CN114409966A - Waste glass fiber recycling and granulating method and application thereof - Google Patents

Abstract

A method for recovering and granulating waste glass fibers and application thereof are disclosed, wherein the method comprises the following steps: (1) infiltrating: adding waste glass fiber yarns into the impregnating agent solution, and heating and impregnating to obtain impregnated glass fibers; (2) cutting and grinding: cutting short the infiltrated glass fiber obtained in the step (1), and grinding to obtain glass fiber powder; (3) granulating and drying: and (3) extruding and molding the glass fiber powder obtained in the step (2), and carrying out granulation, drying and packaging to obtain glass fiber particles. The glass fiber particles obtained by the waste glass fiber recycling and granulating method replace the certified glass fibers and are used as the reinforcing modifier for reinforced nylon, reinforced PP or reinforced PBT materials. The quality of the glass fiber particles obtained by the method is close to the level of certified glass fibers, the glass fiber particles have a good reinforcing effect on nylon, PP or PBT materials, the waste utilization rate is high, the method is green and environment-friendly, the process is simple, the cost is low, and the method is suitable for industrial production.

Description

A kind of waste glass fiber recycling granulation method and its application

technical field

The invention relates to a glass fiber granulation method and application thereof, in particular to a waste glass fiber recycling granulation method and application thereof.

Background technique

As a reinforcing material, glass fiber is widely used in the reinforcement and modification of thermoplastic engineering plastics. The production of glass fiber materials in my country has reached 3 million tons per year, and the corresponding annual production of waste glass fiber yarn is about 60,000 to 100,000 tons. Most of these waste glass fibers are used as landfills, and a small part has been recycled and woven into glass fiber cloth recently. in rural septic tanks. Due to the variety of waste glass fiber yarn, the diameter of the monofilament is 11-18mm, the length is different, and it does not form a tow, which is difficult to recycle and process, and can only be discarded. Therefore, the recycling of waste fiber yarn has always been a major problem for domestic glass fiber enterprises.

CN109382233A discloses a spray drying device and method for waste glass fiber residual material, which is mainly used in a waste glass fiber surface treatment agent drying device, and is only a process and device of the waste glass fiber recovery process. The waste glass fiber yarn treated by the method can only be used for low-end applications such as glass fiber reinforced plastics, but cannot be used for reinforcing modified engineering plastics.

To sum up, there is a lack of methods for recycling waste glass fibers in the prior art, and it is urgent to find a method of obtaining glass fiber particles with a quality close to that of genuine glass fibers, good reinforcement effect on nylon, PP or PBT materials, high waste utilization rate, and green environmental protection. , the process is simple, the cost is low, and the method for recycling and granulating waste glass fiber is suitable for industrial production.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, and to provide a kind of glass fiber particles with a quality close to that of genuine glass fibers, good reinforcement effect on nylon, PP or PBT materials, high waste utilization rate, and green environmental protection. , the process is simple, the cost is low, and the method for recycling and granulating waste glass fiber suitable for industrial production and its application.

The technical scheme adopted by the present invention to solve the technical problem is as follows: a method for recycling and granulating waste glass fiber, comprising the following steps:

(1) Infiltration: Add waste glass fiber yarn into the sizing solution, heat and infiltrate to obtain infiltrated glass fiber yarn;

(2) Chopping and grinding: after cutting the infiltrated glass fiber obtained in step (1), grinding to obtain glass fiber powder;

(3) Granulation and drying: the glass fiber powder obtained in step (2) is extruded and formed, and then diced, dried and packaged to obtain glass fiber particles.

Preferably, in step (1), the waste glass fiber is a substandard product or transitional product produced during the glass fiber production process due to process adjustment or product specification adjustment, including various glass fiber yarns with different monofilament diameters and different lengths mixture.

Preferably, in step (1), the mass ratio of the waste glass fiber to the sizing agent solution is 100:40-80. The amount of sizing agent has a great influence on the bonding force between the glass fiber yarns and between the glass fiber and the resin during subsequent modification. A large amount of powder or monofilament is produced, which seriously affects the molding and granulation of glass fiber yarn; if there is too much sizing agent, the production cost will increase.

Preferably, in step (1), the sizing agent solution includes the following components and their parts by weight: 100 parts of water, 20 to 40 parts of a binder (more preferably 30 to 40 parts), and 5 to 10 parts of an emulsifier ( More preferably 8-10 parts), coupling agent 2-6 parts (more preferably 4-6 parts). In the wetting agent, due to the presence of more polar groups on the surface of the glass fiber, the steering group can physically bind water with water molecules, and water as the wetting medium can accelerate the wetting speed of the glass fiber by the auxiliary agent; The adhesive can bond the glass fiber yarn monofilaments into tows. The content of the binder is very important for the glass fiber yarn bonding. When the amount of binder is small, the glass fiber yarn is not tightly or even loosely bonded, and the It is beneficial to the manufacture of glass fiber yarn particles, especially due to poor cohesion, the manufactured glass fiber particles are easy to loosen, and it is easy to produce wool during the downstream customer test process, resulting in unstable extrusion of glass fiber particles or even unsteady feeding. , but when the amount of binder is too large, it will not only increase the production cost, but more importantly, the binder content will be too high, which will reduce the mechanical properties of the reinforced resin composite; the role of the emulsifier is to couple the binder and Oily compounds such as emulsifier are dispersed in water to form fine particles, which is more conducive to improving the uniform and rapid dispersion of the binder and coupling agent on the surface of the glass fiber yarn. The larger the amount of emulsifier, the more uniform the organic binder and coupling agent. , the smaller the particles are, otherwise, the dispersibility of organic matter will be poor, but when the amount of emulsifier is too large, since the emulsifier completely covers the binder, the bonding strength of the binder to the glass fiber yarn will be reduced; even The function of the coupling agent is mainly to improve the bonding force between the glass fiber and the resin, thereby improving the reinforcing effect of the glass fiber on the resin. , the enhancement effect becomes poor, but when the amount of coupling agent used is too large, the chemical combination with the surface of the glass fiber reaches saturation, and some coupling agents that have not reacted with the surface of the glass fiber cannot have a coupling effect and migrate to the surface of the composite material. affect its surface properties or mechanical properties.

Preferably, in step (1), the binder includes one or more of water-soluble epoxy resin, water-soluble polyurethane or polyetheramide. The three binders have good solubility with water, good bonding force with glass fiber yarn, and certain chemical bonding force with polyester and polyamide resin. Considering the binding force of the binder, glass fiber and resin, the comparison order of the binding ability is: water-soluble polyurethane > water-soluble epoxy resin > polyether amide. More preferably, the binder is water-soluble epoxy resin Resin or water-soluble polyurethane.

Preferably, in step (1), the emulsifier includes one or more of anionic emulsifiers, non-ionic fatty alcohol polyoxyethyl ethers or polyol emulsifiers. More preferably, the anionic emulsifier includes one or more of sodium stearate, sodium lauryl sulfate or sodium oleate, etc.; the nonionic fatty alcohol polyoxyethyl ether includes octylphenol polyoxyethylene Diethyl ether (TX-10) and/or nonylphenol polyoxyethyl ether (OP-10), etc.; the polyol type emulsifier includes one or more of ethylene glycol, glycerol pentaerythritol or sorbitan. Anionic emulsifier, non-ionic fatty alcohol polyoxyethyl ether and polyol type emulsifier, the emulsification sequence of the three emulsifiers on the binder and coupling agent is: nonionic fatty alcohol polyoxyethyl ether > polyol type Emulsifier>anionic emulsifier, more preferably, the emulsifier is a non-ionic fatty alcohol polyoxyethyl ether or polyol type emulsifier.

Preferably, in step (1), the coupling agent includes a silane coupling agent and the like. More preferably, the silane coupling agent includes one or more of KH550, KH560 or KH570. Considering the emulsification and dispersibility of the coupling agent, the variety of coupling agent is selected, and the order of viscosity of several coupling agents is combined: KH570>KH560>KH550, more preferably, the coupling agent is KH550.

Preferably, in step (1), the temperature of the heating and soaking is 40-80° C., and the time is 30-60 min. The function of glass fiber yarn infiltration is to make the glass fiber yarn filaments bond to each other into bundles, reduce the static electricity on the glass fiber surface, improve the lubricity of the glass fiber surface, and enhance the adhesion between the glass fiber surface and the polymer. Make recycled glass fibers meet the reinforcement effect of thermoplastic composites. Higher heating and soaking temperature is more conducive to improving the soaking effect, but when the heating soaking temperature is too high, the sizing agent will be volatilized. , the heating and soaking time is too long, which will affect the production efficiency.

Preferably, in step (2), the cutting is shortened to a length of 3-20 mm.

Preferably, in step (2), the feeding amount of the grinding is 40-2000kg/h (more preferably 800-1800kg/h), the rotating speed of the grinding disc is 40-200rpm (more preferably 80-180rpm), and grinding to a particle size It is 1 to 5 mm (more preferably 2 to 4 mm). If the rotating speed of the grinding disc is too fast or the feeding amount is too small, the size of the glass fiber powder will be small, while the length of the glass fiber powder is too small, the reinforcing effect will be small, and when the rotating speed of the grinding disc is too slow or the feeding amount is too large, the glass fiber If the powder size is too large, the surface of the glass fiber reinforced resin material will be rough, which will affect the appearance of its products.

Preferably, in step (3), the rotation speed of the extrusion is 60-150 rpm (more preferably 60-100 rpm), and the temperature is 60-250°C (more preferably 100-200°C). When the rotating speed of the roller extruder is too high, the length of the glass fiber powder becomes smaller, and at the same time, the frictional heat between the glass fiber powders will increase, and the sizing agent will be volatilized too much, resulting in the produced glass fiber particles being loose or unshaped. , when the rotation speed is too low, the length of the glass fiber powder is large; and the extrusion temperature is too high, the sizing agent will volatilize too much, resulting in the produced glass fiber particles being loose or not formed, and the extrusion temperature is too low, it will Causes the sizing to melt incompletely, thereby reducing the extrusion fluidity of the fiber.

Preferably, in step (3), the dicing speed is 40-200 rpm (more preferably 80-180 rpm). When the cutting speed is low, the glass fiber particle size is large, which affects the surface appearance of the reinforced resin composite material, and when the cutting speed is too high, it may lead to the generation of powder.

Preferably, in step (3), the particle size of the cut pellets is 1-10 mm (more preferably 2-6 mm). When the particle shape is non-spherical, the particle size is the equivalent particle size.

Preferably, in step (3), the shape of the cut glass fiber particles is cylindrical, square, polygonal cylindrical, spherical or irregular.

Therefore, it is very necessary to reasonably design the extrusion pelletizing process.

Preferably, in step (3), the drying temperature is 100-200°C (more preferably 100-110°C), and the drying time is 20-60 min (more preferably 20-30 min). The purpose of drying is to remove the moisture of the glass fiber particles, and under the drying conditions, the moisture can be fully volatilized.

The technical solution adopted by the present invention to further solve its technical problems is as follows: an application of the glass fiber particles obtained by the waste glass fiber recycling and granulation method, and the glass fiber particles obtained by the waste glass fiber recycling and granulation method are replaced by genuine glass fibers , a reinforcing modifier for reinforcing nylon, reinforcing PP or reinforcing PBT materials.

The beneficial effects of the inventive method are as follows:

(1) The quality of the glass fiber particles obtained by the method of the present invention is close to the level of genuine glass fibers, which has a good reinforcement effect on materials such as nylon, reinforced PP or reinforced PBT, and has a high waste utilization rate;

(2) The method of the present invention reduces the environmental pollution caused by the waste discharge in the glass fiber production process, is green and environmentally friendly, has a simple process and low cost, and is suitable for industrial production;

(3) The glass fiber particles obtained by the method of the present invention will turn the waste glass fiber yarn that has been discarded and landfilled for a long time into a usable commodity, and can be widely used as a reinforcing modifier for materials such as reinforced nylon, reinforced PP or reinforced PBT. Requirements for engineering plastic reinforcements.

Detailed ways

The present invention will be further described below in conjunction with the examples.

The waste glass fiber yarn used in the embodiment of the present invention is a mixture of glass fiber yarns with different monofilament diameters (including 10mm, 12mm, 14mm, 17mm, 20mm, etc.) and different lengths (ranging from 1 to 20m), which are from Chongqing International Composites Materials Co., Ltd. and Zhejiang Tongxiang Jushi Group; the raw materials or chemical reagents used in the embodiments of the present invention are obtained through conventional commercial channels unless otherwise specified.

Wetting agent solution reference examples 1 to 5

The components and parts by weight of the reference examples 1 to 5 of the sizing solution and the comparative examples 1 and 2 are shown in Table 1.

Table 1 Components and parts by weight of reference examples 1 to 5 and comparative examples 1 and 2 of sizing solution

Note: "-" in the table means no addition; the formulations of the sizing agent solutions of Examples 3 and 4 are the same as those of Example 1; Denoted as sizing solution 1, sizing solution 2, sizing solution 3, sizing solution 4, sizing solution 5.

A kind of waste glass fiber recycling granulation method embodiment 1

(1) Infiltration: Add 1000kg of waste glass fiber to 600kg of sizing agent solution 1, and heat and infiltrate it for 60min at 60°C to obtain infiltrated glass fiber;

(2) Chopping and grinding: after the infiltrated glass fiber obtained in step (1) is cut to a length of 8 mm, the feed rate is 1500 kg/h, the grinding disc rotation speed is 180 rpm, and the particle size is 4 mm with a disc grinding machine. glass fiber powder;

(3) Granulation and drying: add the glass fiber powder obtained in step (2) to a counter-roll extrusion granulator, extrude it at a speed of 100 rpm and a temperature of 200 ° C, and grind it at a speed of 180 rpm. Cut into cylindrical particles with a particle size of 6 mm, dry at 110° C. for 30 min with a fluidized bed dryer, and package to obtain glass fiber particles.

A kind of waste glass fiber recycling granulation method embodiment 2

The only difference between this example and Example 1 is that the wetting agent solution 2 is added in step (1). The same as in Example 1.

A kind of waste glass fiber recycling granulation method embodiment 3

(1) Infiltration: Add 1000kg of waste glass fiber to 800kg of sizing agent solution 1, and heat and infiltrate for 50min at 50°C to obtain infiltrated glass fiber;

(2) Chopping and grinding: after the infiltrated glass fiber obtained in step (1) is cut to a length of 10 mm, the feed rate is 800 kg/h, the grinding disc rotation speed is 100 rpm, and the particle size is 4 mm with a disc grinding machine. glass fiber powder;

(3) Granulation and drying: add the glass fiber powder obtained in step (2) into a counter-roll extrusion granulator, extrude it at a speed of 60 rpm and a temperature of 120 ° C, and grind it at a speed of 100 rpm. Cut into square particles with a particle size of 4 mm, dry at 100° C. for 20 min with a fluidized bed dryer, and package to obtain glass fiber particles.

A kind of waste glass fiber recycling granulation method embodiment 4

(1) Infiltration: Add 1000kg of waste glass fiber to 800kg of sizing agent solution 1, and heat and infiltrate for 50min at 50°C to obtain infiltrated glass fiber;

(2) Chopping and grinding: After the infiltrated glass fiber obtained in step (1) is cut to a length of 6 mm, the feeding amount is 1000 kg/h, the grinding disc rotation speed is 140 rpm, and the particle size is 3 mm with a disc grinding machine. glass fiber powder;

(3) Granulation and drying: Add the glass fiber powder obtained in step (2) into a counter-roll extrusion granulator, extrude it at a speed of 80 rpm and a temperature of 150 ° C, and then grind it at a speed of 140 rpm. Cut into spherical particles with a particle size of 5 mm, dry at 100° C. for 20 min with a fluidized bed dryer, and package to obtain glass fiber particles.

A kind of waste glass fiber recycling granulation method embodiment 5

The only difference between this example and Example 1 is that 600 kg of sizing agent solution 3 is added in step (1). The same as in Example 1.

Application examples 1 to 5 of glass fiber particles obtained by a waste glass fiber recycling and granulation method

The glass fiber particles obtained by the waste glass fiber recycling and granulation methods described in Examples 1 to 5 are used to replace genuine glass fibers, and are used as reinforcing modifiers for reinforcing nylon, reinforcing PP or reinforcing PBT materials.

Comparative Examples 1 and 2

The only difference between the comparative examples 1 and 2 and Example 1 is that the composition of the wetting agent added in step (1) is different (as shown in Table 1). The same as in Example 1.

In order to evaluate the reliability of the sizing agent formulation, sizing process and granulation process used in Examples 1 to 5 of the method of the present invention:

(1) Test the properties of glass fiber particles:

Measure the powder content in the glass fiber particles. The lower the powder content, the better the sizing formulation and its infiltration and granulation process. The results are shown in Table 2;

(2) Indirectly characterize the quality of recycled glass fiber particles:

The glass fiber particles obtained in Examples 1 to 5 of the method of the present invention, the glass fiber particles obtained in Comparative Examples 1 and 2, and the genuine short glass fiber 301HP (Comparative Example 3, purchased from Chongqing International Composite Materials Co., Ltd.) are reinforced and blended with PA6. The mechanical properties of the materials were compared and evaluated. The formulation of PA6 reinforced blend composites is as follows:

The PA6 (YH800 produced by Baling Petrochemical) was mixed with the glass fiber particles obtained in Examples 1 to 5 of the method of the present invention, the glass fiber particles obtained in Comparative Examples 1 and 2, or the genuine short glass fiber 301HP (with a glass fiber content of 30%), and anti- Oxygen agents 1098, 160 and lubricant silicone are blended and extruded according to the existing method to obtain glass fiber reinforced PA6 composite material respectively;

The mechanical properties testing standards of composite materials are as follows: tensile strength/MPa: ASTM D638, flexural strength/MPa: ASTMD790, flexural modulus/MPa: ASTM D790, notched impact strength/kJ/m ² : ASTM D756, unnotched impact strength/ kJ/m ² ; the results are shown in Table 2.

Table 2 Performance comparison table of glass fiber particles and glass fiber reinforced PA6 composites prepared in Examples 1 to 5 and Comparative Examples 1 to 3

It can be seen from Table 2 that the powder content of the glass fiber particles obtained in Examples 1 to 5 of the method of the present invention can be controlled below 5%, and the performance of the reinforced PA6 composite material has the same reinforcing effect as the genuine short glass fiber 301HP, indicating the use of the present invention. The waste glass fiber recycling material obtained by the method has little effect on the performance of the reinforced PA6 product, and it has been proved by the customer that it can completely replace the genuine glass fiber for the production of reinforced nylon composite materials, and the method of the present invention is feasible for the recycling method of the waste glass fiber; However, the glass fiber particles obtained in Comparative Example 1 are powdery because no binder is added, and it is difficult to feed. bonding force, resulting in poor mechanical properties of the prepared composites. It shows that under the appropriate dosage of binder, emulsifier and coupling agent, the surface properties or mechanical properties of the obtained PA6 composite material are better.

Claims (6)

1. A method for recovering and granulating waste glass fibers is characterized by comprising the following steps:

(1) infiltrating: adding the waste glass fiber yarn into the impregnating compound solution, and heating and impregnating to obtain an impregnated glass fiber yarn;

(2) cutting and grinding: cutting short the infiltrated glass fiber obtained in the step (1), and grinding to obtain glass fiber powder;

(3) granulating and drying: and (3) extruding and molding the glass fiber powder obtained in the step (2), and carrying out granulation, drying and packaging to obtain glass fiber particles.

2. The method for recycling and granulating waste glass fiber according to claim 1, wherein: in the step (1), the mass ratio of the waste glass fibers to the impregnating compound solution is 100: 40-80; the impregnating compound solution comprises the following components in parts by weight: 100 parts of water, 20-40 parts of a binder, 5-10 parts of an emulsifier and 2-6 parts of a coupling agent; the binder comprises one or more of water-soluble epoxy resin, water-soluble polyurethane or polyether amide; the emulsifier comprises one or more of anionic emulsifier, nonionic fatty alcohol polyoxyethylene ether or polyol emulsifier; the coupling agent comprises a silane coupling agent; the temperature of the heating and soaking is 40-80 ℃, and the time is 30-60 min.

3. The method for recycling and pelletizing waste glass fiber according to claim 1 or 2, characterized in that: in the step (2), cutting to a length of 3-20 mm; the feeding amount of the grinding is 40-2000 kg/h, the rotating speed of the grinding disc is 40-200 rpm, and the grinding is carried out until the grain size is 1-5 mm.

4. The method for recycling and pelletizing waste glass fiber according to claim 1 or 2, characterized in that: in the step (3), the rotating speed of the extrusion is 60-150 rpm, and the temperature is 60-250 ℃; the speed of the grain cutting is 40-200 rpm; the grain size of the cut grains is 1-10 mm; the shape of the glass fiber particles after being cut into granules is cylindrical, square, polygonal cylindrical, spherical or irregular particles; the drying temperature is 100-200 ℃, and the drying time is 20-60 min.

5. The method for recycling and granulating waste glass fiber according to claim 3, wherein: in the step (3), the rotating speed of the extrusion is 60-150 rpm, and the temperature is 60-250 ℃; the speed of the grain cutting is 40-200 rpm; the grain size of the cut grains is 1-10 mm; the shape of the glass fiber particles after being cut into granules is cylindrical, square, polygonal cylindrical, spherical or irregular particles; the drying temperature is 100-200 ℃, and the drying time is 20-60 min.

6. The use of the glass fiber granules obtained by the method for recycling and granulating waste glass fibers as claimed in any one of claims 1 to 5, wherein the method comprises the following steps: the glass fiber particles obtained by the method for recycling and granulating the waste glass fibers in any one of claims 1 to 5 are used as reinforcing modifiers for reinforced nylon, reinforced PP or reinforced PBT materials instead of the certified glass fibers.