The card is known as the heart of the spinning mill; in this process step the quality of the resulting yarn is significantly defined and influenced. The two decisive parameters for the card are the quality requirements as well as productivity. While production rates of 5 kg/h were common in the sixties, todays rates can be in excess of 200 kg/h, depending on process and application.
As a result of the sturdy construction of textile machinery there are cards that have been in operation for up to 50 years and still fulfil their service. More than an estimated 140 different models of cards are in use worldwide. In order to equip these cards with correct and suitable clothings at the time of reclothing, it is imperative for a card clothing manufacturer such as Graf to know as many of these card models as possible.
Furthermore the dimensions of individual products such as revolving flats, stationary flats, mote knives as well as pre-opening segments have to correspond exactly with the requirements of the card model in question as otherwise the installation would not be possible. Collecting this detailed information can take years and the updating is an ongoing and important process.
Graf, based in Switzerland today keeps the data of more than 100 types of cards to assure that card-specific requirements are considered at the time of reclothing. Today the selection of correct specifications is made more difficult by the increasing number of second-hand machines that require special attention. These cards appear in certain markets as a result of the shifting of the textile industry from the West to the East.
To recommend the most suitable clothing combination for a card it is essential to know the application in terms of end product as well as the raw material to be processed. Such information is gathered by the technical sales team, either directly from the spinning mills or else through Grafs agents. In-depth training, years of experience as well as well founded knowledge of all spinning processes from bale to yarn distinguish the entire team.
On the occasion of visits to customers the detailed requirements are established and taken into consideration for the resulting specification. Grafs experienced specialists will competently assist the customers in the correct setting of blow-room equipment and cards. If newly designed clothings are applied, the responsible technical sales will evaluate the conditions together with the customer and if necessary discuss and introduce the measures required. It is only as a result of such comprehensive know-how being available within Graf that it can provide such service.
To achieve the maximum lifetime of the card clothings impeccable maintenance is inevitable; this is supported by a sound service schedule, which can be established with the support of Grafs specialists. Since each type of material reacts differently, the individual cycles need to be timed correctly. Graf usually hands out a recommendation for the card clothing management, based on average values which however need to be adjusted depending on the application.
It is a matter of great importance to us that Grafs customers achieve the best possible results with its card clothings throughout their entire lifetime. More than with any other product in the spinning mill, the purchase of card clothings is a matter of trust and confidence in the entire package comprising technical advice, the product itself as well as correct service.
(Source: Felix Hasler, Head, Product Management, Graf, Spinnovation. No. 27)