Flight conveyor

Abstract

To provide a flight conveyor reducing adherence of fibers to a flight.SOLUTION: A flight conveyor collects glass fibers and has a planar flight that has thickness of 3 to 4 mm and is disposed so that a principal surface is in parallel with a travel direction of the flight conveyor. The flight has a plurality of open holes penetrating in a thickness direction. Openings of the plurality of open holes have substantially circular shape with a diameter less than 8 mm. Aperture ratio of the flight by the plurality of open holes is 40 to 60%. Air is sucked through the plurality of open holes from an upper side to a lower side of the flight, causing the glass fibers to be collected on the flight of the flight conveyor.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a flight conveyor for collecting glass fibers.

Background Art

[0002] Glass wool used as a material for heat insulating and sound absorbing materials is generally manufactured by accumulating glass fibers coated or sprayed with a binder on a perforated conveyor in a mat shape through a fiber collecting process and then curing the binder (for example, refer to the production line of Patent Document 1). In the fiber collecting process, more specifically, air is sucked from above to below the perforated conveyor through the through holes by a suction device, so that glass fibers are deposited on the perforated conveyor to form a mat-shaped fiber collection. As the perforated conveyor, for example, a flight conveyor in which chains are run on both sides or in the center in the traveling direction and perforated flights (flat plates) are attached to the chains can be used. As the chains travel, the flights convey the glass fibers to the next process while collecting them.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, as the technology for making glass fibers thinner progresses in order to improve the performance of glass wool, the fiber length tends to become shorter and the entanglement between fibers tends to become weaker. In addition, when the fiber length becomes smaller than the pore diameter of the flight, the fibers enter the pores of the flight and are likely to get caught, and many fibers adhere to the flight and remain without being conveyed to the next process, leading to problems such as a decrease in yield and an increase in the burden of cleaning the flight.

[0005] Therefore, the present invention aims to provide a flight conveyor that reduces the adhesion of fibers to the flight. [Means for solving the problem]

[0006] As a result of diligent research, the inventors have discovered that the above problem can be solved by creating through holes of a specific shape and size in a flight with a specific aperture ratio, and have completed the present invention.

[0007] In other words, the present invention is as follows. [1] This is a flight conveyor for collecting glass fibers. It has a flat, plate-shaped flight with a thickness of 3-4 mm, whose main surface is provided parallel to the direction of travel of the flight conveyor. The flight has a plurality of through holes that penetrate in the thickness direction, and the opening shape of the plurality of through holes is substantially circular with a diameter of less than 8 mm. The opening ratio of the flight through the plurality of through holes is 40-60%. As air is drawn in from above to below the flight through the multiple through holes, the glass fibers are collected on the flight. A flight conveyor characterized by the following features. [2] The flight conveyor according to [1], wherein the plurality of through holes are arranged in a 60° staggered arrangement. [3] The flight conveyor according to [1] or [2], wherein the opening shape of the plurality of through holes is approximately circular with a diameter of 3 to 4 mm. [4] The surface of the aforementioned flight is coated with a water-repellent agent. A flight conveyor according to any one of [1] to [3], wherein the water contact angle on the surface of the coated flight is 110 degrees or more. [5] A flight conveyor according to any one of [1] to [4], wherein the average fiber diameter of the glass fibers is 5.0 μm or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a flight conveyor that reduces the adhesion of fibers to the flights. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of the arrangement pattern of through-holes in the flight of the flight conveyor according to this embodiment. [Figure 2] This is a schematic side view showing a part of the manufacturing line for the glass fiber mat used in the examples and comparative examples. [Figure 3] (a) A schematic diagram showing the flight of the glass fiber material immediately after it moves from one flight conveyor to the next in the manufacturing line shown in Figure 2. (b) A schematic diagram of an image taken from the flight in (a), with only the perforated portion of the flight extracted. (c) A schematic diagram of a binarized image obtained by using the image analysis software ImageJ to binarize the image in (b) based on the intensity of the colors. [Modes for carrying out the invention]

[0010] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). The present invention is not limited to the following embodiments, and can be implemented in various ways within the scope of its gist.

[0011] Flight Conveyor The flight conveyor in this embodiment is a flight conveyor for collecting glass fibers, which are collected on the flight and transported to the next process (for example, an oven for hardening the binder added to the glass fibers). Air is drawn in from above to below the flight (from the side where the glass fibers are collected to the opposite side) through multiple perforations in the flight, causing the glass fibers to be collected on the flight. The means of drawing in air are not particularly limited, and suction devices such as exhaust fans can be used.

[0012] The advancing direction of the flight conveyor is not particularly limited, but from the viewpoint of efficiently collecting glass fibers, it is preferably horizontal.

[0013] [Flight] The flight is in the shape of a flat plate with a thickness of 3 to 4 mm, and is provided such that its main surface is parallel to the advancing direction of the flight conveyor. Further, the flight has a plurality of through-holes penetrating in the thickness direction, and the opening shape of the plurality of through-holes is a substantially circular shape with a diameter of less than 8 mm.

[0014] By setting the thickness of the flight in the range of 3 to 4 mm according to the diameter (opening diameter) of the opening of the through-hole, the through-hole can be formed by an inexpensive method (such as punching), and the manufacturing cost of the conveyor can be suppressed. Further, for reinforcement, ribs or the like may be provided on the back surface of the flight (the surface opposite to the side where the glass fibers are collected).

[0015] The plurality of through-holes provided in the flight have a substantially circular opening shape with a diameter of less than 8 mm. The above diameter (opening diameter) is preferably 2 to 6 mm, and more preferably 3 to 4 mm. When the diameter (opening diameter) is less than 8 mm, it is difficult for fibers to enter the through-hole, and the adhesion of fibers to the through-hole can be favorably suppressed. Further, the smaller the fiber diameter of the glass fiber, the more favorably the adhesion of the glass fiber to the flight is suppressed when the opening diameter of the through-hole is made smaller. In the present disclosure, the substantially circular shape means not only a mathematically exact circle but also a shape that can be grasped as approximately circular (a shape that can be approximated to a circle).

[0016] The arrangement (placement) pattern of the multiple through-holes is not particularly limited, but it is preferable that the through-holes are uniformly distributed. For example, it may be a grid arrangement, a staggered arrangement (45° staggered arrangement, 60° staggered arrangement, etc.) as shown in Figure 1. Among these, a staggered arrangement is more preferable from the viewpoint of collecting glass fibers well by reducing the opening diameter of the through-holes to suppress the adhesion of fibers to the through-holes and increasing the opening ratio of the flight by the through-holes to increase the air suction force. A 60° staggered arrangement is particularly preferable because the adhesion of fibers to the through-holes is further suppressed when the center pitch and diagonal pitch are equal. In addition, the pitch of the arrangement may be adjusted as needed to prevent the holes from chipping at the ends of the flight due to manufacturing errors when forming the through-holes.

[0017] The method for forming the through-hole is not particularly limited and includes, for example, punching, drilling, laser processing, etc.

[0018] The opening ratio of the flight with multiple through holes is 40-60%, preferably 40-55%, and more preferably 50-55%. When the opening ratio is 40% or more, sufficient suction force is obtained to collect glass fibers, and the glass fibers can be collected on the flight. When the opening ratio is 60% or less, it is possible to suppress the discharge of glass fibers from the through holes, which prevents a decrease in yield, and the flight has sufficient strength for collecting glass fibers. The aperture ratio can be calculated using the following formula. Opening ratio (%) = (Sum of opening areas of multiple through holes / Area of ​​the main surface of the flight) × 100

[0019] The flight conveyor of this embodiment is equipped with flights in which the opening diameter of the through-holes is less than 8 mm and the opening ratio due to the through-holes is 40 to 60%, resulting in a flight conveyor that strikes an excellent balance between suppressing the adhesion of glass fibers and ensuring sufficient suction power for cotton collection (sufficient performance as a suction conveyor).

[0020] The material of the flight is not particularly limited and may be any material commonly used for the flight of a flight conveyor, such as stainless steel, iron, or aluminum.

[0021] Furthermore, the flight may be coated with a water-repellent agent to further reduce the adhesion of glass fibers. The entire surface of the flight may be coated with a water-repellent agent, or only a portion of the surface (for example, only the perforated portions of both main surfaces, or only the perforated portion of the main surface on which the glass fibers are collected, etc.) may be coated with a water-repellent agent. Glass fibers are sprayed with binders during the cotton collection process. By coating the flight with a water-repellent agent, it is possible to suppress fiber adhesion due to the surface tension of water contained in the binder, and fiber adhesion to the flight tends to be further reduced. The water repellent is not particularly limited, and examples include silicone-based water repellents and fluorine-based water repellents, but silicone-based water repellents are preferred from a cost perspective.

[0022] Examples of silicone-based water repellents include dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, dimethylsiloxane-methylphenylsiloxane copolymers, and modified polysiloxane compounds obtained by introducing amino groups, epoxy groups, hydroxyl groups, or polyether groups, etc., to the molecular ends or side chains of dimethylpolysiloxane. The coating thickness of the silicone-based water repellent is preferably 3 to 200 μm, more preferably 3 to 150 μm, and even more preferably 50 to 150 μm.

[0023] Examples of fluorine-based water repellents include perfluoroaliphatic compounds such as polytetrafluoroethylene and tetrafluoroethylene-hexafluoropropylene copolymers, and polyperfluoroalkyl (meth)acrylates such as polypentadecafluorooctyl (meth)acrylate and polytrifluoroethyl (meth)acrylate. The coating thickness of the fluorine-based water repellent is preferably 3 to 200 μm, more preferably 3 to 150 μm, and even more preferably 50 to 150 μm.

[0024] Water repellents can be used in the form of oil, solution, aerosol, etc. The method of coating with a water-repellent agent is not particularly limited, and examples include impregnating the entire flight with a water-repellent agent and then drying the agent, or applying or spraying the water-repellent agent onto the surface of the flight and then drying it.

[0025] Flights coated with a water-repellent agent preferably have a water contact angle of 110 degrees or more on their surface, more preferably 115 degrees or more, and even more preferably 120 degrees or more. When the water contact angle is within the above range, the water repellency of the flight is high, and the adhesion of glass fibers to the flight tends to be further suppressed. The water contact angle can be measured using a contact angle meter, and specifically, it can be measured by the method described in the examples below.

[0026] [Glass fiber] The glass fibers collected by the flight conveyor in this embodiment are not particularly limited, and examples include those commonly used in the field of thermal insulation and sound absorption materials. Glass fibers may be used individually or in combination of two or more types.

[0027] The average fiber diameter of the glass fibers is not particularly limited and may be, for example, 1.0 to 8.0 μm or 2.0 to 5.0 μm. The smaller the average fiber diameter of the glass fibers, the easier it is for the fibers to penetrate the through-holes of the flight and the weaker the entanglement between the fibers. This tends to increase fiber adhesion to the flight, leading to a decrease in yield and an increased burden on flight cleaning work. However, with the flight conveyor of this embodiment, adhesion to the flight can be reduced even if the average fiber diameter of the glass fibers is small. The average fiber diameter of the glass fibers can be measured using a cottonscopeHD or similar device manufactured by Cottonscope Pty Ltd. Specifically, it can be measured by the method described in the examples below.

[0028] The glass fibers of this embodiment can be manufactured, for example, by melting glass in a glass melting furnace, and then heating it by gas and air combustion and stretching the fibers with compressed air in a fiberization apparatus. Conventional methods of fiberization include the centrifugal method (rotary method), flame method, and blowing method. Among these, the centrifugal method is preferred because it facilitates the creation of fine fibers. An example of a fiberization apparatus for the centrifugal method is a spinner.

[0029] The glass fiber material obtained by collecting cotton using the flight conveyor of this embodiment may contain a binder. The binder is not particularly limited, but a thermosetting resin that hardens by any of the following reactions is preferably used: amidation, imidation, esterification, and transesterification. Specific examples of such thermosetting resins include resins containing a polycarboxylic acid polymerized from ethylenically unsaturated monomers and a crosslinking agent containing an alcohol having an amino group and / or imino group. The binder may be a single type or a combination of two or more types.

[0030] The binder may optionally contain additives such as crosslinking agents, dust suppressants, colorants, colorants, pH adjusters, curing accelerators, silane coupling agents, and neutralizing agents for neutralizing alkaline components leached from glass fibers, in a quantity that does not impair the effects of the present invention. It is preferable to do so. The binder can be prepared by mixing the above components according to conventional methods and adding water to adjust it to a predetermined concentration.

[0031] The glass fiber collection can be manufactured, for example, by applying or spraying a binder onto glass fibers using a spray device, and then collecting the fibers using the flight conveyor of this embodiment. The resulting glass fiber collection is then transported to the next process (for example, an oven to harden the binder added to the glass fibers), and after undergoing the appropriate processes, it becomes a glass fiber mat. [Examples]

[0032] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples unless it exceeds the scope of its essence.

[0033] The measurement and evaluation methods used in the examples and comparative examples are as follows.

[0034] [Average fiber diameter of glass fibers] The average fiber diameter (μm) of glass fibers was determined using a cottonscopeHD manufactured by Cottonscope Pty Ltd. Specifically, fibers dispersed in water were magnified under a microscope, images were captured with a camera and imported into a computer, and the fiber diameter was measured using image processing. The average fiber diameter was determined by averaging the measurements obtained from 30,000 fibers. Furthermore, fibers shorter than 50 μm in length, and short fibers with a length less than three times their diameter, were excluded from the calculation. In addition, to perform calculations that take fiber length into account, for fibers longer than 50 μm, the length was automatically divided using image processing, and the measured fiber diameter of each divided portion was calculated.

[0035] [Water contact angle on the flight surface] For flights coated with a water-repellent agent, the water contact angle on the surface was measured using a contact angle meter (Contact Angle Meter DMo-501, manufactured by Kyowa Interface Science Co., Ltd.). Measurements were taken at five points, and the average value was taken as the water contact angle (degrees).

[0036] [Fiberglass adhesion to the flight] For flights immediately after the glass fiber collection material moved from one flight conveyor to the next (see flights in Figures 2 and 3(a)), a fixed camera (Mitsubishi Electric Corporation "NC-8820", approximately 2.08 million pixels) was used to photograph the flight so that more than 90% of its width (short side) was captured. Next, only the perforated portion of the flight was extracted from the obtained photographs (see Figure 3(b)), and the image was binarized using the image analysis software ImageJ based on the intensity of the colors (see Figure 3(c)). In the binarized image, the area of ​​the fiber-attached portion (white portion) was determined, and the ratio to the area of ​​the perforated portion of the flight was calculated to determine the glass fiber attachment area percentage (%). In cases where setting the binarization threshold was difficult due to camera angle, lighting conditions, etc., the fibers were visually identified and the threshold was set accordingly. Based on the obtained glass fiber adhesion area ratio, the adhesion of glass fibers was evaluated according to the following evaluation criteria. (Evaluation Criteria) A (Excellent): The surface area ratio of glass fibers is 7% or less. B (Good): The area ratio of glass fibers attached is between 7% and 15%. C (Inferior): The surface area ratio of glass fibers is more than 15%.

[0037] [Example 1] (Construction of a flight conveyor) A flight conveyor was fabricated using multiple flights (material: SUS304L, 151mm short side x 2280mm long side x 4mm thickness) each having multiple through-holes (opening shape: circular, opening diameter: 4mm) arranged in a 60° staggered pattern (short side pitch: 5.1mm, long side pitch: 6.0mm), with the main surface of each flight parallel to the direction of travel of the flight conveyor. The through-holes were formed by punching. The opening ratio of the flights due to the through-holes was 40.3%. The term "60° Staggered Arrangement" refers to a specification in which the pitch in the shorter direction is tighter than that of the standard "60° Staggered Arrangement." In the standard "60° Staggered Arrangement," there was a risk of hole chipping occurring at the short-side ends of the flight due to manufacturing errors when forming the through holes. By adjusting the pitch in the shorter direction to create the "60° Staggered Arrangement," this hole chipping was avoided. (Collection of glass fiber cotton) Glass was melted in a glass melting furnace to obtain molten glass. Using the molten glass, fiberization was performed using a fiberization device to obtain glass fibers (average fiber diameter 3 μm). Immediately after fiberization, an acrylic resin binder was sprayed onto the glass fibers. Next, air was sucked from the top to the bottom of the flight conveyor constructed above through through holes using a suction device or suction fan, thereby collecting the glass fibers on the flight conveyor. The collected glass fibers were then transported to the next conveyor by the flight conveyor (see Figure 2). The measurement and evaluation results are shown in Table 1.

[0038] [Example 2] A flight conveyor was fabricated in the same manner as in Example 1, except that a silicone-based water-repellent coating (Toshiko Co., Ltd.'s "Toshikaru S Coating TS-1310", film thickness 10 μm (catalog value)) was applied, and glass fibers were collected. The water contact angle of the flight surface after the silicone-based water-repellent coating was 118 degrees. The measurement and evaluation results are shown in Table 1.

[0039] [Example 3] A flight conveyor was fabricated in the same manner as in Example 1, except that the diameter of the through-holes and other parameters were changed as shown in Table 1, and glass fibers were collected. The measurement and evaluation results are shown in Table 1.

[0040] [Comparative Example 1] A flight conveyor was fabricated in the same manner as in Example 1, except that the diameter of the through-holes and other parameters were changed as shown in Table 1, and glass fibers were collected. The measurement and evaluation results are shown in Table 1.

[0041] [Table 1] [Industrial applicability]

[0042] The flight conveyor of the present invention reduces the adhesion of glass fibers to the flights, thereby suppressing a decrease in yield and an increase in the burden of cleaning the flights. Therefore, it can be suitably used for collecting glass fibers (especially fine glass fibers with a small fiber diameter).

Claims

1. This is a flight conveyor for collecting glass fibers. It has a flat, plate-shaped flight with a thickness of 3 to 4 mm, whose main surface is provided parallel to the direction of travel of the flight conveyor. The aforementioned flight has a plurality of through holes that penetrate in the thickness direction, and the opening shape of the plurality of through holes is substantially circular with a diameter of less than 8 mm. The opening ratio of the flight through the plurality of through holes is 40 to 60%. As air is drawn in from above to below the flight through the multiple through holes, the glass fibers are collected on the flight. A flight conveyor characterized by the following features.

2. The flight conveyor according to claim 1, wherein the plurality of through holes are arranged in a 60° staggered pattern.

3. The flight conveyor according to claim 1 or 2, wherein the opening shape of the plurality of through holes is substantially circular with a diameter of 3 to 4 mm.

4. The surface of the aforementioned flight is coated with a water-repellent agent. The flight conveyor according to claim 1 or 2, wherein the water contact angle on the surface of the coated flight is 110 degrees or more.

5. The flight conveyor according to claim 1 or 2, wherein the average fiber diameter of the glass fibers is 5.0 μm or less.

Images