JP4181360B2 - Pallet manufacturing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for producing a pallet from miscellaneous plant fibers, such as coconut shell fibers, Nanjing bag waste, hemp and corn hulls.
[0002]
[Prior art]
Conventional wooden pallets have rust, crab, pests and moisture absorption, iron has rust, weight and price, all resin has chlorine and price when incinerated, paper has strength and water resistance, and wood powder has melamine The formaldehyde resin and the injection method of pulverized fiber and resin kneaded have problems such as shape moldability and high cost. On the other hand, a method for producing pallets from plant fiber-containing waste materials such as coconut shell fibers is disclosed in Japanese Patent Laid-Open No. 6-270938. According to the technique of this publication, the coconut shell is crushed by a crusher, pulverized by a pulverizer, defibrated by a defibrator, and wound into a web shape. The plant fiber formed in a web shape is impregnated with a phenolic resin aqueous solution, sandwiched between upper and lower molds, and pressed under heating such that the phenolic resin exceeds its curing temperature, and the strength due to the shape of multiple concave and convex grooves in the cross direction A pallet that is a molded product having a predetermined shape and having a reinforced structure is obtained. The pallets produced by this method are mainly made from miscellaneous plant fibers such as coconut, corn husk and acne, and the raw material cost is extremely low. Also, phenopolyphenol resin as a binder resin is Since it is a chlorine-free resin, most of it is decomposed into carbon dioxide, carbon monoxide and water even when burned, and no harmful combustion products such as dioxin are produced, which is excellent from the viewpoint of reducing environmental burden.
[0003]
[Problems to be solved by the invention]
According to Japanese Patent Laid-Open No. 6-270938, a vegetable fiber web impregnated with a phenol resin is molded into a pallet by pressing it with a mold. However, since the plant fiber web has water repellency and contains a large amount of air, a desired amount of resin cannot be evenly distributed inside by simply immersing it in an aqueous resin solution. No pallet was obtained. In addition, the resin is cured by the heat from the mold while forming the web into a predetermined shape with the mold for molding into the pallet, in other words, the molding and the curing are performed simultaneously. There was a problem in quality because uneven thickness and fiber cutting were likely to occur. In addition, the fiber was used for the purpose of increasing the weight, the strength material was not recognized, the resin was the strength material, and there was no idea of adding air permeability.
[0004]
The present invention has been made in view of the above problems, and an object thereof is to stably manufacture a high-quality pallet with a high yield.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, when the water-repellent vegetable fiber web is passed through the aqueous solution of the thermosetting resin, the web aggregate is repeatedly degassed. Web aggregate internal of For the purpose of impregnating the inside of the plant fiber web with a thermosetting resin while exhausting the air completely, and then applying the excess impregnating liquid to the product to give micro-vent holes and the uniformity between the width direction parts. The liquid impregnated with a pinch roller and then impregnated with a thermosetting resin is subjected to low temperature heating evaporation and dehydration, and then molded into a predetermined pallet shape after dehydration. The Pre-molding and thermosetting of thermosetting resin to prevent breakage of long fibers as strength members under the first temperature condition The There is provided a pallet manufacturing method characterized in that it is performed in two stages of the main molding under the second temperature condition to be induced.
[0006]
Plant fiber webs such as coconut fiber are pressurized when passing through the thermosetting resin aqueous solution, and the air is discharged in the space between the fibers during this pressurization, and the next pressure release part The resin is sucked and impregnated. By performing this multiple times, even a fiber having water repellency can be uniformly impregnated with resin. In order to give the product functions such as ventilation, water repellency, and drying properties according to the application, the liquid impregnation amount is controlled by passing the liquid-reducing pinch roll, and the plant fiber in the final product is about 80-60 in specific gravity ratio. By setting the ratio to about%, breathability, water repellency, and drying can be imparted. After the resin impregnation, evaporative dehydration is performed in a low-temperature hot-air oven or the like, and after dehydration, the plant fiber web is preliminarily molded for the purpose of preventing fiber breakage under the first temperature condition so that the resin does not thermally cure. In the pre-molding, a series of deep grooves and concaves and convexes that serve as fork claw insertion parts are formed, and the molding is performed sequentially from the center to the outside at a temperature that does not cause thermosetting. Since it can be carried out smoothly without forcibly pulling the fiber, the long fiber can be sufficiently utilized as a strength member. Resin thermosetting after this preforming But The main formation is performed under the induced second temperature condition. In this main formation, the reinforcing auxiliary shallow groove intersecting the deep groove and the unevenness is formed, and finally formed into a highly rigid pallet. be able to. A pallet with uniform desired characteristics can be obtained without breaking long fibers or uneven thickness due to the configuration of vertical and horizontal intersecting grooves formed by two-stage forming of pre-forming and main forming. And in the pallet after shaping | molding, the product which left innumerable micropores which can perform natural drainage and early drying without producing the accumulation of rainwater in a groove part, maintaining required intensity | strength is produced. Therefore, it is necessary to appropriately set the weight ratio of the plant fiber to the resin and the molding conditions, and the weight ratio of the resin to the plant fiber is preferably about 30% so as not to exceed 40%. In addition, the force during molding is 50 to 200 tf / m ² Is preferred.
[0007]
According to invention of Claim 2, the raw material supply means of a vegetable fiber web and the thermosetting resin aqueous solution are accommodated, The heat which immerses the thermosetting resin aqueous solution in the vegetable fiber web from the said raw material supply means In passing of the curable resin aqueous solution tank and the vegetable fiber web in the aqueous solution of the thermosetting resin, Web aggregate internal of Impregnation means for impregnating the water-repellent vegetable fiber web with a thermosetting resin by pressurizing and degassing the web aggregate a plurality of times for the purpose of discharging air to the outside, and a liquid reducing means by a pinch roller , Dehydration means for heat evaporation dehydration of web impregnated with thermosetting resin, and thermosetting resin thermosetting resin fiber web after dehydration The Means for preforming for the purpose of preventing breakage of the long fiber under the first temperature condition that does not cause the thermosetting resin to heat the preformed vegetable fiber web The There is provided a pallet manufacturing apparatus characterized in that it is constituted by means for performing a main molding under a second temperature condition to be induced.
[0008]
The action and effect of the invention of claim 2 will be explained. By applying the pressure while discharging the air between the fibers in the thermosetting resin aqueous solution to the plant fiber web a plurality of times, the resin is put between the plant fibers having water repellency. By impregnating, and subsequent two-stage molding consisting of liquid reduction, dehydration, pre-molding and main molding, the rainwater pool in claim 1 and the groove can be drained naturally and dried quickly, and the long fibers are not broken. A highly rigid pallet can be obtained.
[0009]
According to a third aspect of the invention, in the second aspect of the invention, the impregnation means is a series of pressure roller pairs spaced apart to press the plant fiber web in a thermosetting resin aqueous solution tank. There is provided a pallet manufacturing apparatus comprising:
[0010]
The action and effect of the invention of claim 3 will be explained. In the thermosetting resin aqueous solution tank, the plant fiber web is alternately subjected to a pressurization and release action by a series of pressure roller pairs at intervals, and at the time of pressurization. The degassing in the vegetable fiber web is performed, and the resin is sucked by the elastic return of the fiber when released. By such alternate degassing and resin suction, sufficient impregnation of the resin in the whole plant fiber web can be realized.
[0011]
According to the invention described in claim 4, in the invention described in claim 2, the impregnation means is composed of a porous press means for pressurizing the plant fiber web in the thermosetting resin aqueous solution tank. A pallet manufacturing apparatus is provided.
[0012]
The operation and effect of the invention of claim 4 will be described. The plant fiber web is pressurized by the porous press means in the thermosetting resin aqueous solution tank, and degassed in the plant fiber web a plurality of times while degassing the plant fiber web. It is possible to impregnate the resin.
[0013]
According to the invention of claim 5, the claim 3 or 4 The pallet manufacturing apparatus is characterized in that the liquid reduction and equalization pinch roller pair includes a deflection preventing means.
[0014]
The action and effect of the invention of claim 5 will be explained. By providing the pinch roller for liquid reduction with a deflection preventing means such as a shoe or a backup roller, the vegetable fiber web can be evenly pressed in the width direction, It can contribute to the uniform impregnation of the resin in the whole plant fiber web. In addition, it is possible to cope with changes in the impregnation rate and the raw fabric thickness by adjusting the gap.
[0015]
According to a sixth aspect of the present invention, in the second aspect of the present invention, the dewatering means comprises a tunnel type hot air drying furnace provided with a temperature equalizing means by forced ventilation. A manufacturing apparatus is provided.
[0016]
The operation and effect of the invention of claim 6 will be described. The plant fiber web impregnated with resin is introduced into a tunnel type hot air drying furnace, and is heated by a heated air flow while passing through the furnace. Because it is constantly ventilated and the furnace temperature is equalized, the residence time can be extended in a temperature range several tens of degrees lower than the resin curing temperature range, and a sufficient amount of steam can be discharged. Thus, ideal heat dehydration can be performed.
[0017]
According to a seventh aspect of the present invention, in the second aspect of the present invention, the preforming means uses a press die to form a plurality of deep grooves and irregularities parallel to the plant fiber web at intervals in the first direction. A pallet manufacturing apparatus is provided in which the shape is preformed before the main forming.
[0018]
The operation and effect of the invention of claim 7 will be explained. Although the pre-molding is performed by a press mold, the mold remains in a temperature range that does not substantially cure, so that the uncured soft fiber is cut or unevenly cut. A plurality of deep grooves and concavo-convex shapes can be formed in the longitudinal direction or the width direction without raising them, and these deep grooves function as an insertion space for a load receiving arm (fork) in a forklift as in Japanese Patent Laid-Open No. 6-270938. Can be made.
[0019]
According to an eighth aspect of the present invention, there is provided a pallet manufacturing apparatus according to the seventh aspect, wherein the press die is configured to sequentially process a plurality of deep grooves.
[0020]
The operation and effect of the invention of claim 8 will be described. By sequentially carrying out the processing of the deep groove and the concavo-convex shape, the fibers are not forcedly strained and uniform molding can be performed.
[0021]
According to the ninth aspect of the present invention, in the seventh aspect of the present invention, the main forming means is spaced by a press die in a second direction intersecting the first direction on the plant fiber web. A pallet manufacturing apparatus is provided in which a plurality of parallel shallow grooves and concavo-convex shapes are preliminarily formed while pulling the original fabric one after another without difficulty.
[0022]
The operation and effect of the invention of claim 9 will be explained. In the main molding, the mold heats and holds the resin in the curing temperature range, but the mold is for deep groove main molding and shallow groove simultaneous molding, and the groove shape Grooves can be formed after resin curing time after molding, and the rigidity in the cross direction is reinforced by forming shallow grooves that intersect with deep grooves, and for the average load generally required for pallets as distribution products It is possible to provide a strength that can be sufficiently tolerated.
[0023]
According to a tenth aspect of the present invention, there is provided the pallet manufacturing apparatus according to the second aspect, further comprising trimming means for the vegetable fiber web after the main forming.
[0024]
The operation and effect of the invention of claim 10 will be described. The desired external dimensions can be obtained by the trimming means. The trimming means is configured, for example, as a work clamper device having two circular saw heads, a rotary table that reciprocates 90 °, and a joint portion that can swing 90 °. Can be reduced and work efficiency can be improved. Although not shown in the figure, there is a system in which two double-headed circular saws are arranged in an L shape and a rotary table is not required, and a forward → 90 ° lateral feed → trimming is completed.
[0025]
According to the eleventh aspect of the present invention, there is provided a pallet manufacturing apparatus according to the second aspect, further comprising means for deodorizing and curing the plant fiber web after the main molding. .
[0026]
The action and effect of the invention of claim 11 will be described. The deodorizing and curing means is configured to accommodate the plant fiber web after the main molding, for example, in multiple stages, and performs heating with warm air while ventilating. Can be configured. Thereby, the use is expanded, such as being suitable for foods that dislike odors.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2, the pallet manufacturing apparatus of the present invention includes a material supply unit 10, a resin impregnation unit 11, a liquid reduction and equalization unit 12, a heating and dehydration unit 14, a preforming unit 16, and a main molding unit 18. A trimming unit 20, a deodorizing and curing unit 22, an inspection unit 24, and a packing unit 26.
[0028]
FIG. 3 shows an embodiment of a detailed configuration from the material supply unit 10 to the resin impregnation unit 11 and the liquid reduction and homogenization unit 12. In the material supply unit 10, 28 represents miscellaneous plant fibers such as coconut shells. The roll of the vegetable fiber web obtained by defibration after crushing and grinding is shown, and the vegetable fiber web roll 28 is supported by the support shaft 30-1 of the support table 30. The vegetable fiber web 32 drawn out from the roll 28 is supplied to the resin impregnation unit 11.
[0029]
The resin impregnating unit 11 includes a compression deaeration roller 34 and a drawing roller 36 as a series of pressure roller pairs spaced apart from the thermosetting resin aqueous solution tank 33, and the liquid reducing and uniforming unit 12 includes a pair of excessive pressure rollers. An impregnation liquid draining pinch roller 38 is provided. The tank 33 contains an aqueous phenol resin solution as a thermosetting aqueous solution. Three pairs of compression deaeration rollers 34 (more may be installed if necessary) are illustrated, and the plant fiber web 32 is nipped between the three pairs of compression deaeration rollers 34 and is transferred to the thermosetting resin aqueous solution tank 33. It advances in the accommodated polyphenol resin aqueous solution. By being nipped between the rollers 34, the web 32 is pressurized from both sides, the air between the plant fibers constituting the web 32 is pushed out (degassed), and when released from the rollers 34, the web 32 is caused by the elasticity of the fibers. The resin is impregnated into the web 32 in an attempt to return to the original state. By providing a plurality of pairs of rollers 34, a series of actions of pressure degassing and resin impregnation is repeated a plurality of times, and the plant fiber web can be uniformly impregnated with phenol resin or the like.
[0030]
The web 32 after being impregnated with the resin is pulled up from the aqueous resin solution by the drawing roller 36, and the liquid is reduced and made uniform by the over-impregnating liquid removing pinch roller 38 in the liquid reducing and uniformizing unit 12. As shown in FIGS. 3 and 4, the pinch roller 38 is supported by the bearing member 42 fixed to the support frame 40 at the shaft portions 38-1 at both ends. Of the bearing member 42, the bearing member 42 that pivotally supports the upper pinch roller 38 is connected to a screw-type adjusting member 43. A plurality of shoes 44 are provided at intervals along the axis of the roller 38, and each shoe 44 is provided in a curved shape so that the inner periphery thereof contacts the outer periphery of the roller 38 in the predetermined angle range. Each shoe 44 in contact with the upper pinch roller 38 among the shoes 44 is connected to a screw-type adjusting member 46.
[0031]
As the plant fiber web 32 passes through the pinch roller pair 38, excess resin is pressurized and reduced. The pressure reduction amount is adjusted by adjusting the distance between the upper pinch roller 38 and the lower pinch roller 38 by adjusting a screw type adjusting member 43 shown in FIG. By adjusting with the type | formula adjustment member 46, the bending (warp) of the pinch roller 38 can be prevented and the web 32 can be pressurized uniformly in the width direction. On the other hand, FIG. 5 schematically shows the state of the pinch roller during pressing of the web 32 when the shoe 44 is not provided, and the pinch roller 38 has a larger deflection δ as the distance from the bearing portion increases. Further, the thickness of the web 32 at the center of the pinch roller 38 is larger than that at both ends, and the liquid removal of the web 32 becomes uneven at both ends and the center, and a pallet of the desired quality may not be obtained. was there. However, as shown in FIGS. 3 and 4, in the configuration of the first embodiment of the present invention, shoes 44 are provided at intervals in the axial direction of the pinch roller 38, and the positions of the shoes 44 with respect to the support frame 40 are adjusted members. 46 can be adjusted independently. Therefore, it is possible to prevent the pinch roller 38 from being bent regardless of the position on the axis, and correct the web to be pressed between the pinch rollers 38 with a uniform thickness in the width direction. Although there is a method in which a counter roller having the same diameter and the same rigidity is added to prevent the pinch roller from being bent, the addition of the counter roller having the same diameter and the same rigidity can only suppress the bending to ½. Increasing the diameter can reduce the deflection, but is expensive. In order to prevent bending with the shoe 44, contact friction with the pinch roller 38 is unavoidable, but the required peripheral speed of the pinch roller 38 in accordance with the molding process in the subsequent process is at most 2 to 3 m / min, and it is sufficient to handle with slipping. Is possible. Since the shoe and its back are fixed, it may be heavy. Therefore, as shown in the figure, if supported by the frame structure 40 of the press, the relief deflection of the pinch roller 38 can be reduced to 1/10 or less, the specific gravity of the impregnating resin is aimed at 30%, and the resin density in the width direction is It is possible to improve the uniformity system.
[0032]
FIG. 6 shows a detailed configuration from the material supply unit 10 to the resin impregnation unit 11 as another embodiment. In the material supply unit 10, the plant fiber web is configured as a sheet 32 ′ instead of a roll as shown in FIG. 3. Is done. The vegetable fiber web sheets 32 ′ are stacked on the support base 200, pulled out one by one, and sent to the resin impregnation unit 11. The resin-impregnated portion 11 is configured as a perforated press means and includes a pair of perforated pressure plates 202, which are driven by a piston rod 206 of a cylinder 204. That is, the porous pressure plate 202 is connected to the piston rod 206 of the corresponding hydraulic cylinder 204, and the cylinder member 204 is configured so that the sheet material 32 ′ in the phenolic resin aqueous solution is repeatedly pressed between the pair of porous pressure plates 202. It is controlled appropriately. In FIG. 6, the porous pressure plate 202 shows a state where the sheet material 32 ′ is being pressed in the left half. The air in the sheet material 32 ′ is discharged from the opening of the porous pressure plate 202 by the pressure between the porous pressure plates 202, and the pressure of the sheet material 32 ′ between the pressure plates 202 is released to release the sheet material 32. Impregnation of phenol resin into ′ is performed. Such pressure-release is repeated a plurality of times, and the cylinder 204 is controlled so that the porous pressure plate 202 is lifted from the polyphenol resin aqueous solution and the pressure is released after impregnation with a desired amount of resin. In FIG. 6, the porous pressure plate 202 shows a state in which the sheet material 32 'is pulled up from the resin aqueous solution in the right half and the pressure is released. Thereafter, the sheet material 32 ′ is pulled out by the roller pair 36, and excess resin is pressure-reduced between the pinch rollers 38 having the shoes 44 in the liquid reducing and uniformizing section 12. It is the same as that of the case of the continuous sheet material in FIG. 3 which shows embodiment.
[0033]
FIG. 7 shows an example of a detailed configuration of the heating and dehydrating unit 14, which is configured as a tunnel-type hot air drying furnace, and the plant fiber web 32 after liquid reduction is introduced into the tunnel-shaped drying chamber 49. A conveyor belt 50 for conveying the web 32 is provided in the chamber 49, and a pulley 51 (preferably a spring float or the like) for adjusting the tension of the conveyor belt 50 is provided. The web 32 is transferred on the conveyor 50 and is dried by hot air. The hot air drying furnace includes a pair of heating heads 52 that are spaced apart in the longitudinal direction, and each heating head 52 includes a gas burner on a side surface (not shown) of the figure (the back side of the paper surface of FIG. 7). A duct 54 is provided, and the hot air introduced into the duct 54 is caused to flow in the direction of an arrow by a fan and circulate in the chamber 49. Further, an exhaust port 56 is provided on the upper surface side at both ends of the chamber 49, and water vapor generated by dehydration from the web is discharged from a fan provided in the exhaust port 56. On the other hand, air blowing ports 58 and 60 are provided on both upper and lower end surfaces, and fresh air is replenished into the chamber 49 by the fans provided at the air blowing ports 58 and 60. In order to heat the air circulating in the chamber 49, a part of the air in the chamber 49 is introduced into the duct 54 and heated by the flame of the burner, and the heated air is blown out from the duct 54 and returned to the chamber 49. Further, a swing damper 62 is provided near the inlet and outlet of the duct 54, and a swing damper 64 is also provided on the lower surface side of the conveyor belt. By adjusting the opening degree of these dampers 62, 64, the inside of the chamber can be adjusted. The temperature of the hot air is controlled to an appropriate temperature (130 ° C. in the case of phenolic resin) that is considerably lower than the thermosetting temperature of the phenolic resin impregnated in the vegetable fiber web 32, and a large amount obtained by heating and dehydrating the web 32. The steam is discharged from the exhaust port 56 as shown by the arrow. As a result, the web 32 can be dehydrated while the plant fiber web 32 passes through the chamber 49 at a low speed (the furnace length is 20 to 30 meters and the transit time is 8 to 12 minutes). If the furnace length is 30 meters, the necessary expansion / contraction allowance due to thermal expansion is approximately 40 mm, but the thermal expansion is absorbed regardless of the long furnace length. The entire furnace is placed on a seat plate 66 that is free from thermal expansion. That is, it is possible to absorb the large thermal expansion as described above by fixing the leg part only at one place and by making the other support part slip freely. In order to keep the temperature in the furnace, the furnace is preferably affixed with a heat insulating material, and a radiant heat reflecting plate 68 can be provided in the main part.
[0034]
FIG. 8 shows a heat dehydration unit 14 according to another embodiment. In this embodiment, the furnace length is short (about 10 m), the moisture is relatively small, and it is suitable for drying an object having a wide curing temperature range. That is, only one heating head 52 is provided, and hot air heated by a burner (not shown) is applied to the web 32 on the conveyor belt 50, and dehydration and drying are performed while discharging water vapor from the discharge ports 56 at both ends. .
[0035]
As shown in FIG. 1, a preforming section 16 is provided downstream of the heating and dehydrating section 14, and the preforming section 16 forms a large number of deep grooves and uneven shapes on a resin-impregnated vegetable fiber web 32 after drying as a workpiece. The deep groove functions as a fork insertion space in the pallet as described in JP-A-6-270938. Preliminary molding is performed in a temperature range that does not cause curing of a binder resin such as a phenol resin. FIG. 9 shows a first specific configuration of the preforming portion 16, which is composed of a fixed female die 70 and a series of sequential push-in male dies 72. The male mold 72 is connected to a driving cylinder 74, and the male mold 72 is sequentially driven from the center toward both ends by a predetermined sequence. That is, as shown in the left half of FIG. 9, before starting molding, the cylinder 74 is controlled so that all the male dies 72 are retracted, and when molding is started, as shown in the right half of FIG. In the center, the first male mold 72 is lowered toward the female mold 70, and one deep groove or one hole recess is formed in the plant fiber web 32. After molding by the first male mold 72 at the center, the second male mold 72 outside is driven to form a second deep groove or a recessed hole, and then the third male mold 72 is driven. A deep groove or a recessed hole is formed by sequentially driving the mold 72. In such a sequential formation process, the temperatures of the molds 70 and 72 are controlled so as to be maintained in a temperature range appropriately lower than the curing temperature of the resin. A plurality of deep grooves or concave holes parallel to the longitudinal direction or the width direction can be formed while sequentially sliding the sheet 32 sideways without causing fiber cutting or uneven thickness by sequential molding under a temperature condition less than the resin curing temperature. it can. For example, assuming an example in which five grooves having a depth of 70 mm are provided in the longitudinal direction, the length of the cloth in the longitudinal direction is 70 × 5 (pieces) × 2 (walls) ÷ 2 ≠ 350 mm. Although it is impossible to perform simultaneous molding, it can be realized by the sequential male mold 72 as shown in FIG.
[0036]
FIG. 10 shows another embodiment of the preliminary forming portion 16, and in this embodiment, a simultaneous molding male mold 76 is used instead of the sequential pushing male mold 72 as shown in FIG. 9. In this embodiment, the male molds 76 are driven simultaneously, but each mold 76 is provided with a push pin 78 in a float manner by a spring or cylinder (not shown). The push pins 78 are successively higher at the center and lower toward the both sides. For this reason, the push pin 78 of the central male die 76 is first brought into contact with the simultaneous driving of the die 76, the central groove is formed, and when the formation is completed to the lowest end, the push pin 78 is spring or Next, the outer push-in pins 78 are molded against the hydraulic pressure, and the push-pins 78 are sequentially moved back against the spring or the hydraulic pressure. Concavity and convexity are formed. In this embodiment, there are concerns about some problems such as breakage of the pin and resin encapsulation in the gap, but it is possible to form deep grooves and recessed holes without causing fiber cutting or uneven thickness as in the embodiment of FIG. It is what. In addition, it can also serve as this shaping | molding.
[0037]
In the next main forming portion 18, the shallow groove for reinforcement is formed simultaneously with the main forming of the deep groove in a temperature range in which the resin (phenol) is cured. The shallow groove is formed by the preforming portion 16 and is formed in a direction intersecting with the deep groove functioning as a fork insertion space, and at the same time, the phenol resin is cured. That is, the deep groove formed by preforming in the shape of the pallet 83 as the final product shown in FIG. 14 is indicated by 80, the bottom surface of the deep groove 80 functions as the support leg 82 of the pallet, and the upper surface between the deep grooves 80 is the pallet mounting. It becomes the mounting surface 84. In the main molding, the shallow grooves 86A and 86B in the direction intersecting the deep groove 80 are formed on the upper and lower surfaces. Since the grooves 86A and 86B to be formed are shallow, they can be formed by a simple female mold and a male mold. The shallow grooves 86A and 86B can achieve a strut-like function extending between the deep grooves 80, and can impart desired rigidity to the pallet.
[0038]
The pallet after the main molding is sent to the trimming unit 20. FIG. 11 shows a first embodiment of the trimming unit 20, 83 ′ shows a pallet before trimming, and the edge portion is still formed and is not balanced. A single (single-head) circular saw head 88 is provided so as to be able to reciprocate, and the pallet 83 'after the main molding is placed on a table, and the first side of the pallet is trimmed by the reciprocation of the circular saw head 88 ( Then, the work is clamped by the clamp head 92 at the tip of the work clamper 90, turned 90 ° (process 3), and the second side is trimmed by the reciprocation of the circular saw head 88 (process 4). → 5). Thereafter, similarly, rotation of the clamp head and reciprocation of the circular saw head 88 are repeated twice (step 6 → 11) to complete trimming of the four sides of the pallet. Then, the turntable reverses by 270 ° and returns to the original position, and moves to trimming of the next pallet (step 12). That is, in this embodiment, trimming is performed in 12 steps in one cycle. The final pallet 83 after trimming is indicated by a broken line.
[0039]
FIG. 12 shows a second embodiment of the trimming unit 20, and circular saw heads 88A and 88B are provided in a pair (double-headed) on both sides. The two sides of the pallet are trimmed by reciprocating the circular saw heads 88A, 88B on both sides (Step 1 → 2), the clamp rotates 90 ° (Step 3), and the pallet is reciprocating on both sides of the circular saw heads 88A, 88B. The remaining two sides are trimmed (step 4 → 5), the clamp reverses 90 °, and returns to the original position (step 6). Therefore, this embodiment is suitable for mass production because the number of steps is halved compared with FIG. Further, since the turning and positioning are only 0 ° and 90 °, the trimming accuracy of the product is improved. Therefore, there is an effect that the defective rate can be suppressed. Although not shown, there is also a four-head trimming method in which double-headed circular saws are arranged in an L shape.
[0040]
FIG. 13 shows the detailed structure of the deodorizing and curing unit 22, and the trimmed pallet is placed on the carriage 93 in a stacked state and placed in the furnace 94. Hot air from the fan 95 as a heating source is introduced into the furnace space as indicated by an arrow, and a damper 96 is provided at the outlet of the fan 95. Openable and closable openings 97A and 97B are provided above and below the furnace. Further, the inner wall of the furnace is provided with a lining made of a radiation-type reflecting plate 98. By controlling the damper 96 and the openings 97A and 97B, an air flow can be obtained in the entire furnace utilizing the turbulence effect, preventing deterioration due to local overheating, and saving energy by improving heat insulation and heat insulation. . The treatment of the pallet 83 in the furnace 94 is performed for about 30 minutes at a temperature of, for example, 150 ° C. when the binder resin is a phenol resin, and it is possible to take all possible measures such as dehydration and deodorization and “abare” after shipment.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of an entire pallet manufacturing apparatus according to the present invention.
FIG. 2 is a schematic side view of the entire pallet manufacturing apparatus according to the present invention.
FIG. 3 is a schematic cross-sectional view showing a first embodiment of a portion from a material supply section to a resin impregnation section and a liquid reduction section of the pallet manufacturing apparatus of the present invention.
FIG. 4 is a diagram for explaining a state in which the liquid reducing portion pinch roller is restrained from being bent when the shoe of the present invention is provided.
FIG. 5 is a view for explaining a bending state of the liquid reducing portion pinch roller when the shoe of the present invention is not provided;
FIG. 6 is a schematic cross-sectional view showing a second embodiment of the portion of the pallet manufacturing apparatus according to the present invention from the material supply section to the resin impregnation section and the liquid reduction section.
FIG. 7 is a schematic cross-sectional view of a tunnel-type heating and dehydrating unit.
FIG. 8 is a schematic cross-sectional view of a simple tunnel heating and dehydrating unit.
FIG. 9 is a schematic view of a preforming portion having a male mold of a sequential drive type with a multi-head cylinder.
FIG. 10 is a schematic view of a preforming portion having a male die with a float type push pin that is driven by a single-head cylinder.
FIG. 11 is a schematic view of a trimming unit having a single-head circular saw head.
FIG. 12 is a schematic view of a trimming unit having a double-headed circular saw head.
FIG. 13 is a schematic cross-sectional view of a deodorizing and curing unit.
FIG. 14 is a schematic perspective view of a pallet manufactured according to the present invention.
[Explanation of symbols]
10 ... Material supply section
11 ... Resin impregnation part
12 ... Liquid reduction uniformizing section
14 ... Heat dehydration section
16 ... Preliminary molding part
18 ... Main forming part
20 ... Trimming part
22 ... Deodorization curing unit
24 ... Inspection Department
26 ... Packing part
28 ... Plant fiber web roll
33 ... Plant fiber web
34. Compression deaeration roller
36 ... Drawer roller
38 ... Over-impregnating liquid draining pinch roller
42. Bearing member
43 ... Adjustment member
44 ... Shoe
49. Drying chamber
50 ... Conveyor belt
52 ... Heating head
62, 64… Swing damper
70 ... fixed female mold
72 ... Sequential push male type
76 ... Simultaneous molding male mold
78 ... Sequential push pin
80 ... Deep groove
83 ... pallet
86A, 86B ... Shallow groove
88 ... Circular saw head
92 ... Clamp head
93 ... cart
95 ... Fan
96 ... Damper

Claims (11)

In a pallet manufacturing method that uses a web that has been matted with long fibers to effectively utilize the long fibers as strength members, not as a material for increasing the length of fibers shortened by crushing, etc., the vegetable fiber web is water-soluble. when passing the aqueous solution of the sex thermosetting resin, a water-soluble heat within the plant fiber web by a plurality of times pressurized degassing said web assembly in order to discharge the web assembly inside air to the outside In order to sufficiently impregnate the curable resin and leave the fine ventilation holes, the excess impregnating liquid is reduced to a suitable impregnating liquid ratio and passed through a pinch roller for the purpose of equalizing the impregnation ratio between the width direction parts. later then web impregnated with a thermosetting resin evaporates dehydrated by low-temperature heating, long fiber of the molding to a predetermined pallet shape after dehydration at a first temperature condition which does not cause thermal curing of the thermosetting resin Stamping pallet manufacturing method is characterized in that to carry out at two stages of the molding at the second temperature condition to induce thermoset preform and a thermosetting resin of preventing breakage. A raw material supply means for a vegetable fiber web, a thermosetting resin aqueous solution tank for containing a thermosetting resin aqueous solution, and dipping the thermosetting resin aqueous solution in the vegetable fiber web from the raw material supply means, and a thermosetting resin upon passage of the plant fiber web in an aqueous solution of thermosetting within the plant fiber web by a plurality of times pressurized degassing said web assembly in order to discharge the web assembly inside air to the outside The impregnation means for impregnating the resin and the excess impregnation liquid were reduced for the purpose of providing a microscopic space for imparting air permeability, and the thermosetting resin was impregnated after passing through a pinch roller for equalizing the impregnation rate of each part. Dehydrating means for performing low temperature heating evaporation dehydration of the web, means for preliminarily molding the dehydrated plant fiber web to cope with the unevenness of the product shape under the first temperature condition that does not cause thermosetting of the thermosetting resin, Molded Pallet manufacturing apparatus characterized by a vegetable fiber web is composed of a means for the molding at a second temperature condition for raising the thermal curing of the thermosetting resin. The invention according to claim 2 is characterized in that the impregnation means comprises a series of pressure roller pairs spaced apart for pressure degassing the vegetable fiber web in the thermosetting resin aqueous solution tank. Pallet manufacturing equipment. 3. The pallet manufacturing apparatus according to claim 2, wherein the impregnating means comprises a perforated plate pressing means for pressurizing and deaerating the vegetable fiber web in the thermosetting resin aqueous solution tank. 5. The pallet manufacturing apparatus according to claim 3 or 4, comprising a pinch roller provided with a deflection preventing means for reducing the excess liquid and making the impregnation uniform after the pressure deaeration device for impregnation. . 3. The pallet manufacturing apparatus according to claim 2, wherein the dehydrating means is composed of a tunnel-type hot air drying furnace provided with temperature equalization by forced ventilation and moisture exclusion means. The invention according to claim 2 is characterized in that the preforming means is configured to form a plurality of deep grooves and concavo-convex shapes parallel to the plant fiber web at intervals in the first direction by a press die. Pallet manufacturing equipment. 8. The pallet manufacturing apparatus according to claim 7, wherein the press die is configured to sequentially process a plurality of deep grooves and uneven shapes. The invention according to claim 7, wherein the main forming means includes a plurality of shallow grooves parallel to the plant fiber web spaced apart in a second direction intersecting the first direction by a press die. A pallet manufacturing apparatus characterized by being formed simultaneously with molding. 3. The pallet manufacturing apparatus according to claim 2, further comprising trimming means for the vegetable fiber web after the main molding. 3. The pallet manufacturing apparatus according to claim 2, further comprising means for deodorizing and curing the plant fiber web after the main molding.

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