JP2001010710A - Conveyor chain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a conveyor chain capable of sufficiently preventing degrada tion due to hydrochloric acid/chlorine as compared with a conventional conveyor belt, at the same time, difficult to charge due to low surface resistivity and volume resistivity, and capable of sufficiently enduring also a dry use, reducing a coefficient of friction and improving a sliding characteristic. SOLUTION: In this conveyor chain, a conveyor chain main body 1 is constituted by chaining many top plate links 2 having flat upper surfaces to carry articles by connecting pins 3. The top plate links 2 are made chlorine water resistant polyacetal resin materials to which compound containing zinc and one kind or more compounds containing metal selected from a hydrotalcite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to an accumulate conveyor for storing, on a conveyor chain, only conveyed articles placed on a flat upper surface of a synthetic resin top plate link, or a conveyed article made of synthetic resin. Used for sorting conveyors that diverge and merge on top plate links, and also for cleaning conveyed articles and conveyor chains,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyor chain using a top plate link made of a synthetic resin, which is used in a place where chlorine water is applied or washed on a conveyor chain for the purpose of disinfection or the like.

[0002]

2. Description of the Related Art Conventionally, for example, in a conveyor chain using a top plate link made of a synthetic resin, a polyacetal resin material (POM) is generally used in terms of strength, dimensional stability, wear resistance, cost, and the like. Used in

[0003]

However, recently,
For example, to prevent mold and pathogenic Escherichia coli, cleaning and disinfection of conveyed articles and conveyor chains are performed during operation (for example, running tap water, hot water, diluted sodium hypochlorite, etc. Then, the polyacetal resin is gradually deteriorated by chlorine contained in tap water, and in particular, there is a problem that it is difficult to use the polyacetal resin in an environment having a high chlorine concentration. It became so. That is, the chlorine is present in the chlorine water in a state as shown in Table 1 below. In this case, the polyacetal resin is considered to be decomposed by an acid due to existing chlorine and oxidized by hypochlorous acid. It is believed that the degradation by acid decomposition has a greater effect. Furthermore, after a conveyor line that uses water, hot water, liquid, etc. for cleaning, disinfection, and lubrication, in an accumulate conveyor or a dry conveyor that does not use water and liquids for sorting, transport, etc. There is a problem that the chain is charged and dust and abrasion powder are attracted to and adhere to the conveyor chain. In recent years,
The speed of the line is being increased, and further reduction in friction is required for this type of conveyor chain.

[0004]

[Table 1]

Accordingly, the present invention has been made in view of the above-mentioned various circumstances, and has been developed by adding a stabilizer which exhibits a certain degree of resistance to hydrochloric acid and has little influence on physical properties. Conveyor chain using polyacetal resin material with improved chlorine water resistance.
An object of the present invention is to provide a conveyor chain that is difficult to be charged and a conveyor chain that has a small influence on physical properties and has a low coefficient of friction. In addition, the conveyor chain of the present invention can adapt to each environment when the environment is different depending on the work process, realize the performance required of each environment with the same one conveyor chain, and run these work processes continuously. The purpose is to provide a conveyor chain.

[0006]

According to the present invention, there is provided a conveyor chain in which a plurality of top plate links each having a flat upper surface for transporting articles are linked by connecting pins. The link is made of a chlorine-resistant water-resistant polyacetal resin material to which one or more metal-containing compounds selected from a zinc-containing compound and hydrotalcite are added. Further, a means for adding one or more antioxidants selected from hindered phenols and hindered amines to the polyacetal resin material to which the metal-containing compound is added is employed. Further, a means for adding a fluororesin to the polyacetal resin material to which the metal-containing compound is added is employed. Then, a means is employed in which the metal-containing compound is at least one selected from hydrotalcite, zinc oxide, zinc hydroxide and zinc carbonate containing zinc. Then, a means was employed in which a molded article made of the polyacetal resin material to which the metal-containing compound was added contained a substance having at least one of a formaldehyde-reactive amino group, an amide group, and a hydroxyl group.

[0007] In the conveyor chain according to the present invention configured as described above, the chlorine-resistant water-resistant polyacetal in which the top plate link is added with at least one metal-containing compound selected from a zinc-containing compound and hydrotalcite. By using resin material, the weight change is about 4 times or more and the tensile property retention rate is about 3 times or more as compared with the conventional one, and the surface resistivity and volume resistivity are low, and the antistatic effect is reduced. Was obtained. Furthermore, it has been found that the polyacetal resin material to which the metal-containing compound is added can obtain a lower friction coefficient by adding a fluorine resin.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The conveyor chain main body employs a plastic slat band chain (UTD type) in which a number of top plate links 2 made of chlorine-resistant water-resistant polyacetal resin material having a flat upper surface for carrying articles are connected by connecting pins 3. And the top plate width of the conveyor chain main body 1 is 82.6 mm or 114.3 mm or 1
90.5 mm, maximum allowable load 110 kgf, approximate mass 1.0 kg / m or 1.1 kg / m or 1.6 k
g / m. Then, a conveyed article is placed and conveyed on the flat upper surface of the top plate link 2 of the conveyor chain main body 1. As other plastic slat band chains, explanations by illustration are omitted, but for example, TTD type / TTDS type plus rat band chain, TTD-HH type double hinge plus rat band chain, STD type plus rat top chain , PO type, PC type, PO12-2S type plastic block chain, 50UNS uni plastic curve chain, etc.
By the way, the type, shape, size, and the like of the chain employed in the present invention can be freely determined.

The polyacetal resin material constituting the top plate link 2 is a chlorine-resistant water-resistant polyacetal resin material to which one or more metal-containing compounds selected from a zinc-containing compound and hydrotalcite are added.
Specifically, for example, the metal-containing compound is at least one selected from hydrotalcite, zinc oxide, zinc hydroxide, and zinc carbonate containing zinc. And, the range of the addition amount of the metal-containing compound component is, for example, 0.01 to 1 with respect to 100 parts by weight of the polyacetal resin.
0.0 parts by weight, preferably 0.05 to 5.0 parts by weight, particularly preferably 0.10 to 2.0 parts by weight. Further, a low friction coefficient can be obtained by appropriately adding a fluororesin to the polyacetal resin material to which the metal-containing compound has been added.

Further, one or more antioxidants selected from hindered phenols and hindered amines, and high-molecular-weight piperidine derivative polycondensates are added to the polyacetal resin material to which the metal-containing compound is added. It is. The range of the addition amount of the antioxidant component is, for example, 0.01 to 100 parts by weight of the polyacetal resin.
5.0 parts by weight.

Further, a substance having at least one of a formaldehyde-reactive amino group, an amide group and a hydroxyl group in a molded article made of the polyacetal resin material to which the metal-containing compound is added can sufficiently enhance the effects of the zinc-containing compound and hydrotalcite. It may be suitably used as an auxiliary agent for causing the expression.

[0012]

EXAMPLES Next, examples according to the present invention will be described based on a comparison between a conventional product made of a conventional polyacetal resin material and a product of the present invention having improved chlorine water resistance according to the present invention. For the chlorine-resistant water resistance, a tensile test piece was immersed in test water having a chlorine concentration of 10 ppm with hypochlorite-resistant soda, a temperature of 60 ° C. and a pH of 7 to evaluate changes in appearance, weight and physical properties with respect to the number of days of immersion. As a result, as shown in FIG. 2 (change in tensile strength retention with immersion time), FIG. 3 (change in tensile elongation retention with immersion time), and Table 2 below, the product of the present invention weighs less than the conventional product. More than 4 times change (5% decrease)
It can be seen that the tensile strength retention (95% retention) is about 3 times or more resistant.

[0013]

[Table 2]

FIG. 4 (change in tensile strength retention with immersion time), FIG. 5 (change in tensile elongation retention with immersion time) and Table 3 below show that the tensile test pieces had a chlorine concentration of 1500 pp.
m, immersed in test water with hypochlorite-resistant soda at a temperature of 60 ° C., and evaluated for changes in appearance, weight, and properties with respect to the number of days of immersion. As a result, it can be seen that the product of the present invention is more resistant to weight change and retention of tensile physical properties than the conventional product.

[0015]

[Table 3]

FIG. 6 (change in tensile strength retention according to immersion time), FIG. 7 (change in tensile elongation retention according to immersion time) and Table 4 below show that tensile test pieces had a chlorine concentration of 200 pp.
m, immersed in test water with hypochlorite-resistant soda at a temperature of 80 ° C., and evaluated for changes in appearance, weight, and physical properties with respect to the number of days of immersion. As a result, it can be seen that the product of the present application (including the fluorine-added product) has a higher resistance to weight change and retention of tensile properties than the conventional product. In particular, it can be seen that the product of the present invention is resistant to weight change and retention of tensile physical properties as compared with the conventional product even when a fluororesin is added.

[0017]

[Table 4]

The line graph shown in FIG. 8 shows the friction coefficient (μ) on the vertical axis and the name of the article placed on the flat upper surface of the top plate link 2 on the horizontal axis, and the line graph A shows the resistance according to the present invention. Top plate link 2 made of a polyacetal resin material having an improved chlorine aqueous solution (that is, a chlorine-resistant water-resistant polyacetal resin material added with one or more metal-containing compounds selected from a zinc-containing compound and hydrotalcite).
The line graph B is the average dynamic friction coefficient of the top plate link 2 obtained by adding a fluororesin to the polyacetal resin material having improved chlorine water resistance according to the present invention. On the other hand, the chlorine-resistant water-resistant top plate link 2 to which the fluororesin was added exhibited a lower friction coefficient.

Table 5 below compares the antistatic effect of a general polyacetal resin product with the product of the present invention.
Compared with general polyacetal resin material products,
It can be seen that both the surface resistivity and the volume resistivity are low, making it difficult to be charged, and having an antistatic effect. In addition, this product is
In particular, an effect equivalent to that of an antistatic polyacetal resin for antistatic purposes can be obtained.

[0020]

[Table 5]

[0021]

As described above, according to the present invention, the top plate link is made of a chlorine-resistant water-resistant polyacetal resin material to which one or more metal-containing compounds selected from a zinc-containing compound and hydrotalcite are added. Deterioration due to hydrochloric acid and chlorine can be sufficiently prevented as compared with the conventional conveyor chain, and at the same time, the surface resistivity and the volume resistivity become low, making it difficult to be charged. In other words, the conveyor chain of the present invention can adapt to each environment and realize the performance required of each environment with the same single conveyor chain, even if the environment differs depending on the work process. It becomes possible to provide a conveyor chain that can run continuously in the process. In addition, the addition of the fluororesin can sufficiently prevent deterioration due to hydrochloric acid and chlorine, and can further reduce the friction coefficient to further improve the sliding characteristics.

[Brief description of the drawings]

FIG. 1 shows a conveyor chain according to an embodiment of the present invention, wherein (a) is a plan view and (b) is a side view.

FIG. 2 is a comparative graph showing a change in retention of tensile strength with immersion time.

FIG. 3 is a comparative graph showing a change in tensile elongation retention depending on immersion time.

FIG. 4 is a comparative graph showing a change in retention of tensile strength with immersion time.

FIG. 5 is a comparative graph showing a change in tensile elongation retention depending on immersion time.

FIG. 6 is a comparative graph showing a change in tensile strength retention depending on immersion time.

FIG. 7 is a comparative graph showing a change in tensile elongation retention with immersion time.

FIG. 8 is a comparison line graph of an average dynamic friction coefficient.

[Explanation of symbols]

1: Conveyor chain 2: Top plate link 3: Connecting pin

Claims (5)

[Claims] 1. A conveyor chain in which a plurality of top plate links each having a flat upper surface for conveying an article are linked by connecting pins, wherein each top plate link is at least one metal-containing compound selected from a zinc-containing compound and a hydrotalcite. Conveyor chain characterized in that it is made of chlorine-resistant polyacetal resin material to which is added. 2. The conveyor chain according to claim 1, wherein one or more antioxidants selected from hindered phenols and hindered amines are added to the polyacetal resin material to which the metal-containing compound has been added. 3. A polyacetal resin material to which said metal-containing compound is added, wherein a fluororesin is added.
Conveyor chain as described. 4. The conveyor chain according to claim 1, wherein the metal-containing compound is at least one selected from zinc-containing hydrotalcite, zinc oxide, zinc hydroxide, and zinc carbonate. . 5. The molded article made of a polyacetal resin material to which the metal-containing compound is added contains a substance having at least one of a formaldehyde-reactive amino group, an amide group and a hydroxyl group. Conveyor chain.