WO2012172450A1

WO2012172450A1 - Reticular endless conveyor belt

Info

Publication number: WO2012172450A1
Application number: PCT/IB2012/052728
Authority: WO
Inventors: Federico SEGURA RODA
Original assignee: Esbelt, S. A.
Priority date: 2011-06-17
Filing date: 2012-05-31
Publication date: 2012-12-20
Also published as: ES2396390A1; ES2396390B1; EP2720963A1

Abstract

Reticular endless conveyor belt (1), of the type able to be coupled to a closed-loop conveyor device, formed by one or more modular sections (2) joined adjacently by their respective ends in the longitudinal direction of transport. The conveyor belt (1) is manufactured from a flexible plastic material provided with a plurality of passage holes (3) through the surface thereof. The junction area (2a) between modular sections (2) is flat and homogeneous with respect to the rest of the surface of the belt (1), thus defining a belt (1) with a continuous surface in the form of an endless ring. A reduction in the accumulation of waste, such as dirt, soil or stones, is thus achieved, facilitating elimination thereof while maintaining the drainage flow rate, as well as a reduction in maintenance and electricity consumption of the conveyor device.

Description

RETICULAR ENDLESS CONVEYOR BELT

The present invention relates to a reticular endless conveyor belt. It is applied particularly to the processing, washing and transport of food products such as vegetables, fruit or frozen foods, as well as to drainage of liquids and screening of solid waste.

Background of the invention

Conveyor belts for washing, draining and transporting vegetables by way of a mosquito net-type reticular mesh having different passage widths, formed from monofilament polyester thread which provides certain rigidity, are known to exist in the state of the art.

In order to be able to use this mosquito net-type mesh as a conveyor belt, i.e. in order to prevent the belt from becoming detached or deformed due to working in continuous mode, a smooth reinforcement belt glued to either side made of PVC or thermoweldable polyurethane, multi-fabric and approximately 4 cm in width, is included. However, in order to be able to close this type of mesh as an endless ring, another two smooth reinforcement belts glued to the ends whereto a staple is fixed using a pin or by means of vulcanised fusion splicing. Additionally, the nature of this type of polyester mesh does not allow passage widths greater than approximately 5x5 mm, limiting use thereof to the mere filtration of liquids.

Plastic articulated modular belts, manufactured from polypropylene, polyethylene or acetal, formed by modular sections joined together by means of a pin until achieving the desired length and defining multiple articulations, are also known in the state of the art. In order to move as a conveyor belt, the driving drum of the conveyor mechanism on which it is mounted must be formed by gear wheels. Nevertheless, the existence of pins causes the belts to become saturated, blocked or broken in the presence of dirt, small stones or soil in the vegetable or fruit washing and drainage processes. This hampers the operation of the conveyor belt considerably, causing premature wear and continuous malfunctions due to breakage of some of its elements.

Screening meshes in the form of reticular belts for dry screening of damp and argillaceous aggregates, manufactured from polyurethane are also known in the state of the art. Said meshes are static and fixed by their lateral ends to a support by means of tensioning claws. Usually, said screening meshes are internally reinforced by means of metal cables disposed between the tensioning claws or transverse metal frames destined for resting upon the screen. Nevertheless, it must be noted that these types of screening meshes not designed for use as conveyor belts or for treating food.

Fibre optic or Kevlar belts for high-temperature applications are also known in the state of the art. Due to their reduced thickness and low breaking load they are destined for lightweight applications, such as shrink tunnels, thermofixing, and painting and varnishing processes, among others. In order to prevent fraying of these fibre optic meshes, the sides must be reinforced using strips of the same smooth material, approximately 25 mm in width. Their mesh-like structure is mainly due to the fact that it allows passage of heat better than a smooth surface. It is obviously not used for any type of drainage or transporting a certain weight.

Metal belts, such as steel belts, which are used mainly in applications involving extreme temperatures, high and low, in the presence of contaminating agents or chemical corrosion, are also known in the state of the art. They are applied to biscuit baking ovens, chocolate dipping machines, deep fryers, etc. Their cost is high compared with any other type of belt.

On the other hand, rigid polyurethane belts, manufactured in a single piece and completely smooth, i.e. without holes, are known in the state of the art. They are destined for transporting and handling food, mainly meat. The main characteristic of these types of belt is their rigidity and cutting resistance. Due to their smoothness, they are not used for washing or draining food. They are mainly used as an alternative to modular belts. Description of the invention The objective of the reticular endless conveyor belt of the present invention is to resolve the drawbacks of the belts or meshes known in the state of the art, providing a reticular endless conveyor belt that allow less accumulation of remains, such as dirt, soil or stones, allowing elimination thereof and maintaining the optimum drainage flow rate, as well as a reduction in the cost of the conveyor device whereto it is coupled and in maintenance costs and electricity consumption.

The reticular endless conveyor belt object of the present invention is of the type able to be coupled to a closed-loop conveyor device, formed of one or more modular sections joined adjacently by their respective ends in the longitudinal direction of transport, and is characterised in that it is manufactured from a flexible plastic material provided with a plurality of passage holes through the surface thereof, and in that the junction area between modular sections is flat and homogeneous with respect to the rest of the belt surface, thus defining a belt with a continuous surface in the form of an endless ring.

The main advantages of the conveyor belt of the invention are described below:

- Greater durability of the modular sections. The belt of the invention is homogeneous and continuous throughout its length, without articulations, projections or reinforcements, as opposed to the static screening meshes or modular articulated conveyor belts known in the state of the art. Due to the fact that the belt of the invention is formed by a single flexible body, continuous and homogeneous, it does not become blocked or break due to the accumulation of stones or soil thereupon during the drainage processes. Additionally, its flexibility helps to eliminate any small stones that may remain incrusted therein. Further, it is long lasting, up to four times that of a modular articulated belt used for the same applications as the conveyor belt of the invention.

- Cleaner and less consumption of water and time. The simple and uniform structure of the conveyor belt of the invention allows faster, simple and effective cleaning.

- Reduction in maintenance costs. On being more flexible, lighter and having less points of support or friction against the conveyor device, it does not damage or wear the structure thereof as happens in the case of more rigid and heavier belts.

- Reduction in electricity consumption. Due to its lighter weight and low friction coefficient, it requires less electricity to be moved in comparison with other, heavier articulated belts.

- It does not require gears to move, i.e. it is mounted on completely smooth driving drums.

Preferably, the plastic material comprises polyurethane with an internal reinforcement of aramid.

Polyurethane is a light, flexible material resistant to abrasion and tear. Therefore, other advantages of the belt of the invention are:

- Resistant to abrasion.

- Resistant to hydrolysis.

- Weather resistant.

- Flexible. It allows small flexing and backflexing, even at low temperatures.

- Easily replaceable. Possibility of replacing a smooth PVC o polyurethane belt known in the state of the art by the conveyor belt of the invention without modifying the conveyor device.

- No noise.

- Good performance on exposure to oils and acids. The number of breaks, malfunctions or unexpected stoppages is thus dramatically reduced. On the other hand, the structure of the conveyor device is not damaged by abrasion or wear, and also allows the belt to be easily centred and guided.

Advantageously, the conveyor belt is manufactured from a non-poisonous plastic material suitable for use with food products.

It is manufactured from polyurethane especially formulated to be completely non-poisonous, as the conveyor belt of the invention is mainly intended for handling food. According to tests carried out in an approved laboratory, it complies with EU Regulation 10/201 1 of the Commission, of 14 January 201 1 , on plastic materials and objects destined for coming into contact with food, applicable as of May 201 1. On the contrary, the polyurethane meshes for screening known in the state of the art are not designed as a product for washing and transporting food products or for use as conveyor belts.

Preferably, the passage holes have a passage width with a preferably quadrangular cross-section, of between 2x2 mm and 15x15 mm.

Therefore, the belt of the invention allows adaptation to different granulometries of solids or water flow rates. Different passage widths of up 15x15 mm can be achieved, facilitating drainage of liquids or other materials such as soil and sand when washing vegetables such as leeks and carrots.

Preferably, each modular section is approximately 15 m long and approximately 1.5 m wide.

The conveyor belt of the invention is generally manufactured from 15 m rolls, a length which can be extended by adding more modular sections by means of splicing, without altering the shape or characteristics of the belt at that junction point, up to any required length. On the contrary, the polyurethane screening meshes known in the state of the art normally have a standard length of only up to 2.5 m.

In accordance with another aspect, the invention also relates to the manufacturing method of the previously described conveyor belt, which comprises the following stages:

a) Obtaining the modular sections of flexible plastic material provided with a plurality of passage holes; and b) Joining the modular sections together to obtain an endless continuous belt, in such a manner that the junction areas are flat and homogeneous with respect to the rest of the belt surface.

Optionally, during or after stage a) in which the modular sections are obtained, a non-poisonous treatment is applied to the plastic material used.

In accordance with a preferred embodiment, stage b) in which the modular sections are joined together is carried out by means of vulcanised fusion splicing.

Advantageously, prior to vulcanised splicing, the junction areas of the modular sections are reduced in height for overlapping therebetween, while maintaining uniformity with the rest of the surface of the modular sections.

As a result, the splicing area has the same shape, size, mechanical strength and aspect as the rest of the belt, which facilitates the regular, continuous and centred operation thereof on the conveyor device.

In accordance with another preferred embodiment, stage b) in which the modular sections are joined together is carried out by means of stapling.

Preferably, said stapling is carried out using a series of staples formed by two hooking bodies, each of which is joined to an end of the modular section, and joining said hooking bodies together by means of a cross pin.

Optionally, fixing of the staple bodies to the ends of each modular section is carried out by impact or pressure. The use of staples facilitates assembly and disassembly of the belt when the structure of the conveyor device does not allow installation in the form of an endless ring. Brief description of the drawings

In order to help better understand the foregoing description, drawings are attached which, schematically and merely by way of non-limiting example, represent practical cases of embodiment of the reticular endless conveyor belt of the invention, wherein:

Figure 1 shows a cross-sectional view of the two modular sections prior to joining by means of vulcanised fusion splicing, according to a first embodiment;

Figure 2 shows a top plan view of both modular sections of figure 1 , subsequent to the vulcanised fusion splicing process;

Figure 3 shows a schematic view of the tool used to carry out vulcanised fusion splicing;

Figure 4 shows a cross-sectional view of two modular sections prior to joining by means of impact stapling, according to a second embodiment;

Figure 5 shows a top plan view of both modular sections in figure 4, subsequent to joining by means of impact stapling;

Figure 6 shows a schematic view of the impact stapling tool used to join the modular sections;

Figure 7 shows a cross-sectional view of two modular sections prior to joining by means of pressure stapling, according to a third embodiment;

Figure 8 shows a top plan view of the two modular sections of figure 7, subsequent to joining by means of pressure stapling; and

Figure 9 shows a schematic view of the pressure stapling tool used to join the modular sections. Description of preferred embodiments

In reference to figures 1 and 2, the reticular endless conveyor belt 1 of the invention, which can be coupled to a closed-loop conveyor device (not shown), is formed of one or more modular sections 2 joined adjacently by their respective ends in the longitudinal direction of transport, and is manufactured from a flexible plastic material provided with a plurality of passage holes 3 through the surface thereof.

The junction area 2a between modular sections 2 is flat and homogeneous with respect to the rest of the surface of the belt 1 , thus defining a belt 1 with a continuous surface in the form of an endless ring, as will be explained later. The plastic material used is polyurethane with an internal reinforcement of aramid. Likewise, the polyurethane is especially formulated to be completely non-poisonous, as the application of the conveyor belt of the invention is mainly intended handling food.

The passage holes 3 have a passage width with a quadrangular cross-section of for example: 2x2 mm, 4x4 mm, 6x6 mm, 12x12 mm or 15x15 mm, which adapt to different granulometries of solids or water flow rates. Therefore, different passage widths of up to 15x15 mm can be achieved, facilitating drainage of liquids or elimination of other materials such as soil and sand present when washing certain vegetables such as leeks and carrots.

According to an example, the belt 1 of the invention can be manufactured with a passage width of 6x6 mm and a weight of 3.2 Kg/m², while the screening meshes having a passage width of 6x5 mm known in the state of the art have a weight of 5.2 to 6.7 Kg/m², depending on the material, due to which the belt 1 of the invention is much lighter. The belt 1 of the invention is generally manufactured in 15 m long x 1.5 m wide rolls. Said length can be extended by adding modular sections 2 by means of splicing, without altering the shape or characteristics of the belt at said junction point, up to any required length. On the contrary, the polyurethane screening meshes known in the state of the art usually have a standard length of up to 2.5 m.

The manufacturing method of the conveyor belt 1 of the invention comprises the following stages: a) Obtaining the modular sections 2 of flexible plastic material provided with a plurality of passage holes 3; and b) Joining the modular sections 2 together to obtain an endless continuous belt, in such a manner that the junction areas 2a are flat and homogeneous with respect to the rest of the belt 1 surface. During or after stage a) in which the modular sections 2 are obtained, a non-poisonous treatment is applied to the plastic material used.

In accordance with a first embodiment of the method shown in figures 1 to 3, stage b) in which the modular sections 2 are joined to form the endless ring is carried out by means of vulcanised fusion splicing.

In this case, prior to vulcanised fusion, the junction areas 2a of the modular sections 2 are reduced in height for overlapping therebetween (see figure 1 ), while maintaining uniformity with the rest of the surface of the modular sections.

As a result, the spliced area has the same shape, size, mechanical strength and appearance as the rest of the belt, which facilitates the regular, continuous and centred operation thereof on the conveyor device.

Figure 3 shows a press 4 for carrying out vulcanised fusion splicing which includes two press heads 5, two diffuser plates 6 and a silicone mould 7. The junction area 2a of the two modular sections 2 is disposed between the two diffuser plates 6, placing the silicon mould 7 on top of said junction area 2a.

In accordance with a second embodiment of the method shown in figures 4 to 6, stage b) in which the modular sections are joined together to form the endless ring is carried out by means of impact stapling.

Stapling is carried out by means of a series of staples formed by two hooking bodies 8, each of which is joined to an end of the modular section 2, and joining said hooking bodies 8 together by means of a cross pin 9.

Fixing of the staple bodies 8 to the ends of each modular section 2 is carried out by impact using the appropriate tool 10 (see figure 6).

In accordance with a third embodiment of the method shown in figures 7 to 9, stage b) in which the modular sections are joined together to form the endless ring is carried out by means of pressure stapling.

In this case a series of staples formed by two hooking bodies 8' are also used, each of which is joined to an end of the modular section 2 and joining said hooking bodies 8' together by means of a cross pin 9'.

Fixing of the staple bodies 8' to the ends of each modular section 2 is carried out by pressure using the appropriate tool 10' (see figure 9).

The use of staples facilitates assembly and disassembly of the belt 1 when the structure of the conveyor device does not allow installation thereof in the form of an endless ring.

Therefore, a conveyor belt 1 is obtained which allows a reduction in the accumulation of waste, such as dirt, soil or stones, facilitating elimination thereof while maintaining the drainage flow rate, as well as a reduction in the cost of the conveyor device whereto it is coupled, and in maintenance and electricity consumption costs.

The applications of the conveyor belt 1 of the invention include all those wherein it is necessary to transport, rinse or drain in continuous mode, such as:

- Transport, washing and rinsing of vegetables, olives, fruit, fish, etc.

- Preparation of ready-made food such as, for example, salads.

- Desalting meat.

- Treatment of industrial grey waters in general.

The industrial sectors whereto the conveyor belt 1 of the invention can be applied are: olives, vegetable preserves, fish, and vegetable and meat processing, among others.

Claims

1. Reticular endless conveyor belt (1 ), of the type able to be coupled to a closed-loop conveyor device, formed by one or more modular sections (2) joined adjacently by their respective ends in the longitudinal direction of transport, characterised in that it is manufactured from flexible plastic material provided with a plurality of passage holes (3) through the surface thereof, and in that the junction area (2a) between modular sections (2) is flat and homogeneous with respect to the rest of the belt (1 ) surface, thus defining a belt (1 ) with a continuous surface in the form of an endless ring.

2. Belt (1 ), according to claim 1 , wherein the plastic material comprises polyurethane with an internal reinforcement of aramid.

3. Belt (1 ), according to claim 1 or 2, manufactured from a non-poisonous plastic material suitable for use with food products.

4. Belt (1 ), according to claim 1 , wherein the passage holes (3) have a passage width with a preferably quadrangular cross-section of between 2x2 mm and 15x15 mm.

5. Belt (1 ), according to claim 1 , wherein each modular section (2a) is approximately 15 m long and approximately 1.5 m wide.

6. Method for manufacturing a reticular endless conveyor belt (1 ), according to any of claims 1 to 5, characterised in that it comprises the following stages:

a) Obtaining the modular sections (2) of flexible plastic material provided with a plurality of passage holes (3); and

b) Joining the modular sections (2) together to obtain an endless continuous belt (1 ), in such a manner that the junction areas (2a) are flat and homogeneous with respect to the rest of the belt (1 ) surface.

7. Method, according to claim 6, wherein during or after stage a) in which the modular sections (2) are obtained, a non-poisonous treatment is applied to the plastic material used.

8. Method, according to claim 6, wherein stage b) in which the modular sections (2) are joined together is carried out by means of vulcanised fusion splicing.

9. Method, according to claim 8, wherein prior to vulcanised fusion, the junction areas (2a) of the modular sections (2) are reduced in height for overlapping therebetween, while maintaining uniformity with the rest of the surface of the modular sections (2).

10. Method, according to claim 6, wherein stage b) in which the modular sections (2) are joined together is carried out by means of stapling.

1 1. Method, according to claim 10, wherein stapling is carried out using a series of staples formed by two hooking bodies (8, 8'), each of which is joined to an end of the modular section (2), and joining said hooking bodies (8, 8') together by means of a cross pin (9, 9').

12. Method, according to claim 1 1 , wherein fixing of the staple bodies (8) to the ends of each modular section

(2) is carried out by impact.

13. Method, according to claim 1 1 , wherein fixing of the staple bodies (8') to the ends of each modular section (2) is carried out by pressure.