Turnkey expertise for PMC (Paper Machine Clothing)

Since FEHRER´s acquisition of MORRISON BERKSHIRE, INC. heat setting and finishing intellectual property and its co-operaton with THIBEAU/ASSELIN for the supply of complete papermaker felt production lines, FEHRER is able to quote for lines incorporating fibre preparation, carding, cross-folding, needling and thermosetting. Optimum technical solutions are realised with the co-operation of experts from all partners.

The NSC NONWOVENS DIVISION consists of the THIBEAU company, which produces cards and ASSELIN, which manufactures cross-lappers. One of NSC's latest developments is ProDynŽ, a comprehensive control system with self-regulation in both a machine and transverse direction that is suitable for all non-woven lines making batts with a Dynamic card and a Dynamic cross-lapper. Simplicity, user-friendliness and cost efficiency were the three main factors considered during the development of the ProDynŽ system, which is based on four elements. The first of these is an entry auto-leveller, called Servo-X, which controls the MD regularity of the end product. The second is comprised by a complementary card and cross-lapper with Dynamic systems for the CD regularity of the end product. The third and fourth elements consist of a scanning gauge before the winder and software, which controls all the line parameters. The software continuously compares the average sigma value indicated at the gauge and regulates the Servo-X and the Dynamic card and cross-lapper, in order to obtain optimised regularity. The sigma value of 110 g/m˛ at the winder is not higher than the 1.1 g/m˛ checked at the gauge.

The operator merely needs to use a few simple instructions displayed on the screen of the line control panel and the THIBEAU Dynamic card and ASSELIN Dynamic cross-lapper automatically optimise the end result. This system is equally efficient at 30 m/min and 150 m/min card web delivery speed, irrespective of the lay-down width. The design of Dynamic cards and Dynamic cross-lappers, as well as of their electronic drive and software controls, creates no special maintenance needs and avoids complicated settings.

The needling sections of such non-woven lines include the FEHRER NL 16 pre-needling machine with relevant winding equipment and are followed off-line by an NL 19 or NL 20 finishing machine. In the case of direct feeding, an NL 19 or NL 20 can be connected directly to the cross-folder. All FEHRER papermaker needle punching machines are designed according to the modular design system. This is the only system available, which allows highest stroke frequencies in continuous operation and cost saving service intervals of several thousand hours. The use of drive modules facilitates the construction of needle punching machines with widths of 15 m and above and continuous operational speeds of up to 1200 stroke/min. The FEHRER NL 19 was the first machine on the market to permit simultaneous needling from both sides with 1 or 2 outside needling zones and 1 or 2 inside needling zones. The FEHRER NL 20 represents a technology for simultaneous needling from both sides with parallel and counterpunching and is available in different variations with up to 8 needling zones.

The NL 16 pre-needling machine features a cantilever stripper, a special air-guiding system to prevent the web damage caused by air turbulence, special inlet rollers with guiding fingers and a winding system with web weight compensation. The NL 16 is equipped with MMD ("Multi Motion Drive"), in which needle boards make a horizontal movement while penetrating the web. This reduces substantially the draft, resulting in a greater evenness of the preneedled web.

The NL 19 and NL 20 finish needling looms are equipped with a single- or double-hitch tension carriage for full or partial felt tensioning. The machines are fitted with an automatic needle board changing system for handling the needle boards, which provides precise board orientation and automatic clamping in the exact position required. An optional external storage unit is available for fully automatic board exchange.

As an option, one of the outside needling zones on the NL19 or NL20 can be equipped with the patented "H1" needling technology with curved bed and stripper plates for increased entangling of the individual fibres. Better interlocking of the fibres on the base fabric is obtained due to the X-shaped stitching channels. Both the "H1" and flat needling systems, for outside and inside needling, can be equipped with MMD. MMD is applicable for the entire speed range up to 1200 rpm and the horizontal stroke length can be smoothly adjusted during machine operation. The main advantage is an improvement of the felt surface through a minimisation of needle marking.

Extensive testing facilities are available in our lab. For example, a 2.5 m wide NL 18 MMD machine, including a tension carriage for needling under full tension, is at the disposal of our customers. The machine can be operated as a pre-needling or a finishing machine and with or without H1 needling zone. The machine is also fitted with MMD which allows our customers to make comparable tests using their own materials. We have installed a "Penetration force measurement system" on this lab machine, which gives customers the opportunity to measure the punching load on different felt qualities and using various types of needles.

Another unique feature of Fehrer papermaker needle punching machines is the "VARIOFELT" system. Quality demands by the industry require improved felt surface homogeneity and reduced paper machine vibrations. "VARIOFELT" is used to apply a batt of any structure onto an endless base fabric or felt. A single module traverses the entire working width, helically tacking on the web, which has a width of around 1 m. Felts made using "VARIOFELT" run quietly, allow higher speeds and provide a smoother surface. They offer felt designers the opportunity to create a unique range of new types of felts.

The intellectual property acquisition of MORRISON BERKSHIRE, Inc. technologies for heat setting and finishing equipment has generated considerable interest throughout the industry. FEHRER customers in all papermaker clothing disciplines can profit from design advantages such as the full bridge retraction cart, which generates higher quality fabrics with lower maintenance. Our unique press roll system brings many new features to the market specifically for felt producers. Sophisticated protection pans keeps all pneumatic and electrical equipment dry and shielded from liquid, while at the same time leading fluids to troughs and drains so that the floor stays clean. Easy access to all parts, which are exposed to process chemicals, is also provided, along with the possibility of automating the cleaning process. The design of the support rolls for the press roll prevents press nip marks and is combined with singular evenness of the pressure throughout the whole press nip. Our hot roll design is a benchmark for the industry with exact manufacturing tolerances and temperature profile across the working width. This generates the highest quality paper machine clothing fabrics. These features will now be linked to FEHRER's Windows-based electronic and visualisation system and with the company's familiar engineering capabilities.

As Monika Fehrer explains, "This full range of machinery for the papermaker felt industry underlines FEHRER's ongoing commitment to the market. As the number of players in this area has been greatly reduced due to major mergers and acquisitions during the last 10 years, customers are looking for partners who can offer support throughout a major section of their value added chain. The strategic steps taken with regard to alliance policy, the acquisition of technology and proprietary development by FEHRER, create optimum solutions in this regard. Moreover, the co-operation between leading experts in all fields represents a major contribution to customer profitability in the paper machine clothing sector."

(Fehrer Focus No.28 / September 2001)