Textiles: manufacturing – Thread finishing – Surface modification of running length
Reexamination Certificate
2001-12-26
2004-12-28
Calvert, John J. (Department: 3765)
Textiles: manufacturing
Thread finishing
Surface modification of running length
Reexamination Certificate
active
06834417
ABSTRACT:
TECHNICAL SCOPE
This invention relates to a method and a device for treatment of filament yarn in a yarn channel of a nozzle with a supply of blowing medium into the yarn channel.
STATE OF THE ART
Treatment of continuous filament yarn has mainly two functions. First, a textile character and technical textile properties are to be imparted to the yarn which is produced from filaments synthesized industrially. Secondly, the yarn is treated from the standpoint of specific quality features for further processing and/or for the end product. To some extent, grades of yarn must be manufactured that are not necessary and cannot be achieved with products produced from natural fibers. The fields of application are in industrial processing of textiles, e.g., for the construction sector, the automotive sector as well as for carpet production and for special textile products for use in the sports and leisure industries. Furthermore, spun yarn is to be treated for the best possible industrial processing by applying of certain preparations, and the processing operation is to be optimized for yarns and fabrics. Optimization in this sense also includes maintaining or increasing certain quality criteria and lowering production costs, even with respect to downtime along the entire processing route.
Various treatments such as preparation and finishing of yarn by way of yarn treatment nozzles are an important part of filament spinning. The change in structure from a smooth yarn to a textured or interlaced yarn is achieved by means of mechanical air forces. In the case of texturing, a textile character is to be imparted to the smooth yarn. Small loops in the filaments are produced with a supersonic flow, and thus a greater volume is achieved over the entire yarn. In interlacing, knots are formed in the yarn at short intervals, increasing cohesion of the yarn and imparting more stable running of the yarn in processing and in spooling. Air treatment nozzles are used to improve the structure of a yarn. One very demanding process is the improvement in quality by treatment with superheated steam, e.g., for relaxing a yarn as part of a drawing operation or after a previous process measure. In all cases, the nozzle bodies are made of a highly wear-resistant material, because otherwise their lifetime would be too short. The preparation step is a not insignificant source of problems for yarn treatment nozzles. In this process, yarn is provided with protective substances immediately after the spinning operation or after production of individual filaments. These protective substances should be of assistance in subsequent processing. The substances used for this preparation step result in an oily lubricant property, so that the sliding friction of the yarn remains as low as possible over the entire path of processing, the risk of damage and yarn breakage is reduced, and abrasion on the friction surfaces of the conveyance and processing installations can be minimized. However, there are a number of other factors such as static charge buildup on which the preparation or preparation agent can have a positive influence. Another field of application is for protection of yarn from fungal attack during storage times between the various processing stages.
The drawing operation is another very important process step for filament yarn. After filaments leave the spinnerets, the yarns formed from them must be drawn. This drawing presupposes that the yarn is more or less smooth, although that is no longer the case when processing a textured yarn. In a great many applications, there is a need for imparting a minimal interconnection to the yarn. However, this interconnection may only be intense enough so that it does not have a negative effect on downstream processing operations. It is known that an intermingling nozzle can be arranged downstream from the site of application of preparation agents in a spinning operation. In this case, only very weak knots are formed in the yarn, or even better, only the beginnings of knots are formed to stabilize the transport operations which follow directly. One disadvantage here is finding optimum conditions or an optimum compromise between no knots at all and just the beginnings of knots. The intermingling nozzles known so far are characterized by poor utilization of the air treatment or a weak eddy formation, especially with a relatively low pressure of the processing air. In practice, the uniformity and constancy of the resulting yarn structure often suffer. In the state of the art there is no stable yarn treatment option or a corresponding device which produces enough filament interconnection that calm and stable yarn running is assured without any negative effects on downstream procedures or process stages or with respect to structural changes.
German Patent 41 02 790 describes a special problem in regard to false twist crimping machines and proposes a delivery nozzle. To this end, the delivery air is blown into the nozzle channel at an angle of 20° to the direction of yarn travel, for example. In the case of a delivery effect almost exclusively, the yarn remains almost unchanged. U.S. Pat. No. 4,214,352 proposes a texturing nozzle for production of a looped yarn. An angle of approx. 45° for introduction is mentioned.
EXPLANATION OF THE INVENTION
The object of this invention was to develop a method as well as yarn treatment nozzles which would permit prebonding of the yarn interconnection, in particular with the greatest possible constancy of a gentle structural operation. The goal was to produce the interconnection even at the highest speeds of yarn transport, e.g., at speeds of 3000-7000 m/min, directly downstream from the spinnerets and in direct conjunction with the application of preparation agents. Part of the object of this invention was to improve the situation for treatment of yarn from the standpoint of preparation agents, productivity, especially quality, even at the highest speeds.
The method according to this invention is characterized in that the blowing medium is directed into the yarn channel somewhat in the direction of thread travel and at an angle of introduction with an angle deviation &agr; from the perpendicular to the direction of thread travel, said angle deviation being greater than 15° but less than 45°, with the filaments of the prepared yarn being blended and slightly crossed without producing knots.
The device according to this invention is characterized in that the device is designed as a migration nozzle having a compressed air feed channel into the yarn channel, said compressed air feed channel being aimed in the direction of yarn travel and arranged in the yarn channel with an angle deviation greater than 15° but less than 45° from a perpendicular to the direction of yarn travel.
This invention also relates to the use of this device for thorough mixing and uniform distribution of preparation agents on filament yarn, whereby the filaments are joined to form a slightly crossed but knot-free yarn, and the preparation agent is at the same time distributed optimally over the entire yarn.
This invention permits a large number of especially advantageous embodiments. In this regard, reference is made to claims
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Practice has shown that with an increase in yarn transport speed, namely to more than 3500 m/min in the case of polyester, for example, more than 3000 m/min in the case of polypropylene and more than 4200 m/min in the case of polyamide, thread running becomes unstable and erratic despite the preparation. This instability increases further with any further increase in spinning yarn speed. This becomes problematical in the case of higher multi-end spinning positions. This is true in particular of deflection rollers and drawing rollers in pre-oriented POY and finished-oriented FOY as well as fully drawn FDY spinning operations. Another factor is that a progressively smaller separation between adjacent yarn runs is desired, not least of all for reasons pertaining to mechanical engineering and the process technology, s
Calvert John J.
Heberlein Fibertechnology, Inc.
Hurley Shawn R
LandOfFree
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