SE516853C2 - Conveyor belts for storage and transport of components and process for making them - Google Patents

Abstract

The invention relates to a transport tape made of polymer for storage and transport of products, which transport tape consists of an upper side, a lower side, side edges extending along the length of the transport tape and pockets, each of which is provided with a carrier surface to carry at least one product, the carrier surface being connected to the upper side by means of a wall comprising the enclosure of the pocket and, on the upper side, extending parallel to the longitudinal direction of the transport tape, with attachment surfaces for a protective cover strip to protect the products, the transport tape being provided with a coating (27) of antistatic surface treatment agent. The invention also relates to a procedure for producing this transport tape.

Description

another nina »20 25 30 5 1 6 8 5 3 __ 2 The conveyor belts are today advantageously manufactured with anti-static properties, since electrical components transported in the belt are sensitive to electrical shocks. To solve the problem of static electricity possibly charged in the belt, conveyor belts on the market have been provided with electrically conductive properties. It is important that static electricity does not occur in the belt as an electrical surge can cause damage to the products being transported, mainly electronic components.

Known conveyor belts, however, generally suffer from the disadvantage that they are expensive to manufacture. They are also often soft, which makes it difficult to handle the belts when they are to be fed into, for example, a feed machine.

Experiments have been made in which anti-static agents have been mixed directly into the polymer for the manufacture of conveyor belts. This has caused major problems, as the rigidity of the belt deteriorates while the agent leaks from the polymer.

It has been shown that plastic conveyor belts for transporting medicines and foodstuffs destroy these goods, because the goods have a plastic taste.

The object of the present invention is to provide a belt with antistatic properties, which belt is transparent for optical control, has a low manufacturing cost and can be used for transport and storage of electrical components intended for the electronics industry.

The band should also show good rigidity.

This is accomplished by a conveyor belt of the type indicated in the introduction, wherein the conveyor belt comprises layers of anti-static surface treatment agents.

By applying a layer of anti-static surface treatment agent to the strip, static electricity in the strip is prevented. This is done by conducting electricity over this layer, whereby the strip is prevented from receiving a different electrical charge than the surroundings. »Nano ansa: 20 25 30 5 16 8 5 3, _ 3 Electrical components are thus not exposed to electrical shocks in the belt. The use of such a layer with anti-static surface treatment agent results in a lower manufacturing cost of tapes with anti-static properties than is currently possible.

The elimination of the use of, for example, electrically conductive "carbon black", which is common, in the belt further means that the belt can be transparent for optical control of the details. Likewise, the lighter material allows different colorings of different bands, depending on the type of details, etc.

Since the polymer which forms the conveyor belt may be pure from other substances, the belt is still rigid, which simplifies the handling of the belt when, for example, it is to be threaded into grooves in a feeding device.

Another object of the invention is to provide a conveyor belt according to the invention according to a method.

This is accomplished by a method of making conveyor belts according to the present invention, comprising the steps of: injection molding a polymer forming a film, dividing the film into equally wide strips by means of a cutting device, heating the respective strip by means of an oven and pre-pressing each strip by means of a die pressing device. whereby the conveyor belt is produced with fi ckor.

By applying the layer with anti-static surface treatment already during the fi adjustment of the foil, the obtained foil can be cut into strips for standard widths.

The strips are then used in turn for the manufacture of conveyor belts according to the invention. These strips are cut to such a width that the strip, after compression molding, obtains the desired standard width. Thus, the foil is divided into strips, which can then be used directly for the manufacture of conveyor belts according to the invention.

By applying a layer of antistatic surface treatment agent to a film during the actual production of the film, this film being able to be used for the production of tapes according to: vase: were present invention, manufacturing steps for applying agents with anti-static properties are the actual manufacture of the conveyor belt with its axes.

The invention will in the following be described in more detail with the aid of examples of the schematics shown in the accompanying drawings, in which fi g. 1a shows a perspective view of a conveyor belt according to the invention according to a first drying example, fi g. lb shows a perspective view of the conveyor belt in fi g. la according to the section A-A, fi g. 2a shows a perspective view of a conveyor belt according to the invention according to a second exemplary embodiment, fi g. 2b shows a perspective view of the conveyor belt in fi g. 2a according to the section A-A, fi g. 3a-3b show a side view and a plan view, respectively, of a production device for the production of foil, fi g. 4a-4b show a side view and a plan view, respectively, of a manufacturing device for manufacturing conveyor belts according to the invention, and fi g. 5a-5b and fi g. 6 shows different methods of applying a layer of anti-static surface treatment agent to a plastic foil.

For the sake of clarity, for the invention no essential parts are not reproduced in the figures.

I fi g. 1a shows a perspective view of a conveyor belt 1 according to the invention according to a first embodiment. The conveyor belt 1 has a length corresponding to about ten meters.

Conveyor belts can be even longer and have different widths. Figures 1 and 2a show one end of the conveyor belt 1. Holes 2, or continuous recesses, are provided in the side portions 3 of the conveyor belt 1. not shown) in.

The conveyor belt 1 is designed with fi ckor 4. In fi ckoma, products 5 are placed for transport. Product 5 is in fi g. a pocket 6. The pocket 4 is formed by four walls 8 and a .soon »nina 20 25 30 5 1 6 8 5 3 _, 5 receiving surface 10. The walls 8 comprise insides 9, which face the product 5.

The receiving surface 10 forms a bottom 11 of the fi key 4. The battery 6 is placed against the receiving surface 10 in the 4 edge 4 in such a way that the walls 8 of the fi edge 4 enclose the tablet.

The conveyor belt 1 has an upper side 12 and a lower side 14. The receiving surface 10 is connected to the upper side 12 by means of the walls 8.

The bottom 11 forms with its side opposite the receiving surface 10, a portion of the underside 14 of the conveyor belt 1.

A protective agent 16 in the form of a cover tape 17 is shown with a section only partially shown.

The cover tape 17 can be welded or glued to fastening surfaces 20.

I fi g. 1b shows a cross section of the conveyor belt 1 in fi g. la. The edge areas 18 of the cover tape 17 are heated or welded to the fastening surfaces 20 of the upper side 12 of the conveyor belt 1. The fastening surfaces 20 extend parallel to the longitudinal direction of the conveyor belt 1.

When products 5, which are to be transported to, for example, a pick-up hall (not shown), are placed in the respective fi cka 4, the tape 17 is heated or welded according to traditional technology and known methods to the upper side 12 of the conveyor belt 1 within the area of the fastening surfaces 20. 5 to the pick-up hall, where feed units (not shown) according to the prior art provide a pick-out position for each product 5, in which the products 5 can be picked out from the respective 4 cka 4 after the cover tape 17 has been removed.

I fi g. 1b it is clearly shown that the product 5 abuts the receiving surface 10 of the wall 4 and the insides 9 of the walls 8, respectively. Since the conveyor belt 1 of a polymer is coated with a thin layer 22 of anti-static surface treatment agent on the receiving surfaces 10 and the inner sides 9 of the wall 4, the product 5 is protected from the influence of polymer. This is made possible by the fact that the product 5, when it settles in the pocket 4, is only in contact with the ana-u: nina 20 25 xn rs: »pr o A ao I« uo now 516 6853 layer 22. The layer 22 also acts as a protective layer and prevents the product 5 from being affected by the polymer.

The enlarged section HI shows the layer 22 in the wall 4 and how the product 5 abuts the inside 9 of the wall 8. The layer 22 is applied to a plastic foil 129 according to a method, which will be described in more detail below in connection with the wall. 5a-5b and fi g. The plastic film 129 is made of polystyrene (PS), styrene / butadiene block copolymer (S / B / S), polystyrene, styrene / butadiene block copolymer and polystyrene, acrylonitrile-butadiene-styrene (ABS) and styrene-acrylonitrile ( SAN).

The bottom 11 of the wall 4 is intact and together with the cover tape 17 and the walls 8 forms a closed space. The cover tape 17 thus protects the product 5 in this room against dirt and moisture during transport. Since the conveyor belt 1 is transparent, the product 5 can be identified without the need for an inspection hole.

Extending in the longitudinal direction of the conveyor belt 1 are side edges 24. The side edges 24 can be received in grooves in the feed units for feeding. The side edges 24 are formed during adjustment of the conveyor belts 1, which is described below.

I fi g. 2a shows a perspective view of a conveyor belt 1 according to the invention according to a second embodiment. According to this embodiment, the conveyor belt 1 is coated with a blank layer 22 on both the upper side 12 and the lower side 14 (the layers 22 are not shown in Fig. 2a). The thickness of the layer is 0.0001-0.5 mm, preferably 0.001-0.01 mm. Reference designations with the same reference correspond to those in fi g. la and fi g. lb showed the parts and parts and has a similar function.

The product 5, which is located in 4 ckan 4, is an electronic component, such as an electrical circuit 26. This is in fi g. 2b illustrated with dashed line. The conveyor belt 1 is according to fi g. 2b shown after a section A-A in fi g. 2a.

In the bottom 11 of the hole 4 a bore 28 is arranged. This housing 28 is provided n 11111 20 25 “in I 5 1 6 8 5 3 .... .. so that the electrical circuits 26 can be pushed out of the box by means of a pin (not shown) when the component is to be picked for mounting to for example, an electronic device (not shown). The electrical circuits 26 are during transport and storage in the compartment 4 against mainly the receiving surfaces 10, which are formed in the bottoms 11 of the compartment 4.

According to the invention, for its purpose, the rigid conveyor belt 1 with its electrically conductive properties eliminates the risk of electrical flashover, which could cause damage to the electronic circuits 26.

I fi g. 3a-3b show a device which, according to a method according to the invention, provides a foil 29, which forms a basic material for the conveyor belt 1. In an injection molding machine 30, polymer is melted. Polymer granules are held in a funnel 32 arranged at the injection molding machine 30. The polymer is melted and formed into foil 29 by means of a nozzle 36, which forms a slit-shaped outlet (not shown). The foil 29 can now be wound on a roll 38. When the roll 38 is full, the foil 29 is cut off by means of a cutting device 40.

The foil 29 is rolled by the roller 38 at a web pressing device 42 and cut into strips 44 by means of a cutting device 45. In fi g. 4a-4b show schematically how the procedure takes place after the foil 29 has passed the position m. At the position mi fi g. 3a and fi g. 4a, the foil 29 can either be rolled up on a roll 38 or processed into conveyor belt 1 directly. The roller 38 can be transported to a factory, where the surface layer 22 is applied according to the invention.

The foil is then rolled off the needle 38 and heated before immersing in a room temperature bath with antistatic surface treatment agent mixed with distilled water, after which the foil is dried in an oven in which water supplied to the agent evaporates. Only the anti-static surface treatment agent remains as a solid surface layer on the foil after drying. Other methods can of course also be used within the scope of the invention. The cutting device 45 divides the foil 29 into equal parts or strips 44. The width of the strips 44 is adapted so that the conveyor belt 1 after the pre-pressing by means of the molding devices 20 25 '30. Now the 516 8853 ring 42 has a desired standardized width, the side edges 24 being formed at this moment.

After the foil 29 has been divided into strips 44, these run over guide rollers 47 and pass through an oven 46. In the oven 46 the strips 44 are heated to approximately 120-130 degrees Celsius, the strips 44 being canned to conveyor belt 1 according to the invention by means 4 by means of the molding device 42 The compression device 42 comprises an upper part and a lower part 43, which according to the prior art forms the foil 29 into conveyor belt 1 according to the invention. The conveyor belts 1 are then wound on wheels 50 which are rotatably driven about an axis x by means of a motor (not shown). When the wheel 50 is rolled with a wound conveyor belt 1, an operator cuts off the belt and inserts a new end (not shown) into a new wheel 50.

F ig. 5a-5b and fi g. 6 schematically shows how the layer 22 with anti-static surface treatment agent can be applied to a plastic foil 129. Reference numerals with the same reference correspond to the previously shown parts and portions and have a similar function.

Once the plastic foil 129 has just been formed and comes from the injection molding machine 30, the plastic foil 129 is passed over rollers 52 to a room temperature bath 54 consisting of the antistatic surface treatment agent in a vessel 55, while the plastic foil 29 is still hot, after the injection molding. In the tub 55, tin wools 57 are stored, which lead the plastic foil 129 down into the bath 54. The plastic foil 129 is coated in the bath 54 with a layer 22 on both sides. During transport from the bath 54, the surface treatment layer dries and any excess of the anti-static surface treatment agent flows via the groove 56 back down into the bath 54.

The foil 29 with the layer 22 applied on both its sides can, after the position n, be wound up on a mill 38 shown. 3a or divided into strips, which are compression molded to conveyor belt 1 in direct connection therewith, as shown in fi g. 4a.

I fi g. 6 shows in a side view how the anti-static surface treatment agent is applied by means of rubber wheels 58 and steel rollers 60. Between the rubber wheel 58 and the steel roller 60 the agent is continuously supplied from a container 64 via tube 66. When the rubber wheels 58 rotate against the plastic foil 129 with a membrane (not shown) of anti-static surface treatment agent applied to the plastic foil 129 at position S. The foil 29 thus comprises, after the passage of the rubber wheels 58, layer 22 with anti-static surface treatment agent. This is schematically illustrated with a thicker line 29 ”. In reality, each layer is 0.001-0.01 mm thick.

I fi g. lb, only one layer 22 has been applied according to the method shown in fi g. 6, where, for example, the lower rubber wheel is not sprayed with anti-static surface treatment agent. This is done by closing the tube 66, which leads to this rubber wheel, by means of a throttle valve (not shown).

By means of an adjusting device 68, the steel rollers 60 can be adjusted against the rubber wheels 58 with different pressures, which means that different amounts of antistatic surface treatment agent end up on the rubber wheels 58. In order to provide the rubber wheels 58 with a smaller amount of means, an operator reduces the pressure, i.e. the distance a increases at the same time as a control valve (not shown) restricts the supply of means in the tube 66. This can be adjusted manually by means of a knob (not shown). If only one layer 22 is desired on one side of the plastic foil 129, the ut is completely throttled into one tube 66 by means of the control device.

The antistatic surface treatment agent may consist of benzalkonium chloride, which includes alkyldimethylbenzyluronium chloride and alkyldimentyldimethylethyl together with sodium salt, sodium chloride and isopropanol which accelerates evaporation. Alternatively, the solution can be mixed with distilled water. The mixture can then consist of 2-3% chemicals and the rest of water.

Another mixture is cyastate LS / SN. This mixture can also be added to distilled water, in which the mixture is 0.5-2% cyastate LS / SN and the rest water.

Other anti-static surface treatment agents are included, including quaternary armnonium compounds such as staticides 2001, 2002, 3000 and 5001. Water can also be mixed here.

You can also mix in polysulfone, which means that the polystyrene absorbs moisture, which improves the anti-static properties.

Claims (8)

4___.:_í._______.í__ 20 25 30 516 853 10 Patent claim Conveyor belt of a polymer for storage and transport of products (5), which conveyor belt 1 comprises an upper side (12), a lower side (14), in the longitudinal belt of the conveyor belt (1) extending side edges (24) and corners (4), each of which is formed with a receiving surface (10) for receiving at least one product (5), wherein the receiving surface (10) is connected to the upper side (12) by means of a circumferential wall (8) forming a wall (4), and on the upper side (12) parallel to the longitudinal direction of the conveyor belt (1) extending fastening surfaces (20) for protective means (16) for protection of the products (5), characterized in that the conveyor belt (1) comprises layers (22) with anti- static surface treatment agent. Conveyor belt according to claim 1, characterized in that the receiving surfaces (10) and insides (9) of the conveyor belt (1) of the walls (8) of the kom ckomas (4) are coated with a layer (22) of anti-static surface treatment agent in this way that the products (5) come into contact with the layer (22) when they reach the coma (4). Conveyor belt according to one of Claims 1 or 2, characterized in that the upper side (12), the lower side (14), the receiving surfaces (10) and the walls (8) are coated with a layer (22) of anti-static surface treatment agent to give the conveyor belt (1) electrically conductive properties. Conveyor belt according to claims 1-3, characterized in that the entire conveyor belt (1) is covered with a layer (22) with anti-static surface treatment agent. Conveyor belt according to one of Claims 2 to 4, characterized in that the anti-static surface treatment agent forms a 0.001-0.01 mm thick layer (22). A method of manufacturing conveyor belts (1) according to claim 1, comprising the steps of: injection molding a polymer forming a film (29, 129), dividing the film (29, 129) into equally wide strips (44) by means of a cutting device ( 45), heating the respective strip by means of an oven (46), and compression molding the respective strip (44) by means of a compression device (42), the conveyor belt (1) being produced with pockets (4), characterized in that a layer (22 ) with anti-static surface treatment agent is applied during the production of the film (29, 129). Method according to Claim 6, characterized in that the layer (22) is applied after the foil (29, 129) has been injection-molded. Method according to claim 6, characterized in that the anti-static surface treatment agent is applied after the foil (29, 129) has been injection molded and is still hot.