Working with Cangilones

The cost advantages associated with this change in technology vary considerably from company to company according to their own specific conditions. It is therefore always advisable to carry out a technical and economic viability study to compare a company's existing setup with the situation which would occur if the Cangilones drum system was installed. Cangilones drums are manufactured by Spanish drum making specialists, Olcina. Such a study provides a basis for decision-making, as it gives a fairly accurate idea of the financial advantages of the new technology. It also enables the rate of return to be calculated on the required investment. The comments below are based on studies Karachov carried out in different countries where this technology is used, and mainly on his own experience at a company which regularly produces all their daily production with a Cangilones drum system, and which to date have satisfactorily produced 85,000 hides (liming and tanning, with green fleshing and wet-blue splitting), meeting all their quality standards across their whole range of articles. A battery of two Cangilones drums was set up, with the support of four traditional drums to soak, homogenise and preserve hides of widely differing origins, sizes and levels of conservation (large and small, fresh, salted and pickled hides). The company need to process a wide range of hides in order to produce 20 metric tons (MT) per day. In general, it can be said that at this company, and with this technology, improvements were obtained in quality, costs, output and productivity. Its use made for greater technical and production versatility, and it is also environmentally friendlier, as it is a clean technology. Knowing the theoretical and practical working system of the Cangilones drum, and implementing the logical and necessary adjustments to the workplace (type of hides, articles, equipment, climate, skill levels and idiosyncrasies of personnel, expectations and interests of company owners, etc), this became a standard, safe form of production. There were no insurmountable obstacles, in spite of the pressure of producing 20 MT during the very first trials. The process is highly modular, and sufficient space and time is available to let the final process take shape and correct any difficulties which might crop up. Work can be done safely and with no risk to the hides. Karachov was able to observe the following operational results: * The Cangilones drum process was able to homogenise and provide wet-blue hides with no appreciable quality differences, in spite of the wide variety of hides. * Standard, continuous production has been implemented with five Cangilones drums working 20 MT each per week. Tests are now being carried out with 21 MT. * The personnel responsible for the processes must be permanently aware of the readings of the process indicators and must know the status of the hides inside the Cangilones drum, as would also be the case for traditional drums. Thus, under easily implemented safety and control standards, processes can be handled by a single well-trained operator per shift, with a general supervisor working a swing shift. * For the critical points of the process as regards temperature (adding of acids, caustic soda - this is optional, but is cheaper and more environmentally friendly), Karachov also set up annexed circuits which enable preparations and advance checks to be made to remove any risk of problems or error here. * A highly efficient piece of equipment to control and maintain temperatures within required limits is available with the Cangilones and difficulties should not crop up as long as water at 18-20ºC is available. Nevertheless, it is advisable that chilled water, at around 4ºC, be at hand to forestall any unforeseen temperature surge during the process, which may be due to unexpected exothermic reactions, local climate, time of the year, ambient temperature, relative humidity, etc. When readily available, ice is a most effective, easy to use, cheap method for cooling should chilled water be lacking. * The hides obtained are of better quality, and more open especially at the heads and necks. As the system works with controlled swelling, the leather was observed to be more elastic and without fixed wrinkles. With good subsequent mechanical work, smoother, less taut leather is obtained, with no wrinkles or kinks. * No significant changes needed to be made in the retanning and dyeing formulae as a result of the changes in liming and tanning. * The hides retain their properties for the various articles produced (softness, firmness, springiness, pore type, absorption, etc). * Significant improvements have been obtained in tensile strength for both grain and splits. The actual results obtained in this process were as follows: * A set of nine traditional tanning drums was replaced by two Cangilones drums, resulting in a saving of 255 HP in power capacity requirements. * Under the same conditions, 95 hours less operation time is now needed in the drums to do the same work. * 250 m³ less water is used than with the former system for every 20 MT of salted leather processed. * To date, savings in chemicals have worked out at 20%. * 50% less labour is required to handle the Cangilones drum system. * An overall trend towards gains in yield is observed, ranging from 0.5-1.0 sq ft per side. Viability study data The viability study revealed overall savings associated to the change of technology of around Euro35,800 (US$32,623) per month (for a basic output of 20 MT per day of hides and 20 days production per month). The breakdown of individual savings is as follows: 1) Savings in chemicals: Euro27,270 (US$24,850) 2) Use of sewage system: Euro600 (US$547) 3) Water costs: Euro3,600 (US$3,280) 4) Softening of hard water (energy + chemicals): Euro1,120 (US$1,021) 5) Energy due to reduced drum use time: Euro570 (US$519) 6) Energy in transfer (system mix): Euro40 (US$36) 7) Energy in boiler use: Euro1,310 (US$1,194) 8) Savings in labour: Euro1,290 (US$1,175) The following items were not readily evaluated at the time of the study, but they also generate quite significant savings associated with the use of this technology: 1) Cost of treatment of liquid effluent. 2) Cost in man-hours and spares of maintenance on the old tanning drums. 3) Cost of noise pollution. 4) Savings in the investment in equipment and installation costs which would have been required if traditional equipment had been brought in to obtain the same output.