CN112458586B

CN112458586B - Method for manufacturing core yarn pre-bulked core-spun yarn for asbestos-free brake band

Info

Publication number: CN112458586B
Application number: CN202011467403.9A
Authority: CN
Inventors: 钱华; 史玉庆; 钱忠标; 余淑莉; 史睿阳
Original assignee: Dongtai Huayang Glass Fiber Co ltd
Current assignee: Dongtai Huayang Glass Fiber Co ltd
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2022-04-26
Anticipated expiration: 2040-12-14
Also published as: CN112458586A

Abstract

The invention provides a method for manufacturing a core yarn pre-bulked core-spun yarn for an asbestos-free brake band, which comprises an outer layer and an inner core, wherein the glass fiber in the inner core is subjected to medium-pressure and medium-temperature micro-bulking treatment to obtain better infiltration rate of the glass fiber, and an improved type impregnating compound is used to obtain better tensile strength of the glass fiber and reduce the friction coefficient of the surface of the glass fiber, so that the service performance and the service life of the brake band are improved.

Description

Method for manufacturing core yarn pre-bulked core-spun yarn for asbestos-free brake band

Technical Field

The invention relates to the technical field of brake bands, in particular to a method for manufacturing a core yarn pre-bulked core-spun yarn for an asbestos-free brake band.

Background

The brake band is widely applied to manual and hydraulic brake systems such as truck decks and the like. The existing brake band is mainly an asbestos-free brake band and is woven by core-spun yarns containing glass fibers. The brake band is bound on the goods of the truck, and two ends of the brake band are fixed on a rope tightener of the deck of the automobile. The brake band is mainly used for fixing large goods, such as wood and mechanical equipment, on a truck deck, and preventing the goods from moving forwards or backwards under the action of inertia when the truck brakes or accelerates, so that a truck head or a rear breast board is damaged, and a driver or the truck is damaged.

Chinese patent document (publication No. CN 108930735A) discloses a ceramic composite fiber brake pad. The brake pad comprises the following components in parts by weight: 2123, 15-20 parts of resin, 8-12 parts of graphite, 5-10 parts of rubber powder, 6-9 parts of barium sulfate, 3-7 parts of modified glass fiber, 5-7 parts of wollastonite, 3-5 parts of ceramic fiber and 12-18 parts of composite fiber. The composite fiber reinforced brake pad has the advantages that the glass fiber, the ceramic fiber and the composite fiber are used for enhancing the framework, the cracking and crazing phenomena in the processing and using processes of the brake pad are reduced, and in addition, the stability of the friction coefficient of the brake pad and the noise reduction effect can be improved through the compounding among the glass fiber, the ceramic fiber and the composite fiber.

The glass fiber used in the existing brake band has small contact area without being puffed and has limited protective effect on the glass fiber, so that the existing glass fiber can not meet the production requirement, and the brake band made of the glass fiber can not meet the use requirement of a user.

Disclosure of Invention

The invention provides a method for manufacturing a core yarn pre-bulked core-spun yarn for an asbestos-free brake band, which solves the technical problems of easy damage and short service life of the existing brake band.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a method of making a core spun yarn for an asbestos-free brake tape, comprising: step S1, firstly, sending the glass liquid to a porous bushing for high-speed extrusion, and cooling the extruded glass liquid into glass fiber raw yarns through a sprayer; s2, feeding glass fiber raw yarns into a bulking machine for micro-bulking treatment, S3, coating impregnating compound on the surfaces of the glass fiber yarns by using an oiling device, separately drawing the coated glass fiber yarns by using a buncher, and finally bundling the separately drawn alkali-free glass fibers by using the buncher; s4, conveying the collected glass fibers to a high-speed twisting machine, and twisting the glass fibers and the brass wires into yarns by the high-speed twisting machine; s5, uniformly winding a wrapper formed by mixing acrylic fibers and viscose fibers on the surface of the twisted yarn through an air friction spinning machine to prepare the rope-shaped yarn with a core-spun structure, so as to form the reinforced base material applied to the asbestos-free brake band.

The glass fiber of the brake band is subjected to puffing treatment, so that the glass fiber is fully puffed and becomes thick, the contact area between the glass fiber and the impregnating solution is increased on the original basis due to the thickening of the diameter, and the permeability of each glass fiber is improved. The glass fiber is puffed in other industries, the working pressure of a puffing cavity of the conventional puffing machine is generally set to be 0.6-0.7 MPa, and after the glass fiber is puffed, the glass fiber can be fully expanded, but the tensile strength of the glass fiber can be rapidly lost. The expanded glass fiber has common mechanical properties and unsatisfactory use effect.

The invention adopts the imported bulking machine which can carry out micro-bulking treatment on the glass fiber so as to enable the glass fiber to be subjected to micro-bulking, thereby enabling the glass fiber to keep the original tensile strength.

Further, the working pressure of the puffing chamber of the puffing machine in the step S2 is 0.1 MPa. The inlet bulking machine is adjusted to ensure that the working pressure in the bulking cavity is 0.1 MPa, so that the glass fiber can be subjected to micro-bulking.

Further, the working temperature of the puffing cavity of the S2 puffing machine is 150 ℃. The subsequent permeability of the glass fiber can be improved by high-temperature treatment, and the subsequent permeability of the glass fiber is highest at the working temperature of 150 ℃ through repeated tests.

Furthermore, the impregnating compound in the step S3 comprises the following components in parts by weight: 0.4-1.2% of coupling agent, 0.3-1% of surfactant, 4.5-7.5% of binder, 0.02-0.11% of mildew preventive, 0.3-0.8% of pH value regulator and 85-94% of deionized water. The impregnating compound has a good soaking effect, and can improve the tensile property and the anti-breaking capacity of the glass fiber.

Further, the binder is one or a mixture of two of water-soluble unsaturated polyester resin and water-soluble epoxy resin. Compared with the emulsion-shaped film forming agent, the low-molecular-weight water-soluble film forming agent has stronger adhesive force on the surface of the fiber and better ductility, and can form an effective and continuous protective layer on the surface of the glass fiber, so that the glass fiber has better bundling property, is easy to expand and cannot be adhered together.

Further, the brass wire of step S4 has a cross-sectional diameter of 0.12mm, and has a copper content of 62% and a zinc content of 38% by weight, or has a cross-sectional diameter of 0.15mm, and has a copper content of 65% and a zinc content of 35% by weight. Continuous experiments show that the brass wires with the two common specifications can form a better matching effect with the micro-expanded glass fiber, so that the braided brake band is not easy to break.

Further, the twist multiplier of the high speed twister pair of step S4 is 28 twists per mm. Therefore, the brass wires and the alkali-free glass fibers can be tightly connected, and the core-spun yarn cannot be curled after being used for a long time due to the twisting.

Compared with the prior art, the invention carries out micro-bulking treatment on the glass fiber which is the base material for forming the brake, so that the glass fiber has better infiltration rate and better tensile property and anti-fracture property compared with the common glass fiber. Meanwhile, the glass fibers have better bundling property by using the treating compound after the improved process, so that the friction coefficient among the glass fibers is reduced, and the friction loss among the glass fibers is reduced. The service life of the brake band is prolonged by the measures, and the safety of the brake band is improved.

Detailed Description

The existing asbestos-free brake band is woven from core-spun yarns by a machine, and is mainly used for binding goods carried on a truck. The brake band is capable of withstanding large instantaneous tensile forces, since large loads tend to move during acceleration and sudden braking of the truck. The glass fiber of the existing core-spun yarn has poor tensile property and is easy to break because of too small infiltration amount.

The invention relates to a method for manufacturing a core yarn pre-bulked core-spun yarn for an asbestos-free brake band, which comprises the following steps: firstly, delivering the glass liquid to a porous bushing for high-speed extrusion, and cooling the extruded glass liquid into glass fiber raw yarns through a sprayer. Then feeding the glass fiber raw yarn into a feeding port of an inlet bulking machine, adjusting an air compressor of the bulking machine to enable the working pressure of a bulking cavity to be 0.1 MPa, and heating the temperature of the bulking cavity to 150 ℃. As is well known, the primary use of puffing is a process of expanding a workpiece by heating, pressurizing, and then instantaneously depressurizing and cooling. The temperature and pressure will affect the puffing degree of the processed material. On the other hand, high temperature and high pressure also destroy the molecular structure of the workpiece, and change the chemical properties and physical properties of the workpiece.

The glass fiber is excessively expanded due to the excessively high temperature and the excessively high pressure during the expansion, so that the tensile property of the glass fiber is reduced, and the service life of the brake band is directly influenced. The glass fiber is subjected to micro-puffing treatment, the glass fiber puffing time is reduced, the glass fiber puffing time is controlled to be 2-3 seconds, and then circulation is carried out for 5-6 times, so that the original mechanical property of the glass fiber can be kept after the glass fiber is puffed.

Coating an impregnating compound on the surface of the puffed glass fiber yarn by using an oiling device, wherein the impregnating compound comprises the following components: 0.4-1.2% of coupling agent, 0.3-1% of surfactant, 4.5-7.5% of binder, 0.02-0.11% of mildew preventive, 0.3-0.8% of pH value regulator and 85-94% of deionized water, wherein the components in the impregnating compound are calculated by weight. The raw materials and the formula technology of the impregnating compound are the most critical technology for reflecting the internal quality of various glass fiber products and are essential industrial consumables in glass fiber production. The impregnating compound can play an important role in lubricating and bonding the glass fibers, increasing the wear resistance and tensile strength of the glass fibers, eliminating static electricity and the like. Through continuous research and debugging of an orthogonal experimental method, the impregnating compound with the formula can further endow the glass fiber with better tensile property. Wherein the binder is one or a mixture of two of water-soluble unsaturated polyester resin and water-soluble epoxy resin, and the two substances can play a certain coating role on the glass fiber. The bundling performance of the glass fibers is improved, and the friction force among the glass fibers is reduced. The glass fibers may contact each other during use and may be broken down quickly if the bundling property of the glass fibers is poor.

The surface of the alkali-free glass fiber yarn is coated with the sizing agent through an oiling device, and the alkali-free glass fiber yarn is split and drawn through a beam splitter and then bundled to a spindle through a bundling device. In the process of collecting the yarn, 1000 to 2000 alkali-free glass fiber yarns are twisted in the S direction and then wound on a spindle. Then the tail end of the alkali-free glass fiber formed by twisting a plurality of filaments on the spindle is fed into a high-speed twisting machine. A pre-twisting device can be arranged on the high-speed twisting machine or between the high-speed twisting machine and the concentrator independently, and the alkali-free glass fiber and the brass wire are twisted by the pre-twisting device. The pre-twisting device is a circular rotating body, the circular rotating body is driven by a motor to rotate, the circular rotating body is provided with two bayonets, and brass wires and alkali-free glass fibers are respectively placed in the bayonets to be twisted. Preferably, the axis of rotation of the spindle, the center of the pre-twisting device and the feed inlet of the high-speed twisting machine are arranged on a single line, so that the brass wire and the alkali-free glass fiber form a uniform twisting angle. The alkali-free glass fiber and the brass wire are twisted into a yarn, and the yarn forms an inner core of the core-spun yarn for manufacturing the brake band base material.

Here, the high-speed twister twists the yarn using pre-twisting, and the high-speed twister twists the yarn with a twist multiplier of 28 twists per mm. The brass wire has a cross section diameter of 0.12mm, and contains copper 62% and zinc 38%. Brass wires with a cross-sectional diameter of 0.15mm, wherein the copper content is 65% and the zinc content is 35%, can also be selected. The contents of copper and zinc are in parts by weight. The two brass wires and the alkali-free glass fiber can form better matching, the two brass wires can be tightly attached in a twisting mode of S-direction 28 twisting, the brass wires and the alkali-free glass fiber are not easy to separate, and the formed core-spun yarn is not easy to knot.

And finally, uniformly winding the acrylic fiber and viscose fiber mixed layer on the surface of the pre-twisted yarn by an air friction spinning machine to prepare the rope-shaped yarn with the core-spun structure, wherein the core-spun yarn forms the reinforcing base material applied to the asbestos-free brake band.

Claims

1. A method for manufacturing a core yarn pre-bulked core-spun yarn for an asbestos-free brake band is characterized by comprising the following steps of:

step S1, firstly, sending the glass liquid to a porous bushing for extrusion, and cooling the extruded glass liquid into glass fiber raw yarns through a sprayer;

step S2, feeding the glass fiber yarn into a bulking machine for micro-bulking treatment, wherein the working pressure of a bulking cavity of the bulking machine is 0.1 MPa;

step S3, coating impregnating compound on the surface of the glass fiber yarn by using an oiling device, separately drawing the coated glass fiber yarn by using a buncher, and finally bundling the alkali-free glass fiber after being separately drawn by using the buncher;

step S4, conveying the collected glass fibers to a twisting machine, and twisting the glass fibers and the brass wires into yarns by the twisting machine;

and step S5, uniformly winding leather yarns formed by mixing acrylic fibers and viscose fibers on the surface of the twisted yarns through an air friction spinning machine to prepare rope-shaped yarns with a core-spun structure, wherein the rope-shaped yarns form a reinforcing base material applied to the asbestos-free brake band.

2. The method of claim 1, wherein the working temperature of the expansion chamber of the expander is 150 degrees centigrade in step S2.

3. The method of claim 2, wherein in the step S3, the components of the sizing agent are as follows: 0.4-1.2% of coupling agent, 0.3-1% of surfactant, 4.5-7.5% of binder, 0.02-0.11% of mildew preventive, 0.3-0.8% of pH value regulator and 85-94% of deionized water.

4. The method of claim 3, wherein the binder is one or a mixture of water-soluble unsaturated polyester resin and water-soluble epoxy resin.

5. The method of claim 1, wherein in step S4, the brass wire has a cross-sectional diameter of 0.12mm, and has a copper content of 62% and a zinc content of 38% or a cross-sectional diameter of 0.15mm, a copper content of 65% and a zinc content of 35% by weight.

6. The method of claim 5, wherein the twisting machine is configured to twist the yarn at a twist multiplier of 28 per meter in step S4.