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Consistency Leads To Higher Profits

Improved management and technological advances help package dyers meet customer needs.

 Today it is important for a manager of a dye house to develop a consistent system and follow the system to improved quality and quick turnaround. How can you achieve this with your current equipment and what will help you justify the purchase of new equipment This article should show you areas where consistency will lead to improved profits and faster turnaround. If your dyehouse cannot meet the following criteria, perhaps it is time to rethink and install a new dye house.  QualityQuality is a given in todays market. If you dont have consistent quality, you cant stay in business. Just as you seek to buy quality products from your suppliers, if your product does not have consistent quality, your customer will find a supplier that does. Therefore you must insist on consistently receiving quality products from your suppliers and be willing to find alternative sources if your supplier fails to meet your standards.

OBEM's API/O improves load reduction and flexibility of load capacity. Has ISO 9001 made a difference Many dyers now admit that qualifying for ISO certification has forced suppliers to write down procedures, provide documentation to customers and guarantee uniformity in supply.Quality improvement is the direct result of a good management system. There are software companies that specialize in operations management programs. When they implement a program at a dye house and see it through to completion, the dye house will have a totally integrated data base system for all manufacturing forecasting, planning, scheduling, production, financial, shipping and delivery.Quality does not come from simply managing existing, obsolete equipment. If, in the analysis of your installation, you find that the world has passed you by, it is time to retool and move on into the future with competitive systems. Outside The Dye HouseFiber supply has changed over the years as suppliers were challenged from abroad with high-quality, low-cost products. Yarn suppliers continued to search for unbranded suppliers of polyester and acrylic to replace more expensive brand names.Polyester plants have closed in the United States as polyester capacity expanded worldwide, and the recent Asian financial crisis forced suppliers to dump surplus fiber in cash rich countries like the United States. Acrylic fiber supply has increasingly come from Turkey, and the quality is excellent. Package PreparationYarn packages in the United States are typically wound on cylindrical plastic dye tubes of uniform linear dimension.In Europe, tapered cones are often preferred. The tubes are usually molded with a male and female end to allow stacking and nesting without dye tube spacers.
Packages dyed in OBEM's API/O.  Yarn reserves can be wound on a male end collar or on the female end. These reserves can be used by those desiring to go to a let-off creel without intermediate back winding, often called Direct Ship.Most dyers must use a stainless steel spacer to hold the shape of the package ends to allow for smooth unwinding. Backwinding to paper cones and intermediate lubrication is more common, but costs time and money. Successful dyers have mastered the direct ship ideas and bypass backwinding. Package HandlingThe technology for robotic package handling has been available for more than a decade. Suppliers such as Gualchierani have shown systems at ITMA since 1983.As dye houses moved to automation of package handling, dyers have had to insist that more consistent package density and uniformity be delivered from winding. Some companies now demand +/- 1/8 inch (3 mm) in package diameter and +/- 0.25 ounces (7 grams) in weight. Compression of a series of packages on a spindle will help overcome small differences on density along the column. Uniform density assures even dye liquor flow rate through the package and uniform dye uptake during the cycle.Robotics demands the ultimate in uniformity. Unlike human beings whose hand/eye coordination allows us to reach a little further to get a yarn package; simple robots expect the package to be in a very specific location.One example of an attempt at cost savings was observed during a recent visit to a dye house. The beautifully wound packages had been placed in the correct holes on a polymer spacer pallet.The second spacer was added and packages filled each spacer until ten or more layers had been built. However, the supporting polymer material was not stiff enough to keep the packages uniformly straight up and down. Packages on the corner of the pallet tilted ever so slightly, thereby causing the robot to miss picking the corner package.The cardboard pallets however were stiff and supported all packages. I suspect the polymer pallets were cheaper and would certainly last longer than cardboard, but a few pennies saved here were lost in lower efficiency later on.  The Dye HouseIn order to save energy, chemicals and water, machine vendors have designed and redesigned dye machines to have the lowest practical liquor to goods ratio. Not too many years ago, a 10:1 liquor ratio was the norm for large cylindrical package dye machines. Today, vendors such as OBEM have lowered the ratio to 4:1. They have achieved this miraculous reduction by standardizing the dye vessel as a series of tubes, which are manifolded together.If packages are wound to fill the dye chamber to the practical limit, the liquor required to fill the chamber and associated pipe and pump is minimized. Machines can be specified to allow several machines to share the same dye liquor. Customer orders can then expand to be larger than one machine and still have the same dye exposure.Conversely a larger available machine can be used to dye small orders by closing the manifold and inserting blank displacement chambers to fill the space of unneeded packages. Laboratory CorrelationAll new formulas must be dyed in the lab before ever being attempted in production. The closer the liquor ratio agreement between the lab and production, the better the final results will be. The dye machine vendor should supply a machine with close correlation. SuppliersMost dyers now insist on a limited number of suppliers. The basis for this decision is uniformity of product quality and cost. No one has the time to check every shipment and every container. You must assume the supplier has done his part and guarantees the result. Costs have been driven to the minimum. Service by the large vendors has been limited to only the very best customers. Dye house managers interested in cost alone soon hire expensive consultants to get them out of a fix or sometimes end up in bankruptcy. DyesDye supply has become more and more problematic. Formerly, minor suppliers shopped the world for low prices on commodity items, imported and repackaged. Today, all major dye suppliers have formed joint ventures with leading producers in China, India and Indonesia. Dyes from one vendor may be made in any of several locations worldwide. The quality delivered from the major suppliers is worth the money paid. MaintenanceMany people view maintenance time as a lost opportunity to produce dyed sales yarn. This view soon proves to be an expensive decision. Preventive maintenance on your schedule is clearly less expensive than unscheduled downtime and a spoiled dyeing. Computer-Aided DyeingFor a number of years, Fredgar Hoffmann and his colleagues at DyStar have worked with package dyers to develop a series of parameters that allow optimization of dyeing.Exhaust dyeing procedures supplied by dye vendors are far from optimum. They must be generalized to meet a wide range of conditions in the field. The dyeing parameters of the individual fibers and dyes are generally not taken into account.By implementing the DyStar Compudye System, one commission package dyer in Germany has reduced acrylic dyeing batch time by 29 percent, retarder usage by 51 percent and virtually eliminated shading operations for repeat dyeing of the same shade. This optimization program has been in operation for over six years. Well over 20,000 batches of acrylic, wool, polyester/wool and polyester yarn packages have been dyed.  Color KitchensThe technology to automate color kitchens has been available for a long time. Lawer has been in this business for nearly 30 years. The first widespread systems were installed in print plants more than two decades ago, when costs had been reduced and were justified in the United States.Almost everyone today depends on bulk delivery of auxiliary chemicals. There are two systems used. One uses bulk storage tanks and pumps to the dispensing head. The other uses a bulk container that is typically stacked on top of the dispensing tank. When the primary tank is emptied, chemicals in the bulk container are gravity-discharged into the lower tank and replaced with a fresh bulk container. This feature allows a virtual chemical pipeline from the supplier.Powder dyes typically arrive by drum. The contents are vacuum-transferred into storage containers or silos. Dispensing technology for this system has also been available for more than a decade, so the results are consistent. Todays dye houses require accuracy to +/- 0.1 gram. Almost as important but hardly ever mentioned is a consistent program to dilute and mix the dye solutions.If dyes are mixed at too high a temperature or for too long a time, the results will vary. Eliminate the variation and enjoy the consistent result. Editors Note: Dr. Gary N. Mock is a professor of textile engineering, chemistry and science at the North Carolina State University College of Textiles, Raleigh, N.C.

November 1999