WO1997031719A1

WO1997031719A1 - Adjustable flow of particles and fibres

Info

Publication number: WO1997031719A1
Application number: PCT/SE1997/000300
Authority: WO
Inventors: Gunnar Forsberg; Matti Hakala
Original assignee: Sealcoat 1 Ab
Priority date: 1996-02-29
Filing date: 1997-02-26
Publication date: 1997-09-04
Also published as: SE9600800L; SE508733C2; EP0879093A1; SE9600800D0; AU2108397A

Abstract

The present invention solves the problem of controlling the amount of particles of fibres which are emitted in a nozzle from a gas flow when these are transported by the gas flow through a flexible hose or some other canal from a container. Due to the fact that the amount of fibres or other particles which are emitted can be controlled in a simple way, an accurate control of the density of a layer which is applied can be made, an even layer can be achieved and unnecessary material consumption can be avoided. The problem is solved primarily in that a gas flow containing the particles is conducted in a canal to a valve arranged where the particles are to be emitted, a second canal leads from the valve to a suction source and the vent comprises regulating means for controlling the size of the gas flows to the suction source and to the outlet of the valve. By means of this construction a continuous flow of fibres or particles can be guided towards the valve and that part which is not emitted to the nozzle is conveyed further by the suction source and is collected. By means of the above-mentioned method an application of fibres or particles in an adhesive layer, applied with, for example, melt adhesives or cold adhesives, may be guided during a course which can be continuous or intermittent.

Description

ADJUSTABLE FLOW OF PARTICLES AND FIBRES Arrangement and method for adjusting the amount of particles or fibres which shall be dissipated from a flow of gas.

When fibre flock is to be applied on a surface a technique is usually used which comprises guiding the surface through a substantially closed apparatus, or in the case of smaller articles introducing them into a basket funnel or the like, so that flock covering can be brought about by transferring short, electrically charged fibres to the article whereupon they fasten in an adhesive on the article, whereas surplus fibres are collected in the apparatus or the basket funnel so that they are not spread out to the surrounding area.

Such a technique is difficult to use when smaller and delimited surfaces on larger articles are to be covered with flock, for example in connection with assembly of vehicles and the like.

Accordingly, an object of the present invention is to bring about a method and an arrangement for covering a surface or an article completely or partly with fibre flock or with other particles. The method and the arrangement shall be suitable to be used together with other production and assembly equipment and it shall dissipate a minimal amount of fibres or particles to the surrounding area. Through the creation of the present invention, flocked surfaces can, for example, be covered in environments and used for purposes which earlier were not possible.

Accordingly, the present invention solves the problem of controlling the amount of particles or fibres which are emitted through a nozzle from a flow of gas when these are transported by the flow of gas through a flexible hose or some other canal from a container. At the nozzle, an application arrangement may, for example, be provided which directs and forms the flow of the particles emitted. The invention is intended primarily for particles in the form of short fibres of synthetic material, such as for example polyamide, having a length of up to 5 mm, but the invention can also be used, for example, for particles which are in the form of a powder. Due to the fact that the amount of fibres or other particles which are emitted can be controlled in a simple way, an accurate control of the density of a layer which is applied can be made, an even layer can be achieved and unnecessary material consumption can be avoided.

According to the invention, the problem is solved primarily in that a gas flow containing the particles is conducted in a canal to a valve arranged where the particles are to be emitted, a second canal leads from the valve to a suction source and the vent comprises regulating means for controlling the size of the off-flow of gas containing particles through the second canal whereby the remaining part of the gas flow is also regulated and emitted to the nozzle at the outlet of the valve. By means of this construction a continuous flow of fibres or particles can be guided towards the valve and that part which is not emitted to the nozzle is conveyed further by the suction source and is collected.

By allowing the fibres or the particles to be transported continuously in a gas flow in a canal, these will also have a higher and more even charge when they are charged in the canal by means of the friction method (tribo-electrically) . The amount of fibres or particles which can be taken out via the valve from the continuous flow may also be substantially greater and the flow more even than if they were not transported continuously in the gas flow past the valve. The relation between the amount of fibres and the amount of air may also be substantially larger. For example, when fibres are applied into an adhesive layer the risk of film forming on the surface will therefore be less than if they were not transported continuously in said gas flow.

By means of the above-mentioned method an application of fibres or particles in an adhesive layer, applied with, for example, melt adhesives or cold adhesives, may be guided during a course which can be continuous or intermittent. An example of such a course is application on plastic details and components to be mounted in cars, where the function of the application is to eliminate squeaking and other noise which is created by parts which are in contact with each other moving or rubbing against each other. By means of the present invention, existing technique/methods, manual application of tape having a textile surface can be eliminated and replaced by application of fibre flock which is brought about in an automated process which is repeatable and measurable and therefore is able to ensure quality.

Further features of the present invention will appear from the succeeding patent claims.

The invention will now be described more in detail in connection with the drawing.

Fig. 1 shows schematically the construction of an apparatus which is used to carry out the invention.

Fig. 2 shows schematically the construction of a valve arrangement (bypass unit) according to the invention.

Fig. 3 shows schematically and in section the construction of a second embodiment of a valve arrangement (bypass unit) according to the invention.

Fig. 4 shows schematically and in section the construction of a third embodiment of a valve arrangement (bypass unit) according to the invention.

As appears from Fig. 1, an apparatus according to the invention consists of a flocking machine 1, which by means of a fan 3 from a container 2 gives a controllable amount of flock in a flow of gas, preferably air, to a blowing canal 4. The blowing canal leads to a valve unit 6 which also is connected to a suction canal 5 which guides a not dissipated part of the flock flow F to a storage container 11 provided with a vacuum pump 10. The storage container 11 can be arranged above the container 2 of the flocking machine but is normally separated from this by a separation wall 12 in which an openable part for emptying to the container 2 of the flocking machine may be arranged. The vacuum pump 10 is provided, like a vacuum cleaner, with a filter unit 13 which separates the fibres in the flow of air.

The valve unit or bypass unit 6 gives the possibility to choose between different conditions between the openings Al, A2 and A3, whereby the amount of flock fibres 8 which is emitted to the nozzle 7 against a surface 9 can be varied and the remainder of the fibres from the blowing canal 4 returns via the suction canal 5.

An embodiment of a valve arrangement (bypass unit) 6 according to the invention is shown in Fig. 3. Here, the entering fibre air flow FI from the blowing canal is arranged in line with the nozzle 7 having a valve 14 so arranged that the suction canal catches the outgoing fibre air flow F2 whilst the part which is conducted through the valve 14 is blown through the nozzle 7.

A third embodiment of a valve arrangement (bypass unit) according to the invention is shown in Fig. 4. Here, the nozzle 7 is surrounded by a bellows or a collar 15 which is intended to extend to the surface 9 which is to be covered with fibre flock or other particles. A second suction canal 16 is arranged from the space which is surrounded by the bellows, whereby any remaining fibres in the bilge may be removed. The second suction canal 16 may be connected to the suction canal 5.

Charging of the fibres which are to be emitted can be brought about in a known way by friction charging at the nozzle and/or in the blowing canal 4 or by means of high voltage electrodes arranged in the fibre flow.

The invention is not limited to the above-mentioned embodiments but can be varied in different ways within the scope of the claims.

Claims

1. Method for covering a delimited surface with fibre flock, c h a r a c t e r i z e d i n that the surface is provided with a layer of adhesive, that a flow of charged fibres from a nozzle is directed towards the surface and that the flow of charged fibres from the nozzle is regulated and interrupted by leading the fibre flow from a canal to the orifice, from which none or a controllable amount is directed towards the surface and the remainder is conducted to a storage container through a suction canal.

2. Method according to claim 1, c h a r a c t e r i z e d i n that the adhesive layer consists of a melting adhesive.

3. Method according to claim 1, c h a r a c t e r i z e d i n that the adhesive layer consists of a cold adhesive.

4. Method according to any of the preceding claims, c h a r a c t e r i z e d i n that layers of adhesive and flock intended to prevent squeaking and noise are applied on surface parts which, after mounting, may come into contact with other parts.

5. Method according to any of the preceding claims, c h a r a c t e r i z e d i n that the application of the adhesive layer and the flow of fibres towards the adhesive layer is carried out in an automated process.

6. Method for controlling the amount of fibres or other particles which are emitted from a gas flow, c h a r a c t e r i z e d i n that a gas flow containing particles is conducted in a canal to a valve arranged where the particles are to be emitted, a second canal leads from the valve to a suction source, and the valve comprises regulating means for controlling the size of an off-flow of gas containing particles through the second canal whereby also the remaining part of the gas flow can be controlled and emitted to the outlet of the valve.

7. Arrangement for controlling an amount of fibres or other particles which are emitted from a gas flow, c h a r a c t e r i z e d i n that a gas flow containing particles is conducted in a canal to a valve arranged where the particles are to be emitted, a second canal leads from the valve to a suction source and the vent comprises regulating means for regulating the size of the flow of gas containing fibres or particles which are emitted to a nozzle whereby the remaining part of the gas flow with fibres and particles is sucked away from the valve through the second canal.

8. Arrangement according to claim 7, c h a r a c t e r i z e d i n that the nozzle is surrounded by a bellows which extends to a surface which is to be covered.

9. Arrangement according to claim 8, c h a r a c t e r i z e d i n that the space within the bellows is connected to a second suction canal.

10. Use of a method according to any of claims 1-6 or an arrangement according to any of claims 7-9 to eliminate squeaking or other noise between surfaces by covering at least a part of one of the surfaces with fibre flock.