EP0982418A2 - Apparatus and method for stufferbox crimping a synthetic yarn - Google Patents

Abstract

An apparatus and a method of stuffer box crimping a synthetic multifilament yarn, wherein the yarn is advanced in a conveying nozzle by means of a heated conveying gas into a stuffer box and compressed to a yarn plug. At the outlet of the stuffer box, a pair of rolls form a conveying gap for advancing the yarn plug and which has a width smaller than the cross section of the plug leaving the stuffer box so as to compress the yarn plug. The internal passage of the stuffer box is constructed with a cross section that increases in the direction of advance in such a manner that no significant cohesive force develops on the yarn plug, and the resistance to the forward pressure in the yarn plug resulting from the heated conveying gas is provided essentially only by the force on the yarn plug generated by its compression in the conveying gap.

Description

The invention relates to a device for upsetting a synthetic multifilament thread according to the preamble of claim 1 and a method for crimping a synthetic thread according to the preamble of the claim 16.

The device and the method are known from DE 26 32 082.

With crimping, a multifilament thread is fed into a by means of a conveying nozzle Stuffer box conveyed, compressed into a thread plug and crimped in the process. For this purpose, the conveying nozzle is provided with a conveying means, preferably a hot one Gas, which acts on the thread within a thread channel to the stuffer box promotes. The thread plug is formed within the stuffer box. The thread is deposited in loops on the surface of the thread plug and is compacted by the conveyor, which is above the thread plug can escape from the stuffer box through slots. The thread plug will then led out of the stuffer box and by means of a subsequent cooling device cooled down. After cooling, the thread plug becomes the crimped one Thread dissolved.

The intensity of the crimp of the thread is determined by the Plug formation and influenced by the thermal treatment of the thread plug. The formation of the thread plug in the stuffer box is therefore opposite the delivery pressure of the conveyor a holding force or counterforce on the thread plug generated. To ensure that training and treatment remain as constant as possible of the thread plug must now allow a certain ratio between the delivery pressure and the counterforce are observed.

DE 26 32 082 discloses an apparatus and a method in which the counterforce arises from the friction between the thread plug and the Stuffer box wall as well as from the conveying speed of the at the exit of the Stuffer box arranged roller pair determined. This is where the problem occurs on that the surfaces of the stuffer box wall with progressing term change in their friction behavior due to wear, what inevitably results in a change in the counterforce.

A device is known from EP 0 554 642, for example, in which the counterforce to plug formation exclusively from the friction between the Plug and the stuffer box results. However, this already leads to the counterforce changes over a short period of time. Constant adaptation measures are essential here.

Accordingly, it is an object of the invention, the known device and the known Method for upsetting a synthetic multifilament thread in such a way to further develop that a uniform formation of the thread plug and a uniform thermal treatment of the thread plug is guaranteed.

Another object of the invention is to provide a thread stopper with a lint-free one Manufacture filament composite.

The object is achieved by a device with the features according to claim 1 and solved by a method with the features according to claim 16.

The invention is characterized in that regardless of the surface quality and wear of the thread-guiding or plug-guiding Components essentially always have the same conditions for treating the thread plug available. To the influence of the friction between the thread plug and To minimize the stuffer box wall, the device according to the invention a stuffer box with an increasing cross section in the conveying direction. In order to the plug becomes essentially resistance-free without substantial holding force passed through the stuffer box. The cross-sectional enlargement can be infinitely variable or in stages. To the counter pressure required for plug formation build up, the pair of rollers at the exit of the stuffer box Conveying gap that has a width s that is smaller than the plug diameter D when exiting the stuffer box. The plug diameter D becomes determined by the cross section of the stuffer box in the inlet area. The entry area the stuffer box essentially extends from the entrance to the Stuffer box up to the beginning of the air outlet openings, which preferably as Longitudinal slots are formed in the chamber wall. In relation to the total length the inlet area is in the upper half of the stuffer box, preferably in the upper third or upper quarter of the stuffer box. By The narrow conveying gap between the rollers essentially becomes the stopper compressed transversely to its conveying direction. The opposing force depends on the Circumferential speed of the pair of rollers from the change in cross section of the Thread plug. With even delivery pressure and uniform peripheral speed the pair of rollers thus becomes essentially constant Back pressure for plug formation is generated, which is essentially independent of the Surface quality and wear of the plug-carrying components.

The additional compression of the thread plug also causes the crimp in the thread positively influenced in its intensity. Already with a compression of this effect can be seen at least 10%. Here, the conveyor gap of the pair of rollers has a minimum width s of approx. 90% of the plug diameter. The conveyor gap of the pair of rollers is preferably set to a width s, which is less than 60% of the plug diameter D, i.e. s <0.6 * D. So that can The plug in the conveying gap can be compressed by more than 30%.

The frictional effect on the stopper in the area of the stuffer box To minimize the holding force, the stuffer box is advantageously conical, so that the cross-section of the stuffer box increases continuously. Here is an opening angle of the stuffer box of at least 2 °, preferably at least 5 °, but preferably less than 10 °.

In order to build up a relatively high back pressure to form the thread plug, the embodiment of the invention according to claim 4 is particularly advantageous.

A particularly preferred embodiment of the invention according to claim 5 or 6 has the advantage that the thread plug at a constant speed without slippage between the pair of rollers and the thread plug from the stuffer box is promoted. In addition, the rough surface structure on the circumference the rollers reach a secure engagement on the thread plug. The thread plug is compressed evenly in cross-section and securely by the pair of rollers promoted without a slip between the thread plug and one of the Rolling of the pair of rollers occurs.

The design of the device according to the invention is particularly advantageous for which the surface structure of the rollers is designed as a toothing. This can be both straight and helical teeth. This also breaks open the surface of the thread plug, what especially the subsequent cooling of the thread plug improved.

The development of the device according to the invention according to claim 8 is in particular suitable for setting the conveying direction. With rollers with the same large extent in the contact area for thread plugging is the same Drive speed of the rollers a particularly straight conveying direction of the plug reached. In contrast, circumferential areas of unequal size can he rolls a kinking run of the thread plug can be achieved. In addition when the stopper is conveyed with different diameters of the rollers the thread plug due to the different peripheral speeds and Loops loosened, which is particularly the case with the subsequent cooling leads to an even and more intensive cooling of the thread plug.

In order to be able to optimally adjust the thread plug formation when the process starts, the device according to claim 9 offers the possibility of the peripheral speed to change the rollers. This essentially allows the Influence the dwell time of the thread plug within the stuffer box. Here there is also the possibility of using both rollers with the same or different ones To drive speeds.

In a further particularly preferred embodiment of the device according to Claim 11 there is the possibility to change the back pressure. This is at least one of the rollers of the pair of rollers can be changed in its position. In order to can reduce the width of the delivery gap to increase the back pressure or be increased to reduce the back pressure.

In a particularly advantageous embodiment of the device according to claim 12, the thread can flow into the stuffer box at a very high flow rate be promoted. For example, in the narrowest part of the thread channel the funding to a speed of approximately the speed of sound accelerated, the formation of the thread channel allows that the flow rate approximately until reaching the stuffer box stops. The conveying means then expands within the stuffer box. The high flow rate also ensures that inside in the stuffer box the stopper increases the cross section in the conveying direction the stuffer box fills evenly.

The invention according to claim 14 shows a particularly preferred embodiment the device. Here, the stuffer box is surrounded by a wall in the conveying direction increasing wall thickness formed, so that the stuffer box to the outside has a conical shape. In the wall there are several evenly around the circumference Distributed longitudinal slots arranged, the wall parallel to the conveying direction penetrate. This configuration of the stuffer box is particularly enables the production of a lint-free yarn. It is known that during the expansion of the conveyor directly at the entrance to the stuffer box Individual filaments of the thread are blown into the longitudinal slots. Due to the conical stuffer box with increasing in the conveying direction As the thread plugs progress, the individual filaments become secure and drawn evenly into the thread plug. The one from the stuffer box escaping thread plug thus has no protruding individual filaments and is particularly characterized by a stable filament composite.

In order to cool the thread plug evenly after the heat treatment and thus to fix the crimp, the thread stopper with one through the roller surface Formed compression surface over the cooling surface of the cooling drum guided. On the one hand, this makes one over the entire thread cross-section achieved even contact with the cooling device and another even flow of a cooling medium through the plug.

Further advantageous developments of the invention are in the subclaims Are defined.

An embodiment is shown below with reference to the accompanying Drawings described in more detail.

Fig. 1

schematisch eine Schnittansicht eines ersten Ausführungsbeispiels der erfindungsgemäßen Vorrichtung;

Fig. 2

eine Draufsicht auf ein Walzenpaar zum Stauchen eines Fadenstopfens;

Fig. 3

schematisch eine Schnittansicht eines weiteren Ausführungsbeispiels der erfindungsgemäßen Vorrichtung ohne Kühleinrichtung;

Fig. 4

schematisch eine Schnittansicht eines weiteren Ausführungsbeispiels der erfindungsgemäßen Vorrichtung.

They represent:

Fig. 1

schematically shows a sectional view of a first embodiment of the device according to the invention;

Fig. 2

a plan view of a pair of rollers for upsetting a thread plug;

Fig. 3

schematically shows a sectional view of a further embodiment of the device according to the invention without a cooling device;

Fig. 4

schematically shows a sectional view of a further embodiment of the device according to the invention.

In Fig. 1 is a first embodiment of a device for crimping of a synthetic thread. The device initially consists of a Delivery nozzle 1 with a central thread channel 3. The central thread channel 3 is constructed here as in the device known from EP 0 539 808. So far reference is made to this publication.

The fadeu channel essentially consists of two sections that pass through a narrowest cross section are separated. In the first section shortly before the narrowest cross section, several nozzle bores 5 open into the Thread channel 3. The nozzle bores 5 are connected to an annular chamber 6. The annular chamber 6 is connected via the supply line 4 to a pressure medium supply (here not shown) connected.

The thread channel widens in the second section below the narrowest cross-section 3 with a very small opening angle, which is preferably in the range from 0.5 ° to 5 °. At the end of the thread channel 3, the closes immediately Stuffer box 7. The stuffer box 7 is through the stuffer box wall 8 educated. The stuffer box in the entrance area has one in comparison to the thread channel slightly larger cross-section, which extends in the conveying direction up to Exit of the thread plug essentially expanded continuously. For this is the Inside the stuffer box wall is conical with an opening angle of> 2 °, preferably> 5 °. The stuffer box wall 8 is through penetrated a plurality of longitudinal slots 14 evenly distributed around the circumference. The longitudinal slots 14 extend substantially over the Entire length of the stuffer box 7. The stuffer box wall faces outwards 8 also conical in such a way that a wall thickness is established, the increases in the direction of conveyance. The wall thickness can be both continuous as well as gradually increasing in strength.

A pair of rollers 10 is arranged below the stuffer box. The pair of rollers 10 consists of the rollers 11 and 12. Between the rollers 11 and 12 is a Conveying gap 15 is formed. The conveyor gap 15 is designed with a width s that is smaller than the plug diameter D (see FIG. 2). The conveyor gap is here set to a width in the range of s <(0.9 * plug diameter D), preferably s <0.6 * plug diameter D, is. Rollers 11 and 12 are driven at the same speed.

A cooling device 13 is provided below the pair of rollers 10. The Cooling device 13 is in this case designed as a rotating cooling drum, on the other Scope of the thread plug 9 is performed for cooling purposes up to one Expiry point. At the drain point, the thread plug 9 is released into a thread.

In the device shown in Fig. 1, the thread 2 is heated by means of a Funded through the thread channel 3 into the stuffer box 7. For this the hot conveyor, preferably as hot air or steam, over the Nozzle holes 5 introduced into the thread channel 3. At the beginning of the process is first the stuffer box 7 is closed on the outlet side, so that a Plug 9 forms by depositing the thread 2 in loops and loops. The end the thread channel 3 at approximately the speed of sound emerging funds can via the longitudinal slots 14 made in the stuffer box wall 7 emerge above the thread plug. After a thread plug in the Has formed stuffer box 7, the stuffer box is opened and the process can start. Here, the thread plug first plants up to the delivery gap 15 of the pair of rollers 10 continued. The thread plug 9 is now in the conveying gap 15 compressed between the surfaces of the rollers 11 and 12. Because of the upsetting, which is at least 10%, preferably at least 30%, becomes that for formation the thread plug 9 applied in the stuffer box 7 required counterforce. For example, a thread made of polypropylene with a thread plug diameter of 5 mm and a conveyor gap width of 2 mm advantageously textured become. In the case of a polyamide thread, for example, the thread stopper was used with a diameter of 4 mm for crimping through a gap of 2 mm guided.

The pair of rollers 10 then feeds the thread plug 9 to the cooling drum 13. The thread plug 9 wraps around the cooling drum 13 on the circumference. The cooling drum 13 has openings in the jacket in order to be able to suck in cooling air. The Cooling air flows through the stopper. The thread plug is at the end of the cooling section 9 dissolved to the crimped thread, which by means of a delivery mechanism (not shown here) and for example a winding device fed.

In Fig. 2, a plan view of a pair of rollers is shown schematically as it could be used, for example, in the device from FIG. 1. The pair of rollers consists of the rollers 11 and 12. The roller 11 is via a shaft 19 with the Drive 17 connected. The roller 12 is in a shaft 20 with a drive 18 connected. The rollers 11 and 12 are arranged opposite one another in one plane and form a conveyor gap 15 between them. The rollers 11 and 12 are cylindrical, so that the conveyor gap over the length of the roller substantially has constant width s.

At this point it should be noted that the conical or profiled shape of the Rolling the conveyor gap over the roll length with different widths can be carried out is.

The rollers shown in Fig. 2 have several axially on the peripheral surface Grooves 16 extending in the direction. The grooves 16 are even on the circumference of the rollers 11 and 12 distributed in the surface. Through the profiled Surface structure of the rollers 11 and 12, which are independent of each other are driven by the drives 17 and 18, the thread plug 9 is safe detected on its surface and drawn into the conveyor gap 15. The thread plug 9 has a substantially circular after leaving the stuffer box Cross section with diameter D. Due to the narrow conveyor gap the thread plug is compressed by the pair of rollers. Here is a change the plug density reached, which improves the subsequent cooling.

The rollers 11 and 12 of the pair of rollers shown in Fig. 2 are the same size executed and are usually driven at the same speed. Thereby becomes a uniform, essentially straight-line conveyance of the thread plug 9 causes. However, it is also possible to use different rollers 11 and 12 To drive speeds. In this case the thread plug will come out from the conveyor nip towards the roller with a lower peripheral speed is driven, redirected.

3 schematically shows another embodiment of the invention Device shown. The delivery nozzle 1 and the subsequent stuffer box 7 are identical to the embodiment shown in FIG. 1. So far refer to the description of FIG. 1.

The delivery nozzle 1 opens with the thread channel 3 into the stuffer box 7. The thread channel 3 is compared to the stuffer box 7 with increasing in the conveying direction Cross section out. Here, the opening angle β is in the range of 0.5 ° to 5 °, preferably up to 2 °. In Fig. 3 the opening angle is in Cross-section of the thread channel entered with ½β. Through this training achieved that the flow rate of the conveyor substantially is maintained along the thread channel. This allows high tensile forces on the Thread to be built up. In the subsequent stuffer box 7, the thread placed on the plug surface and in through the inflowing funding the stuffer box 7 is compressed.

The stuffer box 7 is formed by the stuffer box wall 8. 3 is the stuffer box 7 shown in half section. The stuffer box 7 faces from Inlet to outlet have an increasing cross section. The thread plug diameter D is thus formed by the cross section of the stuffer box 7. For this purpose, the stuffer box wall 8 is arranged at an opening angle α. The Opening angle α is entered in the half section in Fig. 3 with α / 2. The opening angle α is now designed such that between the stuffer box wall 8th and the thread plug 9 no substantial holding forces built up by friction become.

The stuffer box wall 8 is air-permeable, so that the funding can flow out of the stuffer box 7 above the thread plug. For this are a plurality of longitudinal slots 14 in substantially parallel to each other the stuffer box wall 8 introduced. The longitudinal slots 14 penetrate the Stuffer box wall 8 at least over a partial length of stuffer box 7.

Due to the outflowing funding, individual filaments are partly in the longitudinal slots 9 are drawn. So that the filaments are securely in the thread plug can be drawn in, the stuffer box wall 8 with increasing Wall thickness trained.

The thread plug 9 is conveyed out of the stuffer box via the pair of rollers 10 and further conveyed to a cooling device not shown in FIG. 3. The The roller pair 10 shown in FIG. 3 again consists of the rollers 11 and 12. In this exemplary embodiment, the roller 11 has teeth on the surface 23 also on the periphery of the roller 12, a toothing 24 is formed. The rollers form between them the conveyor gap 15, which is due to the cylindrical Shape of the rollers 11 and 12 a substantially constant Width s. The roller 12 is coupled to an adjusting device 21 and mounted in a guide 22 such that a displacement by the adjusting device the conveyor roller can be carried out transversely to the conveying direction. So that can change the width of the conveyor gap s.

By the teeth 23 and 24 on the peripheral surfaces of the rollers 11 and The thread plug becomes 12 despite the compression on its compression surfaces 28 and 29 broken up. During the subsequent cooling, a cooling air flow becomes transverse the compression surfaces directed towards the stopper. Because of the broken up Upset areas have a much more intensive cooling effect on the thread plug, which results in a shortening of the cooling section.

4 is a schematic longitudinal section through a further embodiment shown the device according to the invention. The delivery nozzle 1 and the Stuffer box 7 are identical to the exemplary embodiment from FIG. 1 executed. In this respect, reference is made to the description of FIG. 1.

In the embodiment shown in Fig. 4 is directly at the exit the stuffer box 7 a tube 25 between the stuffer box 7 and the pair of rollers 10 arranged. On the exit side of the tube 25 is the pair of rollers 10 arranged. The pair of rollers 10 consists of the rollers 26 and 27. The rollers form the conveyor gap 15 between them. The roller 27 has a diameter smaller than the roller 26. Both rollers are at the same speed driven. Due to the smaller size of the roller 27, the thread plug conveyed on the side of the roller 27 at a lower speed. On the opposite side, the thread plug is determined by the roller 26 Circumferential speed promoted. The difference between the two Circumferential speeds cause the thread plug to exit from the Conveying gap 15 is deflected. This redirection is particularly advantageous around the thread plug with its upsetting surface on a subsequent rotating one Put down the cooling drum. The speed difference at both upsetting surfaces the thread plug also loosens the thread plug.

In the embodiment shown in Fig. 4, the tube 25 serves the Increase the dwell time of the hot thread plug. Especially one Perform shrinking of the yarn. This could be, for example in addition, the pipe 25 may be heated. However, it is also possible to cross one Hot air flowing through a pipe with porous walls to conduct thermal treatment of the thread plug.

The exemplary embodiments of the invention shown in FIGS. 1 to 4 Devices are all suitable for carrying out the method according to the invention. This can be threads, especially carpet yarns, made of polyamide, polypropylene or polyester can be crimped. The yarns stand out in particular characterized by an intense and homogeneous crimp.

Reference list

1

Delivery nozzle

2nd

thread

3rd

Thread channel

4th

Supply line

5

Nozzle bore

6

Ring chamber

7

Stowage chamber

8th

Stowage chamber wall

9

Thread plug

10th

Pair of rollers

11

roller

12th

roller

13

Cooling drum

14

Longitudinal slot

15

Conveyor gap

16

Grooves

17th

drive

18th

drive

19th

wave

20th

wave

21

Adjustment device

22

guide

23

Gearing

24th

Gearing

25th

pipe

26

roller

27

roller

28

Upsetting area

29

Upsetting area

Claims (18)

Device for crimping a synthetic multifilament thread (2) with a delivery nozzle (1) which has a thread channel (3) for Guide and promotion of the thread (2), with one at the end of the thread channel (3) designed stuffer box (7) for receiving a thread plug (9), with one at the exit of the stuffer box (7) arranged pair of rollers (10) to promote the thread plug (9) and with a cooling device (13), characterized in that the stuffer box (9) increases in the conveying direction Cross-section is formed that no substantial holding force on the thread plug (9) arises, with the thread plug (9) the stuffer box (7) with a through the cross section in the inlet area of the Stuffer box (7) leaves certain plug diameter (D), and that the pair of rollers (10) has a conveyor gap (15) with a width (s) smaller than the plug diameter (s <D). Device according to claim 1, characterized in that the conveyor gap (15) a width (s) in the range of s <0.9 * D, preferably s <0.6 * D. Device according to claim 1 or 2, characterized in that the Stuffer box (7) conical with an opening angle of larger 2 °, preferably greater than 5 °. Device according to one of claims 1 to 3, characterized in that the conveyor gap (15) through opposite cylindrical rollers (11, 12) of the pair of rollers is formed. Device according to one of the preceding claims, characterized in that that the rollers (11, 12) of the pair of rollers (10) on the circumference compared to the thread plug (9) a rough surface structure exhibit. Apparatus according to claim 5, characterized in that the rough Surface structure through a multitude of longitudinal grooves (16) is formed in the roll surface. Apparatus according to claim 5 or 6, characterized in that the rough surface structure through a toothing (23) in the roller surface is formed. Device according to one of claims 1 to 7, characterized in that that the rollers (11, 12; 26, 27) of the pair of rollers (10) in the contact area for thread stuffing (9) the same size or in its scope are of different sizes. Device according to one of claims 1 to 8, characterized in that that at least one roller (11, 12; 26, 27) of the pair of rollers (10), preferably both rollers (11, 12; 26, 27) of the pair of rollers (10) is / are drivable with variable peripheral speed. Device according to claim 9, characterized in that the rollers of the pair of rollers (10) can be driven at the same or different speed are. Device according to one of claims 1 to 10, characterized in that that at least one roller (12) of the roller pair (10) for Changing the width of the conveyor gap (15) can be changed in its position is. Device according to one of the preceding claims, characterized in that that the thread channel (3) from a narrowest point up to the stuffer box (7) a continuously with substantially constant Opening angle has increasing cross section. Device according to claim 13, characterized in that the opening angle 0.5 ° to 5 °, preferably 0.5 to 2 °. Device according to one of the preceding claims or the preamble of claim 1, wherein the wall (8) of the stuffer box (7) several longitudinal slots evenly distributed around the circumference (14), the wall (8) parallel to the conveying direction penetrate, characterized in that the wall (8) of the stuffer box (7) formed with increasing wall thickness in the conveying direction is, so that the stuffer box (7) to the outside a substantially has a conical shape. Device according to one of the preceding claims, characterized in that that the cooling device is a cooling drum (13), and that the thread plug (9) with one of the facing the roller surface Upset areas over the cooling surface of the cooling drum (13) is feasible. A method of upsetting a synthetic thread, in which the thread is conveyed into a stuffer box with a hot gas becomes, in which the thread within the stuffer box into a Thread plug is pressed, in which the thread plug promoted the stuffer box and placed on a cooling device is characterized in that the thread plug after leaving the stuffer box and before placing it on the cooling device essentially is compressed transversely to its conveying direction. A method according to claim 16, characterized in that the thread plug between two areas by at least 10%, preferably is compressed at least 30%. A method according to claim 16 or 17, characterized in that the compressed thread plug has a cross section with two compression surfaces and that the thread plug with one of the upsetting surfaces is made in contact via the cooling device.

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