CN110193921A - A kind of production method of polypropylene crystal form design toughening modifying optical cable loose tube - Google Patents

Abstract

The invention relates to a production method of a polypropylene crystal form design toughened modified optical cable loose tube. An automatic feeder is installed at the PP feeding place of the extrusion molding production equipment of the β-crystalline polypropylene optical cable loose tube, including Color masterbatch feeder and β-nucleation masterbatch feeder, adjust the screw speed of the automatic feeder to adjust the amount added; the added color masterbatch, β-nucleation masterbatch and PP are discharged through the φ50 single-screw extruder. The casing, after the casing comes out of the machine head, it quickly enters the water tank for rapid cooling, and then enters the first water bath wheel for heat treatment. After heat treatment, it enters the second water bath wheel and is cooled by air blowing and then enters the wire take-up machine. The invention is simple to operate, easy to grasp and control, and convenient to popularize and apply.

Description

A kind of production method of polypropylene crystal form design toughening modified optical cable loose tube

technical field

The invention relates to the technical field of material modification and optical cable production, in particular to a production method of a polypropylene crystal form design toughened modified optical cable loose tube.

Background technique

In the field of optical communication, loose tube is the core component of stranded and central bundle tube optical cables, and its main function is to protect the optical fiber from internal stress and external lateral pressure. The raw material of loose tube is usually polybutylene terephthalate (PBT), which has the advantages of high Young's modulus and low expansion coefficient, but PBT is easy to hydrolyze, brittle and relatively heat resistant. It is poor and the price is high; its crystallization performance is also weak, and there is shrinkage after extrusion in the extrusion molding process, which affects the control of the excess length of the optical fiber in the loose tube.

Polypropylene (PP), as one of the five general-purpose plastics, has good mechanical and processing properties, good heat resistance and chemical stability. In recent years, some optical cable manufacturers have begun to use PP as the raw material for loose tubes, but the toughness of PP tubes is also poor, and the heat resistance often does not meet the processing requirements of subsequent processes. The main reason is that PP is a A semi-crystalline polymer, α, β, and γ are the most common crystal forms, of which α-PP is the most stable, but it is brittle and has poor impact performance. The latter two belong to the metastable state, which can only be obtained under certain conditions. β-PP has better heat resistance than α-PP, and has excellent impact performance, that is, β-PP is tough PP. Generally speaking, the content of β crystals in commercial PP is very low. To obtain high β crystal materials, there are mainly shear orientation methods, temperature gradient methods, and nucleating agent addition methods. It is generally believed that adding a β-nucleating agent is the easiest and quickest way to obtain high β-crystal PP, but in actual production, especially in extrusion molding, the effect of adding a nucleating agent to obtain a high β-crystal content is not good, only Cooperating with temperature control (temperature gradient method) can increase the content of β crystals. This is because the nucleation and growth of PP β crystals mainly occur in a specific temperature range. In addition, the growth rate of α crystals is greater than that of β crystals. crystal growth rate, thereby inhibiting the growth of β crystals. Therefore, in the production of extrusion sleeves, only relying on the addition of β-nucleating agent is not enough to obtain a high content of β-crystals, and temperature control is also required.

Contents of the invention

For the defects existing in the prior art, the present invention aims to provide a kind of production process control method for obtaining high β crystal content PP loose tube extrusion molding.

To achieve the above object, the technical solution provided by the invention is:

A production method of polypropylene crystal form design toughening modified optical cable loose tube, in which an automatic feeder is installed at the PP feeding place of the extrusion molding production equipment of β crystal polypropylene optical cable loose tube, including color masterbatch feeder Feeder and β-nucleation masterbatch feeder, adjust the screw speed of the automatic feeder to adjust the amount added; the added color masterbatch, β-nucleation masterbatch and PP are discharged through the φ50 single-screw extruder into a casing, After the casing comes out of the machine head, it quickly enters the water tank for rapid cooling, and then enters the first water bath wheel for heat treatment. After heat treatment, it enters the second water bath wheel for traction and air blowing to cool it again and then enters the wire take-up machine.

Among them, the first cooling is water tank cooling, and the length of the water tank is 3-6m; the heat treatment and the second cooling are all water bath pulleys, the pulley diameter is 60-900mm, and the number of turns is 3-10.

The first cooling water temperature range is 30-45°C, the heat treatment water temperature is 60-90°C, the second cooling water temperature range is 35-50°C, and the air blowing cooling temperature is 20°C.

Further, the line speed of casing production is 150-300m/min, preferably 200m/min.

Further, the PP is a special material for commercial modified loose tube PP, the amount of β-nucleating masterbatch added is 0.1-3wt% of PP mass, and the amount of color masterbatch added is 1.0-4wt% of PP mass.

Further, the color masterbatch and β-nucleation masterbatch are fed at the same time, and the tube is extruded with PP in an extruder at 190-240°C. During extrusion, the temperature of the melting section is 190-220°C, and the temperature of the neck and head section is 210-230°C.

Further, the nucleating agent of the β-nucleating masterbatch is one or any combination of carboxylate, amides, and rare earths.

Compared with prior art, the beneficial effect of the present invention is:

(1) In the present invention, the high content of β crystal provides PP with better impact resistance and casing bending resistance. Compared with traditional α-PP, β-PP has higher heat resistance , which can effectively prevent the occurrence of casing scratches in the subsequent manufacturing process, and the invention only needs to be slightly improved on the existing production line, and the manufacturing process and production system are simple.

(2) Since the nucleation and growth of PP β crystals require a certain temperature range (70-120°C) and compete with α crystals for growth, it is difficult to obtain high β crystal content on existing equipment even if β nucleating agents are added Therefore, the present invention slightly improves the existing equipment, introduces a heat treatment device in the cooling of the casing, and adopts a temperature gradient method to obtain a PP loose casing with high β crystal content.

Description of drawings

Fig. 1 is a schematic diagram of the feeding system for the loose tube of the β-crystalline polypropylene optical cable of the present invention.

Fig. 2 is a flow chart of the extruding process of the loose tube of the β-crystalline polypropylene optical cable of the present invention.

Fig. 3 is a polarizing microscope image of the loose tube obtained in Example 1 of the present invention.

Fig. 4 is a polarizing microscope image of the loose tube obtained in Example 2 of the present invention.

Fig. 5 is a polarizing microscope image of the loose tube obtained in Example 4 of the present invention.

Fig. 6 is a polarizing microscope image of the loose tube obtained in Example 6 of the present invention.

Fig. 7 is a polarizing microscope image of the loose tube obtained in Example 9 of the present invention.

Fig. 8 is a polarizing microscope image of the loose tube obtained in Example 10 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not as a limitation of the present invention. All embodiments all adopt φ50 single-screw extruder, and the specifications of implementing loose tube are 2.3/1.6-12B1 and 2.1/1.5-6B1, and the optical fiber is common G652.D colored fiber. In each embodiment, the optical fiber pay-off tension, the sleeve pulling tension, and the sleeve take-up tension are 100g, 600g, and 700g, respectively.

Example 1

The special modified PP for secondary coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703, the addition amount is 2wt%) is melted and produced by a single-screw extruder 2.3 /1.6-12B1 specification loose tube, the temperature of the four zones of the extruder body is 190°C, 200°C, 210°C, 220°C, and the temperature of the three zones of the head is 220°C, 225°C, 230°C . After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then it enters the heat treatment water bath pulley, winding 5 times, the water temperature is 80°C, and enters the water bath pulley cooling after heat treatment , Winding 5 full circles, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 2

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, addition amount 1wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted through a single-screw extruder to produce 2.3/1.6-12B1 specification pine As for the casing, the temperature of the body of the extruder is 190°C, 200°C, 210°C, and 220°C, and the temperature of the head is 220°C, 225°C, and 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank. The length of the water tank is 4m, and the water temperature is 35°C. Then it enters the heat treatment water bath wheel puller, wraps 5 times, and the water temperature is 80°C. After heat treatment, it enters the water bath wheel puller for cooling , winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 3

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, addition amount 1wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted through a single-screw extruder to produce 2.3/1.6-12B1 specification pine As for the casing, the temperature of the body of the extruder is 190°C, 200°C, 210°C, and 220°C, and the temperature of the head is 220°C, 225°C, and 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then enters the heat treatment water bath pulley, winding 5 times, the water temperature is 90°C, and enters the water bath pulley after heat treatment Cooling, winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 4

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, addition amount 1wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted through a single-screw extruder to produce 2.3/1.6-12B1 specification pine As for the casing, the temperature of the body of the extruder is 190°C, 200°C, 210°C, and 220°C, and the temperature of the head is 220°C, 225°C, and 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then enters the heat treatment water bath pulley, winding 5 times, the water temperature is 60°C, and enters the water bath pulley after heat treatment Cooling, winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 5

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, addition amount 1wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted through a single-screw extruder to produce 2.3/1.6-12B1 specification pine As for the casing, the temperature of the body of the extruder is 190°C, 200°C, 210°C, and 220°C, and the temperature of the head is 220°C, 225°C, and 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then enters the heat treatment water bath pulley, winding 5 times, the water temperature is 40°C, and enters the water bath pulley after heat treatment Cooling, winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 6

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, the addition amount is 0.25wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted and produced by a single-screw extruder 2.3/1.6-12B1 Specification loose tube, the temperature of the body of the extruder is 190°C, 200°C, 210°C, 220°C respectively, and the temperature of the head is 220°C, 225°C, 230°C respectively. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then it enters the heat treatment water bath pulley, wraps 3 times, the water temperature is 80°C, and enters the water bath pulley for cooling after heat treatment , winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 7

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, the addition amount is 2wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted by a single-screw extruder to produce 2.3/1.6-12B1 specifications Loose tube, the temperature of the body of the extruder is 190°C, 200°C, 210°C, 220°C, and the temperature of the head is 220°C, 225°C, 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then it enters the heat treatment water bath pulley, wraps 3 times, the water temperature is 80°C, and enters the water bath pulley for cooling after heat treatment , winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Example 8

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, the addition amount is 1.5wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted and produced by a single-screw extruder 2.3/1.6-12B1 Specification loose tube, the temperature of the body of the extruder is 190°C, 200°C, 210°C, 220°C respectively, and the temperature of the head is 220°C, 225°C, 230°C respectively. After drawing the tube and threading the fiber, the high-speed production speed is 100m/min respectively and enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then enters the heat treatment water bath wheel, wraps 3 times, the water temperature is 80°C, and enters the water bath wheel after heat treatment Pull and cool, wind 5 times, the cooling temperature is 35°C, and then enter the air-cooled drying equipment, the cooling temperature is 20°C, and then enter the winding machine to wind.

Example 9

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, the addition amount is 2wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted by a single-screw extruder to produce 2.3/1.6-12B1 specifications Loose tube, the temperature of the body of the extruder is 190°C, 200°C, 210°C, 220°C, and the temperature of the head is 220°C, 225°C, 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 300m/min and enters the cooling water tank, the length of the water tank is 4m, the water temperature is 35°C, and then enters the heat treatment water bath wheel, wraps 3 times, the water temperature is 80°C, and enters the water bath wheel after heat treatment Pull and cool, wind 5 times, the cooling temperature is 35°C, and then enter the air-cooled drying equipment, the cooling temperature is 20°C, and then enter the winding machine to wind.

Example 10

Modified PP for secondary plastic coating (produced by Jiangyin Aikesen, brand GPP3030), color masterbatch (produced by Yangzhou Jinsen, blue color masterbatch, brand 703), β-nucleating masterbatch (Nanjing Chengkuan Trading Co., Ltd., brand : MNT-C, adding amount 1wt%), the main body of the β-nucleating masterbatch is a mixture of 30wt% carboxylate nucleating agent and PP, and the three are melted by a single-screw extruder to produce 2.1/1.5-6B1 specification pine As for the casing, the temperature of the body of the extruder is 190°C, 200°C, 210°C, and 220°C, and the temperature of the head is 220°C, 225°C, and 230°C. After drawing the tube and threading the fiber, the high-speed production speed is 200m/min and it enters the cooling water tank. The length of the water tank is 4m, and the water temperature is 35°C. Then it enters the heat treatment water bath wheel puller, wraps 5 times, and the water temperature is 80°C. After heat treatment, it enters the water bath wheel puller for cooling , winding 5 times, the cooling temperature is 35°C, and then enters the air-cooled drying equipment, the cooling temperature is 20°C, and then enters the winding machine for winding.

Table 1

Representative examples (1, 2, 4, 6, 9, 10) were selected, and the crystal morphology was observed with a polarizing microscope (PLM). Sample preparation method: cut a section about 10 μm thick in the axial direction of the loose tube, put it on a glass slide, drop a drop of liquid paraffin, fix it with a cover glass, and observe it under 600 times PLM. The results are shown in Figure 3 to Figure 8.

It can be seen from the PLM photos that the casing without β-nucleation masterbatch has only a small amount of β-crystals (the β-crystals present a bright Maltese cross crystal form), and the grain size is relatively large. Under the action of β-nucleating masterbatch, a large number of fine β-crystals can be observed (Figure 4). After the heat treatment temperature was lowered, the β-crystal size increased slightly and the number decreased (Fig. 5). After reducing the content of β-nucleation masterbatch, the β-crystal content is reduced, and the production speed is increased, which is equivalent to shortening the heat treatment time, so the β-crystal content also decreases. The wall thickness of the casing decreases, the effect of heat treatment is significantly enhanced, and the content of β crystals increases (Figure 8).

In summary, the advantages of the present invention are:

(1) Combining the addition of β-nucleation masterbatch and temperature gradient method, slightly improve the existing production line, perform rapid cooling-heat treatment-water cooling-air cooling mode, heat treatment in a specific temperature range to promote the growth of β crystals, and at the same time through gradual The cooling method maintains the content of β crystals and reduces internal stress, reducing shrinkage after casing.

(2) The heat treatment time of the casing can be freely controlled by the number of turns of the water bath rim, so it can be freely matched with specific process parameters such as extrusion speed, traction speed and cooling rate, and can be quickly adjusted according to actual conditions.

(3) When the method of the present invention can be used to increase the start-up speed to 250m/min, the β-crystal content in the casing can still be kept above 40%.

(4) This invention only needs to be slightly improved on the original PBT or PP plastic coating production line, and is simple to operate, easy to grasp and control, and also convenient to popularize and apply.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any skilled person who is familiar with the profession, without departing from the scope of the technical solutions of the present invention, according to the technical essence of the present invention, Any simple modifications, equivalent replacements and improvements made in the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. a kind of production method of polypropylene crystal form design toughening modifying optical cable loose tube, it is characterised in that: in Beta-crystalline polyacrylic Install automatic feeder at the PP charging of optical cable loose tube extrusion molding production equipment additional, including color masterbatch feeder and β are nucleated masterbatch Feeder adjusts automatic feeder screw speed and adjusts additive amount；Color masterbatch, β nucleation masterbatch and the PP being added are single by φ 50 It is casing that screw extruder, which goes out head, and casing, which goes out after head to quickly enter sink, to be rapidly cooled, subsequently into the first water-bath Wheel leads and is heat-treated, enter after heat treatment the second water-bath wheel lead and air-blowing is air-cooled cool down again after enter admission machine.

2. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 1, feature exist In: it is cooled to sink cooling for the first time, sink length is 3-6m；Heat treatment and secondary cooling are that water-bath wheel is led, and wheel leads diameter For 60-900mm, can pitch of the laps number be 3-10 circle.

3. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 2, feature exist In: first time coolant water temperature range is 30-45 DEG C, and heat treatment water temperature is 60-90 DEG C, and second of coolant water temperature range is 35-50 DEG C, air-blowing wind chill temperatures are 20 DEG C.

4. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 1, feature exist In: the linear velocity of casing production is 150-300m/min.

5. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 1, feature exist In: the linear velocity of casing production is 200m/min.

6. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 1, feature exist In: the PP is commercial modified Loose tube PP PP Pipe Compound, and the additive amount that β is nucleated masterbatch is the 0.1-3wt% of PP mass, color masterbatch Additive amount is the 1.0-4wt% of PP mass.

7. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 1, feature exist In: color masterbatch and β nucleation masterbatch while feeding squeeze out trombone slide in 190-240 DEG C of extruder with PP.

8. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 7, feature exist In: the temperature of melt zone is 190-220 DEG C when extrusion, and the temperature of machine neck and head section is 210-230 DEG C.

9. the production method of polypropylene crystal form design toughening modifying optical cable loose tube according to claim 1, feature exist In: β is nucleated the nucleating agent of masterbatch as one kind or any combination of metal carboxylate, amides, terres rares.