Line for the coating of nonwovens for automobiles
Today, a modern automobile contains between 20 up to 30 kg of fibres from the tyres to the sky. These fibres are used - visibly and invisibly - in many textile products for example as tyre cord, adhesive tape of the seat cover, claddings, sound proofing or insulating material but also for floor coverings. In first-class vehicles mainly knitted fabrics are contained as visible textile sheets but in many of the more than 65 million cars produced every year also nonwovens as lower priced alternative are used. Thus, an automobile contains possibly more than 21 m² of nonwovens in the most different appearances.
Brückner has recognized this trend already long ago and offers for many of the mentioned areas of application innovative machines and lines for a resource-saving production of technical textiles used in modern vehicles. This begins with lines for the production of acoustic nonwovens continues with lines for the production of substrate for woven textile tapes, finishing lines for woven air bag fabric to coating lines for interior cladding based on needled nonwovens as supplied to and set into service at a customer in Russia recently.
The company OOO Nomateks lies in the region Uljanows near the South-Russian city of Samara. Nomateks was founded in 1961 at that time the first producer of tufting floor coverings in the former USSR. Nomateks developed in its history which goes back 50 years and became one of the biggest and most important nonwovens producers in Russia. With more than 180 workers and employees, the company produces high-quality nonwovens to be used in geo or automotive textiles with their own PP and PET fibres. Every year Nomateks produces more than 50 million m² of nonwovens.
A jointly realized project focused mainly on the customer’s request for highest flexibility and productivity with minimized use of resources. Therefore the line is able to coat, depending on the type of fabric and process, more than 15 million m² nonwovens per year for the use in automobiles. It is possible to finish velour needle felt carpets as well as unstructured needled nonwovens. With a length of more than 70 m it is one of the biggest lines Brückner ever supplied for the finishing of needled nonwovens.
To meet the above mentioned requirements, above all the preparation times had to be optimzed and the thermal and electrical energy demand had to be reduced considerably in comparison to the existing line. Since the project is a completely independent production line, the supply of the line with raw material has been considered from another point of view and a real alternative compared to the conventional preparation process in the batch has been found.
The use of an inline mixer of the Various Mix type produced by Messrs. Hansa Industrie Mixer allows to meter water, latex, chalk and possible additives directly from the big bag discharging station into the line and to prepare a highly homogeneous compound. This compound is converted into an instable foam and is supplied directly to the application unit. A BRÜCKNER knife-over-table foam unit is installed for the application. The gap between the knife and the table and thus the application quantity can be adjusted with a motor. The adjustment is made with a lifting spindle. The reproducibility of the settings is ensured by an absolute value transmitter. Normally the adjustment is made on both sides, but also corrections only on one side are possible. The squeegee roller can be balanced pneumatically via a four-bar linkage. Due to the rotary movement around the articulation, the squeegee roller parts not only vertically in case of a seam but also horizontally. This prevents impacts or material cracks.
The foam is supplied via a traversing distribution pipe directly in front of the knife and is automatically adapted when the production speed changes. In order to adapt the penetration depth of the foam into the nonwovens a height-adjustable braying roller is installed behind the coating knife. It is water-cooled to prevent an adhesion of Latex. The coated nonwovens is dried in a more than 27 m long BRÜCKNER DUO-THERM dryer, finished with a horizontal chain tensioning system to transport the fabric. This type of dryer is proven for the coating of carpets and nonwovens. The dryer which is directly heated via fan-supplied gas burners allows temperature differences of up to 60 °C due to separate heating and air circulating systems above and below the fabric web. In addition to the separate temperature adjustment on the coating and pile side also the air speed and thus the air circulation intensity can be adjusted independently by using the frequency-controlled circulating air fan drives. This provides for a high drying performance with very gently treatment of the pile and a high efficiency. This prevents pile deformations reliably.
The use of the proven Venturi system for a homogeneous mixing of the hot flue gas with the circulating ambient air leads to a very homogeneous temperature distribution across the width. The geometrically optimized Venturi nozzle needs absolutely no mechanical mixing elements and achieves with this a maximum efficiency. In addition, the line is provided with a two-stage heat-recovery unit air/air and air/water. On the one hand it heats up with the exhaust air heat a part of the fresh air which is required for drying. This heated fresh air is added to the process at various points which has the effect that the drying process can be operated always with the best fresh air/exhaust air ratio.
On the other hand the ECO HEAT air/water heat-recovery unit is used to heat process water for further use at other machines and lines of the NOMATEKS works. Depending on the production process the above described system can reduce the thermal energy consumption by about 30 % and allows thus a significant reduction of the production cost. Heat-exchange processes lead to a cooling of the exhaust air and thus to a condensation or a separating of pollutant particles. With this process the heat-recovery unit contributes considerably to the cleaning of the exhaust air.
In order to achieve the flexibility described above not only in the coating and drying sector several different winding and cutting systems are provided. The finished fabric can be treated on y two-roller ascending batcher as well as on an A-frame trolley. In addition, a Parker Hannifin longitudinal cutting and batching unit is installed in-line. The HAUSER - QLA offers the possibility to cut almost any material economically, to batch it and to treat it possibly further if required. The line is flexible due to its modular construction and perfectly appropriate for the processing of very different nonwovens. An integrated longitudinal cutting unit allows to make up to 4 cuts and to stack the fabric cut to length.
The line has of course a highly-modern control system with a Siemens PLC and all important production parameters are memorized in a recipe administration system and can be re-called by push-button. Sensors measuring permanently the consumption of electrical/thermal energy allow a further exact monitoring of the production. And of course all drives are supplied by BRÜCKNER in the highest-possible energy efficiency class. With this project all partners have worked out a tailor-made solution for our customer NOMATEKS. This is another BRÜCKNER coating line, which has been set into production to the customers’ complete satisfaction.