JP2584419B2 - Belt with bar for food transportation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crossed belt mainly used for conveying foods containing fats and oils such as fish, meat and fried foods. This type of conveyor crossed belt is generally used to simultaneously convey food while sorting, cooking, packing, and the like on the belt.

[0002]

2. Description of the Related Art In order to prevent meandering and lateral deviation during traveling, a conventional general transport belt is provided with a crown attached to a pulley or a belt corresponding to a groove of a grooved pulley. A belt with a transport beam attached to the back of the main body is used. Also, in the case of a belt with a transport crosspiece, a thin, high and relatively hard material (for example, soft vinyl chloride or polyurethane) is used in order to effectively prevent meandering. The crosspiece is formed into a band having a predetermined cross-sectional shape by an extruder, and is welded to the back surface of the belt body at the same time as the extrusion, or is formed into a band shape, cooled, and then bonded to the belt body with an adhesive. .
Also, the polyurethane used for the crosspiece usually has a hardness of 80 °.
Based on the above (JIS-A), when used for a pulley having a small diameter, a plasticizer is added to soften the bar itself, and at the same time, the height of the bar / the top surface width of the bar (referred to as the cross-sectional flatness in the present application). Attempts have been made to reduce this.

[0003]

However, in the meandering adjustment using the pulley crown, the meandering tendency varies depending on the hardness, width, length, diameter of the pulley, and the like of the belt. There is a problem that the adjustment is time-consuming due to the large number.

Further, there is a method of continuously welding the back surface of the belt body (the surface where the belt comes into contact with the pulley) while extruding the crosspiece. In this case, if the softening point of the material is too high, it is sufficient. It is not possible to obtain a sufficient adhesive force, and there is a possibility that the cross section between the crosspiece and the back surface of the belt body may peel during use. On the other hand, when the softening point is too low, the shape of the crosspiece becomes uneven and traveling becomes unstable. Also, if the hardness of the bar is unnecessarily hard, the side of the bar will be worn due to the engagement between the bar and the pulley groove, and if it is too soft, the bar will be deformed and the meandering of the belt cannot be sufficiently prevented. .

[0005] Further, the adhesive strength can be improved by increasing the width of the upper surface of the crosspiece, but the cross-section modulus is increased, so that it becomes difficult to bend at the pulley portion. It may swell and irregularities may appear on its surface. In addition, there is a problem that the joint portion of the belt peels in a relatively short time. The term "joint part" refers to a part in which both ends of a molded belt having a fixed length are joined in order to finish the endless belt.
Further, there is a problem that an increase in the section modulus of the crosspiece increases the load on an electric motor that drives the belt. These problems become more remarkable as the space for the conveyor belt device is reduced and the diameter of the pulley is reduced due to special applications.

Therefore, there is a method of adding a plasticizer (eg, DOP) to polyurethane as a raw material of the crosspiece to soften the crosspiece in order to improve the adhesive strength of the crosspiece and reduce the bending stress. However, if the belt with the crosspiece thus manufactured is used for conveying and processing foods containing oils and fats, the plasticizer may be extracted by the oils and fats, which is preferable from the viewpoint of health and hygiene. In addition, there is a problem that the crosspiece hardens and breaks easily.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and by improving the adhesive force between a crosspiece and the back surface of a belt body, separation of a joint portion is prevented, and swelling of the belt surface is improved. An object of the present invention is to provide a belt with food crosspieces that can solve health and safety problems due to extraction of a plasticizer.

[0008]

Means for Solving the Problems In order to achieve the above object, a food-conveying belt with a crossbar according to the present invention has a hardness of 50 to 75 ° (JIS-A) and a plasticizer on the back surface of the belt body. A beam mainly made of amorphous polyurethane that does not contain is attached.

In addition, it is desirable that the amorphous polyurethane has a Vicat softening point of 60 to 100 ° C., thereby further improving the adhesive strength between the crosspiece and the belt body. It is more desirable that the Vicat softening point be 90 ° C. or lower.

[0010]

When the hardness of the amorphous polyurethane is less than 50 °, the bar is deformed to reduce the meandering prevention effect, while the amorphous polyurethane has a hardness of less than 50 °. In this case, the rigidity of the crosspiece becomes excessively large, and the crosspiece portion on the belt surface may swell, irregularities may occur, and the joint may peel off.

[0011] In the belt with food carrying bar according to claim 2, the amorphous polyurethane has a Vicat softening temperature of 60.
If the temperature is lower than 100 ° C., when the bar is welded to the back surface of the belt, solidification is delayed, and the shape of the bar is not stabilized, and there is a possibility that the bar becomes uneven. If it exceeds, the polyurethane will not melt sufficiently and the adhesive strength will be weak. For this reason, the temperature is more preferably set to 90 ° C. or lower. If the extrusion temperature is too high in order to improve the adhesive strength, the physical properties of the core may be impaired and the cover material on the belt surface may be damaged. As another method of bonding the crosspiece and the back surface of the belt main body, it is also possible to form a belt-shaped crosspiece in advance and then bond it with an adhesive. Also in this case, a similar effect is seen in the relationship between the rise of the crosspiece portion on the belt surface, the material of the crosspiece, and the cross-sectional flatness.

By using amorphous polyurethane as the material of the crosspiece, a sufficiently soft crosspiece can be obtained without containing a plasticizer. This amorphous polyurethane is extruded into a predetermined shape by an extruder, and is melt-bonded to a cross-bar mounting position on the back surface of the belt body.

[0013] Now, the above-mentioned belt with a food transport crosspiece according to the present invention, the crosspiece is fitted into a groove provided in a pulley,
By controlling the force which tries to move in the lateral direction by the height and rigidity of the crosspiece, the belt is prevented from meandering. The belt with a crossbar for food transport of the present invention improves the adhesive strength between the crossbar and the belt body by limiting the characteristics of the amorphous polyurethane used for the crossbar to a certain range, thereby preventing meandering and harmony between swelling and swelling. I'm trying.

By setting the hardness of the polyurethane used for the crosspiece to 50 ° (JIS-A) or more as described above,
Due to its rigidity, it can be securely fitted to the pulley groove, and a meandering preventing effect can be obtained. In addition, the hardness is 7
By setting it to 5 ° or less (JIS-A) or less, it has sufficient flexibility and flexibility, and even when it is used by being suspended on a small-diameter pulley, the crosspiece rises on the surface side of the belt. There is no. Further, due to its flexibility, the width of the upper surface of the crosspiece can be widened, and the adhesion between the crosspiece and the belt main body is improved. In addition, by using amorphous polyurethane, sufficient softness can be obtained without including a plasticizer, so that there is no problem in food safety and hygiene, and it is contained in food. The plasticizer is not extracted by the oil and fat, and the crosspiece is not hardened.

Further, when the polyurethane used has a Vicat softening point of 100 ° C. or less as in the belt according to the second aspect, the temperature at which the crosspieces are bonded is restricted to a certain temperature or less by the characteristics of the belt body. Nevertheless, the molten state can be sufficiently ensured, and the necessary and sufficient adhesive force between the crosspiece and the back surface of the belt can be ensured. This temperature can be reduced by the material used as the core body or by the pretreatment of the back surface of the belt body.

By setting the Vicat softening point of the polyurethane to 60 ° C. or higher, it is possible to maintain a constant cross-sectional shape until the polyurethane is extruded, melted and adhered to the back surface of the belt, and then solidified. When the Vicat softening point is lower than 60 ° C., the shape is lost before the crosspiece is fixed, and the effect of preventing meandering is reduced.

By setting the cross-sectional flatness of the crosspiece to 0.4 or less, the upper surface width of the crosspiece is made larger than the height of the crosspiece to increase the bonding area. Does not peel. Also, by reducing the height of the crosspiece, it is possible to prevent the crosspiece shape from being changed due to side wear, and to maintain the belt meandering prevention effect. By setting the cross-sectional flatness to 0.1 or more, the crosspiece does not shift beyond the pulley groove, and the meandering preventing effect can be maintained.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a belt with food carrying bars according to the present invention. FIG. 1 is a partially omitted perspective view showing a state in which a belt 7 with a food carrying bar according to the present embodiment is stretched over a pulley 5, and FIG. 2 is an enlarged view of the belt with a food carrying bar according to the present embodiment. FIG.

As shown in FIG. 1, the cross belt 7 is suspended and driven between a plurality of pulleys 5 (only one is shown). The pulley 5 is provided with a pulley groove 6 corresponding to the beam 3 of the belt 7, and the belt 77 with the beam 3 is rotated while the beam 3 of the beam 7 is fitted, so that the beam 7 with the beam runs right and left ( Meandering in the direction of arrow A).

FIG. 2 is a cross-sectional view of a belt 7 with a crossbar for conveying food according to the present embodiment.
As shown in FIG. 1, a surface layer 1, a core 2, and a bar 3 are provided from above. For the surface layer 1, a polyurethane sheet is used. The belt body 4 is formed by the surface layer 1 and the core body 2. The core 2 is usually formed by laminating one or more layers of canvas made of synthetic fibers such as polyester and nylon. The surface side of the core body 2 (the surface for transporting an object) is
Is covering. As the material of the surface layer 1, a sheet of polyurethane, soft non-plasticized vinyl chloride, or the like is usually used, and is selected according to the application. These surface layers 1 include
Due to health and safety issues, it does not contain any plasticizers that could be extracted by fats and oils. The back surface of the belt body 4 can be covered with a cover made of polyurethane or the like in the same manner as the front surface, but usually, the canvas is exposed.

The amorphous polyurethane used for the crosspiece 3 is adipic acid ester (methylpentane adipate) and MD
I (diphenylmethane-4,4'-diisocyanate) and a relatively small molecular weight (eg, weight average molecular weight = 1.34 × 105, number average molecular weight = 5.
26 × 104) and a hardness of 50 to 75 ° (JIS-A). The physical properties of the amorphous polyurethane used in the above examples are a hardness of 65 ° and a Vicat softening point of 70 ° C. as shown in Table 1 below.

[0022]

[Table 1]

The procedure for forming the food carrying cross belt 7 using these materials is as follows. First, the above-mentioned canvas is glued and laminated according to the application, and the core 2 is formed and wound into a long length. A belt body 4 was manufactured by laminating one surface of the core body 2 by melt bonding while extruding a polyurethane serving as the surface layer 1 into a sheet shape. The bar material was extruded by an extruder at the mounting position of the bar 3 on the back surface of the belt body 4 (the surface of the core body 2), and was fused and bonded to form the bar 3 integrally. As shown in FIG. 1, the dimensions of the bar 3 are such that the upper surface width A, the height H, and the lower surface width B are 10 mm, 3 mm, and 7 mm, respectively.
(Section flatness = 0.3). Regarding the cross-sectional shape of the bar 3, the cross-sectional flatness is 0.1 to 0.4.
When the cross-sectional flatness is less than 0.1, the meandering prevention effect is poor. When the cross-sectional flatness exceeds 0.5, the cross-section of the cross-section of the belt 3 rises when the transport belt 7 is used, and the unevenness is uneven. This causes problems such as cracks in the joints.

This long belt member is cut into a predetermined length, the end thereof is cut into a deep corrugated shape, and the two hands are butt-joined together (referred to as a finger joint). An endless transport belt 7 was formed. The belt 7 with a crosspiece is connected to a pulley having a diameter of 20 mmφ,
Pulley center distance 500mm, operation speed 30m / mi
n, and the results of the evaluation are shown in the column of Examples in Table 2.

COMPARATIVE EXAMPLE 1 As the material for the crosspiece 3, a conventionally used polyurethane having a weight average molecular weight of 3.43 × 105, a number average molecular weight of 6.91 and a hardness of 82 ° (JIS-A) is used. Except for the above, a transport belt was manufactured in common with the above-described embodiment,
The results of the evaluation performed in the same manner as in the examples are described in the column of Comparative Example 1 in Table 2.

Comparative Example 2 As the material of the crosspiece 3, the above-mentioned conventional polyurethane was used.
The dimensions of the crosspiece (upper surface width A, height H, lower surface width B) are each 7
A transport belt was manufactured in the same manner as in the above example, except that the width was set to 5 mm, 5 mm, and 3 mm (cross-sectional flatness = 0.7), and evaluated in the same manner as in the above example. It described in.

Comparative Example 3 As the material of the crosspiece 3, the above-mentioned conventional polyurethane was used.
The dimensions of the crosspiece (upper surface width A, height H, lower surface width B) are each 5
mm, 3 mm, and 2 mm (flatness = 0.6) except that the conveyance belt was manufactured in the same manner as in the above example, and evaluated in the same manner as in the example. The results are described in the column of Comparative Example 3 in Table 2. did.

[0028]

[Table 2]

[0029]

As is apparent from the above description,
ADVANTAGEOUS EFFECTS The belt with food crosspieces according to the present invention has the following excellent effects.

(1) Compared to a conventional belt with food carrying bars, the side surface of the bars is less worn, and the bars and the belt main body are not separated. In addition, even when used in a conveyor belt device for a small-diameter pulley, the shape of the crosspiece does not rise on the belt surface, the joint does not break, and the device can be reduced in size. Furthermore, since it does not contain a plasticizer, the plasticizer is not extracted even when used for transporting food, and there is no health or hygiene problem at all.

(2) In the belt according to the second aspect, the bar is securely welded to the back surface of the belt, and the shape of the bar becomes uniform over the entire length, so that the meandering preventing effect is sufficiently exhibited.

[Brief description of the drawings]

FIG. 1 is a partially omitted perspective view showing a state in which a belt with food carrying bars according to an embodiment of the present invention is stretched over a pulley.

FIG. 2 is an enlarged cross-sectional view showing the food-conveying barbed belt shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Surface layer 2 ... Core 3 ... Bar 4 ... Belt body 5 ... Pulley 6 ... Pulley groove 7 ... Belt with bar

Claims (2)

(57) [Claims] 1. A belt having a hardness of 50 to 75 ° on the back surface of a belt body.
(JIS-A) A crosspiece belt for food transportation, comprising a crosspiece mainly comprising an amorphous polyurethane containing no plasticizer. 2. The belt according to claim 1, wherein the amorphous polyurethane has a Vicat softening point of 60 to 100 ° C.