JP7408523B2 - Wave-type sieving mat and its uses - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wave-type sieving mat for sieving lumps and powder particles such as ores, crushed stone, coke, and chemicals using a wave-type sieve, and its use.

BACKGROUND OF THE INVENTION In order to make the particle size uniform, lumps and powders such as ores, crushed stone, coke, and chemicals are sieved using a screen. Specifically, the sieving is carried out by placing lumps or powdery substances, which are objects to be sieved (objects to be sorted), on the upper surface of a screen and dropping them downward through the openings of the screen. Conventionally, a metal screen has been used as such a screen. However, in recent years, screens made of elastic materials (rubber screens) have become mainstream instead of metal screens due to their longevity, noise issues, abrasion resistance, and ease of installation on vibrating sieve machines. There is.

Furthermore, as a sieving machine for sieving the above-mentioned lumps and powder particles, a vibrating sieving machine that sieves by applying vibration to a screen is widely used, but among these, efficient sieving is Wave sieving machines (jumping screens or jumping screen devices) are known as possible vibratory sieving machines.

As shown in FIG. 1, the wave motion sieving machine has a structure in which a plurality of rectangular screen mats 2 are arranged in parallel between opposing drive side plates 5. Each screen mat 2 is arranged in parallel along the longitudinal direction of the wave-type sieving machine 1 in the width direction, and the screen mat 2 is attached to a flat bar 3 arranged between adjacent screen mats 2 using a screen fixing device. It is fixed at 4. The material to be sorted (processed material) 6 is placed onto the screen mat 2 on the upstream side of the wave motion sieving machine 1, and is transferred toward the downstream side in the direction of the arrow in the figure. A part of the material to be sorted (processed material) 6 falls through the opening 2a of the screen mat 2 during the transfer process, and is thus sieved.

FIG. 2 shows a partially cutaway enlarged view of FIG. 1 for explaining the detailed structure of FIG. 1. In the wave-type sieving machine 1, both ends of one screen mat 2 It is placed on top, and both ends are held down by metal flat bars 3 and fixed by screen fixtures 4 (bolts and nuts). Specifically, in one cross beam 7, one metal flat bar 3 fixes the ends of two adjacent screen mats 2 in an overlapping state. Further, the cross beams 7 arranged in the longitudinal direction of the wave motion sieving machine 1 are alternately fastened to the inner drive side plates 5a and the outer drive side plates 5b. That is, regarding the cross beams 7 (adjacent cross beams) that fix both ends of one screen mat 2, one cross beam 7 is fastened to the inner drive side plate 5a, and the other cross beam 7 is fastened to the outer drive side plate 5a. is fastened to the drive side plate 5b. When adjacent cross beams 7 move horizontally in opposite phases (in the direction of the arrow in FIG. 2), the screen mat 2 fixed to the cross beams 7 repeats the action of tension and loosening.

That is, the adjacent screen mats 2 repeat a wave motion in which when one screen mat 2 is pulled, the other adjacent screen mat 2 loosens in conjunction with the movement of the driving side plates that move in opposite phases. FIG. 3 is a diagram for explaining the repetitive motion of the screen mat 2, and more specifically, a schematic cross-sectional view (along the width direction of the screen mat) for explaining the repetitive motion of the screen mat 2 in FIG. (cross-sectional view). That is, the screen mat 2 in the loosened state shown in FIG. 3(a) is pulled by the driving side plate, and passes through the state shown in FIG. 3(b) to the stretched state shown in FIG. 3(c). This state is reached and such movement is repeated as a wave movement. In this wave motion, in the state shown in FIG. 3(c) where the screen mat 2 is pulled, the object to be sorted 6 is violently thrown up in the direction of the arrow, and in the state shown in FIG. 3(a) where the screen mat 2 is loosened, the material to be sorted is It falls onto Mat 2 and collides violently. At the time of collision, the aggregates of the objects 6 to be sorted are broken up and dispersed. In this way, the wave-type sieving machine (jumping screen) 1 uses this jumping (jumping) in addition to the normal vibrating sieve, thereby enabling more efficient sieving. In particular, with the wave motion sieving machine, this kind of flip-up motion makes it easy to sort even highly adhesive materials, specifically materials with a lot of water and coagulation, or materials with high viscosity. In addition to being able to crush and disperse the material, the wave motion of the screen mat deforms and expands and contracts the openings, which prevents the material to be sorted from clogging. Furthermore, since the sieve surface is composed of a plurality of screen mats, only the damaged parts can be replaced, making maintenance easy.

The following screen mats are known as screen mats for vibrating sieves.

Utility Model Application Publication No. 48-43264 (Patent Document 1) discloses that a metal plate or a plastic plate is made with holes such as square holes, round holes, polygonal holes, etc., and the ears of the holes are bent to form a supporting structure. On top of this support structure, place a single elastic plate with sieve holes smaller than the size of the structure, a reinforced elastic plate lined with or inserted with a plastic film, or a short fiber reinforced elastic body, A screen is disclosed which is formed by bending the ears so as to wrap around the bent ears of the support structure.

Utility Model Publication No. 48-43265 (Patent Document 2) discloses that a woven fabric formed by fixing the overlapped portions of the warp and weft using a plastic film with a thickness of 2 mm or less or an adhesive treatment, or a mixture of short fibers, etc. An elastic screen is disclosed in which sieve meshes are punched out in an elastic plate lined with or embedded inside a relatively thin and soft reinforcing material such as a thin layer of reinforced polyurethane sheet.

Japanese Unexamined Patent Publication No. 2019-141839 (Patent Document 3) describes a first rope that is a plurality of filament bodies arranged parallel to a first direction at intervals; A second rope is formed of a plurality of filament bodies that are arranged and placed at intervals in parallel in a second direction that intersects one direction, and that are joined at their cross-contact parts with the first rope. The first rope includes a first body portion each made of a first elastic material, and a first resistor embedded in the first body portion and extending in the length direction to form a core wire. The second rope is formed of a second body part made of a second elastic material, and a second resistor embedded in the second body part and extending in the length direction to form a core wire. A screen is disclosed that is formed of a stretched body, and in which the first elastic material and/or the second elastic material include a silicone-modified resin containing organosiloxane units.

Further, as a screen mat for a commercially available wave-type sieving machine, a screen mat in which openings are formed by perforating a urethane elastomer sheet is used.

Publication No. 48-43264 Publication No. 48-43265 JP 2019-141839 Publication

However, Patent Documents 1 to 3 do not describe a wave-type sieving machine.

In addition, according to the inventors' studies, even if the screen mats of Patent Documents 1 and 2 and commercially available screen mats are used in a wave-type sieving machine, the non-adhesiveness may be low, and the material to be sorted may contain When the water content is too high or the viscosity is too high, the wave effect alone cannot sufficiently prevent adhesion. Therefore, there was a problem that the objects to be sorted adhered (adhered) and accumulated on the surface of the screen mat, and as the accumulation progressed further, the screen became clogged. In addition, commercially available screen mats are made of a single layer of urethane elastomer sheet, so repeated pulling and loosening movements due to wave motion can cause damage to the parts fixed with metal flat bars (the boundary between the flat bars and the mat). ) cracks developed, requiring early replacement.

Furthermore, according to the studies conducted by the present inventors, cracks occurred in the screen mat of Patent Document 3 as well as in commercially available screen mats, necessitating early replacement. In addition, if the durability of the screen mat is improved by increasing its thickness, clogging becomes more likely to occur, and there is a trade-off between mat durability and clogging prevention, and it is difficult to achieve both. This is a difficult characteristic. Regarding the thickness of the mat, increasing the thickness and increasing its mechanical strength can improve the mat's durability, but if the strength is increased and it becomes too rigid, the mat will be difficult to bend into a wave shape, causing unreasonable undulation. Cracks appear in the mat, causing it to break due to exercise. Therefore, with a wave-type sieving machine that has a jumping function (repetitive pulling and loosening operations due to wave motion), it is not easy to improve only the durability of the mat, and it is even more difficult to simultaneously suppress clogging. Met.

Accordingly, an object of the present invention is to provide a wave-type sieving mat that can suppress clogging and improve durability even when the material to be sorted is likely to adhere to the mat, and its use.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have developed a core body containing fabric and a resin component, and a surface of the core body on the upstream side of the screen (the side where objects to be sorted are fed or placed). By attaching a screen mat that is laminated and includes a surface resin layer containing a silicone modified resin containing organosiloxane units and has sieve openings formed by perforations to a wave-type sieving machine, it is possible to remove easily adhered substances. The present invention has been completed based on the discovery that clogging can be suppressed and durability can be improved even in the case of sorted materials.

That is, the wave-type sieving mat of the present invention is a screen mat that is attached to a wave-type sieving machine for sieving objects to be sorted while vibrating them, and includes a core body containing a fabric and a resin component; It includes a surface resin layer (surface non-adhesive layer) laminated on the screen upstream side of the core and containing a silicone-modified resin containing organosiloxane units, and has sieve mesh formed by perforation. The average thickness of this screen mat may be 2.5 to 5 mm. The tear strength of the screen mat according to JIS K6252 may be 100 to 500 N/mm. In the screen mat, a back resin layer containing a silicone modified resin containing organosiloxane units may be laminated on a surface of the core on the downstream side of the screen (the side through which the material to be sorted passes). In the screen mat, the average thickness of the front resin layer may be greater than or equal to the average thickness of the back resin layer, and the average thickness of the back resin layer may be 0.3 mm or more. The fabric may be a woven fabric having an average thickness of 0.2 mm or more. The average fineness of the threads constituting this woven fabric may be 1200 dtex or more. The thread density of the threads constituting this woven fabric may be 50 threads/5 cm or more. The core may be a plurality of fabric layers interposed with an intermediate resin layer containing a silicone-modified resin containing organosiloxane units. The silicone-modified resin may be a polycarbonate-type polyurethane containing 3 to 15% by mass of organosiloxane units.

The present invention also includes a method of attaching the screen mat to a wave-type sieving machine and sieving a material to be sorted.

The present invention includes a core body containing a fabric and a resin component, a surface resin layer laminated on the screen upstream side of the core body and containing a silicone modified resin containing organosiloxane units, and a sieve mesh formed by perforation. Since the screen mat having the above-mentioned screen mat is attached to the wave-type sieving machine, clogging can be suppressed and durability can be improved even when the material to be sorted is likely to adhere. In particular, by forming a specific back resin layer on the downstream side of the screen of the core and forming the core with a specific laminate, the durability of the screen mat is further improved while clogging is also suppressed. can.

FIG. 1 is a schematic perspective view of a wave motion sieving machine. FIG. 2 is a partially cutaway enlarged view for explaining the detailed structure of the wave motion sieving machine of FIG. 1. FIG. FIG. 3 is a schematic cross-sectional view for explaining the repeated operation of the screen mat 2 of FIG. 1. FIG. 4 is a schematic diagram showing an example of the layered structure of the wave-type sieving mat of the present invention. FIG. 5 is a schematic diagram showing another example of the layered structure of the wave-type sieving mat of the present invention. FIG. 6 is a schematic diagram showing still another example of the layered structure of the wave-type sieving mat of the present invention. FIG. 7 is a schematic diagram showing another example of the layered structure of the wave-type sieving mat of the present invention. FIG. 8 is an arrangement pattern diagram showing an example of the sieve mesh of the wave-type sieving mat of the present invention. FIG. 9 is an arrangement pattern diagram showing another example of sieve meshes of the wave-type sieving mat of the present invention. FIG. 10 is an arrangement pattern diagram showing still another example of the sieve meshes of the wave-type sieving mat of the present invention. FIG. 11 is a plan view showing an example of the wave-type sieving mat of the present invention. FIG. 12 is an enlarged view of the sieve mesh of the wave-type sieving mat shown in FIG. 11. FIG. 13 is a plan view showing another example of the wave-type sieving mat of the present invention. FIG. 14 is an enlarged view of the sieve mesh of the wave-type sieving mat shown in FIG. 13. FIG. 15 is a schematic diagram for explaining the method for measuring the tear strength of the sheet-like base material obtained in the example. FIG. 16 is a plan view of a test piece and an iron plate used to measure the strength of the opening of the sheet-like base material obtained in the example. FIG. 17 is a schematic diagram showing a state in which a test piece is fixed in order to measure the strength of the opening of the sheet-like base material obtained in the example. FIG. 18 is a diagram showing the sieve mesh arrangement pattern of the screen mats used in Examples 1-3, 7-8, 11-13 and Comparative Examples 1-2, 5, and 7. FIG. 19 is a diagram showing the sieve mesh arrangement pattern of the screen mats used in Examples 4-6, 9-10, 14-16 and Comparative Examples 3-4, 6, and 8. FIG. 20 is a schematic diagram for explaining a method of evaluating clogging in the example. FIG. 21 is a diagram showing the sieve mesh arrangement pattern of the screen mats used in Examples 17 to 20 and Comparative Examples 9 to 10.

[Layered structure of wave-type sieving mat]
The wave-type sieving mat (screen mat) of the present invention includes a core body containing a fabric and a resin component, and a surface of this core body on the upstream side of the screen (the side before the material to be sorted passes through), and It may have a layer structure including a surface resin layer containing a silicone-modified resin containing organosiloxane units. The layered structure of the wave-type sieving mat may be any structure as long as it has the core body and the surface resin layer. The core may have a layered structure in which a back resin layer containing a silicone modified resin containing siloxane units is laminated, or the core may have a layered structure including a plurality of fabric layers.

FIG. 4 is a schematic diagram showing an example of a mat layer structure for wave-type sieving according to the present invention, in which a core body 13, a surface resin layer 12 laminated on the surface of the core body 13 on the upstream side of the screen, and It is formed of a back resin layer 14 laminated on the surface of the core body 13 on the downstream side of the screen. The surface resin layer 12 containing a silicone-modified resin can prevent objects to be sorted from adhering (sticking) and accumulating on the surface of the screen mat, and in combination with the core 13 can improve the mechanical strength of the mat. Therefore, it is possible to suppress cracks that occur due to the jumping function (repetition of pulling and loosening operations associated with wave motion), and the durability of the screen mat can also be improved. Furthermore, since the back resin layer 14 is laminated on the back surface of the core body 13, it is possible to prevent lint, fuzz, etc. generated by fraying of the fibers (threads) constituting the core body 13 from getting mixed into the material to be sorted. The durability of the screen mat is further improved in terms of preventing the core body 13 from fraying. Furthermore, since the back resin layer also contains a silicone-modified resin, clogging of the screen is also suppressed. In addition, in this mat, in order to suppress clogging, the front resin layer 12 and the back resin layer 14 contain a silicone-modified resin. Although clogging is suppressed by the silicone-modified resin, the silicone-modified resin Since the adhesive strength is low, delamination is likely to occur due to the jumping function, which is disadvantageous for the durability of the mat. As mentioned above, from the viewpoint of the mechanical strength of the mat, there is a trade-off relationship between clogging prevention and mat durability, but with the screen mat of the present invention having a layered structure, not only the mechanical strength of the mat Although it is necessary to improve interlayer adhesion, the resin component for suppressing clogging has a relationship of decreasing interlayer adhesion. Therefore, with the screen mat of the present invention, it is more difficult to achieve both prevention of clogging and mat durability than with conventional screen mats having a single layer structure. In contrast, in the present invention, it is possible to achieve both suppression of clogging and mat durability by selecting the material constituting the core and the layer structure.

FIG. 5 is a schematic diagram showing another example of the layer structure of the wave-type sieving mat of the present invention, which is the same as the layer structure of the screen mat shown in FIG. 4 except that the back resin layer 14 is not formed. be. Similar to the screen mat shown in FIG. 4, this layered structure also suppresses the substances to be sorted from adhering and accumulating on the surface of the screen mat, improves the durability of the screen mat, and reduces the thickness of the surface resin layer 12. Because of the large adjustment, the mat durability with respect to cracks is equivalent to the mat shown in FIG. 4. Note that since the back resin layer 14 is not laminated, the durability of the mat with respect to fraying of the core tends to be slightly reduced.

FIG. 6 is a schematic diagram showing still another example of the layer structure of the wave-type sieving mat of the present invention, and the layers of the screen mat of FIG. 4 are different from each other, except that the core has a three-layer structure instead of a single-layer structure. The structure is the same. Specifically, the core shown in FIG. 6 has a three-layer structure in which a first fabric layer 13a and a second fabric layer 13c are laminated with an intermediate resin layer 13b interposed therebetween. Even in this layered structure, the surface resin layer 12 prevents the objects to be sorted from adhering to and accumulating on the screen mat surface, and the core forms a three-layered structure, further improving durability. By forming the intermediate resin layer 13b with a silicone modified resin containing organosiloxane units, clogging can also be suppressed. On the other hand, as the number of layers (number of laminated sheets) increases, the mat durability tends to decrease due to delamination. In the present invention, mat durability with respect to delamination can also be improved by combining a specific intermediate resin layer and a specific fabric layer. Furthermore, like the screen mat shown in FIG. 4, the back resin layer 14 further improves the durability against fraying of the core.

FIG. 7 is a schematic diagram showing another example of the layer structure of the wave-type sieving mat of the present invention, which is the same as the layer structure of the screen mat shown in FIG. 6 except that the back resin layer 14 is not formed. be. In this layered structure as well, similar to the screen mat shown in FIG. 6, it is possible to suppress the objects to be sorted from adhering and accumulating on the surface of the screen mat, and the durability is also improved. Although the back resin layer 14 is not laminated, the thickness of the front resin layer 12 is greatly adjusted, so the durability of the mat with respect to cracks is as good as that of the mat shown in FIG. 6, but the fraying of the core body is The durability of the mat is slightly reduced.

The layered structure of the screen mat only needs to include the core and the surface resin layer, and it further includes a back resin layer, since fraying of the core can be suppressed and the durability of the screen mat can be highly improved. is preferable.

The core may have a single layer structure including a single fabric, or may have a laminated structure including a plurality of fabrics. In the laminated structure, the number of fabrics is not particularly limited, and is 2 or more (for example, 2 to 10), preferably 2 to 5 (especially 2 to 4), more preferably 2 to 3, and most preferably 2. A laminated structure is preferred from the viewpoint of easy adjustment of the thickness and mechanical strength of the screen mat, and a single-layer structure is preferred from the viewpoint of improving the durability of the screen mat against delamination.

When the core has a laminated structure, an intermediate resin layer is preferably interposed between the fabric layers in order to improve interlayer adhesion.

The tear strength of the wave-type sieving mat of the present invention may be 100 N/mm or more, for example 100 to 500 N/mm, preferably 150 to 480 N/mm, more preferably 200 to 450 N/mm, most preferably It is 220 to 400 N/mm. If the tear strength is too low, there is a risk that the durability of the screen mat will decrease. On the other hand, if it is too large, it will be difficult for the mat to bend into a wave shape, and there is a risk that cracks will occur.

In the present application, it can be measured by a method based on JIS K6252, and more specifically, by a method described in Examples described later.

The average thickness of the wave-type sieving mat of the present invention is, for example, 1 to 7 mm, preferably 1.5 to 6 mm, and may particularly be 2.5 to 5 mm from the viewpoint of suppressing cracks in the belt. More preferably, it is 2 to 5 mm, more preferably 2.5 to 4.5 mm, and most preferably 3 to 4 mm. If the thickness is too thin, there is a risk that the durability of the screen mat will be reduced, and if it is too thick, there is a risk that the flexibility will be reduced.

In the present application, the average thickness of the screen mat and each layer can be measured by observing a cross section of the screen mat using a scanning electron microscope and calculating the average value of the thicknesses at three locations.

[Structure of sieve mesh]
The wave-type sieving mat of the present invention has sieve meshes (a plurality of openings) formed by perforation. In the present invention, the sieve openings are not openings (mesh) of a net-like body formed by intersecting multiple thread bodies (ropes), but are formed by perforations, so it has excellent durability and can be installed in a wave-type sieving machine. However, it can be used for a long time.

The shape of each opening can be selected as appropriate depending on the type of material to be sorted, such as polygonal shapes such as square, rectangular, rhombus, and parallelogram; It may be a circular shape such as a circular shape. Among these shapes, from the viewpoint of productivity, etc., circular shapes such as square shapes, rectangular square shapes, and perfect circular shapes are preferred, and square shapes are particularly preferred.

The opening diameter of the opening can be selected as appropriate depending on the type of object to be sorted, and can be selected, for example, from a range of about 2 to 35 mm. When the shape of the opening is a square or a perfect circle, the opening diameter (the length of one side of the square or the diameter of a circle) is preferably 3 to 30 mm, more preferably 5 to 25 mm. When the shape of the opening is rectangular, oval, or elliptical, the major axis (the length of the long side of the rectangle) is, for example, 5 to 35 mm, preferably 10 to 25 mm, and more preferably 12 to 25 mm. 20 mm, and the short axis (the length of the short side of the rectangle) is, for example, 2 to 10 mm, preferably 2 to 5 mm.

The arrangement pattern of sieve mesh is not particularly limited as long as it is regularly arranged, and for example, as shown in FIG. 8, a pattern structure in which square openings are regularly arranged at equal intervals in the vertical and horizontal directions is used. , as shown in Figure 9, square openings are arranged at equal intervals in the horizontal direction (the length direction of the screen mat) and are alternately shifted at equal intervals in the vertical direction (the width direction of the screen mat). Staggered pattern structure (horizontal plover pattern structure), as shown in Figure 10, a plover (staggered) pattern in which square openings are arranged at equal intervals in the vertical direction and alternately shifted at equal intervals in the horizontal direction. structure (vertical plover-type structure), etc.

On the surface of the wave sieving mat, the area ratio occupied by the openings (ratio of the total area of the openings) may be 25% or more, for example 25 to 75%, preferably 30 to 70%, more preferably is between 35 and 65%, most preferably between 40 and 60%. If the area of the openings is too large, there is a risk that the efficiency of sieving the objects to be sorted will be reduced, and if the openings are too small, there is a risk that the durability of the screen mat will be reduced.

The planar shape of the wave-type sieving mat is usually rectangular, and as shown in Figure 1, the width direction of the mat is parallel to the longitudinal direction of the wave-type sieving machine, and multiple wave-type sieves are performed in parallel. installed on the machine.

An example of the wave-type sieving mat of the present invention is shown in FIG. 11. As shown in FIG. 12, the screen mat 20 has square openings 21 formed in a vertical zigzag pattern, and the upper end in the width direction. Attachment and fixing holes 22 for attaching to the cross beam are bored at equal intervals in the upper and lower ends. Note that in FIG. 11, the openings are partially omitted.

Another example of the wave-type sieving mat of the present invention is shown in FIG. 13. As shown in FIG. The cross beams are arranged at equal intervals vertically and horizontally, and fixing holes 32 for attaching to the cross beam are bored at equal intervals at the upper and lower ends in the width direction. Note that the openings are partially omitted in FIG. 13 as well.

[Surface resin layer]
In the present invention, since the surface resin layer contains a silicone-modified resin containing an organosiloxane unit, it is possible to prevent the objects to be sorted from adhering to the screen mat, thereby suppressing clogging.

The silicone-modified resin contained in the surface resin layer is a base resin modified with a silicone component, and more specifically, organosiloxane units (silicone units) are copolymerized and incorporated into the molecules of the base resin. The resin (base resin unit) can improve adhesion to the core, and the silicone component can suppress adhesion of objects to be sorted.

The organosiloxane unit is represented by the formula: -Si(-R) ₂ -O- (in the formula, the group R is a substituent), and the substituents represented by the group R include an alkyl group, an aryl group, Examples include cycloalkyl groups. Examples of the alkyl group include C _1-12 alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl. Examples of the aryl group include C _6-20 aryl groups such as phenyl, methylphenyl (or tolyl), dimethylphenyl (or xylyl), and naphthyl. Examples of the cycloalkyl group include C _5-14 cycloalkyl groups such as cyclopentyl, cyclohexyl, and methylcyclohexyl. These substituents can be used alone or in combination of two or more. Among these substituents, C _1-3 alkyl groups such as methyl groups and C _6-12 aryl groups such as phenyl groups are commonly used.

The form of introduction of the organosiloxane unit is not particularly limited as long as it is bonded (copolymerized) into the base resin, and may be introduced into the main chain or into the side chain. The introduction method can be selected depending on the type of base resin, and is based on (poly)organosiloxane monomers that have ethylenically unsaturated bonds (vinyl groups, etc.) and reactive groups (hydroxyl groups, amino groups, carboxyl groups, etc.) It may be introduced by reacting (polymerizing) with a resin or its monomer. The form of copolymerization is not particularly limited, and may be any form of random copolymerization, block copolymerization, or graft copolymerization. Organosiloxane units are often derived from polyorganosiloxane diols.

The molecular weight of the skeleton (polyorganosiloxane diol) into which organosiloxane units are introduced is, for example, 100 to 50,000, preferably 500 to 10,000.

The proportion of organosiloxane units can be selected from a range of about 1 to 50% by mass based on the entire silicone modified resin, for example 2 to 30% by mass, preferably 3 to 25% by mass, more preferably 5 to 20% by mass, Most preferably it is 6 to 18% by weight. In particular, the proportion of organosiloxane units is 3 to 15% by mass, preferably 4 to 15% by mass, based on the entire silicone-modified resin, since it is possible to improve the bonding strength with the core while maintaining non-adhesion to the material to be sorted. It may be 12% by weight, more preferably 5-10% by weight, most preferably 6-9% by weight. If the proportion of organosiloxane units is too small, there is a risk that the non-adhesion to the object to be sorted will be reduced, and if it is too large, there is a possibility that the adhesion to the core will be reduced.

The silicone modified resin may be a thermoplastic resin or a thermoplastic elastomer. In the case of a thermoplastic resin, examples of the base resin include polyolefin, (meth)acrylic resin, polyester, polyacetal, polycarbonate, polyurethane, and polyimide. In the case of thermoplastic elastomers, examples of the base resin include polyolefin elastomers, polyester elastomers, polyamide elastomers, and polyurethane elastomers. These base resins can be used alone or in combination of two or more.

Among these base resins, thermoplastic resins or thermoplastic elastomers are preferred from the viewpoint of handleability, flexibility, etc., and polyurethane or polyurethane elastomers are particularly preferred.

The polyurethane (or polyurethane elastomer) may be a polyurethane obtained by reacting polyols and polyisocyanates.

Examples of the polyols include polyester polyols (including polycaprolactone), polyether polyols, polyether ester polyols, polycarbonate polyols, polyesteramide polyols, and acrylic polymer polyols. These polyols can be used alone or in combination of two or more. Among these polyols, polyether polyols (such as _polyC2-4 alkylene glycols such as polyethylene glycol and polytetramethylene glycol ether), polycarbonate polyols (ethylene glycol and 1, (such as the reaction product of a C _2-6 alkanediol such as 4-butanediol with a di-C _1-4 alkyl carbonate such as dimethyl carbonate or a di-C _6-12 aryl carbonate such as diphenyl carbonate) are preferred.

Polyisocyanates include, for example, aliphatic polyisocyanates [propylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI), and other aliphatic diisocyanates; , 1,6,11-undecane triisocyanate methyl octane, aliphatic triisocyanates such as 1,3,6-hexamethylene triisocyanate], alicyclic polyisocyanates [cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI) , hydrogenated xylylene diisocyanate, alicyclic diisocyanates such as hydrogenated bis(isocyanatophenyl)methane, and alicyclic triisocyanates such as bicycloheptane triisocyanate], aromatic polyisocyanates [phenylene diisocyanate, tolylene diisocyanate ( TDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), naphthalene diisocyanate (NDI), bis(isocyanatophenyl)methane (MDI), toluidine diisocyanate (TODI), 1,3-bis(isocyanato) aromatic diisocyanates such as phenyl)propane].

These polyisocyanates include multimers [dimers, trimers (polyisocyanates with isocyanurate rings), tetramers, etc.], adducts, modified products (biuret modified products, allophanate modified products, urea modified products). etc.) or urethane oligomers having multiple isocyanate groups.

These polyisocyanates can be used alone or in combination of two or more. Among these polyisocyanates, aliphatic diisocyanates such as HDI, alicyclic diisocyanates such as IPDI, araliphatic diisocyanates such as XDI, and aromatic diisocyanates such as MDI and TDI are widely used and have high versatility. Aromatic diisocyanates are particularly preferred.

Among these polyurethanes, polyether-type polyurethane and polycarbonate-type polyurethane are preferable because they have excellent water resistance and chemical resistance.They have excellent non-adhesiveness to objects to be sorted, can suppress clogging, and have excellent adhesion to the core. Polycarbonate-type polyurethane is particularly preferred since it can also improve properties.

When the silicone-modified resin is silicone-modified polyurethane, the surface resin layer may further contain a curing agent. As the curing agent, conventional curing agents such as polyisocyanates, polyols, polyamines, etc. can be used and can be selected depending on the type of polyurethane, but polyisocyanates are preferable from the viewpoint of reactivity. As the polyisocyanates, the above polyisocyanates can be used. Among the polyisocyanates, aromatic diisocyanates are preferred as curing agents from the viewpoint of stable reactivity.

The proportion of the curing agent is, for example, about 1 to 50 parts by weight, preferably 2 to 25 parts by weight, and more preferably about 5 to 10 parts by weight, based on 100 parts by weight of the silicone-modified polyurethane.

The silicone-modified resin of the surface resin layer is preferably an elastomer-type polyurethane silicone-modified resin (silicone-modified polyurethane elastomer) that is not used in combination with a curing agent; elastomers) are particularly preferred.

The surface resin layer may further contain other resin components, such as rubber, elastomer, and non-silicone-modified polyurethane. The proportion of other resin components is 30 parts by weight or less, preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, per 100 parts by weight of the silicone-modified resin (particularly silicone-modified polyurethane).

The surface resin layer may contain conventional additives such as chain extenders, stabilizers (weathering stabilizers, antioxidants, heat stabilizers, light stabilizers, etc.), fillers, plasticizers, lubricants, etc. good. These additives can be used alone or in combination of two or more. The proportion of the additive is 30 parts by weight or less, preferably 0.1 to 20 parts by weight, and more preferably 1 to 15 parts by weight, per 100 parts by weight of the silicone-modified resin (particularly silicone-modified polyurethane).

The average thickness of the surface resin layer is, for example, 0.3 to 7 mm, preferably 0.5 to 5 mm, more preferably 1 to 4 mm, and most preferably 1.5 to 3.5 mm. If the surface resin layer is too thin, there is a risk that non-adhesiveness will be reduced, and if it is too thick, there is a risk that flexibility will be reduced.

[Core body]
The core contains a fabric and a resin component, and the fabric and the resin component may form independent layers, but usually at least a fabric layer impregnated with a resin component between the fibers inside the fabric is used. Contains.

As the fabric (or canvas), fabrics conventionally used for core bodies can be used, such as woven fabrics, knitted fabrics, and the like. Among these fabrics, woven fabrics are preferred because they have excellent strength and productivity.

The woven structure (woven structure) of the woven fabric may be, for example, a plain weave, a twill weave (twill weave), a satin weave (satin weave, a satin weave), or the like. Among these weave structures, a plain weave may be used because of its excellent balance of strength and the like, and a twill weave and a satin weave may be used from the viewpoint of adhesion to the surface resin layer.

In the woven fabric, the yarn density (average value of warp density and weft density) may be 30 threads/5 cm or more (particularly 50 threads/5 cm or more), for example 30 to 150 threads/5 cm, preferably 45 to 100 lines/5 cm, more preferably 50 to 80 lines/5 cm, and most preferably 53 to 60 lines/5 cm. In applications requiring a high degree of belt durability, the density may be, for example, 53 to 65 lines/5 cm, particularly 55 to 62 lines/5 cm. If the thread density is too low, the durability of the screen mat may decrease.

The fibers constituting the fabric may be short fibers, but from the viewpoint of strength, spun yarns (spun yarns) in which long fibers and short fibers are twisted together are preferred. Furthermore, the long fibers may be monofilament yarns or multifilament yarns. Among these, multifilament yarn is preferred from the viewpoint of durability of the screen mat.

The fibers can be made of various materials, such as polyester fibers (polyalkylene arylate fibers such as polyethylene terephthalate and polyethylene naphthalate), polyamide fibers (aliphatic polyamide fibers such as polyamide 6 and polyamide 66, aramid fibers, etc.). , cellulose fibers such as cotton and rayon. Among these, polyC _2-4 alkylene arylate fibers such as polyethylene terephthalate (PET) are preferred because of their excellent balance of strength and flexibility.

The average fineness of the fiber (in the case of woven fabric, the average value of the average fineness of the warp and the average fineness of the weft) may be 1200 dtex or more in the case of monofilament yarn or multifilament yarn, for example 1200 to 3000 dtex, preferably 1300 to 2500 dtex, more preferably 1500 to 2000 dtex, most preferably 1600 to 1800 dtex. In applications requiring high belt durability, the average fineness of the warp is, for example, 1500 to 3000 dtex, preferably 1600 to 2800 dtex, more preferably 1800 to 2500 dtex, more preferably 2000 to 2400 dtex, and most preferably 2100 to 2300 dtex. There may be. If the fineness is too small, there is a risk that the durability of the screen mat will decrease.

The average thickness of the fabric (in the case of combining multiple fabrics, the average thickness of each fabric) may be 0.2 mm or more, for example, 0.2 to 2.0 mm, preferably 0.23 to 1.0 mm, and Preferably it is 0.25 to 0.7 mm, more preferably 0.28 to 0.65 mm, and most preferably 0.4 to 0.6 mm. In applications requiring high belt durability, the average thickness may be, for example, 0.5 to 1.0 mm, preferably 0.6 to 0.9 mm, and more preferably 0.8 to 0.85 mm. good. If the thickness is too thin, the durability of the screen mat may decrease.

The resin component to be impregnated into the fabric for the fabric layer is of the same type as the silicone-modified resin contained in the surface resin layer (i.e., the same as the base resin of the silicone-modified resin) in order to improve the adhesion with the surface resin layer. or similar) resins are preferred. Therefore, when the silicone-modified resin is silicone-modified polyurethane, the resin component of the core is preferably polyurethane. As the polyurethane, the polyurethanes exemplified as the base resin of the silicone modified resin can be used alone or in combination of two or more. Among the polyurethanes, polyether-type polyurethane or polycarbonate-type polyurethane is preferable, and polyether-type polyurethane is particularly preferable, for the same reason as the surface resin layer. The polyurethane of the core may also be combined with the curing agent exemplified in the section of the surface resin layer. The core polyurethane is preferably a prepolymer type polyurethane used in combination with a curing agent, rather than an elastomer type polyurethane. The ratio and preferred embodiments of the curing agent are the same as those for the surface resin layer. In the present invention, by forming the resin component of the fabric layer from such polyurethane, interlayer adhesion can be improved while suppressing clogging.

In the fabric layer, the proportion of the resin component is, for example, 10 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the fabric. If the proportion of the resin component is too small, there is a risk that the strength will be insufficient and the adhesion with the surface adhesive layer will be reduced, and if it is too large, there is a possibility that the flexibility of the screen mat will be reduced.

The core may include a fabric layer in which the fabric is impregnated with a resin component, or may include a fabric layer that does not contain a resin component, but from the viewpoint of improving interlayer adhesion, all the fabric layers are Preferably, the fabric layer is made of a free-flowing fabric impregnated with a resin component.

When forming a laminate with a plurality of fabric layers, an intermediate resin layer may be interposed between the fabric layers. The intermediate resin layer is not particularly limited as long as the fabric layers can be bonded to each other, and a commonly used adhesive or pressure-sensitive adhesive can be used, and the same type of resin as the resin component impregnated into the fabric (for example, polyurethane) may be used. However, it is preferable to use a silicone-modified resin containing organosiloxane units because it can improve the adhesion between fabric layers and prevent clogging of the screen. This silicone-modified resin can be selected from the silicone-modified resins containing organosiloxane units described in the section of the surface resin layer, including preferred embodiments. The intermediate resin layer may also further contain other resin components and conventional additives exemplified in the section of the surface resin layer in similar proportions.

The average thickness of the intermediate resin layer (in the case of combining a plurality of intermediate resin layers, the average thickness of each intermediate resin layer) is, for example, 0.5 to 5 mm, preferably 1 to 3 mm, and more preferably 1.5 to 2.5 mm. be. If the thickness of the intermediate resin layer is too thin, there is a risk that the effect of improving durability will be reduced, and if it is too thick, there is a risk that flexibility will be reduced.

In the core, the number of laminated fabrics (the number of plies) can be selected as appropriate depending on the mechanical strength and flexibility required for the durability of the desired screen mat, but approximately 1 to 5 plies are commonly used. 1 to 3 plies are preferable, 1 to 2 plies are more preferable, and 1 ply is more preferable from the viewpoint of improving mat durability and economical efficiency regarding delamination.

[Back resin layer]
In the wave-type sieving mat of the present invention, a back resin layer may be formed on the surface of the core body on the downstream side of the material to be sorted and the screen. By forming the back resin layer, the durability of the belt can be improved, and in particular, fraying of the core due to long-term use can be suppressed.

The back resin layer is not particularly limited as long as it can be bonded to the core, and any conventional adhesive or pressure-sensitive adhesive can be used, and the same type of resin (for example, polyurethane) as the resin component impregnated into the fabric of the core layer can be used. However, it is preferable to use a silicone-modified resin containing an organosiloxane unit because it can improve adhesion to the core and prevent clogging of the screen. This silicone-modified resin can be selected from the silicone-modified resins containing organosiloxane units described in the section of the surface resin layer, including preferred embodiments. The back resin layer may also further contain other resin components and conventional additives exemplified in the section of the front resin layer in similar proportions.

The average thickness of the back resin layer may be 0.3 mm or more, for example 0.3 to 7 mm, preferably 0.5 to 6 mm, more preferably 1 to 5 mm, more preferably 2 to 4 mm, most preferably 2 It is .5 to 3.5 mm.

The average thickness of the front resin layer may be at least the average thickness of the back resin layer, and the average thickness of the front resin layer is, for example, 1.5 to 10 times, preferably 2 to 10 times, the average thickness of the back resin layer. 8 times, more preferably 3 to 7 times, most preferably 4 to 6 times. If the thickness of the surface resin layer is too small, there is a risk that objects to be sorted will easily adhere to it.

[Production method of wave-type sieving mat]
The wave-type sieving mat of the present invention can be manufactured by a conventional method, such as a lamination step of laminating a surface resin layer precursor on one side of a core precursor to obtain a mat substrate precursor; It is preferable to use a method that includes a heat pressing step in which the obtained mat base material precursor is heat-pressed and integrated, and a perforation step in which the obtained mat base material is perforated to form openings.

In the lamination step, a conventional method can be used to prepare the core precursor to be used. For example, a method of impregnating a fabric in a liquid composition containing a resin component and a curing agent (Japanese Patent Laid-Open No. 11-29212) (such as the method described in ). Examples of the solvent for the liquid composition include hydrocarbons (for example, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene), halogenated hydrocarbons (chloroform, dichloromethane, etc.), Ethers (chain ethers such as diethyl ether, cyclic ethers such as dioxane, tetrahydrofuran), ketones (acetone, methyl ethyl ketone, etc.), esters (methyl acetate, ethyl acetate, etc.), amides (e.g. formamide, N,N -dimethylformamide, etc.), nitriles (eg, acetonitrile, etc.), sulfoxides (eg, dimethyl sulfoxide, etc.), and the like. These organic solvents can be used alone or as a mixed solvent. Among these solvents, hydrocarbons, ethers, ketones, etc. are commonly used. The concentration of the resin component in the liquid composition is, for example, 5 to 50% by weight, preferably 10 to 30% by weight, and more preferably 15 to 20% by weight.

After dipping, it may be heated and dried. The heating temperature is, for example, 60 to 200°C, preferably 80 to 160°C, and more preferably 100 to 140°C. The heating time may be, for example, 1 minute or more, for example 1 to 30 minutes, preferably 3 to 10 minutes.

Furthermore, when a plurality of fabrics are laminated as a core, a laminate of a fabric impregnated with a liquid composition and a sheet-like intermediate resin layer precursor may be used as the core precursor.

When laminating the back resin layer on the other surface of the core, the back resin layer precursor may be laminated on the other surface of the core precursor in the lamination step.

Note that the method of laminating the front resin layer precursor and the back resin layer precursor can be selected depending on the type of precursor, and a coating method of coating on the core precursor may be used, but depending on productivity etc. From this point of view, a method in which a sheet-like precursor is laminated on the core precursor is preferred.

In the hot pressing step, the heating temperature can be selected depending on the type of resin component, but may be, for example, 100°C or higher, preferably 100 to 200°C, more preferably 120 to 180°C. The applied pressure is, for example, 0.1 MPa or higher, preferably 0.1 to 0.6 MPa, and more preferably 0.2 to 0.5 MPa. The hot pressing time may be, for example, 10 seconds or more, and may be, for example, about 1 to 20 minutes, preferably about 3 to 10 minutes.

Note that the heat pressing step is not limited to the step of heat pressing the mat base material precursor all at once, but may be divided into multiple heat pressing steps, for example, each layer precursor is , may be heat pressed.

In the perforation step, a conventional method can be used to form the openings in the mat base material, such as a method of forming the openings by punching holes, cutting plotter, or the like.

The present invention will be explained in more detail below based on Examples, but the present invention is not limited by these Examples.

[Details of materials used]
(Sheet-like precursor for forming front resin layer and back resin layer)
Elastic body 1: Silicone-modified polycarbonate type thermoplastic polyurethane elastomer [“Rezamin PS” manufactured by Dainichiseika Industries Co., Ltd., silicone content 8% by mass], thickness 0.4 to 4.2 mm
Elastic body 2: silicone-modified polycarbonate type thermoplastic polyurethane elastomer [“Rezamin PS” manufactured by Dainichiseika Industries Co., Ltd., silicone content 16% by mass], thickness 0.4 to 2.5 mm
Elastic body 3: Silicone-modified polyether type thermoplastic polyurethane elastomer [“Rezamin PS” manufactured by Dainichiseika Industries Co., Ltd., silicone content 8% by mass], thickness 0.4 to 2.5 mm
Elastic body 4: silicone-modified polyether type thermoplastic polyurethane elastomer [“Rezamin PS” manufactured by Dainichiseika Industries Co., Ltd., silicone content 16% by mass], thickness 0.4 to 2.5 mm
Elastic body 5: polycarbonate thermoplastic polyurethane elastomer [unmodified silicone, "Miractran XN-2001" manufactured by Nihon Miractran Co., Ltd.], thickness 0.4 to 2.5 mm
Elastic body 6: polyether type thermoplastic polyurethane elastomer [unmodified silicone, "Miractran E385" manufactured by Nippon Miractran Co., Ltd.], thickness 0.4 to 2.8 mm.

(Material for forming the core)
Plain woven fabric 1: [Warp: polyester (PET) multifilament (fineness 1670 dtex, number of strands 1, thread density: 57/5cm), weft: polyester (PET) multifilament (fineness 1670 dtex, number of strands 1, yarn Density: 52 pieces/5cm)], thickness 0.58mm
Plain woven fabric 2: [Warp: polyester (PET) multifilament (fineness 1100 dtex, number of strands 2, thread density: 65/5cm), weft: polyester (PET) multifilament (fineness 1000 dtex, number of strands 1, yarn Density: 50 pieces/5cm)], thickness 0.82mm
Resin component: polyether type thermoplastic polyurethane resin (reaction product of polytetramethylene ether glycol and MDI)
Solvent: mixed solvent of methyl ethyl ketone, cyclohexane, and tetrahydrofuran (methyl ethyl ketone/cyclohexane/THF = 15/45/40 (mass ratio))
Curing agent: polyisocyanate composition.

[Core adhesion treatment]
The plain woven fabric 1 or 2 is immersed in a liquid composition consisting of a resin component, a curing agent, and a solvent for 0.5 minutes, taken out, and then heated at 120°C for 5 minutes to dry and remove the solvent to form a core. A precursor was obtained.

[Production of sheet-like base material (1-ply product)]
With the configuration shown in Tables 1 and 2, the sheet-like precursor made of elastic body 1 or 6 and the core body precursor were laminated, and heated and pressed at 150°C and 0.3 MPa for 5 minutes using a press machine to form a sheet-like laminate. After melting the precursor, it was cooled and solidified to produce a laminate that would become a sheet-like base material.

[Physical property test of sheet-like base material]
(tear strength)
Sheet-like substrates 1 to 10 shown in Tables 1 and 2 were measured in accordance with JIS K6252 using a universal material testing machine ("Strograph T" manufactured by Toyo Seiki Co., Ltd.). A trousers-shaped test piece 40 (a rectangular test piece with a 10 cm cut 40a in the length direction from the midpoint of the upper end) shown in FIG. 15(a) was prepared, and as shown in FIG. 15(b), the cut 40a One end and the other end of the film were gripped with grippers 41 and 42, and the force required to tear the film at a speed of 50 mm/min starting from the cut was measured. For base materials 1 to 4 and 6 to 10 containing cores, tests were conducted in the warp direction. The test results were the average value of n=3.

(Strength of opening)
For sheet-like substrates 1 to 10 shown in Tables 1 and 2, test pieces measuring 100 mm in length x 50 mm in width were taken. As shown in FIG. 16, an elongated round opening 50a measuring 12 mm in length and 22 mm in width was punched out so that the center of the test piece 50 was located 16 mm from the lower end of the test piece 50 and at the center of the left and right sides. In addition, iron plates 51 and 52 having openings were also used to measure the strength. The dimensions of the test piece 50 and the iron plates 51 and 52 are as follows.

Test piece 50: 100 mm x 50 mm x 5 mm, hole diameter: 12 mm x 22 mm, the center of the hole is 16 mm from the bottom edge Steel plate 51: 50 mm x 50 mm x 5 mm, hole diameter: φ12 mm, the center of the hole is 25 mm from the top edge 52: 100mm x 50mm x 5mmt, hole diameter: φ12mm, center of hole is 25mm from the top edge

As shown in FIG. 17, a test piece 50 is sandwiched between iron plates 51 and 52, an M10 bolt 53 is passed through the opening and fixed with a nut 54, and the upper part of the test piece 50 and the lower part of the iron plate 52 are held in an air chuck. It was fixed with. Using Autograph (manufactured by Shimadzu Corporation), the maximum strength at which the bolt tears the opening when the test piece is pulled upward at an ambient temperature of 23° C. and a speed of 50 mm/min was measured. The test results were the average value of n=2.

(Adhesion strength between layers)
The interlayer adhesive strength between the surface resin layer and the fabric layer was measured by a method based on JIS K6322.

The obtained evaluation results are shown in Tables 1 and 2.

As is clear from the results in Table 1, in contrast to the base material 5 which does not have a core, base material 1 with a one-ply core layer has a lower tear strength and opening area despite the thinner sheet thickness. The strength was excellent. Although the sheet thickness was the same as that of base material 5, base material 3 having a one-ply core layer was significantly superior in tear strength and opening strength.

In addition, base materials 2 to 4 are examples in which the sheet thickness is changed from base material 1 (a mode in which the core is one ply), but in this range of sheet thickness (2.8 to 5.0 mm), The tear strength and opening strength were excellent. Furthermore, in base materials 1 to 4, sufficient adhesive strength was obtained between the surface resin layer and the core (fabric layer).

Furthermore, although the sheet thickness is the same as that of the base material 2, the base material 6, which is the embodiment shown in FIG. Adhesive strength was obtained.

As is clear from the results in Table 2, the mechanical strength of base material 2 using plain woven fabric 1 is greater than that of plain woven fabric 1 (the total warp fineness is greater and the thread density is also greater). Base material 7, which was changed to plain woven fabric 2, had better tear strength, opening strength, and interlayer adhesive strength than base material 2.

Next, for the base material 2, a base material 8 is prepared in which the back resin layer is changed to an elastic body 6 made of an unmodified silicone material, and a surface resin layer and a back surface resin layer are made of an unmodified silicone material for the base material 2. In base material 9, which was replaced with elastic body 6, the tear strength and the strength of the opening were equivalent to base material 2.

Regarding the adhesion strength between the layers, base material 8 was equivalent to base material 2, but base material 9, whose surface resin layer is unmodified silicone, had a stronger adhesive strength between the surface resin layer and the core than base material 2. Adhesive strength increased. In addition, even in the embodiment of the base material 10 in which the sheet thickness is larger than that of the base material 9 (same thickness as the base material 3), the tear strength and the strength of the opening are the same as the base material 3, and the adhesive strength between the layers is It became larger than base material 3.

Of the substrates 1 to 10 above, screen mats were prepared using the following method for substrates 1 to 2 and 8 to 10, and non-adhesiveness evaluation and clogging evaluation were performed.

[Preparation of screen mat]
Examples 1 and 4
Using a base material 1 with a length of 2500 mm and a width of 1500 mm, a large flatbed cutting plotter (manufactured by Mimaki Engineering Co., Ltd.) was used to measure 21 mm long x 21 mm wide (Example 1) and 7 mm long x 7 mm wide (Example 4). ) square openings were formed to produce a screen mat. Regarding the arrangement of the openings, the screen mat of Example 1 has a pattern shown in FIG. 18, and the screen pattern of Example 4 has a pattern shown in FIG. 19.

Examples 2 and 5
A screen mat of Example 2 was produced in the same manner as in Example 1, except that base material 2 was used, and a screen mat of Example 5 was produced in the same manner as in Example 4.

Examples 3 and 6
A screen mat of Example 3 was produced in the same manner as in Example 1, except that base material 8 was used, and a screen mat of Example 6 was produced in the same manner as in Example 4.

Comparative examples 1 and 3
Using a base material 9 with a length of 2500 mm and a width of 1500 mm, a large flatbed cutting plotter (manufactured by Mimaki Engineering Co., Ltd.) was used to measure 21 mm in length x 21 mm in width (Comparative Example 1) and 7 mm in length x 7 mm in width (Comparative Example 3). ) square openings were formed to produce a screen mat. Regarding the arrangement of the openings, the screen mat of Comparative Example 1 had the pattern shown in FIG. 18, and the screen pattern of Comparative Example 3 had the pattern shown in FIG. 19.

Comparative examples 2 and 4
A screen mat of Comparative Example 2 was produced in the same manner as Comparative Example 1, and a screen mat of Comparative Example 4 was produced in the same manner as Comparative Example 3, except that the base material 10 was used.

[Evaluation of non-adhesion of screen mat]
The screen mats obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were cut into predetermined dimensions (width 215 mm, length 330 mm) to prepare test pieces, and a horizontally movable table (rectangular table) was used. Fix the test piece on top with the length direction of the test piece parallel to the length direction of the stand. Next, an adhesive tape (width 50 mm, length 250 mm) is placed in the center of the surface of the test piece (the top surface of the screen) with the length direction of the adhesive tape parallel to the length direction of the stand and the test piece. Press and paste with a roller. Furthermore, fix the load cell on one side in the length direction of the table, and use a clip to grip and fix one end of the adhesive tape on the opposite side to the side where the load cell is fixed, and the tip of the string fastened to the load cell. . The table is moved in the longitudinal direction away from the load cell at a rate of 300 mm/min, the adhesive tape is peeled off from the surface of the test piece in a 180 degree direction, and the peeling force is measured. Note that the peeling force was an average value excluding the peak value at the initial stage of peeling.

[Screen mat clogging evaluation]
Clogging was evaluated using the screen mats produced in Examples 1 to 6 and Comparative Examples 1 to 4. Each screen mat is cut into predetermined dimensions (width 215 mm, length 330 mm) and placed in a metal frame. Next, as shown in FIG. 20, the screen mat 61 fixed with a metal frame is fixed to an L-shaped angle 62 with an inclination angle of 20 degrees. As samples, a mixture of gravel and crushed stone 63 [particle size: 1 to 5 mm (Examples 4 to 6 and Comparative Examples 3 to 4), 1 to 15 mm (Examples 1 to 3 and Comparative Examples 1 to 2), moisture Amount: 10%] was placed on the screen mat 61 near the center thereof, the screen was vibrated for 60 seconds using the vibrating device 64, and the weight of the sample that had passed through the opening was measured. As an index of clogging, the passage rate was calculated from the weight of the sample that passed through the openings of the screen mat relative to the total weight of the sample placed on the screen mat, as shown in the formula below.

Passage rate (%) = [Weight passed through the opening (g)/Weight placed on the screen mat (g)] x 100.

The evaluation results are shown in Table 3.

As is clear from the results in Table 3, in Example 1 (base material 1) and Example 2 (base material 2) in which elastic body 1 (silicone-modified polyurethane) was used for the front resin layer and the back resin layer, the comparative example Compared to Comparative Example 1 (Substrate 9) and Comparative Example 2 (Substrate 10), the peeling force in the non-adhesive evaluation was lower, so the non-adhesive property was high. In addition, since the pass rate of the clogging evaluation was high, clogging was difficult to occur.

In Example 3 (base material 8), in which the front resin layer was made of elastic body 1 and the back resin layer was made of elastic body 6, the non-adhesiveness was equivalent to that of Examples 1 and 2. In the clogging evaluation, the transmittance decreased and clogging became easier.

In addition, Example 4 (Base material 1), Example 5 (Base material 2), Example 6 (Base material 8), Comparative example 3 (Base material 9), and Comparative example 4 (Base material 8) in screen mats with small openings were A similar tendency was observed in the case of material 10).

[Production of sheet-like base material (2-ply product)]
With the configuration shown in Table 4, a sheet-like precursor made of elastic body 1 or 6 and the core body precursor were laminated, and heated and pressed at 150° C. and 0.3 MPa for 5 minutes using a press machine to form a sheet-like laminated precursor. was melted and then cooled and solidified to produce a laminate that would become the sheet-like base materials 11 to 13.

[Physical property test of sheet-like base material]
(tear strength)
The tear strength of sheet-like base materials 11 to 13 shown in Table 4 was measured in the same manner as for base materials 1 to 4 and 6 to 10.

(Strength of opening)
For sheet-like base materials 11 to 13 shown in Table 4, the strength of the opening was measured in the same manner as for base materials 1 to 10.

(Adhesion strength between layers)
The interlayer adhesive strength between the surface resin layer and the first fabric layer was measured by a method based on JIS K6322.

The obtained evaluation results are shown in Table 4. For comparison, the evaluation results for base material 3 are also shown.

As is clear from the results in Table 4, when comparing sheets with the same thickness (approximately 4.0 mm), the core (fabric layer) is one ply, whereas the core (fabric layer) is one ply. For base materials 11 to 13, which are two-ply, the tear strength and the strength of the opening were increased.

In addition, while the base material 11 uses elastic body 1 (silicone-modified polyurethane) for the front resin layer, intermediate resin layer, and back resin layer, the base material 12 uses unmodified silicone for the intermediate resin layer and the back resin layer. The base material 13 is a base material in which the elastic body 6 is changed, and the base material 13 is a base material in which the surface resin layer, intermediate resin layer, and back surface resin layer are changed to the elastic body 6, which is an unmodified silicone material. Regarding the tear strength and the strength of the opening, Base Materials 11 to 13 were equivalent. The interlayer adhesion strength between the surface resin layer and the first fabric layer was the same for base material 12 as for base material 11, but for base material 13 whose surface resin layer was made of unmodified silicone, it was higher than that of base material 11 and the first fabric layer. The adhesive strength was greater than that of No. 12.

For the above substrates 11 to 13, screen mats were prepared by the following method, and non-adhesiveness and clogging evaluations were performed.

[Preparation of screen mat]
Examples 7 and 9
A screen mat of Example 7 was produced in the same manner as in Example 1, except that the base material 11 was used, and a screen mat of Example 9 was produced in the same manner as in Example 4.

Examples 8 and 10
A screen mat of Example 8 was produced in the same manner as in Example 1, except that the base material 12 was used, and a screen mat of Example 10 was produced in the same manner as in Example 4.

Comparative examples 5 and 6
A screen mat of Comparative Example 5 was produced in the same manner as in Comparative Example 1, and a screen mat of Comparative Example 6 was produced in the same manner as in Comparative Example 3, except that the base material 13 was used.

[Evaluation of non-adhesion of screen mat]
The screen mats produced in Examples 7 to 10 and Comparative Examples 5 to 6 were evaluated for non-adhesion in the same manner as the screen mats produced in Examples 1 to 6 and Comparative Examples 1 to 4.

[Screen mat clogging evaluation]
The screen mats produced in Examples 7 to 10 and Comparative Examples 5 to 6 were evaluated for clogging in the same manner as the screen mats produced in Examples 1 to 6 and Comparative Examples 1 to 4.

The evaluation results are shown in Table 5.

As is clear from the results in Table 5, in Example 7 (base material 11) in which elastic body 1 (silicone-modified polyurethane) was used for the surface resin layer, intermediate resin layer, and back resin layer, the surface resin layer, intermediate resin layer Compared with Comparative Example 5 (Substrate 13) in which Elastic Body 6 (silicone-unmodified polyurethane) was used for the back resin layer, the non-adhesiveness was high because the peeling force in the non-adhesive evaluation was small. In addition, the passage rate of clogging evaluation was high, so clogging was difficult to occur.

In Example 8 (base material 12), in which the surface resin layer was made of elastic material 1, but the intermediate resin layer and the back resin layer were made of elastic material 6, the non-adhesion was equivalent to that of example 7. However, in the clogging evaluation, the transmittance decreased and clogging occurred more easily.

Further, a similar tendency was observed in the case of Example 9 (Base material 11), Example 10 (Base material 12), and Comparative Example 6 (Base material 13) in which the screen mats had small openings.

From the above results, it has been revealed that, like the one-ply product, the use of silicone-modified polyurethane imparts non-adhesive properties to the screen mat, and as a result, it is effective in suppressing clogging.

[Preparation of screen mat]
Comparative Example 7 and Examples 11 to 13
Example except that base material 2 in which elastic body 1 was used for the front resin layer and back resin layer was used as a base material in which elastic bodies 2 to 5 were used for the front resin layer and back resin layer. A screen mat was produced in the same manner as in Example 2.

Comparative Example 8 and Examples 14 to 16
Example except that base material 2 in which elastic body 1 was used for the front resin layer and back resin layer was used as a base material in which elastic bodies 2 to 5 were used for the front resin layer and back resin layer. A screen mat was produced in the same manner as in 5.

[Physical property test of sheet-like base material]
The interlayer adhesive strength of the obtained sheet-like base material was measured in the same manner as for base material 2.

[Evaluation of non-adhesion of screen mat]
The screen mats produced in Examples 11 to 16 and Comparative Examples 7 to 8 were evaluated for non-stick properties in the same manner as the screen mats produced in Examples 1 to 6 and Comparative Examples 1 to 4.

[Screen mat clogging evaluation]
The screen mats produced in Examples 11 to 16 and Comparative Examples 7 to 8 were evaluated for clogging in the same manner as the screen mats produced in Examples 1 to 6 and Comparative Examples 1 to 4.

The evaluation results are shown in Table 6.

As is clear from the results in Table 6, Examples 2 and 11 to 13 in which the front resin layer and the back resin layer were formed of elastic bodies 1 to 4 made of silicone-modified polyurethane (silicone content: 8% by mass, 16% by mass) In this case, the peeling force in the non-adhesive evaluation was small, so the non-adhesive property was high, and the passing rate in the clogging evaluation was high, so it was difficult to get clogged. On the other hand, in Comparative Examples 1 and 7, in which the front resin layer and the back resin layer were formed of elastic bodies 5 to 6, which are silicone-unmodified polyurethane (silicone content: 0% by mass), the peeling force in the non-adhesive evaluation was Due to its large size, it had low non-adhesive properties and had a low pass rate for clogging evaluation, so it was easily clogged.

Furthermore, when comparing the differences in the silicone content of the silicone-modified polyurethane that forms the surface resin layer, as the silicone content decreases, non-adhesiveness and clogging properties decrease, and adhesive strength between layers improves. In the screen mats of Comparative Examples 1 and 7 in which the silicone content was 0% by mass, the clogging property (transmittance) was at a practically unacceptable level. Furthermore, considering the balance between non-adhesiveness (clogging property) and adhesiveness, a silicone content of 16% by mass results in a slight lack of adhesive strength, so a silicone content of 8% by mass was the best. Furthermore, regarding the polyurethane structure of the silicone-modified polyurethane that forms the surface resin layer, the polycarbonate type was slightly superior to the polyether type in terms of both non-adhesiveness (clogging resistance) and adhesiveness. That is, the screen mat of Example 2, in which the surface resin layer was formed of polycarbonate-type silicone-modified polyurethane with a silicone content of 8% by mass, had the best balance.

Further, a similar tendency was observed in Examples 5, 14 to 16, and Comparative Examples 3 and 8 in which the screen mats had small openings.

Examples 17-20 and Comparative Examples 9-10
Using a large flatbed cutting plotter (manufactured by Mimaki Engineering Co., Ltd.) using base material 2, base material 5, base material 6, base material 7, base material 9, and base material 11 with a width of 1915 mm and a length of 249 mm, A screen mat was produced by forming openings in the array pattern shape shown in FIG. 21.

For the durability test, a wave-type sieving machine (manufactured by Eurus Techno) with a path of 6000 mm was used, in which 24 screen mats were arranged in parallel in the width direction along the longitudinal direction. The screen mats are fixed with screen fixtures to metal flat bars (width 45 mm) placed between each adjacent screen mat, and one flat bar is used to connect the edges of two adjacent screen mats. were fixed to one cross beam in an overlapping state. The material to be sorted was placed on a screen mat and sieved by repeating the wave motion of the screen mat. Sieving is carried out for a maximum of 12 months, and if any abnormalities (cracks in the perforations, cracks in the mat, fraying of the core, delamination, severe clogging, etc.) occur in the screen mat before the 12 months have passed, At that point, the test was judged to have reached the end of its service life and the test was discontinued. If no abnormality occurred in the screen mat even after 12 months of sieving, it was determined that the screen mat had excellent durability.

The test conditions are as shown in 1) to 4) below.

1) Opening ratio of effective screen area (portion not fixed by flat bar): 33%
2) Item to be sorted: Sintered ore (particle size composition: 10%: 10 mm or less, 30%: 10 to 5 mm, 60%: 5 mm or more)
3) Moisture content: 3-6% (sprinkle water on the screen to prevent dust)
4) Processing amount: 100 tons/month

The evaluation results are shown in Table 7.

In Table 7, the amount of passage and clogging property were evaluated based on the following criteria.

Passing amount: The amount of material to be sorted that passes over the screen per hour in a path of 6000 mm. The more easily a screen mat is used, the more the material to be sorted accumulates on the screen and the supply becomes stagnant, resulting in a smaller amount of material passing through.

Clogging property: If the material to be sorted was clogged and it was not necessary to use a jig or the like to remove it, it was considered good.

As is clear from the results in Table 7, even if the elastic body 1 (silicone-modified polyurethane) is used in the surface resin layer, in Comparative Example 9 of the screen mat made with the base material 5 without a core, the clogging resistance ( Although the amount of passage (throughput) was good, the bent portion broke and the service life ended after 3 months. On the other hand, in Examples 17 to 19 having a core, the clogging property (passage amount) was good, and no abnormality was observed even after 12 months.

Example 20 is an example of a screen mat made with base material 6 that does not have a back resin layer, and the clogging property (passage amount) was as good as other examples, but after 12 months, fraying of the core was observed.

Comparative Example 10 is an example of a screen mat made with base material 9 that does not use elastic body 6 (silicone-unmodified polyurethane), and although no abnormality was observed even after 12 months, it was easily clogged. Due to the lack of throughput, it was necessary to add a supplementary task to sieving by using a jig to loosen the material to be sorted.

The wave-type sieving mat of the present invention can be used as a screen mat attached to a wave-type sieve for sieving lumps and powder particles such as ore, crushed stone, coke, and chemicals, and in particular, It is useful as a screen mat attached to a wave-type sieving machine for screening highly adhesive materials such as materials with a high moisture content or highly viscous materials.

1...Wave motion sieving machine 2,11...Screen mat 12...Surface resin layer 13...Core 14...Back resin layer

Claims (7)

A screen mat attached to a wave-type sieving machine for sieving a material to be sorted while vibrating it,
A core body containing a fabric and a resin component, and a surface resin layer laminated on the screen upstream side of the core body and containing a silicone modified resin containing organosiloxane units ,
The fabric is a woven fabric with an average thickness of 0.2 mm or more, the average fineness of the threads constituting the woven fabric is 1200 dtex or more, and the thread density is 50 threads/5 cm or more,
The silicone modified resin is a polycarbonate-type polyurethane containing 6 to 18% by mass of organosiloxane units ,
A wave-type sieving mat with perforated sieve mesh. The wave-type sieving mat according to claim 1, having an average thickness of 2.5 to 5 mm. The wave-type sieving mat according to claim 1 or 2, which has a tear strength of 100 to 500 N/mm according to JIS K6252. The wave-type sieving mat according to any one of claims 1 to 3, wherein a back resin layer containing a silicone-modified resin containing organosiloxane units is laminated on the downstream side of the screen of the core. 5. The wave-type sieving mat according to claim 4, wherein the average thickness of the front resin layer is greater than or equal to the average thickness of the back resin layer, and the average thickness of the back resin layer is 0.3 mm or more. The wave-type sieving mat according to any one of claims 1 to 5 , wherein the core is a plurality of fabric layers interposed with an intermediate resin layer containing a silicone-modified resin containing organosiloxane units. A method of sieving a material to be sorted by attaching the screen mat according to any one of claims 1 to 6 to a wave-type sieving machine.

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