DE2229881A1 - Device for the production of core / sheath composite threads - Google Patents

Description

Priority »June 18, 1971 - Great Britain

The invention also relates to a device for manufacture of eccentric core / hull composite threads with a specific Core shape and a uniform cross-section.

Lately there has been the construction of devices for considerable attention has been paid to the manufacture of core / sheath filaments. This is especially true for such threads which the core is arranged eccentrically in the sheath and which as a result can be puffed up by crimping. These Bulging is usually done through some form of thermal relaxation treatment carried out.

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For a particularly desirable cross-section, the core com «- component largely D-shaped and, if possible, in one half of the Fadena arranged, depending on the ratio of the components. Devices, i.e. spinning heads, for the division of such Threads are described in numerous patents. Examples are GB-PS 1 017 639, 1 101 452 and 1 143 773.

Particular difficulties in the manufacture of Eoiapositfäden this type occur when a uniform cross-section between the individual threads and along the individual Threads are to be achieved and if it is to be ensured that the sheath component completely surrounds the core. This the latter fact is particularly important when filaments are made by melt spinning techniques and core components contain, which have a significantly lower melting point than the shell component, since in these cases, if the sheath does not completely surround the core, there is a tendency for the threads to fuse with one another during spinning and also during other processes carried out in the heat «

It has now been found that a particularly suitable combination for the production of core / sheath composite threads with an eccentrically arranged D-shaped core has a spinning nozzle plate which has at least one plateau arranged on the upper surface in which channels with a certain shape are formed which are in communication with a portion of the spinneret plate surface from which the shell polymer flows. The extruelons are arranged in counter bores which are formed in the spinneret plate at the ends of said channels. A rear plate is also provided over the spinneret plate which is in contact with the plateau. There are facilities for the supply of shell polymer aura space between the »

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water plate and the spinneret plate provided. aside from that it contains 3) -shaped openings * those with the extrusion openings are aligned in the spinneret plate * Furthermore are devices for feeding polymer to the D-shaped Openings of said rear plate are present.

So, according to the invention, a spinning head for Hex'position of sheath / core composite threads with an eccentric arranged D-shaped core proposed which the following Has parts * A spinneret with an upper and a lower surface, wherein at least one plateau is provided on the upper surface and wherein a channel in the plateau a is not formed, which has a closed end portion and an extrusion opening counterbore which is connected to an im lower part of the spinneret plate formed extrusion opening communicates; a rear plate disposed over the spinning iron plate and having a lower surface, which is in contact with the plateau so that there is a space between the lower surface of the rear plate unci the upper surface of the spinneret plate is formed, which space is in connection with the channel formed in the plateau; a device in the rear plate with which Shell polymer sum called space between the lower surface of the back plate and the upper surface of the spinneret plate can be guided; and means disposed in the aft plate over the spinneret plate counterbore is to inject a core polymer into the counterbore, this device having a D-shaped opening, which is in the lower surface of the back plate " is trained.

With such a gate direction, the straight part of the D runs in fler D-shaped opening in the rear plate perpendicular to the Flow line of the shell polymer in the channels and in one horizontal plane. The openings mentioned have a diameter

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- a ""

knife, which is preferably the same size as or smaller than the diameter of the extrusion opening counterbores.

The channels formed in the plateau should preferably be bilobed Have end portions so that the flow of the shell polymer is uniform around the curved outer portion of the core component flows. r

The exact position of the extrusion opening counterbores in relation to the channels depends, among other things, on the proportions of the components and on a difference in their melt viscosities.

The invention will now be explained with reference to the accompanying drawings,
which show a special embodiment, explained in more detail.

In the drawings j

Pig, 1 shows a cross section through a spinning head according to the invention;

Pig «. FIG. 2 is an enlarged plan view of the channel arrangement from FIG
Fig. 1;

Fig. 3 is an enlarged plan view of a modified channel ~
arrangement;

Figures 4 and 5 are cross-sections through threads * which are using

the apparatus of Figs. 1 and 2 have been spun j and

Fig. Β is a cross section through threads using
spun by another device _e

According to FIGS. 1 and 2, a package holder 1 contains a spinneret plate 2 with a raised central plateau 3 »in which bilobed channels 4 are formed with lobes 4a and 4b. At the base of counterbores 6 there are extrusion

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openings 5 * The counter-bores are provided on the end parts of the channels 4. A rear plate 7 rests against the plateau 3 and defines an annular tree 8 between the two plates. Polymer feed channels 9 are provided which are in connection with the annular space. "In the plate, openings 10 are provided vertically above the extrusion opening counterbores 6D". A distributor plate 11 is located behind the rear plate and contains polymer feed chambers 12 and 13. Feed openings 14 establish a connection between the chamber 12 and the feed channels 9 in the rear plate. In a similar way, ventilation openings 15 establish a connection between the chamber 13 and a recess 16 which is formed on the underside of the distributor plate and allows polymer to be fed to the D-shaped openings.

A feed channel 9 for the shell polymer is preferably in dtr Near each channel 4 present, which the ringföraigen Raun spewed on.

In the representation of the channels shown in 3? Ig * 2, what already has been pointed out, the counterbore 6 runs to the intersection of the tabs 4a and 4b «The position of the S-shaped Openings in the back plate relative to the counterbore are shown in dashed lines.

In Fig. 3, the counterbore from the intersection of the lobes is dee Kanala moved away to provide additional space for that which forms the shell To create polymer so that it can reach the back of the opening.

Pig. Figure 4 shows a cross section through threads made using the device of fig. 1 and 2 have been produced, the polymer components being present in equal amounts.

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The threads ″ have a core 20 and a sheath 21.

In Pig. 5 are the shell component 30 and the core component 31 available in a ratio of 70/30.

The threads shown in Fig. 6, which cores 40 and sheaths have been made by an apparatus not according to the invention.

Eccentric sheath / core threads in which the core «and the Shell components are found in the same proportions, are made of a nylon-66-Horaopolymer and a 66/6 / 6iP- (80:10:10) Interpolymer made using the apparatus of FIGS. 1 and 2. The 66 polymer turns into an annular shape Chamber 12 introduced, from where it through the feed openings 14 in the distributor plate into the feed channels 9 in the rear plate and then enters the annular space 8, from where it enters the channels 4 and into the counterbores 6 flows. The 66/6 / 6iP ~ core component is from the chamber 13 pressed through the feed openings 15 into the ridge 16 and then through the D-shaped openings 10 through the sleeve polymer contained in the channel 4 and into the counterbore 6 of the extrusion opening injected. The two polymers are then extruded through extrusion openings 5 in composite threads, which have the cross-section shown in FIG.

When the core / shell ratio of the polymer components is up 70/30 is changed, then it is necessary to use the channel arrangement of FIG The core component is completely enveloped and this prevents the threads from sticking together after extrusion.

As an additional aid in achieving a complete envelope around the composite thread, the part of the plateau 3 can be removed.

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that surrounds channel 4. This allows the shell polymer to be used in a very limited amount from all of them Ricatungen flows into the canal.

If the core component is merely injected through the shell polymer, when the latter is not in a channel to safely divide its flow around the extrusion opening, then the threads have cross-sections similar to those in Pig. 6. In these filaments, the core 40 has a constrained appearance and also the thickness of the sheath around the curved portion of the core is not uniform so that the degree of eccentricity of the core coraponent relative to the sheath component that can be achieved is reduced.

Claims

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Claims (5)

Claims 1. Spinning head for the production of sheath / core composite threads with an eccentrically arranged misshapen core, which has the following parts: A spinneret plate (2) with an upper and a lower surface, with at least one plateau (5) is provided on the top surface; an extrusion orifice (5) formed in the lower surface of the spinneret plate is formed and with a counterbore (6) in connection is a rear plate (7), which is behind the spinneret plate arranged and is in contact with the plateau (3) formed thereon, so that a space (8) between the rear plate (7) and the spinneret plate (2) is formed; an in ~ direction (9) in the rear plate for feeding in Polymer. which is to form the shell, to the space (8) between the rear plate and the spinneret plate; and another Device (10) in the rear plate (7) and above the counterbore (6) for the injection of a polymer, which is to form the core, into the counterbore (6), characterized in that the counterbore (6) is located in a channel (4), which has a closed end part formed in the plateau, and that the means (10) in the rear plate (7) for injecting the polymer which is to form the core, has a D-shaped opening in the counterbore (6). 2. Spinning head according to claim 1, characterized in that the channel has a bilobed end part (4a, 4b). 3. Spinning head according to claim 1 or 2, characterized in that that d;: e D-shaped opening its straight part perpendicular to the Horizontalachae of the canal and in the horizontal plane has. 209852/1056 4 β spinning head according to one of claims 1 to 3, characterized in that that the diameter of the D-shaped opening is exactly the same as large as or smaller than the diameter of the counter bore. 5. Spinning head according to one of the preceding claims, characterized characterized in that it has several channels and that the rear plate has an equivalent number of devices for the supply of shell and core polymer, wherein the device for supplying the shell polymer is arranged in the vicinity of the channels, 6 »Spinning head according to one of the preceding claims, characterized in that the in the upper surface of the The plateau formed in the spinneret plate is not in contact with the lower surface of the rear plate in the area surrounding the channel formed in the plateau. MTENTANWXlTf WMNe.UFINCKE, DIPI.-ING. H. BOH * OIW.-ING S.STAEßEP 209852/1056