Tailor-made felts

Virtually all the major tannery machinery manufacturers and a list of 500 tanners are included on the Mattei Guido e Figli customer database. As Mattei only produce felts for the tanning industry, they are able to concentrate their efforts on the particular requirements of the tanner. For example, they have been working very closely with wet-blue tanneries that process zebu cattle hides. The humped cattle breeds known as zebu (or Brahma) are common in Latin America, particularly Brazil, and the Indian subcontinent. 'During the throughfeed sammying/setting-out operations at high pressure, the hump causes the wet-blue leather to fold itself into four layers. In the past this would have caused the felt to be damaged during operation', says Daniele Mattei, managing director. 'With the assistance of some Brazilian tanners and an Italian sammying machine manufacturer, we have managed to develop a felt which does not become damaged when throughfeed wringing zebu hides at high pressures.' Mattei have developed the new MTT/NWB/70SR felt specifically for this operation. The new felt follows on from their unique felt launched 18 months ago which comprises 60% synthetic fibres with 27% wool and 13% MTT fibres (1). The new felt is an evolution of Mattei's MTT fibre technology, which was first introduced with the 60/27/13 felt. The physical structure of the updated product has been developed in such a way that it will not break under extreme pressures and can achieve maximum compression while the hump is passing through the machine. The new felt is then able to spring back to its original position ready for the next hide. Mattei produce a range of fifteen core products. Their range begins with a felt made entirely from wool and includes fourteen other combinations of wool and synthetic raw materials. The felts are supplied to the machinery manufacturer or tanners' specifications. For example, a typical throughfeed sammying/setting felt with dimensions of 3.0m (width) x 3.6m (length) top felt with a 3.0m (width) x 6.1m (length) lower felt would be custom made for the client by Mattei. The felt is then shipped to the customer for installation. Mattei produce felts for the whole range of tannery equipment where felts are used. These include sammying, setting-out, throughfeed sammying/setting-out, continuous ironing and embossing, hydraulic pressing and polishing. 'All of the wet-end machinery manufacturers use our felts and we are increasing our market share supplying felts for finishing equipment', says Mattei. The felt making process The felt making process has already been covered extensively in Leather International (1) and an outline of the procedure is given in Table 1. Effectively, the process is broken down into two parts which are combined at the needling stage. The process involves a woven element, which is produced on a carding machine using a number of threads to give the final woven sheet or sock. The rope is woven together with the required final physical properties to suit the end use. The second part is the non-woven part, which is made up of a mixture of natural wool and synthetic fibres. Mattei source wool from all over the world, depending on the end use of the finished felt. Country of origin, climate, diet and breed all have an impact on the wool type. For example wool from Uruguay will convey different physical properties to wool produced from Australian breeds. Other sources for wool include New Zealand and Argentina. Threads from a number of fibres are automatically spun together to form a rope in the woven process. The rope is then woven into a sheet or sock. Mattei are then able to join the ends of the materials together to form a continuous tube which can be fitted to a roller on a sammying machine, for example. In the non-woven operation, the raw materials are mixed by hand and then blended mechanically. The mixed fibres are then laid out in one direction and then overlaid at 180 degrees to form a criss-cross. Both layers of non-woven material are subsequently passed through a needling machine, which mechanically binds the layers together to form a single sheet. The needling operation works by a series of needles being passed through the non-woven material several times a second. Varying the type of needle used and the speed of the machine can alter the type of felt produced. Each needle is fitted with a serrated edge which grips the thread on the downward motion attaching it to an adjoining thread and releasing the thread on the upward motion. The technique is very simple but very effective. Once the two separate operations have been completed, they are joined together. In a typical process, 4-6 woven sheets are placed on top of each other and the non-woven material placed on top. The woven and non-woven materials are then needled together. After needling, the felt is collected into a roll and then taken to the finishing area. The felt is passed through a buffing paper to even out the thickness, much like a buffing machine in a tannery. A chemical mixture of resins and thermoplastics is applied under heat to stabilise the felt and chemically fix it. Following finishing, the felt is then pressed to achieve the final thickness suitable for the required tannery process. Mattei have installed a purpose built, computer controlled press from Bergi OFB which can operate up to double the pressure of a typical tannery press such as Bergi's Superpress which happens to be the strongest in the tanning sector. Finally, the felt is passed through a metal detector before shipment to the customer. Felt care 'A typical wet-end felt which is cleaned regularly and properly can have a working life twice as long as a felt which is not cleaned adequately', says J P Burlando, sales manager. The shelf life of the felt not only depends on its cleanliness but also on the pressure which is applied to it during operation. During the wet-end stages, a typical felt can expect to process between 380,000-650,000 hides depending on how well it has been maintained and its physical composition. 'Mattei recommend that the felt be cleaned after every four hours of production, especially when processing particularly greasy hides or skins. The felt should also be given a more extensive clean overnight', Burlando told Leather International. A poorly cleaned and maintained felt quickly becomes affected by contamination and can reduce the drainage properties. Most tanners replace the felts on their machines during the annual shut down or maintenance period. Customer service Mattei have been accredited with ISO 9002 for implementing quality management systems into their process. Certification has allowed Mattei to have greater control on the raw materials entering the factory and the final product exiting. 'To be successful in business today you cannot just rely on a strong product but also good customer service', says J P Burlando. 'We believe that we have remained successful because we endeavour to assist our customers with the highest level of service.' Mattei have a policy of providing a customer with a quote on the same day as it is requested and if a customer has a problem with one of their felts, Mattei will send a technician to try and rectify the problem. Every felt is made to the customer's requirement. For example, one tanner may require a felt which offers more (or less) drainage during sammying than another tanner. Mattei will tailor make the felt to suit the job. Details of each customer are kept on an elec-tronic database, where Mattei can refer back to see what was ordered previously. Every felt is accompanied by a production sheet, which follows the felt from raw materials to completion. If a problem occurs with the felt, the production sheet can be used as a reference to observe whether anything unusual happened during manufacture. Each felt is produced within strict physical parameters such as weight, density and thickness. Each measurement is logged on the production sheet. 'Our normal felt manufacturing cycle takes around 15 days. If a customer requires a felt in an emergency situation, we can produce the felt as quickly as 48 hours and ship to them by air', explains Burlando. 'If we fall behind for whatever reason and the customer needs an urgent delivery, we will ship the felt to the customer by air instead of road or sea at our cost. We know that the extra cost will, eventually, be recouped in repeat business', he added. The Mattei Group The factory is located in the town of Castelliri, close to the Apennine mountains, approximately half way between Rome and Naples. The group were founded in 1967 by the current president, Guido Mattei. Previously, Guido Mattei worked for the French felt business COFPA for eleven years as technical director. Mattei's son, Daniele, the current managing director, controls the daily operation of the company. The Mattei Group is split into two companies. Felmat are the production arm of the group and the commercial part of the business is known as Mattei Guido e Figli. The group employ 47 people and sell felts to every leather producing country in the world through their network of international sales agents or from their headquaters in southern Italy. 1. Lampard G L, Leather International, January 2001, pages 29-32 vol 203 No 4707