality and profitability. 3

4 PAD-BATCH DYEING OF COTTON FABRICS UTILITIES COST ASSUMPTIONS: All based on spring 1992 approximate costs for Greenville, SC. Location, usage, and other factors can have a major influence on utility costs. Water Cost Assumption: Greenville (SC) Water System ( ; Contact Kay Barrett) $ 1.32/1000 gals. for first 60,000 gals. $ 0.82/1000 gals. for next 540,000 gals. $ 0.72/1000 gals. for next 5,400,000 gals. Assume an average cost of $0.75/1000 gals. for small textile operation. Sewer Cost Assumution: Western Carolina Regional Sewer Authority, Greenville, SC ( ; Contact Dale Looper) $ 1.83/1000 gals.: Commercial Rate, no surcharges Water & Sewer = $ $1.83 = $2.58/1000 gals. Steam Cost Assumotions: Assume natural gas fuel at 35$/therm = $3.50/million BTU (1 therm = 100,000 BTU) Actual gas costs vary with rate classification. (Contact Jim Grainger at Piedmont Natural Gas, Greenville, SC ) Assume use of package boiler at 80% efficiency. Calculation: ($3.50/106 BTU) (1000 BTU/lb. steam*) + (0.8 boiler efficiency) = $4.38/1000 lbs. steam. Electric Power Cost Assumutions: Assume S.Ot/kWh (Contact Jason Martin at Duke Power, Greenville, SC ) NOTE: Actual billing rate varies with usage and other factors. *Rounded Value 4

5 PAD-BATCH DYEING OF COTTON FABRICS Comparison - Reactive Dyeing 100% Cotton (Starting With Prebleached Fabric.) Item Batch Size Liquor Ratio Water Consumption Steam Consumption Electrical Consumption Salt Total Excluding Dyestuff & Labor Beck Beck Cost Pad-B atch Factor, $ 1000 lbs lbs. 15/ /1 18,889 gals. $ (') 4980 gals. 13,430 lbs. $ (2) 4350 lbs. 60 kwh $ 3.00 (3) < 30 kwh 1000 lbs. $ (4) $ I Pad-Batch 1 Cost Factor, $ --- $ (I) $ (2) $ 1.50(3) 0 $ SAVINGS: $ $33.40 = $ Based on water & sewer cost of $2.58/1000 gals. Based on steam cost $4.38/1000 lbs. of steam. Pad-batch includes extra drying. Based on electric power cost of S.O$lkWh. Based on sodium chloride at 4$/lb. 5