A two-component yarn is created from a fiber component and a component consisting of a filament yarn, in which the fiber component is formed by a drawn sliver that is prestrengthened by means of pneumatic false-twist spinning and is twisted together with the filament yarn.

BACKGROUND AND SUMMARY OF THE INVENTION 
The invention relates to a two-component yarn, having a a fiber component 
and a component consisting of a filament yarn, and to a process for its 
production. 
It is known (U.S. Pat. No. 4,069,656) to produce a two-component yarn from 
a fiber component and a filament yarn. The fiber component passes through 
a drafting frame, and then, together with the filament yarn, through a 
pneumatic false-twisting nozzle, whereby the filament yarn is combined 
with the fiber component. This results in a two-component yarn with an 
alternating twist that cannot be used universally; for example, it cannot 
be used as a sewing thread. 
In the case of sewing threads, a high resistance to tearing and a high 
uniformity are required. Known sewing threads made of filament yarns have 
the disadvantage that, because of their smooth outer surface, they do not 
hold very well in a seam and can easily be pulled out. When the seam is 
broken at one point, very frequently a very long length of the sewing 
thread can be pulled out. For this reason, when a better quality is 
required, sewing threads are used that consist of staple fibers. However, 
sewing threads of this type consisting of staple fibers are very expensive 
to manufacture. 
The invention is based on the objective of providing a two-component yarn 
that can be used as a sewing thread. 
This objective is achieved by forming the fiber component of a drawn sliver 
that is prestrengthened by pneumatic false-twist spinning and twisting it 
together with the filament yarn. 
In the case of this type of two-component yarn, the filament yarn component 
causes the resistance to tearing, while the fiber component provides a 
textile quality to this filament yarn. As a result, it becomes usable as a 
sewing thread even in the case of higher demands, because the fibers cause 
the two-component yarn to be better anchored in a woven or knitted fabric 
or the like. However, the two-component yarn according to the invention 
can be used not only as a sewing thread. It can also be used for 
particularly tear-resistant popelin fabrics, for shirt fabrics or for bed 
sheets. 
In a further development of the invention, a process is provided for the 
manufacturing of the two-component yarn from the fiber component and a 
filament yarn in which, by means of a drawing in a drafting frame and by 
means of a pneumatic false-twist spinning, a prestrengthened fiber 
component is produced from a sliver and is combined and twisted together 
with the filament yarn. Since the fiber component, by means of the 
pneumatic false-twist spinning, is only prestrengthened, very high 
production speeds are possible. The prestrengthening of the fiber 
component must take place to only such an extent that the prestrengthened 
fiber component can be handled and twisted. Since this already results in 
a combination with the filament yarn, the demands on the stability of the 
fiber component may become relatively low. After the twisting-together, 
the resistance to tearing is determined by the filament yarn. 
In order to utilize the advantages of a high production speed as completely 
as possible, it is provided in a further development of the invention that 
the prestrengthened fiber component is guided together with the filament 
yarn and, before the twisting, is intermediately stored on a spool. As a 
result, the producing of the spool from the multiple-wound yarn component 
can be implemented at a high production speed. Since, during the twisting 
of the two yarn components, no spinning twist has to be undone, the 
twisting may also be carried out at a relatively high working speed. 
In a further development of the invention, it is provided that the 
two-component yarn, after the twisting, is cleaned out by rewinding. This 
is particularly advantageous if the two-component yarn according to the 
invention is to be used as a sewing thread. 
Other characteristics and advantages of the invention are contained in the 
following description of the arrangement shown in the drawing. The drawing 
shows an arrangement by means of which a spool is produced from a 
two-component yarn, a staple fiber component and a filament yarn, in this 
case, being cross-wound into a cross-wound spool. 
Other objects, advantages and novel features of the present invention will 
become apparent from the following detailed description of the invention 
when considered in conjunction with the accompanying drawing.

DETAILED DESCRIPTION OF THE DRAWING 
The arrangement shown in the drawing contains a drafting frame 1 to which a 
staple sliver 2 is fed in the direction of the Arrow (A). In the drafting 
frame 1, the staple sliver 2 is drawn to the desired size. The drafting 
frame has bottom rollers 3, 4, 5 that pass through a machine which has 
several work positions arranged next to one another. The bottom cylinders 
3, 4, 5 are driven at one end of the machine. At each work position, 
pressure rollers 6, 7 and 8 are assigned to the bottom cylinders in a 
known way. In the main drafting zone, apron guides are conventionally 
provided of which the top apron 9 is visible. 
After the drafting frame 1, the drawn sliver 2 reaches a false-twisting 
zone 10 in which a pneumatic false-twist spinning is carried out. The 
false twisting zone 10 contains two air nozzles 11, 12 arranged behind one 
another in moving direction (A) that are connected to compressed-air pipes 
13, 14. The air nozzle 11 is normally constructed essentially as an intake 
nozzle that does not yet provide any false twist to the drawn sliver 2 or 
provides only a slight false twist to it. In the air nozzle 12, an air 
whirl is generated that provides the drawn sliver 2 with a false twist. 
Behind the air nozzle 12, this false twist opens up again, in which case, 
however, edge fibers remain wound around the sliver 2 so that a 
prestrengthened yarn component 15 is obtained. This prestrengthened yarn 
component 15 consists of an essentially untwisted sliver core, around 
which the ends of several spread-away fibers are wound. The 
prestrengthened yarn component 15 has a relatively low strength that is 
not high enough for this yarn component 15 to be usable as an individual 
yarn by itself. 
The prestrengthened yarn component 15 is withdrawn by means of a withdrawal 
device 21 that comprises a driven bottom cylinder 22 extending through in 
the longitudinal direction of the machine and of a pressure roller 23. 
Before the yarn component 15 moves into the withdrawal device 21, another 
yarn component consisting of a filament yarn 16 is added to it, so that 
these two enter the withdrawal device 21 as a double yarn 20. The filament 
yarn 16, which may be a multifilament or a monofilament, from a spool or 
the like, is fed in the direction of the Arrow (B), to a delivery device 
17 that is formed by the bottom cylinder 5 of the drafting frame and a 
pressure roller. In the area of the false-twisting zone 10, the filament 
yarn 16 is deflected by means of two guiding elements 18, 19, to the 
prestrengthened fiber component 15 that is moving through in a straight 
line. 
The double yarn 20 formed by the filament yarn 16 and by the yarn component 
15 consisting of a prestrengthened sliver, after the withdrawal device 21, 
is fed to a wind-up device 24 that contains a driven shaft 25 extending 
through in the longitudinal direction of the machine by means of which the 
cross-wound spool 26 is driven. The spool frame of the cross-wound spool 
26 as well as a cross-winding device and other details of the wind-up 
device are not shown. 
The cross-wound spool 26 is used as a feed spool for a subsequent twisting 
during which the two-component yarn is finished. The cross-wound spool may 
be fed to a ring twisting frame or to a double twisting frame. 
Particularly, when extremely high demands are made on the two-component 
yarn with respect to uniformity, the two-component yarn, after the 
twisting, is rewound once more and is cleaned out in the process, so that 
yarn defects, such as thick or thin points, are cleaned out and are 
replaced by another yarn connection, particularly by a splice. In this 
case, it is possible to combine the twisting machine, the arrangement 
shown in the drawing and the wind-up machine into a compound machine or, 
as a composite system, into a machine system. 
Although the present invention has been described and illustrated in 
detail, it is to be clearly understood that the same is by way of 
illustration and example only, and is not to be taken by way of 
limitation. The spirit and scope of the present invention are to be 
limited only by the terms of the appended claims.