DE1435638A1 - Spinneret assembly - Google Patents

Description

Patent attorneys

DR.-ING. WALTER ABITZ 24 July 1964

DR. DIETER MORF " ⁰ YPo cc ο β

Monks 1435638

T Dr, Expl.

B.X DU PONT DE HEMOtIRS AND COMPAKlT

10th and Harket Streets, Wilmington 98, Delaware, V, St.A.

Spinneret arrangement

The invention relates generally to manufacture of threads made of molten organic compounds and, in particular, of a spinning nozzle arrangement that can be used during the spinning process

The spinning of synthetic linear polymers from the melt by means of a device with a metering tape, a filter block and a spinneret plate is described in US Patents Z 266 368 and 2,278,875. Such devices are particularly useful when melt spinning polyamides and polyesters, for example

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wise polyhexamethylene adipic acid amide and polyethylene terephthalate, usable * However, it has often been observed that the quality of the threads, especially in denier, is not entirely uniform despite efforts to feed the polymer to the spinneret at constant values of bridge, temperature and flow rate * Bin reason for this lack of uniformity between the individual threads is to _see that the molten polymer near the periphery of the spinning nozzle plate is cooler than the polymer near the center dsr plate, and sstrar due to the heat losses from the sid © de? Chamber _t when the polymer slowly through the. Filter block occurs. Another reason, which is now regarded as the main cause, is that the loss of heat due to metal parts, especially the spinneret plate and the retaining ring, causes a temperature gradient across the cheese plate The circumference of the spinneret plate can be 5 ° C and even more.Accordingly, the polymer is pressed out more slowly near the circumference of the spinneret plate and solidifies more quickly in the thread than is the case with the polymer pressed out near the center of the plate, from which you can see the irregularity in the yarn properties and denier results in <· Denier differences not only show up in the final fabric, but also cause difficulties in processing, because threads with large denier in a thread group, d _Q h <> in a strand, not the

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Follow the same path as the lighter threads, separate them from the guide parts or pegs, but jump out of loops. These loops often get caught and tear, causing an interruption in the process.

It is the primary object of the invention to provide an improved spinneret assembly to provide better uniformity in denier between the individual threads and a good overall equality of denier between two or more To obtain strands, which polymer obtained from the same ZumeQströmamng. In particular, one destination is the Sehaffong an improved spinneret manifold system which has a Compensates temperature gradients across the spinning and core plate

These and other goals are achieved by an impermeable ▼ distributor plate, which is placed between the filter block and the spinneret plate of a spinneret device is inserted and tapered with a distribution box in its surface, which leads around or in the vicinity of the circumference of the plate Voids in the lower surface and opposing slots is provided at or near the periphery, each slot connecting some or all of the manifold channels to a cavity. Each cavity extends from the associated slot towards the opposite slot and has its maximum

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Depth close to the Schiit ss on, with v@Iol2.em he communicates.

The invention is illustrated in greater detail, for example, with the aid of the figures explained. It shows

Figure 1 is a section through a © spinneret assembly including the Vea? t © ilerplatt © according to the invention,

Figure 1A © in © partial enlargement of the divider plate © and that Filter blocks according to figure t,

FIG. 2 shows a view according to the "LIuIq XZ-XX ix ^ igur 1 _9, ie. An undiscovered view of the Ra & meiianordnuag, s-mnn the spinneret plate and the retaining ring removed

Figure 3 © in © similar to © Looks at eiss © s ssjeitea game,

FIG. 4 shows a section through a spin nozzle arrangement another filter block and a third embodiment the distribution plate and

Figure 5 is a view along the line VV in Figure k "

The example shown in FIGS. 1 and 2 has a spinneret 10 and a Yerieiler plate 2

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which are fastened by bolts 16 to a filter block 1 k. This arrangement is held in position against a spinning machine 18 by a conventional retaining ring 20.

The filter block lh comprises two identical filter cavities 22, each of which contains the usual, sieves, not shown, sand and the like, which separate to filter metered streams of molten polymer of the lines 23, are in the machine 18 2k. The filtered polymer is released from the cavities 22 through holes 25 or “26”.

The spinneret plate 10 is s: it four different groups provided by aligned holes 28, the βία each one A strand of three fractions is spinning, and an additional smile is provided they can be arranged in two or more staggered rows in order to be effective Ensure deterrence au.

The distribution plate 12 has two branches on its surface Channel systems 29, 30, through which the separate, metered flows from the holes 25 »26 to the outside to opposite slots 31, 32 and tapered from there Cavities 34, 35 fly, ¥ ie shown, lie the Slots 31, 32 opposite each other and close to the periphery of the

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Plate 12, Each tapered cavity has its maximum depth at the associated slot and extends approximately over the same width as this »For example, the cavity its maximum depth below dom slot 32 and tapers down to a minimum depth near the center of the plate 12,

Until the mode of action and usefulness of the in Figures 1 and illustrated embodiment is based on the following Example «.

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Nylon is melted, brought to a temperature of 280-295 C and pumped into the filter cavities 22 through lines 23, Zh in sodamx in trezinten, ztigamessauen currents. The channels, slot® and tapered hollow space® in the front tailer plate 12 form separate flow paths between the filter block holes 25, 26 and the associated spinneret 28 o the spinneret plate. 10 is designed to spirant four strands of 20 denier (2 "2 tex) with seven strands of jo strand. Babel is each measured © flow divided into two strands, each of which contains seven threads "with each thread opening up a little less than 3 Benlers per thread. The channels 29, 30 were 3.96 ma (0.156 inches) wide and 0.79 bbh (0 _f 031 inches) deep. The tapered cavities 3 ^ »35 were Cp. 75 inches) wide and 3 ^, 93 aim (1.375 inches) ) long

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with a minimum depth of 0.69 mm (0.027 -inches) and a taper angle of 452 '.

Measurements of the flow of the individual filaments emerging from each spinneret capillary or Looh 28 indicate that the differences in denier between individual filaments and between strands were reduced to less than $ 2. This compares to the $ 15 differences that occur when the manifold plate 12 is replaced with a thin ™ washer to form a single manifold space under each sand cavity 22. Since the temperature gradient between the center and the periphery of the spinneret plate 10 is essentially the same in both cases, the smaller denier differences achieved with the manifold plate 12 are due to the different pressure drops across the different spinneret holes 28, which sub-period due to the taper in FIG the cavities 3k, 35. In other words, the slightly higher pressure drop at the outer hole 28 compensates for the slightly lower plate temperature at this point.

It has heretofore been considered essential that each group of Threads is fed in by a separate metered flow from a metering pump o When using the device according to the invention it has been found possible to a metered flow into two or more strands

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and distribute it evenly and still achieve a better uniformity of denier between the two strands «

If further threads per strand are desired , it is not only necessary to arrange the spinnerets in staggered rows, but also to increase the width of each tapered cavity 34. This can be done to some extent without any adverse effect . If, however, the width of the cavity is made too large in the exemplary embodiment shown in FIG. 2, there is a tendency for the formation of two separate currents * d _e ho, the warm material coming from the central arms of the canal system easily remains in the middle. Lake communicating, tapered cavity, nearer edge colder, coming from the outer arms, the material tends to flow into the outer hand of the cavity, resulting in a difference in denier between the front threads and the rear threads in a strand. This difficulty can be overcome by changing the channel system in the surface of the distributor plate, as shown in FIG.

From Figure 3 it can be seen that the channel system © 29% 30 · are much less branched than those according to

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Figure 2, IHB the greater · relative width of the tapered cavities 34 · compensate ^r 35, and a wider collection above the slots 31 »32 * and over the lengths thereof remains out continuously '· It is important that the speed of the through each Schiita flowing polymerizate is the same at all points, ie », dl · speed in the middle should be the same as the speed at the two ends. In the illustrated embodiment with eight distributor holes 26 *, the projections 33 direct the polymer flow so that a uniform velocity occurs over the entire length of the slot 32 *. This modification is necessary when the cavity width becomes equal to or greater than the cavity length.

The application of the distribution principle according to the invention a spinneret arrangement in which the filter block has only a single cavity is shown in the figures and 5 shown. As shown, a filter block has nine manifold holes 44 which the polymer from a filter cavity 46 into a circular sample space 48 direct. Any changes in the polymer flow through the filter device are caused by feeding of the entire polymer is balanced out by the velvet space 48. A distributor plate 50 and a spinneret plate 52 are arranged directly below the sand holder 42,

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Elements 42, 50, 52 and suitable sealing rings are through a Hing 53 held together, which is a not shown has upper attachment that is screwed into the spinning machine "

The channel 54 is located in the otherwise flat surface of the manifold plate 50, which contacts the filter block 42 and the tapered cavities 56 are located on the opposite face, d _o h., To against the spinneret plate 52. The dargestallte channel 54 has die__selbe width as each _tapered: cavity 56. slots 58 near the outer periphery connecting the two ends of the channel 54 with the tapered cavities 56. wiq in the foregoing Ausführungsbei "play, the maximum height of each tapered Hohlrauines 56 is at its outer end o The spinneret plate 52 has fourteen holes 60 of the same size, which are arranged in a single row. The fourteen monofilaments are quenched by known methods, collected and wound up in individual windings. Excellent uniformity in denier is achieved a

In operation, the polymer is metered into the filter cavity 46, in the äaramelraum 48 through the distributor holes led, split into two currents, one through the right part of the channel 54 and the other through his

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left part flows through two opposite slots 58 and finally into the holes 60 through the tapered cavities 56 distributed.

In practice it has been found that a pressure difference of 0.1 * tl - 0.281 at (2-4 psi) between the pressures * waste in the outer and middle spinneret holes Is required to compensate for a temperature difference of 3-5 0 · Such a pressure gradient is created by suitable design of the channels and the tapered cavities in the distributor plate ensures »Their dimensions can be determined from known factors such as the polymer viscosity and the cavity width, as the pressure gradient increases as the throughput increases, it appears that A given design can only be used at a certain flow rate. When the flow rate increases, however, the pressure difference also increases and is compensated by the larger pressure graduate · That This relationship is demonstrated in the following example.

Example II

Apparatus and ancestors according to Example I were used for spinning of four strands of 4O-13 yarn from two inflow streams used. The spin throughput was changed by $ 10 and it

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There was no noticeable difference in denier as well Strands present »

AufVielcelgeaohvindig - Qegatster Itenier-Ohterechied

speed ia m / min. tvr> a) as between the strands

822.96 (900) t, £ o

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1005.88 (1100) 1

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Claims (1)

1433638 Claims 1 · I-spinning nozzle arrangement, characterized in that a filterblook, a · distributor plate and a spinneret plate · are arranged one above the other, the filterblook and the spinning nozzle plate having flow holes that are spaced apart from one another, the distributor plate is provided with two opposing slots near its circumference, which channels in the surface and tapered cavities in the lower surface of the same, and wherein the channels, slits and cavities form flow paths between the holes of the filter look and the spinneret. 2. Arrangement according to claim I ₉ daduroh characterized in that each cavity extends from one slot to the opposite Sohlita and tapers downwards from a maximum depth, camouflaging the associated slot « 3 «arrangement according to claim 1, characterized in that each cavity sloh extends from one slot towards the opposite slot and its maximum tie-e and width at the associated slot. - 13 - 909809/0360 4. Spinning nozzle arrangement, characterized by "a filter" block and a spinning nozzle plate »tfeloh © islt a g« gaa « lateral distance enclosing »Str & aungslueliem vor» can be seen »and through a Vertöllejeplatta» which the said slaves is inserted, with the mounting plate with the exception of two spaced apart » opposite Sohlits «isndurcSiläsaig is, Channels and cavities in the respective surfaces of the Distribution & ^ plate are arranged, each cavity see nron - one of the slots against the opposite slot extends and calibrates from. a maximum depth at the oisien Schlits vorjungt, and whereby the channels, slits and cavities are two separate struanuigsweg sswisehen the holes of the Form filter blocks and the spinneret plate. 909309/0360