JP5909321B2 - Food conveyor belt - Google Patents

Description

  The present invention relates to a conveyor belt for transporting food used for transporting food and a method for manufacturing the same.

  Conventionally, a conveyor belt for transporting food is known in which layers of a polyurethane resin are laminated on both sides of a polyester base fabric (core body) using a T-die extruder or the like. However, since polyurethane resin has a low melting point, there is a disadvantage that the conveyor belt cannot be washed and sterilized by steam at 120 ° C. For this reason, cleaning in two stages of cleaning with steam at 80 ° C. and cleaning with hypochlorous acid was necessary. Polyurethane resins are poor in oil resistance and are liable to deteriorate due to swelling when in contact with oil.

  Conventionally, a polyurethane belt in which a steel core wire is embedded in a belt body made of polyurethane and the steel core wire is treated with an adhesive made of an aqueous polyurethane emulsion containing an aromatic isocyanate is known (patent) Reference 1).

JP 2005-315317 A

  The present invention has been made in view of such circumstances, and an object thereof is to provide a food conveying conveyor belt excellent in heat resistance, chemical resistance and oil resistance and a method for producing the same.

A conveyor belt for food conveyance according to the present invention includes a woven fabric made of polyester fibers, a base fabric made of a polyester elastomer layer formed on both sides of the woven fabric, and a polyvinylidene fluoride resin layer formed on both sides of the base fabric And an adhesive layer made of a silane coupling agent disposed between the polyester elastomer layer of the base fabric and the polyvinylidene fluoride resin layer, and the woven fabric made of the polyester fiber is impregnated with a PET emulsion resin. The liquid absorption is suppressed .

  ADVANTAGE OF THE INVENTION According to this invention, the conveyor belt for food conveyance excellent in heat resistance, chemical resistance, and oil resistance, and its manufacturing method can be provided.

Explanatory drawing of the endless food conveyance conveyor belt which concerns on the Example of this invention.

Hereinafter, the food conveyor belt according to the present invention will be described in more detail.
In the present invention, as described above, a polyester elastomer layer as a PET elastomer having a high heat resistance temperature is formed on both surfaces of the woven fabric. Therefore, it can withstand 120 ° C. steam cleaning. Moreover, since the polyvinylidene fluoride resin (PVDF) layer is formed on both surfaces of the base fabric, it has oil resistance and can withstand steam cleaning at 120 ° C. Furthermore, although the polyester elastomer layer and the PVDF layer lack the adhesive force for direct connection, a strong adhesive force can be obtained by interposing a silane coupling agent therebetween.

  Here, as the silane coupling agent, the functional group is an epoxy group, amino group, isocyanate group, vinyl group, styryl group, ureido group, mercapto group, sulfide group, preferably the functional group is an epoxy group. , A silane coupling agent which is an amino group or an isocyanate group.

  In the present invention, in order to obtain an endless belt from the belt base sheet, the end portions of the belt base sheet are placed between the lower and upper boards of the heating / pressing press apparatus, and the sheets are melted by heating. It is necessary to unify the clothes. Here, as the heating means, resistance heating using a sheath heater or the like, high-frequency heating, dielectric heating, induction heating, or the like is used, but is not limited thereto, and it is sufficient if the belt base sheet can be heated to a predetermined temperature. .

  In the present invention, the thickness of the woven fabric and the polyester elastomer layer as the core material constituting the food conveyor belt is from the viewpoint of strength and flexibility, the thickness of the adhesive layer is from the viewpoint of adhesive strength, and further, polyvinylidene fluoride. The elastomer layer is preferably set in an appropriate range from the viewpoint of oil resistance and flexibility.

  In the present invention, “non-liquid-absorbing treatment” means that the woven fabric is ground-treated with a PET emulsion resin so that the liquid does not absorb liquid from the cut surface of the woven fabric made of polyester fibers composed of weft and warp. Means.

Next, an endless food transfer conveyor belt according to an embodiment of the present invention will be described with reference to the drawings. Note that the present embodiment is not limited to the following description.
(Example)
Please refer to FIG. The endless conveyor belt 1 for conveying food has a woven fabric 2 in which a warp yarn 2a made of polyester fiber and a weft yarn 2b made of polyester fiber are woven. Here, the cut surface S of the weft yarn 2a and the warp yarn 2b of the woven fabric is non-absorbed (primed) by impregnating the PET emulsion resin. Polyester elastomer layers 3a and 3b are respectively formed on both surfaces of the woven fabric 2, and the woven fabric 2 and the polyester elastomer layers 3a and 3b constitute a base fabric 4. Polyvinylidene fluoride resin (PVDF) layers 6 a and 6 b are formed on both surfaces of the base fabric 4 via an adhesive layer 5, respectively. Here, as the adhesive layer 5, an epoxy silane coupling agent was used in order to ensure good adhesion between the polyester elastomer layers 3a and 3b and the PVDF layers 6a and 6b.

Next, the manufacturing method of the food conveyance conveyor belt of FIG. 1 is demonstrated.
First, a polyester elastomer sheet having a thickness of 150 μm is arranged on both sides of a woven fabric 2 having a thickness of 420 μm, and then these are pressed under heating at 200 ° C. to form a base fabric 4 comprising the woven fabric 2 and the polyester elastomer layers 3a and 3b. Got. Next, 10 μm of PVDF dispersion was applied to both sides of the base fabric 4, dried, and then fired in a temperature range of 160 to 180 ° C. to form PVDF layers 6 a and 6 b on both sides of the base fabric 4. Thereby, the belt base material sheet in which the PVDF layers 6a and 6b were formed on both surfaces of the base fabric 4 via the adhesive layer 5 was obtained. Subsequently, the belt base sheet was placed on the lower and upper panels of a heating / pressing press apparatus using resistance heating (sheath heater) as a heat source in a state where the ends of both ends of the belt base material were butted or overlapped. Furthermore, it hold | maintained under the heating temperature of 180 degreeC for 90 second, and fused the PVDF layers 6a and 6b, and integrated the endless-shaped food conveyance conveyor belt.

According to the above embodiment, since the polyester elastomer layers 3a and 3b as the PET-based elastomer having a high heat resistance temperature are formed on both surfaces of the woven fabric 2, the resulting conveyor belt can withstand 120 ° C. steam cleaning. it can. Moreover, since the PVDF layers 6a and 6b are formed on both surfaces of the base fabric 4, it has oil resistance and can withstand 120 ° C. steam cleaning. Furthermore, since the adhesive layer 5 made of an epoxy silane coupling agent is interposed between the polyester elastomer layers 3a and 3b and the PVDF layers 6a and 6b, the adhesion between the polyester elastomer layers 3a and 3b and the PVDF layers 6a and 6b is improved. It can be secured well. In fact, the adhesion strength between the polyester elastomer layers 3a and 3b and the PVDF layers 6a and 6b was 10.0 N / cm. Furthermore, since the cut surface S of the weft yarn 2a and the warp yarn 2b of the woven fabric 2 is non-liquid-absorbed with the PET emulsion resin, liquid absorption from the cut surface S can be suppressed.

(Comparative example)
The endless food conveying conveyor belt according to the comparative example is different from the conveyor belt of the example in that an adhesive layer is not used between the polyester elastomer layer and the PVDF layer. According to the food conveyor belt according to the comparative example, satisfactory adhesion between the polyester elastomer layer and the PVDF layer cannot be obtained. In fact, in the comparative example, the adhesion strength between the polyester elastomer layer and the PVDF layer was 0.5 N / cm. Moreover, even if it treated the corona surface, it was the same adhesion strength.

The case where the heat resistance, chemical resistance, and oil resistance of the food conveying conveyor belts according to the above Examples and Comparative Examples are compared will be described.
(Heat-resistant)
First, about 120 degreeC steam washing | cleaning, it judged by visually confirming the external appearance after applying a steam to a sample for several minutes using a 120 degreeC steam washing machine. Moreover, the tensile strength of the sample in each temperature environment (-30 degreeC, -20 degreeC, -10 degreeC, 0 degreeC, normal temperature, 50 degreeC, 80 degreeC, 120 degreeC) was measured about the use temperature possible range.

(chemical resistance)
Strength retention ratio after immersing the conveyor belt in a 0.25% sodium hypochlorite (NaClO) aqueous solution, a 5% sodium hydroxide (NaOH) aqueous solution, and a 30% sulfuric acid solution at 40 ° C. for 400 hours ( %) Was measured to determine the chemical resistance of the sample.

(Oil resistance)
Edible oil was put into a sample molded into a ship shape, and the weight change (%) of the sample after 120 ° C. × 24 hours was measured.

  In the above-described embodiment, the case where a silane coupling agent having an epoxy group (epoxy silane coupling agent) is used as an adhesive is described. However, the present invention is not limited thereto, and a silane coupling having an amino group or an isocyanate group is used. An agent may be used. When a silane coupling agent having an amino group or an isocyanate group was used, the adhesion strength between the polyester elastomer layer and the PVDF layer was 5.0 N / cm. Further, the PVDF layer can be formed after the surface of the polyester elastomer layer is subjected to plasma treatment.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.
Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1]
A woven fabric made of polyester fiber, a base fabric made of a polyester elastomer layer formed on both sides of the woven fabric, and
A polyvinylidene fluoride resin layer formed on both sides of the base fabric;
An adhesive layer composed of a silane coupling agent disposed between the polyester elastomer layer of the base fabric and the polyvinylidene fluoride resin layer;
A conveyor belt for food conveyance, wherein the woven fabric made of polyester fiber is non-absorbed.
[2]
The conveyor belt for food conveyance according to [2], wherein the silane coupling agent is any one of an epoxy group silane coupling agent, an amino group silane coupling agent, and an isocyanate group silane coupling group.
[3]
A step of forming a base fabric by pressurizing a polyester elastomer layer under heating on both sides of a woven fabric made of polyester fibers, a step of non-absorbing the base fabric with a PET emulsion resin, and both sides of the base fabric And a step of forming a polyvinylidene fluoride resin layer by applying a polyvinylidene fluoride dispersion to the substrate, drying and firing the product.
[4]
After applying an epoxy-based silane coupling agent on both sides of the base fabric and drying to form a polyvinylidene fluoride resin layer, applying a polyvinylidene fluoride dispersion on both sides of the base fabric, drying and firing The method for producing a conveyor belt for conveying food according to [3], which is characterized by the following.

  DESCRIPTION OF SYMBOLS 1 ... Conveyor belt for food conveyance, 2 ... Woven cloth, 2a ... Warp yarn, 2b ... Weft yarn, 3a, 3b ... Polyester elastomer layer, 4 ... Base fabric, 5 ... Adhesive layer, 6a, 6b ... Polyvinylidene fluoride resin layer.

Claims (2)

A woven fabric made of polyester fiber, a base fabric made of a polyester elastomer layer formed on both sides of the woven fabric, and
A polyvinylidene fluoride resin layer formed on both sides of the base fabric;
An adhesive layer composed of a silane coupling agent disposed between the polyester elastomer layer of the base fabric and the polyvinylidene fluoride resin layer;
A woven fabric made of polyester fiber is impregnated with a PET emulsion resin to suppress liquid absorption , a food conveying conveyor belt.   The food conveyor belt according to claim 1, wherein the silane coupling agent is one of an epoxy group silane coupling agent, an amino group silane coupling agent, and an isocyanate group silane coupling group.

Images