¿Cuáles son los tipos de máquinas de hilar? ¿Cuál es su función principal?

A spinning machine is a machine that makes a fiber-forming polymer solution or melts from filaments. According to different fiber spinning methods, spinning machines are divided into three types: wet spinning machine, melt spinning machine, and dry spinning machine.

Wet spinning machine

Suitable for spinning viscose fiber, acrylic fiber, nylon, etc. The main feature is that the polymer solution is extruded from the spinneret and coagulated into the nascent fiber in the coagulation bath. The spinning speed is low, often below 100 m/min, and the high-speed spinning speed can reach about 200 m/min. Wet spinning machines are divided into short fibers and long fibers.

①Short fiber spinning machine: the spinning dope is introduced from the infusion pipe, accurately metered by the metering pump, filtered by the filter into the spinneret, and extruded from the spinneret hole into the coagulation bath. After coagulation, the nascent fibers are collected through the godet The bundles are washed or stretched with water.

The short fiber spinning machine is characterized by a large number of holes in the spinneret (plate), usually 3,000 to tens of thousands of holes.

②Filament spinning machine: Different from the short fiber spinning machine, the winding mechanism of the solidified thread is added.

The thread from the coagulation bath passes through the godet after washing and enters the high-speed rotating centrifugal tank through the reciprocating guide wire funnel. Such a spinning machine is called a centrifugal tank spinning machine;

If the thread is wound on a bobbin through a godet, it is called a bobbin spinning machine; if there is some post-processing before winding, It is called a semi-continuous spinning machine;

If all procedures of spinning and post-processing are completed continuously on the spinning machine, it is called a continuous spinning machine. The production of viscose cords mostly uses continuous spinning machines. Spinnerets for filament spinning generally have 150 holes or less, and the number of holes for spinning cord fibers is up to 3000 holes.

Melt Spinning Machine

Used in spinning equipment of polyester, nylon, and polypropylene. The characteristic is that the thin stream of melt solidifies into fibers when it meets with the cold air, and the cold air is blown to the thin stream evenly after passing through the high-efficiency filter, the regulating valve, and the diversion device. The spinning speed is relatively high, generally 600-1500 m/min. There are also two types of melt spinning machines.

① Filament spinning machine: The polymer chips are melted after entering the screw extruder from the hopper, and are pushed by the screw and sent into the spinning box through the duct. The melt is metered and transported to the spinneret (plate) by the spinning pump in the box, and the thin stream of melt-extruded from the spinneret meets the cold air in the spinning window to cool and solidify into fibers. The winding mechanism is wound on the bobbin.

The number of holes in the filament spinneret is generally from a few holes to dozens of holes. It can reach about 200 holes when spinning the cord, and there is only one hole when spinning brown silk. At this time, the melt stream is cooled and solidified into silk by a water bath.

The trend of melt spinning filament spinning machines in the 1970s is multi-end spinning, that is, each spinning position is equipped with 2, 3, 4, 6, or even more spinnerets to increase the output of the machine; high-speed spinning For silk, the spinning speed is 3500～4000 m/min, even as high as 5000 m/min. For large packages, the volume of each package can generally reach 10 kg to tens of kg; continuous, spinning, and stretching are in It is completed on a spinning machine at the same time, and there are also spinning, drawing, and texturing processes that are completed on a spinning machine (referred to as BCF production), which has been used in the production of polypropylene and nylon. This machine has a compact structure, a small footprint, and high production efficiency. Besides, the degree of automation of spinning machines is constantly improving.

②Short fiber spinning machine: Compared with the filament spinning machine, it is characterized by the use of a large spinneret with several holes, the general number of holes is 400 to 1100, and it has been developed into a porous spinning machine with several holes as many as 4000; In the spinning shaft, a cooling air blowing system with ring blowing or ring blowing plus side blowing is used. There is no separate winding mechanism for each spinning position. After the yarns of each position pass through the guide plate or the small rotor, the tow is pulled by the traction machine. Lead to the wire feeding wheel, and then lay the tow in the silk bucket. The silk capacity per barrel can reach 450-2000 kg. When large-scale synthetic fiber factories produce short fibers, they often use direct spinning. The melt-spinning short-path spinning machine with a non-spinning tunnel appeared.

Dry spinning machine

Used in the production of acrylic and nylon filaments. The spinning dope enters the tunnel from the infusion tube through the filter, metering pump, and spinneret. The formed trickle encounters hot air in the tunnel, the solvent evaporates, and the polymer solidifies into fibers in the trickle, and then the tow is wound into a certain amount. Of rolls. The dry spinning speed is generally 200-800 m/min. To meet the needs of special spinning processes, dry-wet spinning machines appeared in the 1970s.

Generally, the spinning machine itself has 4 functional areas:

1. High polymer melting device: screw extruder.
2. Melt delivery, distribution, spinning, and heat preservation device: elbow, spinning box (melt distribution pipe, metering pump, spinning head assembly).
3. Thread cooling device: spinning window and cooling sleeve.
4. Wire collection device: wet oiling mechanism, guidewire structure, winding machine, or wire receiving device.

Melting device

1 Function-the supply of solid materials, polymer melting, and quantitative melt extrusion.

2 Three sections of the screw-feeding section, compression section, and metering section.

3 The working principle of the screw extruder is the division of the screw and the movement of the material in each area of ​​the screw.

1. Feeding zone (curing zone) isometric screw.
2. In the first half (cooling zone), cooling water is passed through the jacket coil or the inner core of the screw, <100℃ to prevent premature melting of the material and ring blockage to protect the screw drive mechanism from heat.
3. The second half (preheating zone) prevents sudden changes in the temperature of the material from the feed zone to the compression zone.
4. Compression zone (melting zone) The gradual or abrupt screw melts the material (heating, shearing) and compressing (the volume of the screw groove becomes smaller); returning air or water vapor to the feeding zone.
5. Measuring area (homogenization area) and other shallow screws.

Melt conveying, distribution, spinning, and heat preservation device

1 The melt delivery pipeline from the elbow screw extruder to the spinning box (one end is connected to the screw outlet and the other end is connected to the melt distribution pipe of the spinning machine)-jacketed internal biphenyl-diphenyl ether mixture Heating (melt insulation).

2 Spinning box body, melt distribution pipe, ten biphenyl heating box, spinning pump and its transmission device, and spinning head assembly.

1. Principle of melt distribution pipe
2. Ensure that the melt reaches the same distance to each spinning position. The melt stays in the distribution pipe for a short time; there is less foldback.
3. The form of melt distribution pipe: branch type and radial type.

3 Heating of the spinning box (biphenyl heating box)

1. Function It has the function of heat preservation and heating for the melt distribution pipe, metering pump, and spinning head assembly.
2. Method Biphenyl-diphenyl ether heat carrier (biphenyl/diphenyl ether-26.5%/73.5%), heated by the electric heating rod.
3. Insulation 80～100mm insulation layer, filled with ultra-fine glass fiber or other insulation materials.

4 Metering pump High-temperature gear pump.

5 Spinning head assembly

1. Function: Filter the melt, prevent clogging of the spinneret hole, and reduce the melt viscosity difference, and evenly disperse the melt into each small hole of the spinneret hole to form a trickle of melt.
2. Structure: Combination of spinneret + melt distribution plate + melt filter material + assembly sleeve.

Heating of the spinning box (biphenyl heating box)

1. Function It has the function of heat preservation and heating for the melt distribution pipe, metering pump, and spinning head assembly.
2. Method Biphenyl-diphenyl ether heat carrier (biphenyl/diphenyl ether-26.5%/73.5%), heated with an electric heating rod.
3. Insulation 80～100mm insulation layer, filled with ultra-fine glass fiber or other insulation materials.

Wire rod cooling device

1. Spinning window The filament is only cooled by the directional, quantitative, and qualitative airflow during the cooling process, the cooling rate is uniform, and the fiber solidification position is fixed (not affected by the surrounding airflow).
2. The lower part of the slow cooling chamber is equipped with two front and rear inserts to separate it from the cooling spinning drum, and the upper part has a locker to form a slow cooling zone under the spinneret; the length is 30~200mm; to prevent the cooling wind from blowing cold spray The surface of the silk plate reduces the birefringence of the winding silk and improves the stretchability.