NO820599L

NO820599L - DEVICE AND PROCEDURE FOR EVACUATION AND CLOSING OF BAGS

Info

Publication number: NO820599L
Application number: NO820599A
Authority: NO
Inventors: Alfred Remmele; Josef Hertenberger; Helmut Ferus
Original assignee: Suedpack Verpackungs Gmbh & Co
Priority date: 1981-02-27
Filing date: 1982-02-25
Publication date: 1982-08-30
Also published as: EP0059430A1; DE3107485A1; DK81582A; AU8075582A

Description

Oppfinnelsen angår en anordning så vel som en fremgangsmåte for maskinell evakuering og lukking av plastposer som fortrinnsvis er fylt med ferskt kjøtt og fersk fisk, og luft- pg fuktighetstett, sveisbar plast. The invention relates to a device as well as a method for mechanically evacuating and closing plastic bags which are preferably filled with fresh meat and fresh fish, and airtight, moisture-tight, weldable plastic.

For evakuering og lukking av plastposer fyltFor evacuation and closing of filled plastic bags

med varer er allerede diverse anordninger kjent. Ved vakuumforpakningsanordningen ifølge DE-GM 72 33 15 0, som with goods, various devices are already known. With the vacuum packaging device according to DE-GM 72 33 15 0, which

har stått sin prøve i praksis, er det sørget for to, omtrent i posebredde fra hverandre anordnede su.gedyser som kan føres inn i posen, og ved hvilke denne spennes under has stood the test in practice, two suction nozzles arranged approximately the width of the bag apart, which can be inserted into the bag, and by which this is clamped under

evakueringen. Selv om åpningen mellom sugedysene herved stenges ved hjelp av press-skinner, kan likevel falskluft trenge inn mellom disse og sugedysene og inn i. posen. the evacuation. Even if the opening between the suction nozzles is closed by means of pressure rails, false air can still penetrate between these and the suction nozzles and into the bag.

Uheldig er imidlertid først og fremst det at posen lukkerUnfortunate, however, is primarily that the bag closes

seg raskt i området ved sugedysene, idet deler av posen lukker seg mot hverandre, slik at evakueringen hindres og det danner seg folder. Dessuten er tids- og arbeids-innsatsen betydelig, da de med forpakningsvare fylte posene, som skal evakueres og lukkes, må tilføres sugedysene enkeltvis. rapidly in the area of the suction nozzles, as parts of the bag close against each other, so that evacuation is prevented and folds form. In addition, the time and labor effort is considerable, as the bags filled with packaging material, which are to be evacuated and closed, must be fed to the suction nozzles individually.

Det er følgelig oppfinnelsens formål å fremskaffeIt is therefore the object of the invention to provide

en anordning for maskinell evakuering'og lukking av plastposer, ved hvilken ikke bare en med lav energiinnsats, a device for mechanical evacuation' and closing of plastic bags, whereby not only one with low energy input,

. fullkommen evakuering av en pose kan utføres på kort tid,,. complete evacuation of a bag can be carried out in a short time,,

men ved hvilken også en høy arbeidsytelse ved nesten fullsten-dig automasjon er gitt, Den dertil nødvendige byggeinnsats skal holdes lav,og den skal også være.enkel i bruk for betjeningspersonalet. but by which a high work performance with almost complete automation is also provided. The necessary construction effort must be kept low, and it must also be easy to use for the operating staff.

Ifølge oppfinnelsen er anordningen, ved hvilken dette kan oppnås,karakterisert veden vertikal forskyvbar oppspenningsanordning som tar opp den fylte posen ved poseåpningen og som består av minst to spennbakker, et sugesverd som mellom disse føres inn i posen, og som sammen med oppspenningsanordningen er anordnet i et bærestativ, According to the invention, the device, by which this can be achieved, is characterized by a vertically displaceable tensioning device which picks up the filled bag at the bag opening and which consists of at least two clamping jaws, a suction blade which is inserted between them into the bag, and which, together with the tensioning device, is arranged in a carrier stand,

samt en sveiseanordriing, dannet av relativt til hverandre forskyvbare sveisebakker, ved hvilken poseåpningen étter evakueringen og/eller gassingen av posen kan lukkes og as well as a welding device ring, formed by relatively mutually displaceable welding trays, by which the bag opening can be closed after the evacuation and/or gassing of the bag and

sveises.welded.

Herunder er det særdeles fordelaktig å anordne •oppspenningsanordningen og sugesverdet sammen taktvis forskyvbare i et bærestativ, hvorved posen evakueres og gasses under forskyvningsbevegelsen og poseåpningen kan lukkes og sveises i posens endestilling. Here, it is particularly advantageous to arrange the tensioning device and the suction blade together in a tactically displaceable carrier stand, whereby the bag is evacuated and gassed during the displacement movement and the bag opening can be closed and welded in the bag's end position.

Videre er det hensiktsmessig å støtte opp posene på en rullebane som forløper parallelt med oppspenningsanordningens forflyttningsbevegelse, bg som kan være utstyrt, med fortrinnsvis f jærb&astede, medbringere som kan drives fram synkront med oppspenningensanordningen i horisontal retning," og som kan virke inn på posene eller beholderne som fanger opp disse... Furthermore, it is appropriate to support the bags on a runway that runs parallel to the movement of the tensioning device, bg which can be equipped, preferably with spring-loaded, carriers that can be driven forward synchronously with the tensioning device in a horizontal direction, and which can act on the bags or the containers that capture these...

For på en enkel måte å kunne foreta en tilpasning til poser med ulike høyder, er det videre fordelaktig å anordne oppspenningsanordningen, sugesverdet så vel som sveiseinnretningen og deres drivmekanismer eksempelvis ved en stillbar skruespindel e.l. som sammen er forflyttbar vertikalt i forhold til rullebanen. In order to be able to make an adaptation to bags of different heights in a simple way, it is further advantageous to arrange the tensioning device, the suction blade as well as the welding device and their drive mechanisms, for example by an adjustable screw spindle or the like. which together can be moved vertically in relation to the runway.

For at en'pose alltid skal være garantert en sikker oppspenning, burde minst en av oppspenningsanordningens spennbakker, ved hjelp av en servoinnretning i form av en trykksylinder, en vinkelstangsarm e.l., være anbrakt horisontalt forskyvbar eller svingbar på et ledestykke In order for a bag to always be guaranteed safe tensioning, at least one of the tensioning device's tensioning jaws, with the help of a servo device in the form of a pressure cylinder, an angle rod arm etc., should be placed horizontally displaceable or pivotable on a guide piece

for å kunne ta opp posen. Videre burde, for tilpasningto be able to pick up the bag. Furthermore, should, for adaptation

til ulike poseåpninger, minst en spennbakke være horisontal, forskyvbar eller,med den enden som tar opp posen, være to different bag openings, at least one clamping tray must be horizontal, displaceable or, with the end that picks up the bag, be

anordnet svingbar i retning sugesverdet på et ledestykke, hvorved spennbakkene, for å oppnå godt anlegg for posen, burde ha tverrsnittsform som enkeltvis utadrettede kile-s tykker. arranged pivotable in the direction of the suction blade on a guide piece, whereby the clamping jaws, in order to achieve a good fit for the bag, should have a cross-sectional shape that is individually oriented outward wedge-s thick.

Sugesverdet kan på en enkel måte dannes av to plater som.holdes fra hverandre ved hjelp av avstandslister, hvorved det i platene og/eller avstandslistene, fortrinnsvis sugesverdets ytterkant, kan være innarbeidet avsugsåpninger. Dessuten burde dens ende som føres inn i posen være dobbelt kileformet, eller innskrådd i begge kantområdene. The suction blade can be formed in a simple way from two plates which are kept apart by means of spacer strips, whereby extraction openings can be incorporated in the plates and/or spacer strips, preferably the outer edge of the suction blade. Moreover, its end which is fed into the bag should be double wedge-shaped, or bevelled in both edge areas.

For samtidig å kunne spenne opp to poser,, kan sugesverdet være oppdelt omtrent i midten, og mellom de to sverddelene kan anordnes spenribakker som virker sammen med spennbakkene som er plassert på begge sider av sugesverdet. ' In order to be able to clamp two bags at the same time, the suction blade can be divided approximately in the middle, and between the two blade parts, clamping jaws can be arranged which work together with the clamping jaws which are placed on both sides of the suction blade. '

Fremgangsmåten for maskinell evakuering og lukking av plastposer, fortrinnsvis fylt med ferskt kjøtt eller fersk fisk, av luft- og fuktighetstett, sveisbar plast, erkarakterisert vedat de fylte plastposene ved pose-. åpningen spennes opp i en oppspenningsanordning som består av minst to spennbakker, og som er anordnet i et bærestativ, at derpå" et sugesverd som griper inn i spennbakkene, kjøres inn i posen delvis eller til underlaget på varen som skal innpakkes, at posen deretter evakueres og/eller gasses, og at deretter oppspenningsanordningen så vel som sugesverdet heves vertikalt og føres tilbake i utgangsstillingen og posen samtidig ved hjelp av bevegelige sveisebakker ved poseåpningen lukkes og sveises. The procedure for mechanical evacuation and closing of plastic bags, preferably filled with fresh meat or fresh fish, made of air- and moisture-tight, weldable plastic, is characterized by the fact that the filled plastic bags at bag-. the opening is clamped up in a tensioning device which consists of at least two clamping jaws, and which is arranged in a carrier stand, that then" a suction blade that engages in the clamping jaws is driven into the bag partially or to the base of the item to be packed, that the bag is then evacuated and/or gassed, and that then the tensioning device as well as the suction blade are raised vertically and returned to the starting position and the bag is simultaneously closed and welded using movable welding trays at the bag opening.

Det er videre fordelaktig å anordne oppspennings- ' anordningen og sugesverdet sammen horisontalt forskyvbare i bærestativet, og deretter, i posens endestilling, It is further advantageous to arrange the tensioning device and the suction blade together horizontally displaceable in the carrier stand, and then, in the end position of the bag,

lukke og sveise dennes åpning.close and weld its opening.

Anordningen ifølge oppfinnelsen er ikke bare enkel i den konstruktive utformingen'og derved økonomisk og uten stor byggeinnsats produserbar, men ved hjelp av denne anordningen er det fremfor alt mulig, på en enkel måte sikkert å evakuere og lukke plastposer i løpet av kort tid. Herunder er den store arbeidsytelsen særlig fordelaktig, da én pose kan spennes inn i oppspenningsanordningen allerede mens den forangående posen enda sveises. Dessuten kan en tilpasning til ulike posestørrelser og materialer foretas uten vanskeligheter, også kan det tidsmessige forløp for de enkelte prosess-skritt enkelt styres i henhold til de gitte omstendigheter, slik at en mangesidig nyttigjørelse av anordningen ifølge forslaget er garantert. Og da, ved hjelp av sugesverdet som kan føres inn i posen, luften suges opp umiddelbart over varen som skal pakkes inn, kan evakueringen utføres pålitelig med lavt energiforbruk i løpet av kort tid, uten at derved deler av posen kan leggen seg på hverandre. The device according to the invention is not only simple in its constructive design and can therefore be produced economically and without much construction effort, but with the help of this device it is above all possible, in a simple way, to safely evacuate and close plastic bags within a short time. Here, the high work performance is particularly advantageous, as one bag can be clamped into the tensioning device already while the previous bag is still being welded. In addition, an adaptation to different bag sizes and materials can be made without difficulty, and the temporal course of the individual process steps can also be easily controlled according to the given circumstances, so that a versatile utilization of the device according to the proposal is guaranteed. And then, with the help of the suction blade that can be inserted into the bag, the air is sucked up immediately above the item to be packed, the evacuation can be carried out reliably with low energy consumption within a short time, without parts of the bag being able to lay on top of each other.

I tegningen er et utførelseseksempel av.en anordning for maskinell evakuering og lukking av plastposer, fortrinnsvis fylt méd ferkt kjøtt, av iuft og fuktighetstett, sveisbar plast, med opp.spenningsanordning .som er horisontalt forskyvbar og anordnet i et bærestativ, skjema-tisk fremstilt og i det følgende nærmere beskrevet. Herunder viser: In the drawing, an embodiment of a device for mechanical evacuation and closing of plastic bags, preferably filled with minced meat, made of moisture- and moisture-proof, weldable plastic, with tensioning device, which is horizontally displaceable and arranged in a carrier stand, is shown schematically and described in more detail below. Below shows:

fig. 1 anordningen i vertikalprosjeksjon,fig. 1 the device in vertical projection,

fig. 2 anordningen ifølge fig. 1 i sideprosjeksjon i enfig. 2 the device according to fig. 1 in side projection in a

av oppspenningsanordningens endestillinger,of the end positions of the tensioning device,

fig. 3 anordningen ifølge fig. 1 også i sideprosjeksjon ifig. 3 the device according to fig. 1 also in side projection i

en annen av oppspenningsanordningens endestillinger og another of the tensioning device end positions and

fig. 4 en annerledes utforming av det i anordningen ifølge fig. 4 a different design of it in the device according to

fig. 1 anvendbare sugesverdet.fig. 1 applicable suction sword.

Den i figurene 1 til 3 med 1 betegnede anordning for maskinell evakuering og sveising av poser 2 av luft- og fuktighetstett, sveisbar plast består av en oppspenningsanordning 21, et sugesyerd 2 2 så vel som en sveiseanordning 23, som er bygget inn, tilordnet hverandre, i et todelt bærestativ 11. The device designated by 1 in figures 1 to 3 for mechanical evacuation and welding of bags 2 of air- and moisture-tight, weldable plastic consists of a tensioning device 21, a suction seam 2 2 as well as a welding device 23, which are built in, assigned to each other , in a two-part carrier stand 11.

Bærestativets 11 underdel 12 er herunder utstyrt med en rullebane 19, på hvilken posene 2 som skal lukkes, hhv; "\ beholderne 3 som eventuelt skal tå dem opp lett kan forskyves, og som er utstyrt med innebygde medbringere 20. Dessuten kan overdelen 13 av bærestativet 11, som skal bære oppspenningsanordningen 21, sugesverdet 22 så vel som sveiseanordningen 23, innstilles vertikalt i forhold til underdelen 12. Dertil tjener en skruespindel 15 som er festet på overdelen 13, og som er opplagret i en ledehylse 14 som er anbrakt på underdelen 12, og som kan stilles vertikalt ved hjelp av et tannhjul 16 som kan dreies via en spindel 17 og en veivarm 18. The lower part 12 of the carrier stand 11 is equipped below with a runway 19, on which the bags 2 are to be closed, respectively; "\ the containers 3 which are possibly to toe them up can be easily displaced, and which are equipped with built-in carriers 20. In addition, the upper part 13 of the support stand 11, which will carry the tensioning device 21, the suction blade 22 as well as the welding device 23, can be set vertically in relation to the lower part 12. For this purpose, a screw spindle 15 is attached to the upper part 13, and which is stored in a guide sleeve 14 which is placed on the lower part 12, and which can be set vertically with the help of a gear 16 which can be turned via a spindle 17 and a way warm 18.

Oppspenningsanordningen 11 er dannet av spennbakker 31 og 32 som er opplagret i ledestykker 33 og 34, og på The clamping device 11 is formed by clamping jaws 31 and 32 which are stored in guide pieces 33 and 34, and on

hvilke poseåpningen 3 spennes opp for hånd. Spennbakken which the bag opening 3 is fastened by hand. The tension hill

31 er herunder horisontal forskyvbar ved hjelp av en 31 is herewith horizontally displaceable by means of a

trykksylinder 35, slik at posen 2 uten vanskeligheter kan spennes opp. Og for å foreta en tilpasning til ulike poseåpninger, kan spennbakken 32 blokkeres i forskjellige posisjoner ved hjelp av et langhull 36 i denne eller i lede-stykket 34. Til vertikalforskyvning av oppspenningsanordningen 21 tjener enda en trykksylinder 38, som er festet på pressure cylinder 35, so that the bag 2 can be unzipped without difficulty. And in order to make an adaptation to different bag openings, the clamping tray 32 can be blocked in different positions by means of a long hole 36 in this or in the guide piece 34. For vertical displacement of the tensioning device 21, a pressure cylinder 38, which is fixed on

en plate 37 og som har sylinderen 39 fast forbundet med oppspenningsanordningen 21. a plate 37 and which has the cylinder 39 firmly connected to the tensioning device 21.

Sugesverdet 22, som kan føres inn mellom spennbakkene 31 og 32, består av to plater 41 og 42, mellom hvilke ay-standslistene 4 3 er anordnet, og hvor avsugsboringene 44 .er innarbeidet i yttérområdet. Over en bare delvis fremstilt sugeledning 45 er'sugesverdet 22, hvis ende som kan føres inn i posen 2 er avskrådd i begge kantområdene, tilkoplet en vakuumpumpe. Til vertikalforskyvning av sugesverdet 22 tjener likeså en sylinder 46 som er festet på en plate 37, og hvis stempel 47 står i forbindelse'med sugesverdet 22. The suction blade 22, which can be inserted between the clamping jaws 31 and 32, consists of two plates 41 and 42, between which the ay-stand strips 4 3 are arranged, and where the extraction bores 44 are incorporated in the outer area. Above a suction line 45 which is only partially produced, the suction blade 22, the end of which can be inserted into the bag 2 is chamfered in both edge areas, is connected to a vacuum pump. A cylinder 46 which is attached to a plate 37, and whose piston 47 is in connection with the suction blade 22, also serves for vertical displacement of the suction blade 22.

For horisontal forflyttning av oppspenningsanordningen 21 og sugesverdet 2 2 er det sørget for enda en trykksylinder 49, som innvirker på platen 37, som holdes ved hjelp av stenger 48 som er anordnet parallelt med rullebanen 19. For horizontal movement of the tensioning device 21 and the suction blade 2 2 , a further pressure cylinder 49 is provided, which acts on the plate 37, which is held by means of rods 48 which are arranged parallel to the runway 19.

Sveiseanordningen 2 3 er dannet av to relativt til hverandre flyttbare sveisebakker 51 og 52. I tillegg innvirker en trykksylinder 53 på sveisebakkene 52. The welding device 2 3 is formed by two relatively movable welding trays 51 and 52. In addition, a pressure cylinder 53 acts on the welding trays 52.

I den ene av oppspenningsanordningens 21 ende-punkter, som er kjennetegnet med A (fig.2), spennes den stiplet inntegnede posen 2 opp på spennbakkene 31 og 32 med åpningen 4. I tillegg forskyves spennbakken 31, ved hjelp av trykksylinderen 35 et øyeblikk innover, slik at posen 2 lett kan vendes. Deretter kjøres sugesverdet 22, ved hjelp av trykksylinderen 46, den med a betegnede vei inn i posen 2. Ved hjelp av rullebanens 19 medbringer 20 og/eller trykksylinderen 49, som kan drives synkront, forskyves oppspenningsanordningen 21 så vel som sugesverdet 22 veistrekningen b horisontalt til den andre, med B betegnede, endestillingen (fig. 3). Under denne forskyvningsbevegelsen evakueres posen 2, eventuelt kan den også gasses under denne operasjonen. In one of the end points of the tensioning device 21, which is characterized by A (fig. 2), the dashed bag 2 is tensioned onto the clamping jaws 31 and 32 with the opening 4. In addition, the clamping jaw 31 is displaced, with the help of the pressure cylinder 35, for a moment inwards, so that bag 2 can be easily turned over. The suction blade 22 is then driven, with the help of the pressure cylinder 46, the path indicated by a into the bag 2. With the help of the runway 19's carrier 20 and/or the pressure cylinder 49, which can be operated synchronously, the tensioning device 21 as well as the suction blade 22 are displaced along the road section b horizontally to the other end position, denoted by B (fig. 3). During this displacement movement, the bag 2 is evacuated, possibly it can also be gassed during this operation.

I posisjon B heves sugesverdet 22 og oppspenningsanordningen 21, etter avsluttet evakuering, veistrekningen c hhv. d ved hjelp av trykksylinderen 46 hhv. 38, og sveiseanordningens 53 sveisebakker 51 og 52 trykkes mot posen 2, slik.at ingen falskluft kan trenge inn i denne. Under tilbakekjøringen av oppspenningsanordningen 21 og sugesvefdet 22 til posisjon A (veistrekningen e) kan følgelig poseåpn.ingen 4 sveises og sveisesømmen kan av-kjøles. Men samtidig kan allerede, straks oppspenningsanordningen 21 er senket med veistrekningen f, en ny pose 2 spennes opp, slik at de enkelte arbeidsoperasjoner over- In position B, the suction blade 22 and the tensioning device 21 are raised, after the evacuation has been completed, the road section c respectively. d by means of the pressure cylinder 46 or 38, and the welding trays 51 and 52 of the welding device 53 are pressed against the bag 2, so that no false air can penetrate into it. During the return movement of the tensioning device 21 and the suction web 22 to position A (pathway e), the bag opening 4 can consequently be welded and the welding seam can be cooled. But at the same time, as soon as the tensioning device 21 has been lowered with the road section f, a new bag 2 can be tensioned up, so that the individual work operations over-

i in

lapper hverandre og altså en rasjonell arbeidsmåte er gitt. complement each other and thus a rational way of working is provided.

Selvfølgelig er det uten" videre mulig å tilpasseOf course, it is without further ado possible to adapt

de enkelte bevegelsesforløp til de til enhver tid gitte omstendigheter hhv. kan oppspenningsanordningen også anord-'nes stasjonært, slik at horisontale forskyvningsbevegelser ikke er nødvendige. the individual courses of movement to the given circumstances at any given time or the tensioning device can also be arranged stationary, so that horizontal displacement movements are not necessary.

Det i fig. 4 fremstilte sugesverdet 22' er delt omtrent på midten og mellom de to sverddelene er det an- . ordnet spennbakker 32' og 32'', som arbeider sammen med spennbakker 31' og 31'1 som er anbrakt på begge sider, av sugesverdet 22'. Til dette tjener en trykksylinder 35', som er utstyrt med to stempler som kan forskyves utover, ved hvilken spennbakkene 31' og 31'' er forbundet. På denne måten er det mulig, samtidig å spenne opp to poser 2' og 21'. og å evakuere ved hjelp av sugesverdet 22<*>. That in fig. 4, the suction sword 22' produced is divided approximately in the middle and between the two sword parts there is an- . arranged clamping jaws 32' and 32'', which work together with clamping jaws 31' and 31'1 which are placed on both sides of the suction bar 22'. For this, a pressure cylinder 35' is used, which is equipped with two pistons which can be displaced outwards, by which the clamping jaws 31' and 31'' are connected. In this way, it is possible to simultaneously open two bags 2' and 21'. and to evacuate using the suction sword 22<*>.

Claims

1. Device for mechanical evacuation and closing of plastic bags, preferably filled with fresh meat or fresh fish, of air- and moisture-tight, weldable plastic, characterized by a. vertically movable clamping device (21) which picks up the filled bag (2) at the bag suspension, and which is formed by at least two clamping jaws (31, 32), a suction blade (22) which can be inserted between them into the bag (2), and which together with the tensioning device (21) is arranged <;> a support stand (11), as well as a welding device formed by relative to each other movable welding trays (51, 52),...by which the bag opening (4) can be closed and welded after evacuation and /or fumigation of the bag.

2. Device according to claim 1, characterized in that the clamping device (21) and the suction blade (22) together are arranged horizontally movable in a stepwise manner in the support stand (11).

3. Device according to claim 2, characterized in that with a horizontally movable clamping device (21), the bag (2) can be evacuated and gassed during the pushing movement and the bag opening (4) is closed and welded in the end position (B) of the bag (2).

4. Device according to one or more of claims 1 to

3, characterized in that the bags (2) are supported on a runway. (19) which proceed in parallel with the tensioning device's. (21) displacement motion.

5. Device according to claim 4, characterized in that the runway (19) is equipped with, preferably spring-loaded, carriers (20), which are driven forward synchronously with the tensioning device (21) in a horizontal direction, and which act on the bags (2) or containers ( 3) which captures these.

6. Device according to one or more of claims 1 to 5, characterized by . that the tensioning device (21), the suction blade (22) as well as the welding device (23) and their drive mechanisms (38, 46, 49, 53) are arranged, for example, by an adjustable screw spindle (15) etc., and together are movable vertically in relation to the runway (19).

7. Device according to one or more of claims 1 to 6, characterized in that at least one of the tensioning device (21) clamping jaws (31), by means of <*> a servo device in the form of a pressure cylinder (35), an angle rod arm or the like, is placed horizontally displaceable or pivotable on a guide piece (33) to be able to pick up the bag. (2).

8. Device according to one or more of claims 1 to 7, characterized in that at least one of the tensioning device (21) clamping jaws (32) for adaptation to different bag sizes is arranged to be horizontally displaceable (long hole 36), or with the end that takes up the bag (2) arranged on a guide piece (39), pivotable in the direction of the suction blade (22).

9. Device according to one or more of claims 1 to 8, characterized in that the clamping jaws (31, 32) of the tensioning device (21) have a cross-sectional shape as outwardly directed wedge pieces.

10. Device according to one or more of claims 1 to 9, characterized in that the suction blade (22) is formed by two plates (41, 42) which are held from . each other by means of spacer strips (43), and that the plates (41, 42) and/or the spacer strips (42) incorporate suction openings (44), preferably at the outer edge of the suction blade (22).

11. Device according to claim 10, characterized in that the end of the suction blade (22) which is fed into the bag (2) is double wedge-shaped, or slanted in both cantonment councils.

12. Device according to one or more of the requirements 1 to .11, characterized in that the suction sword.

(22') is divided approximately in the middle and that, in order to be able to simultaneously open two bags (2', 2''), two clamping jaws (32', 32'') are arranged between the two sword parts which work together with the two displaceable clamping jaws (31 <1> , 31'') which are placed on both sides of the suction blade (22 <1> )..

13. Method for mechanical evacuation and welding together of plastic bags, preferably filled with fresh meat or fresh fish, made of air- and moisture-tight, weldable plastic, characterized in that the filled plastic bags (2) at the bag opening (4) are clamped open in a clamping device (21) which consists of at least two clamping jaws (31, 32), and which is arranged in a support stand (11), that then a suction blade (22), which engages in the clamping jaws (31, 32), is driven in in the bag (2) partially or to the base of the item to be wrapped, that the bag (2) is then evacuated and/or gassed, and that then the tensioning device (21) as well as the suction blade (22) are raised vertically and returned to the starting position (A ) and the bag (2) at the same time with the help of movable welding trays (51, 52) in the area of the bag opening are closed and welded.

14.. Device according to claim 13, characterized in that the clamping device (21) and the suction blade (22) together are arranged horizontally displaceable in the support stand (11) and that evacuation and gassing of the bag (2) takes place during the displacement movement and then the welding and gassing is carried out in the end position (B).