GB2168043A - A vibratory cleaning system - Google Patents

Abstract

Foreign debris is removed from containers by first applying vibration to the containers 7 by way of a guide (13, 17) along which they move and then air is blown by means of jets (25), into the containers preferably in the absence of vibration or under the influence of reduced vibration. <IMAGE>

Description

SPECIFICATION A vibratory cleaning system The present invention relates to a method and apparatus for cleaning containers and, more particularly for removing foreign debris in the nature of particulate matter from a container.

It is a requirement to ensure that containers are empty prior to filling with their intended contents.

New containers, for example glass bottles by virtue of their storage conditions may contain particles of cotton, paper and glass which need to be removed before the containers are filled. The traditional method employed is to position the container with its opening lowermost and to direct air into the container. This generates turbulence and an air current in the container which is intended to remove the contamination. In certain designs of containers, for example those with square shoulders and/or relatively narrow necks, one hundred per cent removal of contaminants by this known method has not always been achieved. In our tests one hundred per cent removal by this method has never been achieved.

Accordingly, it is an aim of the present invention to provide a method of cleaning containers which is more reliable.

According to the present invention there is provided a method of removing foreign debris from a container having an opening therein comprising the steps of arranging the container with the opening lowermost, applying vibration to the container, and subsequently directing air into the container by way of the opening.

Preferably, the container is supported on a guide to which the vibration is applied. More preferably, the method is carried out on successive containers in a continuously operating machine. The vibration is applied for a predetermined time over a predetermined distance. An applied force of 100 to 112 newtons and an oscillation rate of 2,500 to 3,000 cycles per minute has been found satisfactory with containers moving at a rate of 60 to 120 per minute. Under these conditions a vibrating guide of 0.5 metre and subsequent exposure to an air jet or jets has been found to remove 100% of the contamination in tests.

The method is particularly suitable for containers having square shoulder and relatively small opening in the neck. Tests have been carried out on glass bottles with 100% success.

According to another aspect of the present invention there is provided apparatus for removing foreign debris from a container comprising a guide supporting the container with its opening lowermost, means for applying vibration to the guide and hence to the container, and means for directing air into the container after subjecting it to vibration.

Preferably, the means for directing air into the containers comprises one or more air jets disposed downstream of the vibrating guide. Conveniently, a further guide is disposed downstream of the vibrating guide to support the containers when the air jet is directed into the containers. More prefera bly the vibrating guide and the further guide downstream thereof are isolated from one another.

The guides preferably form part of a continuous track whereby successive containers can be treated one after the other. The containers are moved through the cleaning section by any convenient means.

The apparatus is preferably used in conjunction with inverting machinery for the containers. These being disposed upstream and downstream of the vibrating section and the air jet section.

Conveniently, the guides comprise two elongate members having a resilient face made of rubber, plastic or the like which are positioned adjacent the sides of the containers to prevent them from becoming disorientated and to keep them in line one behind the other. A further guide is preferably provided above the containers to locate them vertically. Contact between adjacent containers moves them along the guides with movement being generated by a suitable pusher device such as a star wheel. The preferred apparatus is arranged to operate continuously and automatically.

In another embodiment, the guide comprises a rotatable plate, having holes therein to receive the neck of the containers to be decontaminated. The vibration is applied to the plate and the plate is rotated to move the containers past one or more air jets disposed short of the neck of the containers and arranged to direct air upwards. The vibrations applied to the plate are damped down at the air jet so that any residual vibration is not an impe factor to decontamination. The plate may be segmented to avoid vibrations reaching the air jet section. The embodiment of apparatus employing the rotary plate is intended to be semi-automatic in its operation, with the containers being aded and unloaded manually.

The present invention will now be described further hereinafter, by way of example only, and with reference to the accompanying drawing which is a perspective view of one embodiment of apparatus according to the present invention.

Referring to the drawing, a frame 1 provides support for the other integers of the apparatus comprising a first section 3 where vibration is applied, and a second section 5 where air is applied.

The containers to be treated are shown by way of example as bottles 7 having a square shoulder and a relatively narrow neck opening. The containers 7 pass through the apparatus in succession, one behind the other. A star wheel 9 is rotatably driven and contacts successive containers to push them through the apparatus. A rotary inverter 11 is provided in the illustrated apparatus for inverting the containers so that their opening is lowermost. On leaving the inverter, the inverted containers 7 enter between two oppositely disposed side guides, only one of which 13 is visible in the illustration, a top guide 17 and a rail 19 on which they are supported. The guides and rails define the first section 3 to which vibration is applied by means of an actuator 21. The actuator may be air or electrically driven.A suitable actuator applies a force of 100 to 112 newtons to the guide 13 to which it is rigidly secured and has an oscillation rate of between 2,500 to 3,000 cyles per minute. Preferably, the integers of the first section are secured together so that they all vibrate together. The first section 3 may be secured to the frame directly by way of flexible mountings.

The two side guides restrain sideways movement of the containers whilst the guide 17 in conjunction with the rails 19 restrain vertical movement. The containers are free to move along the tracks defined by the guides and rails. The guides 13 and 17 have resilient facings formed of rubber or plastic material to avoid damaging the containers during vibration. The facings are relatively hard so that the vibration is transmitted to the containers.

Downstream of the first section is a further section which comprises similar guides and rails.

These are preferably separated from the first section so that vibration is not applied at the second section. Some vibration may be transmitted by way of the frame but this is largely damped out. A series of air jets 25 are carried by the second section sub assembly and by means of these jets, air is directed into the container openings.

The apparatus as illustrated comprises a further inverter 27 for returning the containers to their upright positions. The inverters employed may utilise a helical scroll as per those illustrated or any alternative inversion means may be employed.

In use, the vibration applied to the containers removes the majority if not all of the debris in the containers, whilst the subsequent air blast removes any remaining particles.

The application of vibration independently of and before the introduction of air has been found to give much improved results compared with merely applying air or applying air simultaneously with vibration.

In tests three pieces of cotton approximately 4 mm long, three pieces of paper approximately 2 mm square and three pieces of glass approximately 2 mm cubed were placed in glass bottles having a square shoulder and a relatively narrow opening approximately 5 mm diameter. The bottles were pushed through the apparatus with vibration applied at between 2,500 and 3,000 cycles per minute at a linear force of 100 to 122 newtons over a 0.5 metre length of track with bottles moving at between 60 to 120 per minute. Following this the bottles passed two successive air jets approximately 0.25 metre apart, travelling at the same rate. One hundred per cent of the contamination was removed.

it is believed that increasing the length of sections one and two from the present 0.5 metre each and possibly increasing the number of spacing of the air jets will enable the speed of treatment to be increased to upwards of 200 bottles per minute with 100% success.

In another embodiment, not illustrated, the containers are loaded in to a rotatable plate, which has cut-outs to receive the necks of the containers. The containers are intended to be loaded manually into the plate, and vibration is applied to the plate to instigate removal of contamination. The open necks of the bottles which are lowermost, are then passed over one or more air jets. The vibration is damped out or down during passage over the air jet so that the vibration does not impede the contamination removal. In one embodiment the plate is divided into segments so that the vibration can be applied sequentially to certain segments, for example by having a vibrator unit located on each segment and operating the vibrator for a predetermined time between loading and the application of air.

By way of example there follows details of the tests being carried out on rectangular aftershave bottles. These bottles are particularly difficult to clean by normal methods because of their very flat shoulders which tend to retain heavy particles and because of the small neck orifice. The tests were carried out on an apparatus substantially as shown in the accompanying drawing and described hereinabove.

Tests 1 and 2 do not employ vibration for comparison with the other tests employing vibration.

Test 1 This test was carried out through a 500 mm long treatment section with four 1/16 bored jets at 75 mm pitch. An air pressure 30 psi was used. The sample size was forty bottles.

The bottles were passed over the jets at a rate approximating to sixty bottles per minute. The bottles contained between one and three particles of glass up to 3 mm across.

Results After the above described treatment 28% of the bottles still had particles of glass in them.

Test (2) As test (1) but at two-hundred bottles per minute.

Results Approximately 70% of the bottles contained glass after treatment.

Test 63) The conditions for this test were identical to those in Test (1) but in addition an orbital sander was hand held against the bottle support frame in order to induce some vibration in it.

Results About 22% of the containers contained glass particles after treatment which looks promising in view of the fact it was discovered the containers were damp which would make removal of particles more difficult.

Test (4) Treatment section 500 mm long, four 1/16 bored jets at 75 mm pitch. Air pressure 30 psi. Sixty three sample bottles used at two-hundred bottles per minute. Four pieces of glass per bottle. Hand held orbital sander vibration.

Results 33% of bottles had glass particles left in them.

Test (5) Generally as Test (4) but this time a proper pneumatic piston vibration induced by this unit was noticeably more severe.

Results Only four bottles contained glass particles. Having achieved this considerable increase in performance we then went on to looking at the effect of increasing the treatment length and in effect time available.

Test (6) 1,000 mm long treatment section, four 1/16 bored jets at 75 mm pitch. Air pressure 30 psi. Sixty three sample bottles were used each with three pieces of glass ranging in size between 1 mm and 3 mm. (These glass quantities were suggested by Quality Control Division). Vibration was induced by the proprietory piston vibrator.

Results This test was run several times and on each occasion after treatment the bottles were found to be 95% - 97% free of glass particles. The test was also run with only one glass particle in and found to be 100% effective.

Test (7) In this test the treatment section was separated into two 500 mm long units. In the first 500 mm vibration alone was applied, in the second 500 mm air jetting alone was applied.

Several test samples of one hundred bottles were run through at sixty bottles per minute. Each bottle as in previous test having three glass particles.

Results On each occasion the bottles were found to be 100% free of glass particles.

Test (8) All conditions the same as in Test (7) but with a throughput of one hundred bottles per minute.

Results Again bottles were found to be 100% free of glass particles.

Test (9) In order to assess the effectiveness relative to the potential contamination each bottle was dosed with three pieces of glass as already described, three pieces of paper 2 mm square and three pieces of cotton up, to 1/2" long. Several tests were carried with the set up generally as previously, that is two separate treatment frames with vibration on the first and air blowing on the second. These tests were carried out at different speeds ranging up to two hundred bottles per minute.

Results At speeds of up to one hundred and twenty bottles per minute the effectiveness of the operation was 100%. As the speed was increased above one hundred and twenty per minute contamination occurred and increased until at two hundred bottles per minute approximately 7% contained paper and 3% contained cotton. It was interesting that even at this speed the bottles were 100% clear of glass particles.

In terms of the immdiate requirements that we are aware of the treatments established and the results obtained appeared to cover them, however we are continuing to test the system further by arranging for different air jetting in order to attempt to achieve more treatment within the same linear length. It is anticipated that for 100% effectiveness at higher outputs i.e. in excess of one hundred and twenty bottles per minute even longer treatment sections will be required.

Claims (21)

1. A method of removing foreign debris from a container having an opening therein, comprising the steps of arranging the container with the opening lowermost, applying vibration to the container, and subsequently directing air into the container by way of the opening.

2. A method as claimed in claim 1 in which the vibration is applied to a guide on which the container is supported.

3. A method as claimed in claim 1 or 2 in which the vibration is applied at an oscillation rate of 2,500 to 3,000 cycles per minute and at a force of 100 to 112 newtons.

4. A method as claimed in claims 1, 2, or 3 and performed on successive containers in a continuously operating machine.

5. A method as claimed in claim 4 in which the containers move at a rate of 60 to 120 per minute.

6. A method as claimed in any preceding claim and performed on containers having square shoulders and a relatively small opening in the neck.

7. Apparatus for removing foreign debris from a container having an opening therein comprising a guide supporting the container with its opening lowermost, means for applying vibration to the guide and hence to the container and means for directing air into the container after subjecting it to vibration.

8. Apparatus as claimed in claim 7 in which the means for applying vibration to the guide comprises an actuator secured to the guide.

9. Apparatus as claimed in claim 8 in which the actuator is air or electrically operated and oscillates at a rate of 2,500 to 3,000 cycles per minute and applies a force of 100 to 112 newtons.

10. pparatus as claimed in claims 7, 8, or 9 in which the means for directing air into the containers comprises an air jet disposed below the opening in the container and aligned to direct air into the openings.

11. Apparatus as claimed in any of claims 7 to 10 in which the guide forms part of a continuous track whereby successive containers can be treated one after the other, and wherein the air jet means for directing air into the containers is disposed downstream of the vibrating guide.

12. Apparatus as claimed in claim 11 in which the track which guides the containers downstream of the vibrating guide and at which the air jet means are disposed, is isolated from the vibrating guide.

13. Apparatus as claimed in claims 11 and 12 in which a first container invertor is disposed upstream of the vibrating guide and a second invertor is disposed downstream of the air jet means.

14. Apparatus as claimed in any of claims 7 to 13 in which the vibrating guide comprises two elongate members having resilient faces which are positioned adjacent the sides of the containers.

15. Apparatus as claimed in claim 14 in which the guide further comprises a rail on which the containers rest, and a top guide above the containers to restrain their upward movement.

16. Apparatus as claimed in any of claims 11, 12 or 13 in which a pusher device is provided to move the containers continuously along the track one behind the other.

17. Apparatus as claimed in any of claims 7 to 10 in which the guide comprises a plate which is rotatable and which has apertures therein to receive the neck of the containers to be cleaned.

18. Apparatus as claimed in claim 17 in which the rotatable plate is made up of segments, and actuator means is provided to apply vibration to successive segments, whereafter the containers in the segment are passed over air jet means.

19. Apparatus as claimed in claim 18 in which each segment is provided with an actuator and the respective actuators are operated sequentially.

20. A method of removing foreign debris from a container substantially as hereinbefore described with reference to the accompanying drawing.

21. Apparatus for removing foreign debris from a container constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.