Extruder head for synchronous production of multi-layer cable sheaths, method of production and use

Abstract

The application belongs to the field of optical cable manufacturing, and specifically discloses an extruder head for synchronous production of multilayer optical cable sheaths, a preparation method and application. The extruder head comprises an extruding section and a smoothing section. The center of the extruding section is provided with an optical cable through hole for passing through a cable core. At least two sheath flow channels are provided on the outside of the optical cable through hole from the inside to the outside at intervals, and are respectively used for feeding the same or different sheath materials to synchronously produce multilayer optical cable sheaths outside the cable core. The outlet of the extruding section is connected with the smoothing section. The inside of the smoothing section is provided with an extension through hole for providing extension plastic shaping for the optical cable covered with the multilayer optical cable sheaths, and ensuring the smoothness of the outer surface of the optical cable. The application can provide extension plastic shaping for the optical cable covered with the multilayer optical cable sheaths by arranging the smoothing section on the extruder head, avoid the problem of poor smoothness of the outer surface of the optical cable caused by different shrinkage properties of the sheath materials, and realize synchronous production of the multilayer optical cable sheaths, thereby effectively improving the production efficiency of the optical cable with the multilayer optical cable sheaths.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical cable manufacturing, and more particularly relates to an extruder head for synchronous production of multi-layer optical cable sheaths and a preparation method and application thereof. BACKGROUND

[0002] Currently, optical cables are usually produced by single-layer sheaths using single-layer extruder heads, but customers and actual application scenarios usually require optical cables coated with multi-layer sheaths. Rodent-proof sheath materials need to be added to the surface of the optical cable, but the rodent-proof sheath materials are not sufficient to provide protection performance for the outermost layer of the optical cable, so the traditional sheath materials need to be used inside the rodent-proof sheath materials.

[0003] Considering that the shrinkage performance of each layer of sheath material is different, the prior art usually adopts a production method of sequentially coating sheath materials from the inside to the outside, so as to ensure that each layer of sheath material is fully shrunk, and thus the performance of the outer surface is good. However, this production method has low production efficiency and cannot be well applied in industry. At the same time, although the prior art provides some multi-layer extruder heads, the application of the multi-layer extruder heads in optical cable production also has the problem that the different shrinkage performances of the materials result in a rough outer surface of the product

[0004] In addition, considering that the size of the extruder head is fixed, the design of multi-layer flow channels on this basis will result in a thin wall thickness between the flow channels, which greatly reduces the service life of the extruder head. Moreover, the temperatures of the materials in the flow channels of the extruder head are different, and only appropriate pipe wall materials and processing technology can be selected to minimize the temperature influence between the flow channels. SUMMARY

[0005] In view of the defects of the prior art, the present application provides an extruder head for synchronous production of multi-layer optical cable sheaths and a preparation method and application thereof, aiming to solve the problem of synchronous production of multi-layer optical cable sheaths.

[0006] According to an aspect of the present application, an extruder head for synchronous production of multi-layer optical cable sheaths is provided, which specifically comprises an extrusion section and a stable section. The center of the extrusion section is provided with an optical cable through hole for passing through a cable core. At the same time, at least two sheath flow channels are provided on the outer side of the optical cable through hole from the inside to the outside at intervals, which are respectively used for passing in the same or different sheath materials to synchronously produce multi-layer optical cable sheaths outside the cable core. The outlet of the extrusion section is connected with the stable section. The inside of the stable section is provided with an extension through hole for providing external plastic shaping for the optical cable coated with the multi-layer optical cable sheaths, so as to ensure that the outer surface of the optical cable is smooth.

[0007] Compared with the prior art, the application can provide outer extension shaping for optical cables with multi-layer cable sheaths, avoid the problem of poor smoothness of the outer surface of the optical cable caused by different shrinkage properties of the sheath materials, and realize synchronous production of multi-layer cable sheaths.

[0008] As a further preferred, the length of the stable section is determined according to the following formula:

[0009]

[0010] In the formula, L is the length of the stable section, P is the allowable pressure of the stable section, a is the index of each sheath flow channel, and the value is 1, 2, 3, …, is the melt consistency of the sheath material in each sheath flow channel, is the non-Newtonian index of the sheath material in each sheath flow channel, and R is the radius of the extended through hole, is the volume flow rate of each sheath flow channel, is the proportion of the cable sheath formed by each sheath flow channel in the optical cable.

[0011] As a further preferred, the diameter of the stable section is 3.0mm-50.0mm.

[0012] As a further preferred, the width of the sheath flow channel gradually decreases along the flow direction near one end of the stable section.

[0013] As a further preferred, the minimum width of the sheath flow channel is 1.0mm-8.0mm.

[0014] As a further preferred, the number of sheath flow channels is 2-4.

[0015] As a further preferred, the outside of the stable section is provided with a water cooling mechanism for accelerating cooling of the optical cable.

[0016] According to another aspect of the application, a preparation method of the above-mentioned extruder head is provided, specifically: pouring a metal liquid into a mold to obtain a casting, and then sequentially annealing, quenching and tempering the casting to obtain the extruder head.

[0017] As a further preferred, the preparation method further includes machining the optical cable through hole, the sheath flow channel and the extended through hole of the extruder head to reduce the roughness thereof.

[0018] According to still another aspect of the application, an extrusion device comprising the above-mentioned extruder head is provided.

[0019] Overall, compared with the prior art, the above technical solutions conceived by the application mainly have the following technical advantages:

[0020] 1. The application can provide outer extension shaping for optical cables with multi-layer cable jacket by setting a stable section on the extruder head, avoid the problem of poor smoothness of the outer surface of the optical cable caused by the different shrinkage properties of the jacket materials, thereby realizing the synchronous production of multi-layer cable jacket, and effectively improving the production efficiency of optical cables with multi-layer cable jacket.

[0021] 2. In particular, the length determination method of the stable section is optimized, and the performance parameters of each jacket material and the size parameters of the prepared optical cable are fully considered, so as to ensure uniform shrinkage of each jacket material and further improve the smoothness of the outer surface of the optical cable.

[0022] 3. In addition, the preparation method of the extruder head is optimized, and the extruder head with high service life can be obtained by using the pouring and heat treatment method. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a cross-sectional view of the extruder head for synchronous production of multi-layer cable jacket provided by the embodiment of the application.

[0024] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein:

[0025] 1 - extrusion section, 11 - optical cable through hole, 12 - jacket flow channel, 2 - stable section, 21 - extension through hole. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the application more clear and explicit, the application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0027] As shown in Figure 1 According to one aspect of the application, an extruder head for synchronous production of multi-layer cable jacket is provided, which specifically includes an extrusion section 1 and a stable section 2. The center of the extrusion section 1 is provided with an optical cable through hole 11 for passing through the cable core. At the same time, at least two jacket flow channels 12 are provided on the outer side of the optical cable through hole 11 from the inside to the outside, which are respectively used to pass through the same or different jacket materials, and the jacket materials are adhered around the cable core by extrusion, thereby synchronously producing multi-layer cable jacket outside the cable core.

[0028] The stable section 2 is connected with the outlet of the extruding section 1, and the inside of the stable section 2 is provided with an extending through hole 21, so that the optical cable covered with the multi-layer cable jacket passes through the extending through hole 21 to be externally shaped, and the limiting effect of the extending through hole 21 ensures that each layer of the jacket material is shrunk while avoiding problems such as bubbling, thereby ensuring the smoothness of the outer surface of the optical cable and improving the production efficiency of the optical cable with the multi-layer cable jacket.

[0029] In actual production, the number of the jacket flow channels 12 and the jacket materials flowing in each jacket flow channel 12 can be determined according to requirements. Too many jacket flow channels 12 will result in an excessively large size of the extruding head, which cannot be applied to existing production devices, and will also result in an excessively thin wall thickness of each jacket flow channel in the extruding head, which will cause difficulty in forming or an excessively low service life. Therefore, the number of the jacket flow channels 12 is preferably 2-4.

[0030] In a preferred embodiment of the present application, the number of the jacket flow channels 12 is two, and different jacket materials, i.e. PE-A and PE-B, are respectively flowed in. In another preferred embodiment of the present application, the number of the jacket flow channels 12 is three, and the innermost layer and the outermost layer are flowed with the same jacket material, i.e. PE-A, and the middle layer is flowed with another jacket material, i.e. PE-B. In still another preferred embodiment of the present application, the number of the jacket flow channels 12 is three, and different jacket materials, i.e. PE-A, PE-B and PE-C, are respectively flowed in.

[0031] More preferably, the outside of the stable section 2 is provided with a water cooling mechanism, which is used to accelerate the cooling of the optical cable by forced water cooling, so that the optical cable can be stably formed in the stable section 2, and defects on the surface of the optical cable caused by shrinkage in later period are avoided.

[0032] Further, an excessively short length of the stable section 2 will result in insufficient shrinkage of each layer of the cable jacket, and the smoothness of the outer surface of the optical cable is insufficient, while an excessively long length of the stable section 2 will result in difficulty in processing of the equipment, which is not conducive to industrial production and application. Therefore, the length of the stable section 2 is determined according to the following formula:

[0033]

[0034] In the formula, L is the length of the stable section 2, P is the allowable pressure of the stable section 2, a is the index of each jacket flow channel 12, which is determined by the number of the jacket flow channels 12 in the extruding head, and can be sequentially recorded as 1, 2, 3, … from inside to outside, is the melt consistency of the jacket material in each jacket flow channel 12, is the non-Newtonian index of the jacket material in each jacket flow channel 12, and R is the radius of the extending through hole 21, is the volume flow rate of each jacket flow channel 12, The proportion of the cable jacket formed by each sheath flow channel 12 in the optical cable, i.e. the thickness of each layer of the optical cable jacket / radius of the optical cable.

[0035] The method for determining the length of the smooth section 2 is optimized in the present application, taking into full consideration the performance parameters of each sheath material and the size parameters of the prepared optical cable, so as to ensure uniform shrinkage of each layer of sheath material and further improve the smoothness of the outer surface of the optical cable.

[0036] Further, the diameter of the smooth section is 3.0mm-50.0mm. The sheath flow channel 12 gradually narrows in width along the flow direction at the end close to the smooth section 2, and the minimum width of the sheath flow channel is 1.0mm-8.0mm, preferably 4.0mm.

[0037] According to another aspect of the present application, a preparation method of the above-mentioned extruder head is provided, specifically: a mold matched with the structure of the extruder head to be produced is prepared, then the molten metal is poured into the mold to obtain a casting, and finally the obtained casting is sequentially annealed, quenched and tempered to obtain the extruder head. Considering that there are a large number of sheath flow channels in the extruder head, the machining method for preparation will lead to high machining precision requirements and high cost, therefore, the present application adopts the pouring method to prepare the casting with preset flow channels. Meanwhile, considering that the size of the extruder head has been controlled, setting multiple flow channels will lead to thin wall thickness between the flow channels, in order to improve the service life of the head, the obtained casting needs to be heat treated including annealing, quenching and tempering to improve the service life of the extruder head.

[0038] Further, since each layer of the extruder head is sensitive to temperature, in order to ensure that it can withstand impact force and alternating stress at high temperature, and to minimize the temperature influence between each flow channel, 3Cr2W8V steel is preferably used to prepare the extruder head, so that the extruder head can normally work between 400℃-700℃, and even can work in an environment above 700℃. The specific heat treatment process is: the casting is subjected to three cycles of spheroidizing annealing, then rapid pre-cooling annealing, first quenching at 1060℃ for 20min, then quenching at 550℃ for 2h, and finally tempering at about 680℃ to obtain the extruder head.

[0039] Further, considering that the roughness of the optical cable through hole 11, the sheath flow channel 12 and the extension through hole 21 of the extruder head after heat treatment is high, therefore, the machining method can be used to process the optical cable through hole 11, the sheath flow channel 12 and the extension through hole 21 to reduce the roughness and ensure the smoothness of the surface.

[0040] According to another aspect of the present application, an extrusion device comprising the above extruder head is provided. The extruder head provided by the present application can replace the extrusion device in the prior art, and a corresponding number of sheath material supply assemblies are provided. The extrusion device can be used to realize the synchronous production of multi-layer cable sheaths.

[0041] In the description of the present application, it should be understood that in the description of the present application, the meaning of "a plurality of" is two or more than two, unless otherwise explicitly and specifically limited. In addition, throughout the specification, the reference to "one embodiment"; "one embodiment"; "one example" or similar language means that the particular feature, structure or characteristic described in connection with this embodiment is included in at least one embodiment of the present application. Therefore, the occurrence of the phrase "in one embodiment"; "in one embodiment" and similar language throughout the specification may, but does not necessarily, all refer to the same embodiment.

[0042] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An extruder head for simultaneous production of a multi-layer cable jacket, characterized in that, The extrusion device comprises an extruding section (1) and a stabilizing section (2), the extruding section (1) is provided with a cable through hole (11) in the center for passing through the cable core, and at least two sheath flow channels (12) are arranged on the outer side of the cable through hole (11) from inside to outside for respectively introducing the same or different sheath materials to synchronously produce the multi-layer cable sheath outside the cable core; the stabilizing section (2) is connected with the outlet of the extruding section (1), the inside of the stabilizing section (2) is provided with an extension through hole (21) for providing the extension shaping for the optical cable covered with the multi-layer cable sheath, and ensuring the smooth surface of the optical cable. The length of the stabilizing section (2) is determined according to the following formula: In the formula, L is the length of the stable section, P is the allowable pressure of the stable section, a is the index of each jacket flow channel, and the value is 1, 2, 3, …, is the melt consistency of the jacket material in each jacket flow channel, is the non-Newtonian index of the jacket material in each jacket flow channel, and R is the radius of the extended through hole, is the volume flow rate of each jacket flow channel, is the proportion of the cable jacket formed by each jacket flow channel in the optical cable.

2. The extruder head of claim 1, wherein, The diameter of the stabilizing section (2) is 3.0mm-50.0mm.

3. The extruder head of claim 1, wherein, The width of the sheath flow channel (12) gradually decreases along the flow direction near the one end of the stabilizing section (2).

4. The extruder head of claim 3, wherein, The minimum width of the sheath flow channel (12) is 1.0mm-8.0mm.

5. The extruder head of claim 1, wherein, The number of the sheath flow channel (12) is 2-4.

6. The extruder head of claim 1, wherein, The water cooling mechanism is arranged on the outside of the stabilizing section (2) for accelerating the cooling of the optical cable.

7. A method of making an extruder head as claimed in any one of claims 1 to 6, wherein, Specifically, the metal liquid is poured into a mold to obtain a casting, and then the casting is sequentially annealed, quenched and tempered to obtain the extruder head.

8. The production method according to claim 7, characterized in that, The preparation method further comprises machining the cable through hole (11), the sheath flow channel (12) and the extension through hole (21) of the extruder head to reduce the roughness. 9.An extruding device comprising the extruder head according to any one of claims 1-6.

Images