JPH07100881B2 - Spinning heads for extrusion - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a spinning head for extrusion processing, in particular for spinning thermoplastic plastic melts, which comprises a stationary head with a pump block and a nozzle receiver. It is of the heating box type and has a replaceable nozzle pack mounted in the nozzle receptacle.

Prior art The nozzle pack of the spinning head must be replaceable without great effort, especially since regular cleaning of the spinning nozzle itself is generally common and necessary. On the other hand, the fixing of the nozzle pack must not only be able to withstand high melt pressures (in the range up to about 200 bar and above), but also the force necessary to additionally and reliably seal. I have to. Various solutions have been proposed in the past, but each has drawbacks.

In the arrangement described in West German patent application publication no. 1096574, the nozzle pack is fixed to the device for supplying the melt by means of a plurality of screws. According to Swiss Patent No. 201920, the fixing of the nozzle pack to the melt supply part is carried out using a kind of cap screw.
The disadvantage of these arrangements is that the replacement of the nozzle packs is very cumbersome, time-consuming and, due to the uneven tightening of the screws, different sealing effects can occur at the outer periphery of the sealing surface. However, the main drawback of the known arrangement is the time-consuming and tedious exchange process, since long interruptions of the sensitive melt flow must be avoided.

Problem to be Solved by the Invention An object of the present invention is to carry out an original replacement process, that is, a spinning process in which a nozzle pack mounted on a spinning head and a cleaned nozzle pack can be replaced in a relatively short time. To get a head.

Means for Solving the Problems The means for solving the above problems is to provide a spinning head of the type described at the outset in which the coupling plug is attached to the pump block such that it projects downwards from the pump block. , The coupling plug guides the molten liquid conduit, and it is pressure-bonded to the molten liquid conduit of the pump block in a pressure-tight manner, and the nozzle receiver can be connected to the coupling plug by the connection member that receives the molten liquid pressure Moreover, when the melt pressure is introduced in the connected state with the coupling plug, the sealing member is configured to perform a self-sealing action to seal the coupling plug.

The pressure-resistant connection between the nozzle receiver and the connection plug includes a mechanical connection that can receive the melt pressure prevailing in the nozzle receiver. This connection is preferably a threaded connection, which may be single- or multi-threaded, or may have one or more turns or, in the form of a bayonet-type connecting element, a partial circumference. It extends only across the surface. In all cases, this connection makes it easy to handle the nozzle receiver from below, i.e. via the head,
It is constructed so that it can be fastened and fastened to the coupling plug without using a great deal of force. The pressure-resistant connection further comprises a self-sealing sealing member by means of which the inner chamber of the nozzle receptacle is sealed against the gap between the nozzle receptacle and the coupling plug, and therefore It is not necessary to exert a sealing force on the outside. Such sealing members are described, for example, in West German Patent Nos. 1529819 and 2248756. However, other sealing mechanisms of the type in which the sealing action is realized by a melt flow are also known and conceivable.

Coupling of the coupling plug with the melt line guided in the heating box or pump block must likewise be such that the pressure exerted by the melt is absorbed and the coupling is tight. . The bond can be made permanent, for example, by welding a bond plug to the heating box and / or the melt line and / or the pump block. However, it is also possible to screw them together by means of a plurality of screws or tension rods. This connection must first be considered as not separable. In other words, removal of the coupling plug from the heating box and / or pump block is not required for operation and maintenance of the spinning head. Further, it is sufficient that the surface of the connection between the coupling plug and the heating box (pump block) on which the melt liquid pressure acts, surrounds the cross section of the melt liquid conduit, and therefore the melt liquid pressure inside the nozzle receiver acts. Consideration should be given so that it is smaller than the face of the coupling plug (this face is larger than the nozzle face). According to this framework, the connection between the connection plug and the heating box (pump block) must be constructed. It is otherwise unimportant.

Embodiments In an embodiment of the invention, the connection plug is fixedly connected to a melt line derived from a heating box or pump block, for example using a suitable number of fixing screws. In this case, the force exerted by the screw is due to the insertion of a seal ring between the coupling plug and the melt conduit, which has an inner diameter equal to the diameter of the melt conduit and a small radial width. Therefore it is advantageous to limit it to a minimum. The coupling plug is in place when the nozzle is replaced.

The coupling plug takes the form of a single-threaded, preferably multi-threaded or bayonet-type connection on the peripheral surface, the inner surface of the nozzle receptacle being provided with a corresponding part. In particular, a bayonet-type connection is selected, the bayonet-type connection being configured as a thread, the thread extending axially in a subrange equal to or greater than the thread range and a thread groove. With a notch that extends up to, nozzle replacement is easier to insert in a shorter time, and for example about 90 °,
Or by turning 60 °.

Other fixing methods of the coupling plug can be applied to the fixing type and the fixing point. The coupling plug may be coupled to the heating box as well as the pump block and the melt line. Single or multiple thread detent threads may be used in place of the fixing screws described above.

In all embodiments, it is important that the sealing cross section of the coupling plug is significantly smaller than the outer or inner diameter of the nozzle receiver or nozzle pack. For this reason, the force required when connecting the coupling plug and the melt supply portion is relatively small. On the other hand, the high force exerted on the piston closing the nozzle pack due to the significant internal pressure is taken up by the coupling plug itself, which is due to the relatively large outer circumference of the coupling plug and the proper selection of threads. There is no difficulty in

Example A spinning beam 1 holds a pump block (or a melt pipe line constituting member) 2 having a melt pipe line 3 which is mounted in a heating box (not shown). Is supplied to the spinning section. In this embodiment, the pump block 2 has a suitable recess, in which the coupling plug 4
Has been inserted. A seal ring 9 is inserted between the coupling plug 4 and the pump block 2 and the contact surface of the seal ring has a high force exerted by a fixing screw in order to obtain a sealing, pressure-resistant connection. The position is almost decided. The inner diameter of the seal ring matches the diameter of the melt channel 3 and also the diameter of the melt channel 8 in the coupling tap 4, which is aligned with the melt channel 3.

A thread 7 is formed on the outer peripheral surface of the coupling plug 4, which thread is a multi-threaded, non-returning thread and thus fast-tight, or configured as a bayonet-type connection. You can stay. The nozzle receptacle 10 for receiving the nozzle packs 11-16 has a suitable counterpart on the inner surface of the upper portion.

The nozzle pack includes a spinning nozzle 11, a support plate 12 having a melt hole 13, and a melt chamber 14 located between them.
It is composed of a screen pack 16 inserted in a pot 15 which is an upper part of the support plate 12. Nozzle packs 11-16 are mounted in the nozzle receiver 10. In order to make a pressure-tight, sealing connection with the connection plug 4,
Nozzle pack on pot 15 with screen pack 16
A piston 18 is arranged which closes 11-16 and is sealed to the pot 15 by a diaphragm 17 which is dish-shaped. Another sealing ring 20 is arranged between the piston 18 and the coupling plug 4. As for the seal ring 20, the description about the seal ring 9 also applies. The thread 7 is a bayonet-type connection, which in the present example is configured as a triple thread, has a notch extending axially in each part of the peripheral surface, which is equal to the thread range, and which extends to the thread groove. Have, and such three notches should be present evenly distributed. The coupling plug 4 and the pot 10 are matched.

To secure, the nozzle packs 11-16 as well as the nozzle receiver 10 with the diaphragm 17 and the piston 18 need only be pushed into the bayonet threads of the connecting plug 4 and then rotated about 60 ° and lightly tightened. At this time, the seal ring 20 is lightly pre-pressed. The high crimping force required for sealing is obtained by the melt itself, and this melt pressure acts on the piston 18 via the diaphragm 17 and the seal ring.
Compress 20. Due to the diaphragm 19, the piston 18
The piston is sealed against the interior of the nozzle receiver 10 which is axially displaceable therein.

It can be seen from the drawing that the force acting in the axial direction of the nozzle receiver, which is obtained from the melt pressure and the cross section of the interior of the nozzle receiver 10, can only be taken up by the connecting plug 4 with the thread 7.
This is because the piston 18 is also supported by the coupling plug 4 via the seal ring 20. The force introduced into the pump block 2 for fixing the coupling plug is defined by the sealing cross section of the sealing ring 20, which seal cross section according to the invention is significantly smaller than that of the coupling plug 4. , The above forces are much smaller than the forces acting within the coupling plug itself.

According to the present invention, the process of replacing the nozzle is decisively simplified and speeded up, and the force introduced into the pump block 2 of the nozzle component due to the high melt pressure is effective in the nozzle pack. It is significantly reduced compared to normal force. Therefore, the heating box can be improved. The heating box is used to receive a liquid and / or vaporous heating medium under pressure and to transfer heat to a member for guiding the melt, in particular a pump block. The heating box is an important component for strength and deformability. According to the invention, the heating box is exempted from the function of receiving the pressure of the melt, so that it can be made weak and yet nevertheless transfers heat to all members which guide the melt, in particular to the pump. The shape stability, which is particularly necessary for this, can be improved.

According to the arrangement of the present invention, the pressure acting in the circular nozzle receiver is not transferred to the heating box or pump block as in the conventional arrangement, but rather a coupling with an intermediate member, i.e. a self-sealing member. On the other hand, the cross section of the connection between the connection plug and the connection between the connection plug and the heating box or pump block is kept relatively small, i.e. the connection is screwed, for example by means of a tensile rod, welded, screwed by a multithread It can be performed by coupling or the like.

[Brief description of drawings]

The drawing is a cross-sectional view of one embodiment of a spinning head according to the present invention. 1 ... Spinning beam, 2 ... Pump block, 3 ... Melt pipe line, 4 ... Coupling plug, 5,6 ... Fixing bolt, 7 ... Thread, 8 ... Melt flow passage, 9, 20 ... Seal ring, 10 ...
… Nozzle receiver, 11… Spinning nozzle, 12… Support plate, 13… Melt hole, 14… Melt chamber, 15… Pot,
16 …… Screen pack, 17 …… Diaphragm, 18 ……
Piston, 19 ... Melt flow path, 21 ... Melt flow passage.

Claims (13)

[Claims] 1. A spinning head for extrusion, comprising a stationary heating box having a pump block and a nozzle receiver, wherein a replaceable nozzle pack is mounted in the nozzle receiver. In which the coupling plug (4) is attached to the pump block (2) so as to project downward from the pump block (2), the coupling plug guiding the melt line (8) and It is press-fitted tightly to the melt pipe line (3) of 2), and the nozzle receiver (10) can be connected to the connecting plug (4) by a connecting member that receives the melt pressure, and the connecting plug is also connected. An extrusion process, characterized in that it is configured so as to be sealed to the coupling plug (4) by a seal member that performs a self-sealing action when a melt pressure is introduced in a state of being connected to (4). For spinning Head. 2. The spinning head according to claim 1, wherein the connecting plug (4) is connected to the pump block (2) by fixing bolts (5, 6). 3. The first claim according to claim 1, characterized in that the coupling plug (4) is connectable to the nozzle receiver (10) by means of a thread (7).
Item 2. The spinning head according to Item 2 or Item 2. 4. A spinning head according to claim 3, wherein the threads (7) are detented. 5. The spinning head according to claim 3 or 4, wherein the thread (7) has multiple threads. 6. A nozzle receiver (10) is provided so that the end face of the nozzle receiver (10) is in metallic contact with the corresponding edge of the heating box (1) or pump block (2) or coupling plug (4). Spinning head according to any one of claims 3 to 5, which is associated with a coupling plug (4). 7. The method according to any one of claims 3 to 5, wherein the screw thread is a bayonet-type connecting portion (7).
The spinning head according to the item. 8. A bayonet-type connecting portion (7) has a thread on its peripheral surface having a plurality of threaded areas and a plurality of axially extending threadless areas (notches) between these areas. The spinning head according to claim 7, wherein the area without threads is larger than the area with threads in the circumferential direction. 9. The coupling plug (4) is screwed into the pump block (2) in a sealing manner, as claimed in any one of claims 1 and 3 to 8. Spinning head. 10. A pump block (2) for a coupling plug (4).
Spinning head according to any one of claims 1 to 9, wherein the seal diameter for the melt conduit (3) is significantly smaller than the outer or inner diameter of the nozzle receiver (10). 11. The spinning head according to claim 10, wherein the sealing diameter of the coupling plug (4) is defined by the contact surface of the sealing ring (9). 12. A coupling plug (4) and a nozzle pack (11-16).
A piston (18) fitted in the nozzle receiver (10) is arranged between the piston and the diaphragm (1).
7. A seal ring with respect to a nozzle receiver (10) by 7) and capable of being crimped to a coupling plug via a seal member (20). The spinning head according to item 1. 13. The spinning according to claim 12, wherein the sealing member (20) is another sealing ring, the sealing diameter of which is significantly smaller than the diameter of the coupling plug (4) and the piston (18). head.