WO1997000204A1

WO1997000204A1 - Method and device for packing open cell cellular plastic

Info

Publication number: WO1997000204A1
Application number: PCT/FI1996/000344
Authority: WO
Inventors: Matti HYÖKKI; Helmut Wiemers
Original assignee: Espe Oy
Priority date: 1995-06-14
Filing date: 1996-06-11
Publication date: 1997-01-03
Also published as: AU6006596A; FI952923A; FI100049B; FI952923A0

Abstract

The objective of the invention is a method for packing an elastic and compressible material, especially an open cell cellular plastic or a foamed plastic sheet or other corresponding material, in which method the material (1) is fed between two belt conveyors moving in the same direction, a first belt conveyor (4) and a second belt conveyor (5). The compressed material coming from between the belt conveyors (4, 5) is made to roll up into a roll (16) controlled by the guide roll (6) inside the pocket (22) expanding according to the size of the roll (16) formed by the belt system (8), whereupon packing material (10) is fed around the roll (16).

Description

METHOD AND DEVICE FOR PACKING OPEN CELL CELLULAR PLASTIC

The objective of the invention is a method for packing an elastic and compressible material, especially an open cell cellular plastic, a foamed plastic sheet or other correspond¬ ing material. The objective of the invention is additionally a device for the application of the method.

Packing foamed or open cell cellular plastic into a small space is difficult. Unpacked open cell cellular plastic is very bulky. Due to its lightness quite much "empty" space is left during transportation. The transport equipment could take a heavier weight but the volume of the transportation capacity is full. Compressible materials are usually packed for transportation or storing to be less bulky, e.g. in rolls, which are wrapped in paper or plastic. A method has been disclosed in which the compressible material is com¬ pressed by placing the foamed product into an airtight bag having one end open. The bag is pressed so that the air comes out of the bag opening, whereafter the bag is closed tightly. This method is however fairly difficult and generally only suitable for handling e.g. small pillows. It is further not applicable for compressing big quantities of compressible materials, because an even compression is difficult to achieve.

The method according to the invention provides a considerable improvement of the above mentioned disadvantages. The embodi¬ ment of this is mainly characterized in what is presented in the characteristic parts of claims 1 and 8.

A significant benefit of the invention is that large quanti¬ ties of compressible material can be rolled up simulta¬ neously. An even compression is also achieved on the whole roll and/or a thick pile of material.

One form of embodiment of the invention is below presented by examples and with reference to schematic drawings, in which figs. 1-4 illustrate different phases of the method according to the invention, and fig. 5 presents an example of the equipment used in the method.

Figs. 1-4 present the feeding of the piled foamed plastic material, i.e. the so called bale, to the compression device. The material, e.g. pile 1 of foamed plastic mattresses, comes along the conveyor having at its end a photocell which ob- serves the mattress pile 1 and stops the conveyor 2 if the previous packing phase is unfinished.

When the previous packing phase is finished, the conveyor 2, the belt conveyors 4, 5 accommodated to compress the materi- al, one of which 4 is placed from at least part of its length obliquely in relation to the other conveyor 5, and the guide roll 6 are started. The guide roll 6 is at least initially rotated according to the motion direction of the belt 2 (direction P), thus enabling the belt 8 to rotate the guide roll 6.

When the front edge 7 of the mattress pile 1 reaches the guide roll 6, which is also identified by e.g. the photocell, the rotation direction of the rotation roll 6 is changed (indicated by arrow P') and it does not touch the belt 8, and the belt 8 is simultaneously tightened by adjusting the pressure difference of the tension cylinder 18 (fig. 2). The basic pressure difference is e.g. approx. 2 bar. It can be increased to 2-6 bar by the control logic for approx. 1 second (the cylinder always in drive, minimum pressure di ference approx. 2 bar) .

The change of the rotation direction of the guide roll 6 secures that the frontal end of the compressible material 1 turns into the developing roll 16 thus preventing the material from being conveyed e.g. in between the conveyor belt 4 and the belt system 8. Especially thinner open cell cellular plastic and foamed plastic sheets tend to turn away from the compressing direction due to their very elastic expansibility. The guide roll 6 has also a corresponding significance in connection with thicker compressible material piles, when however the change of the rotation direction is not necessary.

The conveyor 5 rolls up the foamed plastic sheet so that the compressed material coming from between the belt conveyors 4, 5 is made to roll up from its end into the roll 16 inside the pocket 22 expanding with the size of the roll 16 formed by the belt 8, the packing material 10 is fed around the roll 16 rotating the roll 16 and is jointed. The compressed material 16 is made to roll up against the rotation roll 6, which rotation direction is changeable, and which is provided on the other side of the pocket 22 opening 23.

The rolling up time for a roll of approx. 2 m is about 8 seconds. The pressure difference of the tension cylinder 18 can be adjusted so that the diameter of the finished roll is standard independent of the length and cubic weight of the pile, or the tension is essentially the same for the whole area of the roll 16. The location of the tension cylinder 18 can thus be changed between two different positions.

The standard diameter is obtained by the belt stretcher 9 carriage location data, from which there is a control connec¬ tion to the cylinder pressure.

The cylinder pressures have to be adjusted also during the rolling in order to provide an as even-grained roll as possi¬ ble. This is also attended to by the control logic by adjusting the cylinder pressures.

Feeding of the packing material, preferably a filmy wrapping plastic 10, is started during the rolling and the front edge 11 of the plastic comes immediately after the mattress pile 1. The wrapping plastic feed rollers 12 start approx. 8 seconds after the predetermined time of the starting of the conveyors 5 and feed the wrapping plastic 10 during e.g. two rotations. To stabilize the feed of the wrapping plastic and to maintain the direction, a device 3 is preferably provided in the front edge 11 area of the wrapping plastic 10 to remove the static electricity. This device could e.g. consist of an antistatic bar or corresponding going transversely over the width of the wrapping plastic. The running out of wrapping plastic 10 is monitored by a limit switch 13 sensing the minimum diameter of the roll. The wrapping plastic 10 covering the roll 16 is fed after the head of the material along the same conveyor 5 as the compressible material.

The conveyors 2, 4 and 5 and the rotation roll 6 and the plastic feed rollers 12 are stopped when the mattress pile is packed into roll 16. Thereafter the resistance beam 19 located between the conveyors 2 and 5 and being in a standby position (not shown) for the cutting and jointing of the wrapping plastic is moved against the roll 16 e.g. with a pneumatic or hydraulic transfer gear 14, initially quickly and final motion slowly (limit). The compression force of the beam 19 against the roll 16 can also be adjusted. The resistance beam 19 is supported from both sides of the belt conveyor 8. The resistance beam is moved (it is movable by e.g. the chain conveyors 15) between two positions, in one of which the beam is provided between the conveyors 2 and 5 during rolling up, and in the other one the beam 19 is placed to touch the prepared roll 16 and also to joint the wrapping plastic 10 and to cut the wrapping plastic 10.

When the wrapping plastic 10 is cut, also the plastic feed rollers 12 draw the wrapping plastic 10 head back to waiting position 17 and the resistance beam 19 is returned to initial position between the two conveyors 2 and 5.

The tension of the belt 8 is reduced by adjusting the pres¬ sure difference of the cylinders to the basic setting of approx. 2 bar, whereafter the reverse roll 20 is turned up with the elevation cylinders 30 (fig. 5). The ready roll 16 pushed by the belt 5 rotates to the transverse roller conveyor 21. Controlled by the sensors the roll 16 is pushed aside by the transfer cylinder and simultaneously the piston returns the reverse roll. An opening 23 bigger than the roll is provided in the pocket opening 23 from which the belt 8 pushes the ready roll out (fig. 4). Thereafter the reverse roll is lowered with the elevation cylinders (limit) . A compression load of approx. 6 bar is left in the cylinders.

Packing of a new mattress pile can thereafter start.

The belt speed is adjusted to approx. 0,25 m/s. The work cycle time is thus maximum 2 min. All control devices are connected to an emergency stop-power failure-system, providing for the stopping of all motions.

Fig. 5 presents one form of embodiment of the equipment, in which preferably the cylinder 18 of the belt tension device 9, around which the belt 8 is accommodated to run, is placed to move in the carriage. The cylinder 18 is moved by the pneumatic cylinder 30 between positions presented in figs. 1 - 4. The compression beam is moved by the chain conveyors 24, which also are controlled by the pneumatic cylinder 31, the piston movement of which makes the gear rotate through a connection provided between the piston and the gear 25 thus moving the chain conveyors 24. For the moving of the complet¬ ed roll, the belt conveyor reverse roll 20 provided at the end of the arm, is turned up by turning the arm 26 with the pneumatic cylinder 32. In fig. 5 the steering arm and the reverse roll positions are presented both in upper (dashed line) and lower position.

The invention has been described above only with reference to one of its preferable forms of embodiment. The invention is, however, not to be considered as so restricted, but several modifications, e.g. the pneumatic cylinder can be substituted by a hydraulic cylinder, etc, are possible within the scope of the inventive idea according to the claims below.

Claims

1. A method for packing an elastic and compressible material, especially an open cell cellular plastic, a foamed plastic sheet or corresponding, in which method the elastic material (1) is fed between a first belt conveyor (4) and a second belt conveyor (5) and the compressed material coming from between the belt conveyors (4, 5) is made to roll up into a roll (16), c h a r a c t e r i z e d in that the roll (16) is formed inside a pocket (22) expanding along with the roll (16) size formed by the belt system (8), the forming of the roll (16) is controlled by a guide roll (6) provided in the area of the pocket (22) opening (23) receiving the material, and that packing material (10) is fed around the roll (16).

2. Method according to claim 1, c h a r a c t e r i z e d in that the compressed material is made to roll up at the pocket (22) opening (23) area against the guide roll (6), which rotation direction is changeable, and which is provided on the side of the first belt conveyor (4).

3. Method according to claims 1 and 2, c h a r a c t e r ¬ i z e d in that the ready roll (16) is removed from the rolling device by turning the belt system (8) reverse roll (20) provided on the other side of the pocket (22) opening (23) away from the opening so that the opening (23) becomes bigger than the roll, whereby the belt system (8) pushes the ready roll (16) out.

4. Method according to one of the claims above, c h a r a c ¬ t e r i z e d in that the tension of the belt system (8) is adjusted by tension means (9), which is a cylinder (18), the location of which can be moved steplessly between two diffe¬ rent positions, and that the belt system (8) tension is changed when forming the roll (16) and removing the ready roll (16).

5. Method according to one of the claims above, c h a r a c ¬ t e r i z e d in that the packing material (10) covering the roll (16) is fed after the material head along the same conveyor (5) as the compressible material (1).

6. Method according to claim 5, c h a r a c t e r i z e d in that the feeding of the packing material (10), e.g. a filmy wrapping plastic, is controlled by the feed rollers (12), the limit switch (13) and the device (3) removing the static electricity.

7. Method according to one of the claims above, c h a r a c ¬ t e r i z e d in that the jointing and cutting device (19) is moved against the ready roll (16) by supporting the device (19) from both sides of the conveyor (8).

8. An equipment for packing an elastic compressible material, especially an open cell cellular plastic or a foamed plastic sheet or corresponding, which equipment comprises essentially opposite each other accommodated a first belt conveyor (4) and a second belt conveyor (5) for receiving and compressing the elastic material, and devices for rolling up the material (1) into a roll (16), c h a r a c t e r i z e d in that the devices for rolling up the material (1) comprise the belt system (8), adapted for forming the pocket (22) expanding according to the size of the roll (16), a guide roll (6) is provided in the pocket (22) opening (23) area receiving the material (1) for controlling the forming of the roll (16), and that the equipment comprises the means (12, 13, 3) for feeding the packing material (10) around the roll (16).

9. An equipment according to claim 8, c h a r a c t e r ¬ i z e d in that the guide roll (6) is changeable to its rotation direction and accommodated on the pocket (22) opening (23) area on the side of the first belt conveyor (4).

10. An equipment according to claim 8, c h a r a c t e r - i z e d in that the means for feeding the packing material, preferably a filmy wrapping plastic (10), comprise the packing material feed rollers (12) and an adapted limit switch (13) for controlling the packing material feed and the device (3) for removing the static electricity.