Customer service is a priority at Graf’s and professional support for our customers is not just an empty phrase but a promise. This Graf fulfills, from the initial evaluation of the clothings to the installation up to the ?end of life‘ of its products. The esteemed customers can count on proven experts that are at their service on-site as well as in the head office in Rapperswil (CH).

Detailed information on the raw material processed and the intended yarn count are the key parameters in the selection of the correct clothings for the components of a card. While the eventual yarn count can be considered quite easily in the specification in this early stage of the spinning process since it just depends on the fibre length and the carding fineness (eventually the density), the raw material is far more difficult to handle. For cotton and/or man-made fibers Graf differentiates between a total of 25 different processes, each with 2 to 3 production rates and for each process defines a number of different clothing combinations  for the main cylinder, doffer, licker-in and flats. These specifications are optimized for the more than 200 types of cards and their characteristics. For rollers with larger diameteres, for example, metallic card clothings with a more aggressive working angle are installed and, depending on the operating speed or the throughput respectively, different densities and tooth shapes are chosen. Not only the wire geometry or the choice of alloy are at the centre of this consideration, but always the interaction of the individual clothings and customer’s machinery, too. Graf, for decades, has gained experience and has optimized its clothing combinations, in some cases  specifically for individual types of cards and card makers; resulting in the availability of around 1’500 different clothings to perfectly meet all conceivable requirements of the customers’.

The trash content in the cotton can be compensated to a certain degree by the choice of the clothings, e.g. with more sturdy flat clothings. However there are physical limits resulting in the confrontation with a classical problem of optimization. A lower rate of waste extraction in the blow room increases the material yield and economic efficiency – but also the trash content in the subsequent processes. This causes damage, and the premature wear of the clothings on the card results in lower quality, decreased revenue and an increase in maintenance costs. Graf provides its customers with support in accurately matching the settings in the blow room, mote knives etc. to ensure production in an optimal operating point –economically as well as technically.

Picture 1: Excessive contamination of flat clothing with subsequent damage due to wrong settings in the blow room

Following the selection of the best possible clothing combination, a professional installation and maintenance is decisive for the clothings to perform to their full potential. Graf continuously strives to convey the correct use of its products to its clientele and the quality-assurance laboratory at the head office in Rapperswil provides an indispensable contribution in determining the action required. Most of the defects reported and problems encountered by customers are consequential damage resulting from incorrect handling of material and equipment – which basically is easy to prevent provided the critical points are known and observed.

Common error patterns are illustrated in the picture spread. Horizontal storage or wrong positioning of coil when mounting damages the tooth points of the clothing and renders it unusable from the start (picture 2and3). The periodic markings at the wire base are clearly visible, caused by contact with the tooth points. Quite frequent damage symptons are shown in picture 4-5: a crash of the flat clothings with the cylinder. As a result of the increasing production speeds and working widths of thecards the permissible machinery parameters and tolerances become closer, and as such also the margin for inaccuracies and faults.

Picture 2-3: damaged tooth points caused by contact with wire base

Picture 4-5: clear signs of crash on the tooth points and the tooth radius

While subsequently the cause of the damage is evident the necessary measures  can vary greatly. Further analysis indicates whether the flat clothings were correctly resharpened at the time of service, whether the carding gap was set correctly or whether customer’s production process was run incorrectly and excessive thermal stress may have led to deformation and thus a contact. Depending on the findings corrective measures may be taken in the supply chain, the (service-)processes or the training of the staff.

Graf + Cie AG maintains 36 workshops worldwide in close co-operation with its local partners (picture 6) and supports their customers with regular service work , troubleshooting and optimizing of processes at site. Furthermore the technical customer consultants and agents are constantly engaged with selecting the best possible clothing combinations for the customers‘ production processes. In doing so they can count on the full assistance of the engineers and the technical staff from development, quality assurance and production at Graf’s who, on request, realize unusual customers‘ wishes and work out individual solutions for customers.

Eventually the key to the success of Graf + Cie AG is the success of its customers – this is what Graf works on day for day.

In some cases the cause of the problems is in the operation but not the clothing itself as the example of a successful troubleshooting of Graf illustrates:

The doffer of a customer’s card continued to choke and the machine needed to be stopped and cleaned every second day. Various reclothings with different types of metallic card clotings did not result in any improvement, subsequently Graf was consulted. Following an in-depth analysis of the situation at site, the Graf specialist noticed that the actual cause was insufficient suction at the location of the card. Since a new suction concept would have meant a considerable investment, a more cost-efficient solution of the problem was searched and finally found. Graf’s proposal was to slightly increase the speed of the draft web-belt of the card and adjust the coiler tension accordingly.

As a result of the new parameterisation of the card the process runs flawlessly and customer’s problem could be solved  lastingly.

Choked doffer at customer’s site, requiring cleaning every other day

Doffer following successful troubleshooting and operation of some weeks

Graf Workshops, Status at 07.2017