CN108950705B

CN108950705B - Polylactic acid spinning box

Info

Publication number: CN108950705B
Application number: CN201811074950.3A
Authority: CN
Inventors: 陈中碧; 马德金; 谢贤勇; 杨阳
Original assignee: Anhui Fengyuan Bio Fiber Co Ltd
Current assignee: Anhui Fengyuan Bio Fiber Co Ltd
Priority date: 2018-09-14
Filing date: 2018-09-14
Publication date: 2021-03-09
Anticipated expiration: 2038-09-14
Also published as: CN108950705A

Abstract

The invention provides a polylactic acid spinning box, wherein the outer surface of a box body of the spinning box is coated with a heat insulation layer for heat insulation; a metering pump seat capable of placing a metering pump and a component head sleeve capable of fixing a spinning component are relatively fixed in the box body; the metering pump seat is connected with the component head cover through a melt conveying pipe; the component head cover is a hollow cylinder, penetrates through the top and the bottom of the box body and is positioned at the front part in the box body; the melt inlet is positioned on the top surface of the box body and is connected with a metering pump feed inlet on the metering pump seat through a melt conveying pipeline, and a needle valve is arranged at the joint; the inside heat medium pipe that evenly is provided with of box, heat medium pipe entry and heat medium pipe export set up in the box outside from top to bottom respectively. The polylactic acid fiber prepared by the spinning box can avoid thermal degradation of polylactic acid in a molten state, and ensures that a fiber-grade polylactic acid material keeps excellent spinning performance in a hot state.

Description

Polylactic acid spinning box

Technical Field

The invention belongs to the technical field of chemical fiber machinery manufacturing, and particularly relates to a polylactic acid (PLA) spinning box.

Background

Polylactic acid (PLA) fiber is one of the green fibers with great development prospect at present, and has the advantages of environmental protection, no toxicity, antibiosis, flame retardation, allergy prevention, degradability and renewable raw materials. The polylactic acid fiber has excellent physical characteristics and wide application, has high dry and wet strength and initial modulus, good dimensional stability, integrates the comfort of cotton, the draping of viscose, the strength of terylene and the hand feeling of real silk into a whole, has excellent wearability, and is widely applied to the fields of clothing, fabrics, underwear, home textiles, sanitary materials, health care products and the like.

The spinning box is a key device in a short fiber melt spinning production line, and is used for pressurizing, metering and collecting high molecular polymer melt in a spinning assembly, and spraying the high molecular polymer melt into filaments to prepare nascent filament bundles.

Spinning boxes related in the prior art are mainly designed for traditional petroleum-based products such as terylene. The polylactic acid and petroleum-based product terylene have great difference in molecular composition and structure, the terylene molecule consists of short aliphatic hydrocarbon chain, ester group, benzene ring and terminal alcoholic hydroxyl group, the tolerance value to temperature is 260-280 ℃, the polylactic acid is obtained by polymerizing lactic acid molecules, the polylactic acid has very high sensitivity to temperature, once the temperature is high and the polylactic acid stays in a spinning box for a long time, the polylactic acid is degraded and even carbonized, so that the spinnability is poor, and the spinning is difficult. The conventional spinning box has the problems of long melt retention time, easy degradation and influence on spinning effect, and cannot be suitable for spinning of a new material, namely polylactic acid. Therefore, a spinning box specially for polylactic acid is urgently needed to overcome the problems of poor spinnability and difficult spinning of polylactic acid fibers.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention aims to provide a polylactic acid spinning box.

The outer surface of the box body of the polylactic acid spinning box is coated with a heat insulation layer for heat insulation, a metering pump seat capable of containing a metering pump and a component head sleeve capable of fixing a spinning component are relatively fixed in the box body, and the metering pump seat and the component head sleeve are in one-to-one correspondence; the metering pump seat is connected with the component head cover through a melt conveying pipe; the component head cover is a hollow cylinder and penetrates through the top and the bottom of the box body; the melt inlet is positioned on the top surface of the box body and is connected with a metering pump feed inlet on the metering pump seat through a melt conveying pipeline, and a needle valve is arranged at the joint; the inside heat medium pipe that evenly is provided with of box, heat medium pipe entry and heat medium pipe export set up in the box outside from top to bottom respectively.

The polylactic acid spinning box provided by the invention has the advantages that a plurality of groups of metering pump bases and component head sleeves which correspond one to one can be arranged in the box body. Technical personnel in the field can design the spinning case of different specifications size according to the needs of production scale, can set up multiunit metering pump seat and subassembly headgear in the box, forms a plurality of spinning positions, after installing metering pump and spinning subassembly, can realize parallelly having multiunit spinning simultaneously to improve spinning efficiency.

The head cover of the assembly in the polylactic acid spinning box is positioned at the front part of the box body.

According to the polylactic acid spinning box provided by the invention, the spinning component is positioned in the component head sleeve, and the top surface of the component head sleeve is provided with the top cover, so that the heat preservation effect is achieved. The spinning assembly is a special polylactic acid spinning assembly.

According to the polylactic acid spinning box provided by the invention, the melt conveying pipe is arranged in the box body and is distributed in the box body through the melt inlet in an equal-diameter and equal-length manner.

In production practice, in order to facilitate handling and fixing the box, a bracket for fixing the box can be arranged on the outer side surface of the box.

Preferably, temperature and pressure measuring ports inserted with a temperature sensor and a pressure sensor are distributed in the box body of the spinning box, and the temperature in the box body is ensured to be 235-250 ℃ through a temperature measuring instrument.

Furthermore, the heat-insulating layer of the wrapping box body of the polylactic acid spinning box provided by the invention is a rare earth heat-insulating material and/or an aluminum silicate glass fiber material combination.

The invention provides application of the polylactic acid spinning box in preparation of polylactic acid fibers.

The invention has the beneficial effects that: since polylactic acid has very high sensitivity to temperature, once the temperature is high and the residence time is long, the polylactic acid is degraded and even carbonized, so that the spinnability is poor and the spinning is difficult. Therefore, the polylactic acid spinning box provided by the invention takes the factors into consideration during design, the pipe pass of the melt conveying pipe is greatly shortened in the box body, the layout of the polylactic acid spinning box is more reasonable, and the filtering device is not arranged at the bottom of the metering pump, so that the residence time of the melt in the pipe and the box body is shortened, the melt is prevented from being degraded, the metering pump is prevented from being blocked, and the spinnability of spinning is improved.

Drawings

Fig. 1 is a top view of the inside of the polylactic acid spin tank of the present invention, in which 1 is a tank, 2 is a metering pump base, 3 is a needle valve, 4 is an assembly head cover, 5 is a melt delivery pipe, 6 is a melt inlet, 7 is a heat medium pipe inlet, 8 is a heat medium pipe outlet, 9 is a heat insulation layer, 11 is a fixing bolt, and 12 is a bracket for fixing the tank.

FIG. 2 is a front view of the exterior of the polylactic acid spin tank of the present invention, wherein 6 is a melt inlet, 7 is a heat medium pipe inlet, 8 is a heat medium pipe outlet, 9 is a heat insulating layer, and 11 is a fixing bolt.

Fig. 3 is a sectional view taken along line a-a of fig. 1, in which 2 is a metering pump holder, 3 is a needle valve, 7 is a heat medium pipe inlet, 8 is a heat medium pipe outlet, 10 is a spin pack, and 11 is a fixing bolt.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

Example 1 polylactic acid spinning beam

As shown in fig. 1, the outer surface of a box body 1 of the polylactic acid spinning box is coated with an insulating layer 9 for heat insulation, a metering pump seat 2 capable of placing a metering pump and a component head cover 4 capable of fixing a spinning component 10 are relatively fixed in the box body, and the metering pump seat 2 and the component head cover are in one-to-one correspondence;

the metering pump seat 2 is connected with the component head cover 4 through a melt conveying pipe 5; the component head sleeve 4 is a hollow cylinder and penetrates through the top and the bottom of the box body; the melt inlet 6 is positioned on the top surface of the box body and is connected with the metering pump on the metering pump seat 2 through a melt conveying pipe 5, and a needle valve 3 is arranged at the joint; the inside heat medium pipe that evenly is provided with of box, and heat medium pipe entry 7 and heat medium pipe export 8 set up in the box 1 outside from top to bottom respectively. The heating medium pipes are uniformly distributed in the box body so as to ensure the balance of the temperature in the box body.

In fig. 1, four sets of metering pump seats and component head covers are arranged in the box body in one-to-one correspondence.

The assembly head cover 4 is positioned at the front part in the box body.

The spinning component 10 is positioned in the component head sleeve, and the top surface of the component head sleeve 4 is provided with a top cover.

The melt conveying pipe 5 is arranged in the box body and is distributed in the box body in equal diameter and equal length through the melt inlet 6.

The outer side surface of the box body is provided with a bracket for fixing the box body.

In the spinning process, in order to know and control the temperature of the box body and the pressure of the components in time, a person skilled in the art can use a temperature measuring and pressure measuring instrument to be inserted into a temperature measuring and pressure measuring port distributed in the box body, and the temperature in the box body is ensured to be 235 plus 250 ℃.

The heat-insulating layer is a combination of rare earth heat-insulating materials and/or aluminum silicate glass fiber materials.

When the polylactic acid spinning box is used, the spinning process is that polylactic acid melt enters a melt conveying pipe 5 of the spinning box from a melt inlet 6, passes through a needle valve 3 (the melt passes through a switch) and a metering pump seat 2 (a metering pump is arranged at the position) and is metered and pressurized, the melt is conveyed into a component head sleeve 4 (a spinning component 10 is arranged at the position), and the melt is sprayed out to form filaments through a spinneret plate in the spinning component 10. The melt flows in the melt conveying pipeline 5 all the time from entering the spinning box to being sprayed into filaments, and the heat medium pipes are uniformly distributed in the box body 1, so that heat medium steam can be supplied by the electric heating furnace to heat the melt, and the melt can be ensured to operate at a stable temperature all the time in the spinning process.

The temperature of the spinning box is uniformly distributed, and the temperature in the box body is controlled to be 235-250 ℃; the setting of each subassembly has shortened the tube side of fuse-element conveyer pipe greatly in the box, makes its overall arrangement more reasonable to at the measuring pump bottom filter equipment of not installing, all be in order to shorten the dwell time of fuse-element in pipeline and box, prevent that the phenomenon of fuse-element degradation and jam measuring pump from taking place, thereby improve the spinnability of spinning.

Claims

1. A polylactic acid spinning box is characterized in that the outer surface of a box body of the spinning box is wrapped with a heat insulation layer for heat insulation, a metering pump seat capable of containing a metering pump and a component head sleeve capable of fixing a spinning component are relatively fixed in the box body, and the metering pump seat and the component head sleeve are in one-to-one correspondence; the spinning assembly is a special polylactic acid spinning assembly;

the metering pump seat is connected with the component head cover through a melt conveying pipe; the bottom of the metering pump is not provided with a filtering device, so that the retention time of the melt in the pipeline and the box body is shortened, and the metering pump is prevented from being blocked; the component head cover is a hollow cylinder and penetrates through the top and the bottom of the box body; the spinning assembly is positioned in the assembly head sleeve, and the top surface of the assembly head sleeve is provided with the top cover, so that the heat preservation effect is achieved; the melt conveying pipe is arranged in the box body and is distributed in the box body in equal diameter and equal length through the melt inlet; the melt inlet is positioned on the top surface of the box body and is connected with a metering pump feed inlet on the metering pump seat through a melt conveying pipe, and a needle valve is arranged at the joint; the heating medium pipes are uniformly arranged in the box body, the heating medium pipe inlet and the heating medium pipe outlet are respectively arranged on the outer side of the box body from top to bottom, and the heating medium pipes are uniformly distributed in the box body so as to ensure the temperature in the box body to be balanced; temperature measuring and pressure measuring ports inserted with temperature sensors and pressure sensors are distributed in the spinning box body, and the temperature in the box body is ensured to be 235 plus 250 ℃ through a temperature measuring instrument.

2. The polylactic acid spinning manifold according to claim 1, wherein a plurality of groups of metering pump bases and component head sleeves which correspond to each other one by one are arranged in the manifold body.

3. The polylactic acid manifold as recited in claim 1 wherein the assembly sleeve is located at the front of the housing.

4. The polylactic acid spinning beam as claimed in claim 1, wherein a bracket for fixing the beam is provided on the outer side of the beam.

5. A polylactic acid manifold according to any one of claims 1 to 4, wherein the insulation layer is a rare earth insulation material and/or an aluminosilicate glass fiber material.

6. Use of the polylactic acid spinning manifold according to any one of claims 1 to 5 for the preparation of polylactic acid fibers.