A Melt Line For Advancing A Molten Plastic Between A Delivery Means And A Discharge Arrangement And A Method Of Manufacturing Lines For A Spin Beam

Abstract

(57) The present Invention relates to a melt line a method of manufacturing the melt line and a spin beam equipped therewith. The melt line (3) serves to advance a molten plastic, in particular a polymer between a delivery means and a discharge an-angement. the melt tine comprising a first leg (13) and a lower lying second leg (17). which have a unidirectad gradient, the first leg <13) and the second leg (17) being interoonneoted by an elbow (16). the elbow (16) having likewise a unidirected gradient over its entire length as the firat leg (15) and the second leg (17). and following in particular substantialty the pattern of a helix.

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Specification

The invention relates to a melt line for advancing a molten plastic, in particular a polymer between a delivery means and a discharge arrangement. The invention also relates to a spin beam equipped therewith for spinning a plurality of synthetic filament yams, as well as a method of manufacturing such a melt line.
Known from German Patent: No 22 18 23S is a spin bean, vhich is constructed as a hollow body. This spin bean is heated fron the inside, for exaxple, by a liquid medium. In the hollow body, selt lines are laid for high r^clt press'Jxes. These aelt lines terminate in spin heads vhich are arranged in one row. Therefore, each melt line consists of straight legs and elbows, each elbow being arranged between two straight legs. To make sure that the Kelt discharges conpletely upon shutting down the pump, it is necessary to construct the lines between the melt inlet end and the spin head with a gradient.
Until now, it has been common practice to construct a line cf this t^-pe such that the line was bent in one plane, and that subsequently the ends of the line were pulled out of the plane of the bend. This configuration of the lines resulted in that the region of the elbow had a different gradient than the remaining line sections. In particular, at one point, a gradient was even absent.
It is therefore the object cf the present invention to further develop the known celt line and spin beans equipped therewith, so that the relt line has all

over a unidirected gradient, so as to permit the melt to flow out as much as possible without leaving residues. This is to be accomplished in particular with an as compact construction of the spin beam as is practicable and an ease of fabrication.
In accordance with the invention, this object is
achieved with a melt line comprising the features of claim
1, and a spin beam of claim S or a method of claim 10.
Advantageous further developments are subject matter of
the respectively dependent claims. '
The melt line of the present invention is characterized in that it comprises at least two legs inclined relative to one plane, and that an elbow is formed between the legs, which has a gradient all over, and describes in particular a helix. As result of this configuration of the line, the overall height .of the spin beam is minimized, since the curvature is no longer formed in one plane.
To curve a tube, same is normally bent in one plane. If both legs the thus-bent tube are to have a unidirected gradient, the tube will inevitably have no gradient in the region of the bend. Should the pump or other delivery means fail or be shut down, the melt will be xnable to flow out under its gravity, but accumulate and solidify in the region of the bend. As a result of the spatial configuration of the curvature as proposed in accordance with the invention, a unidirected gradient remains between the two legs of the tube.
According to a further concept, it is suggested that all lines be constructed with the same gradient and/or same curvature,thereby reducing the cost of manufacture.
To avoid differences in quality of the spun synthetic filament yarns, it is normally provided that in a spin beam the stretched length of each line is

identical. This ensures that the dwelling time of the melt is the same in each line.
Advantageously, the legs merge, without tnnsition, tangentially into the helical elbow, the gradient of which remains constant for all desired looping angles, so that no additional space for installation is required. As a result of the tangential transition of the legs into the helical curvature of the line, a unifonn gradient of the legs and the carrature of the line is achieved.
Preferably, each line his a starting section and an end section, which are made axis parallel to one another. These starting and end sections serve to instill tho line between a delivery means (for example, an extruder or pump), or the melt distribution units and the discharge nozzles or spinnerets. The type of spinnerets and the kind of fabricated products are of no special importance for the present invention.
To construct a curved melt line, same is bent about a cylinder, so as to obtain the curvature, the cylinder corresponding to the desired radius. In so doing, the line is caused to extend at the same time in axial direction along a helix.
Further aspect of the invention is directed to a method of maaufactnring lines for a spin beam. The said method comprises the steps of placing the line taageotially into a bending tool, clamping the line of manufacturing, lines for a q)in beam, the metiiod comprising die steps of
' placing the line tangentially into a bending tool;
' clamping the line on the bending tool by means of a clamping jaw; beading the line about a predetermined angle along a helix; and
' removing the bent line. The method also includes a further step of bending a line section about a predetermined angle prior to or after bending the line along a helix.

Accordingiy, the present invention relates to a melt line for advancing a molten plistic between a deiivery means and a discbarge arrangement,
• the melt line comprising a first leg and a lower lying second leg, which
have a unidirected gradient, and
the first leg and the second leg being interconnected by in elbow, characterized in that
- also the elbow his over its entire length a nnidirected gradient as the first
leg and the second leg.
Accordingly, the present invention relates to a method of minnfacturing, lines for a beam, the method comprising the steps of:
placing the line tangentiilly into a beading tool;
• clamping the line on the bending tool by means of a clamping jaw;
bending the line about a predetaimined angle along a helix; and
- removing the bent line.
Further features and advantages of the invention are described in more detail with reference to embodiments, but without limitation to same.
With reference to the accompanying drawings, in which
Figure 1 is a schematic front view of a spin beam;
Figure 2 is a side view of the ^in beam of Figure 1 from the left; and
Figure 3 is a perspective view of a melt line.
Shown in Figure 1 is I schematic view of the layout of a spin beam. The spin beam includes a melt distribution unit 1, which is connected via lines 3 to a

spinneret unit 2. In this arragement, it is especially advantageous, when the stretched length of all melt lines 3 is identical, since this allows to obtain the same production conditions for all spinnerets. However, the accommodation of the lines will require specific configurations, when the lines are to be laid with a gradient.
The melt distribution unit l comprises several pump connection plates 4, which are arranged on a plate-shaped support S. In Figures 1 and 2, the pumps which are mounted on connection plate 4, are left out. The pump connection plates 4 are connected to lines 3. A nelt supply line 6, which is connected via a melt distributor 7 to a main melt line 8, terminates likewise in pump connection plate 4.
The lines 3 are joined to connection plates 9, which are again mounted on a support 10. Each connection plate 9 is followed by a spin head 11. Each of the spin heads 11 is arranged in a recess 12. The recesses 12 are formed in support lO.
Not shown in Figures 1 and 2 is the const—-ction of the spin beam walls, which accommodate between them the melt distribution unit and the spinneret unit. Inside the spin beam, the lines 3 are heated by a heating medium.
The lines 3 have a starting section 13 and an end section 14. The starting section 13 is followed by a first straight lead-in leg IS tangentially adjacent to an elbow 16. The elbow 16 merges into a second straight outgoing outlet leg 17. The second leg 17 is followed by end section l*. The starting section 13 is joined to pump connection plate 4, and the end section 14 to connection plate 9. The lead-in and outgoing legs 15, 17 are inclined relative a common plane. The angle of inclination is preferably 3'.

As can be noCed from Figure 3, the elbow 16 is helically bent.
As a result, of its configuration in accordance with the invention, the melt line exhibits all over a unidirected gradient, and a spin besn equipped therewith has nonetheless a small volume. Since spin beams of this type are heated by a heating nadiiin, they are insulated lUcewise toward the outside. Since their overall volime remains saall, heat losses and spaca requirenents are likewise SEall.


1 Melt distribution unit
2 Spinneret unit
3 Line
4 Pump connection plate
5 Support
6 Kelt supply line
7 Distributor
a Main melt line
9 Connection plates
10 support
11 spin head
12 Recess
13 Starting section
14 End section
15 First leg
16 Curved line section
17 sacond leq

WE CLAIM:
1. A melt line (3) for advancing a molten plastic between a delivery means (1)
and a discharge arrangement (2),
- the melt line (3) comprising a first leg (15) and a lower lying second leg
(17), which have a unidirected gradient, and
- the first leg (15) and the second leg (17) being interconnected by an elbow,
characterized in that
- also the elbow (16) has over its entire length an unidirected gradient as the
first leg (15) and the second leg (17).
2. The melt line (3) as claimed in claim 1, wherein the elbow (16) follows substantially the pattern of a helix.
3. The melt line (3) as claimed in claim 2, wherein the first leg (15) and/or the second leg (17) have the same gradient as the helix.
4. The melt line (3) as claimed in claim 1, 2 or 3, wherein the line (3) has a substantially constant gradient over its entire length, in particular also all over in the region of the elbow (16).
5. The meh line (3) as claimed in any one of claims 1 to 4, wherein the inside cross section remains substanlially constant over the entire length of the line
(3).
6. The melt line (3) as claimed in any one of claims 1 to 5, wherein the first leg
(15) and the second leg (17) extend along a tangent to the helix.

7. The melt line (3) as claimed in any one of claims 1 to 6, wherein the line (3) has a starting section and an end section (13, 14), which are constructed approximately axis parallel to one another, and extend in particular in vertical direction.
8. A spin beam for spinning a plurality of synthetic filament yams comprising the melt line as claimed in any one of the preceding claims.
9. The melt line as claimed in any one of the claims 1 to 8, wherein the molten plastic is a polymer.
10. A method of manufacturing lines for a spin beam, the method comprising the steps of:

- placing the line (3) tangentially into a bending tool;
- clamping the line (3) on the bending tool by means of a clamping jaw,
- bending the line (3) about a predetermined angle along a helix; and
- removing the bent line (3).

11. The method as claimed in claim 10, wherein comprising the step of bending a line section about a predetermined angle prior to bending the line along a helix.
12. The method as claimed in claim 10 or U, wherein comprising the step of bending a further line section about a predetermined angle after bending the line along a helix.

13. A melt line for advancing a molten plastic between a delivery means and a
discharge arrangement substantially as herein described and exemplified with
reference to the accompanying drawings.
14. A method of manufacturing lines for a spin beam, substantially as herein
described and exemplified with reference to the accompanying drawings.

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