Disclosure of Invention
The invention aims to provide an in-situ uncoiling method for asphalt fibers, which overcomes the defects of the existing mechanical uncoiling technology, has easily controlled uncoiling driving force compared with the conventional mechanical force, basically has no damage to the fibers, has strong designability and is suitable for the production takt of engineering.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides an in-situ uncoiling method for asphalt fibers, which comprises the following steps:
1) in the winding process, the asphalt fiber is sequentially subjected to oiling and bundling treatment and drying treatment;
2) in the uncoiling process, an electrostatic layer is formed on the surface of the asphalt fiber, and the asphalt fiber is uncoiled continuously under the synergistic action of static electricity and gravity;
3) after uncoiling, the pitch fibers are subjected to static electricity removal treatment.
Preferably, the pitch fiber includes one or both of isotropic pitch fibers and mesophase pitch fibers.
Preferably, the oiling and bundling treatment in the step 1) is carried out by using water-soluble functional group modified polydimethylsiloxane, and the functional group is phenyl, amino, epoxy or polyether.
Preferably, the drying treatment in the step 1) is carried out at the temperature of 30-80 ℃ for 1-5 h.
Preferably, in the step 2), the dried pitch fiber after being unwound is rotated in the winding direction and air-purged to form an electrostatic layer, then the pitch fiber end is drawn out, unwound in the 3 o' clock direction of the pitch fiber bobbin, and after the drop height is 1 to 5m, the winding direction is reversely rotated.
Preferably, the humidity of air blown by the air is less than or equal to 30%, the wind speed is 2-5 m/s, the section width of the air port is 2-5 mm, and the blowing time is 5-20 min.
Preferably, the rotating speed is 30-60 m/min.
Preferably, the static electricity removing treatment in step 3) is to remove static electricity by dropping the unwound pitch fiber onto a conveyor belt.
Preferably, the material of the conveyer belt is steel, aluminum alloy or C/C composite material.
Preferably, the speed of the conveying belt is 0.1-0.5 m/min.
Compared with the prior art, the invention has the following positive effects:
the asphalt fiber is hard and brittle and is easy to damage, the mechanical uncoiling force needs to be controlled to be very small, the force is very accurate, the fault tolerance rate is low, and the design, manufacture and maintenance cost of the equipment is high. The method utilizes dry air to sweep the surface of the asphalt fiber, and the surface of the asphalt fiber generates proper static electricity by controlling the air speed, the air quantity and the humidity, and the electrostatic force applies weak repulsion force to drive the fiber tows to separate when the fiber is uncoiled; meanwhile, the gravity of the asphalt fiber is used as another driving force for uncoiling, and the electrostatic force and the gravity cooperate with each other to induce the uncoiling of the asphalt fiber, so that the uncoiling of the asphalt fiber is a moderate, soft, continuous and low-cost engineering method.
The asphalt fiber is blown down and then static electricity is removed by utilizing the conveying belt made of the conductive material, so that the negative effect generated by the static electricity is avoided, the conveying speed is adjusted according to the uncoiling speed and the paving state of the asphalt fiber, the asphalt fiber can directly enter a subsequent oxidation working section, the operability is strong, and the asphalt fiber is suitable for high-rhythm production beats. In addition, the manual intervention unwinding mode is adopted, and the yield of each station is 0.2 km/h; by adopting the unwinding mode of the invention, the long-time continuous unwinding can be realized, the product quality is stable, the yield of each machine position is 2.7km/h, and the productivity is greatly improved.
Detailed Description
The invention provides an in-situ uncoiling method for asphalt fibers, which comprises the following steps:
1) in the winding process, the asphalt fiber is sequentially subjected to oiling and bundling treatment and drying treatment;
2) in the uncoiling process, an electrostatic layer is formed on the surface of the asphalt fiber, and the asphalt fiber is uncoiled continuously under the synergistic action of static electricity and gravity;
3) after uncoiling, the pitch fibers are subjected to a destaticizing treatment.
In the present invention, the pitch fiber is preferably a melt-spun pitch fiber, and the kind thereof preferably includes one or both of an isotropic pitch fiber and a mesophase pitch fiber.
In the invention, the oiling and bundling treatment in the step 1) is preferably carried out by water-soluble functional group modified polydimethylsiloxane, and the functional group is preferably phenyl, amino, epoxy or polyether.
In the present invention, after the oiling and bundling treatment, the pitch fiber is preferably wound around a cylinder made of an insulating material, the diameter of the cylinder is preferably 200 to 500mm, and more preferably 300 to 400mm, and the material is preferably an insulating engineering plastic such as PVC, polytetrafluoroethylene, or organic glass.
In the invention, the temperature of the drying treatment in the step 1) is preferably 30-80 ℃, more preferably 40-70 ℃, and even more preferably 50-60 ℃; the time is preferably 1 to 5 hours, more preferably 2 to 4 hours, and even more preferably 3 hours; the dried asphalt fiber has no free moisture on the surface.
In the invention, the uncoiling in the step 2) is preferably carried out on an uncoiler, the dried asphalt fiber rotates in the coiling direction and is subjected to air purging to form an electrostatic layer, then an asphalt fiber thread end is led out, uncoiling is carried out in the 3 o' clock direction of an asphalt fiber thread barrel, and after the dropping height is 1-5 m, the reverse rotation in the coiling direction is carried out; wherein the vertical height is further preferably 2-4 m.
In the invention, the humidity of the air blown by the air is preferably less than or equal to 30 percent, and more preferably less than or equal to 20 percent; the wind speed is preferably 2-5 m/s, and more preferably 3-4 m/s; the section width of the tuyere is preferably 2-5 mm, and further preferably 3-4 mm; the length is the same as the length of the wire cylinder; the blowing time is preferably 5 to 20min, and more preferably 10 to 15 min.
In the invention, the rotating speed is preferably 30-60 m/min, more preferably 35-50 m/min, and still more preferably 40-45 m/min.
In the present invention, it is preferable that the electrostatic elimination treatment in step 3) is performed by grounding the unwound pitch fiber on a conveyor belt.
In the invention, the material of the conveying belt is conductive material, preferably steel, aluminum alloy or C/C composite material.
In the present invention, the speed of the conveyor belt is preferably 0.1 to 0.5m/min, more preferably 0.2 to 0.4m/min, and still more preferably 0.3 m/min.
The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.
Example 1
1) And (3) a winding process: melt spinning to prepare mesophase pitch fiber, oiling and bundling treatment is carried out by using phenyl modified polydimethylsiloxane aqueous solution, and the mesophase pitch fiber is wound on a PVC cylinder with the diameter of 300mm for drying treatment, wherein the drying treatment temperature is 50 ℃, and the drying treatment time is 2 hours.
2) Uncoiling: the dried asphalt fiber is placed on an uncoiler, the uncoiler rotates in the coiling direction, dry air is used for blowing, the humidity of the blown air is 20%, the air speed is 4m/s, the width of the cross section of an air port is 3mm, the length of the air port is the same as that of a yarn barrel, the blowing time is 10min, an electrostatic layer is formed on the surface of the blown asphalt fiber, the end of an asphalt fiber thread is led out of the yarn barrel after the rotation is stopped, the asphalt fiber thread is uncoiled in the 3 o' clock direction of the asphalt fiber yarn barrel, the reverse rotation in the coiling direction is carried out after the dropping height is 2m, the rotation speed is 40m/min, and the asphalt fiber is uncoiled continuously under the synergistic action of static electricity and gravity.
3) And (3) a static electricity removing process: the uncoiled mesophase pitch fiber falls on a conveyor belt of 304 steel, and static electricity is removed by grounding, wherein the speed of the conveyor belt is 0.3 m/min.
Example 2
1) And (3) winding process: melt spinning to prepare mesophase pitch fiber, oiling and bundling treatment are carried out by using amino modified polydimethylsiloxane aqueous solution, the mesophase pitch fiber is wound on a polytetrafluoroethylene cylinder with the diameter of 200mm for drying treatment, the temperature of the drying treatment is 30 ℃, and the time is 4 hours.
2) Uncoiling: the dried asphalt fiber is placed on an uncoiler, the uncoiler rotates in the coiling direction, dry air is used for blowing, the humidity of the blown air is 10%, the air speed is 2m/s, the width of the cross section of an air port is 2mm, the length of the air port is the same as that of a yarn cylinder, the blowing time is 5min, an electrostatic layer is formed on the surface of the blown asphalt fiber, the asphalt fiber yarn end is led out of the yarn cylinder after the rotation is stopped, the asphalt fiber yarn end is uncoiled in the 3 o' clock direction of the asphalt fiber yarn cylinder, the reverse rotation in the coiling direction is carried out after the dropping height is 3m, the rotation speed is 30m/min, and the asphalt fiber is uncoiled continuously under the synergistic action of static electricity and gravity.
3) And (3) a static electricity removing process: the uncoiled mesophase pitch fiber falls on a conveyer belt of aluminum alloy, and static electricity is removed by grounding, wherein the speed of the conveyer belt is 0.1 m/min.
Example 3
1) And (3) winding process: melt spinning to prepare isotropic asphalt fiber, using epoxy group modified polydimethylsiloxane aqueous solution to carry out oiling and bundling treatment, winding the isotropic asphalt fiber on an organic glass cylinder with the diameter of 500mm to carry out drying treatment, wherein the temperature of the drying treatment is 80 ℃, and the time is 3 hours.
2) Uncoiling: the dried asphalt fiber is placed on an uncoiler, the uncoiler rotates in the coiling direction, dry air is used for blowing, the humidity of the blown air is 30%, the air speed is 5m/s, the width of the cross section of an air port is 5mm, the length of the air port is the same as that of a yarn barrel, the blowing time is 15min, an electrostatic layer is formed on the surface of the blown asphalt fiber, the end of an asphalt fiber thread is led out of the yarn barrel after the rotation is stopped, the asphalt fiber thread is uncoiled in the 3 o' clock direction of the asphalt fiber yarn barrel, the reverse rotation in the coiling direction is carried out after the dropping height is 4m, the rotation speed is 60m/min, and the continuous uncoiling of the asphalt fiber is completed under the synergistic effect of static electricity and gravity.
3) And (3) a static electricity removing process: the uncoiled isotropic pitch fiber falls on a conveying belt of the C/C composite material, static electricity is removed by grounding, and the speed of the conveying belt is 0.5 m/min.
The strength of the pitch fibers obtained in examples 1 to 3 was examined, and the results are shown in Table 1.
TABLE 1 Properties of Pitch fibers
Examples
|
Strength of pitch fiber
|
Example 1
|
2.4GPa
|
Example 2
|
2.35GPa
|
Example 3
|
2.42GPa |
The conventional mechanical force uncoiling mode is adopted to uncoil the asphalt fibers, the strength of the bundle filaments of the asphalt fibers is 2GPa, and the uncoiling mode can reduce the mechanical property damage of the asphalt fibers and increase the strength of the asphalt fibers by 17.5-21% by comparing the results of mechanical force uncoiling and electrostatic and gravity cooperative uncoiling.
From the above embodiments, the present invention provides an in-situ unwinding method for asphalt fibers, which uses air blowing to generate static electricity on the surface of asphalt fibers, and uses the gravity of the asphalt fibers as another driving force for unwinding, and ensures continuous unwinding of the asphalt fibers under the synergistic induction of the static electricity and the gravity. Meanwhile, the conveying belt made of conductive materials is used for removing the static electricity of the asphalt fibers, so that the negative effect generated by the static electricity is avoided, the conveying speed is adjusted according to the uncoiling speed and the paving state of the asphalt fibers, the asphalt fibers can directly enter a subsequent oxidation working section, the operability is high, and the asphalt fiber conveying device is suitable for high-rhythm production beats.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.