JPH08310512A - Packaging device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To package an article packaged in a pouch at a specified high vacuum level by attaching a probe assembly telescopically extended or contracted by a guide member so as to be axially transferable and providing the pouch with a clamp means and a seal means. SOLUTION: This vacuum packaging device is constituted of a frame 54 supporting a pouch 10, a sesl assembly 58 having upper and lower sealing jaws, a clamp assembly 60 including upper and lower clamping jaws, and a probe assembly 62 telescopically extending/contracting along a guide member. The probe assembly 62 is attached to a fitting part 64 by an extensible/contractible means 65 for the probe so as to be axially extensible, and connected to a vacuum source. An objective 20 and the probe assembly 62 are inserted into the pouch 10 in a state that the probe is stretched, and fixed by the clamp assemly 60 and then, the inside of the pouch 10 is vacuumized. Then, the probe is retracted and the pouch 10 is hermetically sealed by the seal assembly 58.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for packaging objects, and more particularly to an apparatus and method for vacuum sealing objects in various sizes of pouches.

[0002]

BACKGROUND OF THE INVENTION Various devices and methods for packaging or pouching objects, particularly objects made of flexible material, in containers are well known. These known devices and methods have limited ability to be easily adjusted as the size of the object and / or the size and / or type of the container changes. Many of these known devices and methods also have a limited ability to package or pouch objects that require more careful handling, because the objects are easily damaged or the structure is not stable. . For example, a slippery sheet-shaped stack of X-ray films has a high sensitivity to scratches and pressure marks of the film and must be handled with care. Furthermore,
The deposits of these objects have a slippery surface which makes it easier to slip out of the desired correct rectangular deposit shape to pouch irregularly misaligned deposits, and It is difficult to package. The target is often vacuum sealed in the pouch to prevent the target from slipping out of the stack. The degree of vacuum affects the quality of the packaging when heat sealing to maintain the vacuum in the sealed pouch. Sufficient vacuum and sealing are required to ensure that the object fits within the pouch while allowing the user to tear and release the pouch to remove the object.

FIG. 15 shows a typical pouch and target part.
The pouch 10 can be formed from a pair of, preferably congruent, side walls 12, 14 that are opposed. Side wall 12, 1
The peripheral portions 4 are fixed to each other by a peripheral seal portion 16, for example, continuous heat fusion, but one side end portion is not fixed, thereby forming an opening or a mouth 18. The secured sides have features such as flaps, lips, strips, etc. that are desirable for a particular application.
A typical example of an object to be packaged is a single object or a stack 20 of essentially rectangular sheet material. Deposit 20
The top and bottom sheets of are covered with dunnage plates 22, 24 to protect the objects during handling. Once the object is positioned within the pouch 10, the pouch 10 can be evacuated so that the sidewalls 12, 14 generally conform to the shape of the object. Opening 1
8 is closed by a seal 26 to protect the packaged object of the general shape shown in FIG.

US Pat. No. 5,265,397, incorporated herein by reference, discloses a flexible device and method for loading and sealing pouches. Referring to FIG. 17, the pouch 10 is positioned for evacuation and sealing. A pouch evacuation device 28 is provided. This pouch evacuation device is equipped with a pneumatic actuator 30. A working rod of an actuator 30 extends to the rear of the device and supports a support block 32 extending in the transverse direction so as not to move. The support block 32 supports a pair of vacuum exhaust probes or vacuum exhaust pipes 34 (only one of which is shown in FIG. 17). The probe 34 is located generally on the centerline of the open opening 18 of the pouch 10 and is connected to a suitable vacuum source. Upper and lower pouch closure, sealing jaws 36 are disposed above and below the probe 34. The closing sealing jaw 36
It has a pair of pneumatic upper and lower actuators 38. The vertical actuator 38 has a working rod 40, and the working rod 40 has a mounting bar 42 extending in the transverse direction.
I support. Mounted to the mounting bar 42 are a pair of transversely extending heat-sealing bars or sealing jaws 44 that are aligned in a line and are opposed to each other. Working bar 46 of pneumatic upper and lower actuator 48
Is a pair of transversely extending pouch closure bars or clamping jaws 5 that are arranged in parallel and are opposed to each other.
We support 0. Each of the clamping jaws 50 has a pressing layer 52 of foamed rubber or similar elastic material on the side facing the probe. Actuator 30
The action rod 34 is extended so that the pouch 10 is extended through the opening.
Insert into the vicinity of the object packaged inside. Then
The actuator 48 is actuated and the clamping jaws 50 are advanced to contact the sidewall of the pouch 10. Thus, the pressing layer 5
2 mechanically seals the two sidewalls and the perimeter of the probe 34 from each other. Vacuum is then applied to the probe 34 for a time sufficient to evacuate the pouch, after which
The probe 34 has a heat fusion bar 44 with a vacuum applied.
Is pulled back to behind. Then, the actuator 38
Is activated to press the sealing jaw 44 into contact with the pouch 10 to form the seal portion 26, and the packaging is completed. The vacuum is then stopped and the actuators 38, 48 are stopped to release the package.

[0005]

Problems to be Solved by the Invention US Patent Publication No. A-5
265397 has achieved some success, but the vacuum level of the sealed pouch is not constant. Therefore, there is a continuing need for a device that accurately controls the vacuum in the vacuum sealing process, maintains a constant vacuum level inside the finished pouch, and achieves a high vacuum level during the vacuum sealing process. Further, there is a need for a method of selectively heat-sealing a pouch to provide a heat-sealed portion.

It is an object of the present invention to provide a packaging apparatus that precisely controls the vacuum level, keeps the vacuum level of the packaged object constant, and achieves a high vacuum level during the vacuum sealing process. is there.

A further object of the present invention is to provide a device for mechanically sealing in a vacuum evacuation process.
Further, the present invention is to provide a device that does not become clogged during the vacuum sealing process. A further object of the present invention is to provide a method for selectively controlling the heat fusion process.

These objects will be achieved by the illustrated example, but will be apparent to those skilled in the art as other objects and advantages inherent in the disclosed invention. The invention is defined by the scope of the claims.

[0009]

According to the present invention, there is provided a packaging device for packaging an object in a pouch, that is, a pouch having side walls secured to each other and having open openings. A frame having a support surface for supporting the pouch is provided. A probe assembly is supported on the frame. The probe assembly includes a probe and a probe guide member that telescopically extends and contracts to surround the probe. The probe is provided so as to be movable in the axial direction relative to the probe guide member, and has an end that is inserted into the pouch through the opened opening. The probe is further formed with an axial channel through which air flows, and when vacuum is applied to the axial channel, air is removed from the pouch. A clamp assembly is mounted transversely to the probe assembly. The clamp assembly includes a pair of clamping jaws that are movable relative to each other in an open position and a closed position. Engage and pinch the pouch around the probe guide member when the clamping jaws are in the closed position. A seal assembly is mounted transversely to the probe assembly and is disposed between the object in the pouch and the clamp assembly. The seal assembly includes a pair of sealing jaws that are relatively movable between an open position and a closed position. In the closed position, a sealing jaw engages the pouch between them to form a seal in the open opening.

According to another feature of the invention, the device comprises
A frame having a supporting surface for supporting the pouch and the probe assembly is provided. The probe assembly includes a probe guide member that telescopically extends and surrounds the probe. The probe is provided so as to be movable in the axial direction relative to the probe guide member, and
It has an end that passes through the open opening and is inserted into the pouch. Means are provided for moving the probe between an advanced position and a retracted position for entering the pouch. The probe is further formed with an axial channel through which air flows. Air is removed from the pouch when a vacuum is applied to the axial channels. A clamp assembly is mounted transversely to the probe assembly and includes a pair of clamping jaws movably mounted in an open position and a closed position. Each of the clamping jaws has a notch that defines an opening. The opening has a shape substantially complementary to the outer shape of the probe guide member. The opening engages and clamps the pouch around the probe guide member when the clamping jaws are in the closed position. A seal assembly is mounted transversely to the probe assembly and is disposed between the object in the pouch and the clamp assembly. The seal assembly is
It includes a pair of sealing jaws that are relatively movable between an open position and a closed position. In the closed position, a sealing jaw engages the pouch between them to form a seal in the open opening.

According to yet another aspect of the invention, there is provided a method of selectively applying heat to a sealing jaw to heat seal an open opening in a pouch. The method comprises selecting a total thermal cycle time for applying heat to the pouch by the sealing jaws, selecting a cycle time increment shorter than the total thermal cycle time, and a maximum time shorter than the time increment. Selecting an increment, i.e. the maximum time increment during which heat can be applied to the sealing jaws during this time, and a desired temperature, i.e. the temperature at which the sealing jaws are heated to heat fusion, and the desired temperature. Selecting a lower baseline temperature, that is, a baseline temperature at which the application of heat to the sealing jaws is regulated. The heating time is calculated as follows. That is, the actual temperature of the sealing jaw is detected, the difference between the desired temperature and the actual temperature is determined, and if the difference is equal to or higher than the baseline temperature, the heating time is set to the maximum time. When the difference is larger than 0 and smaller than the baseline temperature, the heating time is set to a value smaller than the maximum time, and when the difference is 0 or less, the heating time is set to Set to 0. The sealing jaws are heated by the heating time and cooled by not heating the sealing jaws for the rest of the cycle time increment. The calculation step and the heating and cooling steps are repeated at each cycle time increment until the total heating cycle time is reached.

According to yet another aspect of the invention, there is provided an apparatus for selectively applying heat to a sealing jaw to heat seal an open opening of a pouch. The apparatus comprises means for selecting a total thermal cycle time for applying heat to the pouch by the sealing jaws, means for selecting a cycle time increment that is less than the total thermal cycle time, and a maximum time that is less than the time increment. Means for selecting an increment, i.e. the maximum time increment during which heat can be applied to the sealing jaw during this time, and a means for selecting a desired temperature, i.e. the temperature at which the sealing jaw is heated to heat seal, and said desired temperature. Means for selecting a lower baseline temperature, i.e., a baseline temperature at which the application of heat to the sealing jaws is regulated. This apparatus further comprises means for detecting the actual temperature of the sealing jaw, means for calculating the heating time based on the difference between the desired temperature and the actual temperature, means for heating the sealing jaw with the heating time, and Means for not heating the sealing jaw for the remainder of the cycle time increment.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the accompanying drawings, similar components are designated with the same reference numerals.
Referring again to FIG. 15, the pouch used in the present invention may be made of any material that is gas impermeable and heat-sealable. Such pouches can be stacked flat and easily picked up and transported by conventional means such as suction cups arranged in an array. The deposit 20 is, for example, a deposited X-ray film sheet or photographic paper. The opening 18 is held in an open state by a conventional means such as a suction cup arranged in an array.
Positioned in pouch 10 through 8.

FIG. 1 illustrates the device of the present invention. The apparatus includes a frame 54 having a support surface 56, a seal assembly 58 having upper and lower sealing jaws 44, a clamp assembly 60 having upper and lower clamping jaws 50, and a pouch vacuum having a probe assembly 62. An exhaust assembly 28, an attachment portion 64 for attaching the probe assembly 62 to the frame 54, probe extension means 65,
And a vacuum source cooperating with the probe assembly 62. As described in detail below, the probe assembly 62 holds the pouch 1 while the clamp assembly 60 secures the pouch 10.
Evacuate 0. When the air is evacuated, the seal assembly 58 seals the pouch 10 and then the clamp assembly 6
0 releases pouch 10.

A support surface 56 supports the pouch 10. A pouch source or hopper (not shown) may co-operate with or be attached to the support surface 56. The pouch 10 is removed from the pouch source and transported to the support surface 56 by any suitable means, such as manual or programmable robots. The support surface 56 is provided with guide fixtures (not shown) to orient the pouch 10 for sealing.

As shown in FIGS. 2 and 3, the probe assembly 6
2 includes a probe support member 66, an elongated probe guide member 68 having a tip 69, and an elongated substantially hollow probe 70 having a tip 72. The probe guide member 68 telescopically extends and surrounds the probe 70. That is, the first channel 74 extends axially through the probe guide member 68 and the probe support member 66. The probe 70 is tightly fitted within the first channel 74, i.e. inserted with a minimum clearance, to minimize leakage from between the probe 70 and the first channel 74. There is. Probe 70
Is movable axially within the first channel 74, and the probe extension means 65 allows the tip 72 of the probe to project outwardly from the tip of the probe guide member. The probe extension means 65 can be composed of, for example, the pneumatic actuator 30. In such a configuration, the probe 70 forms the inner tube of a telescoping telescopic probe and is capable of extending or contracting (ie, pulling back) from the guide member 68. Probe 70
A second channel 76 extends through the air passage, and air flows through the second channel to evacuate the pouch 10. In an alternative embodiment, the probe support member 6
6 telescopically expands and contracts to surround the probe guide member 68. That is, the probe guide member is axially disposed within the probe support member 66, for example, the pneumatic actuator 30.
The probe 70 can move axially within the probe guide member 68.

Referring to FIGS. 4-8, the seal assembly 5
8 are arranged transversely on the support surface 56 so as to be arranged between the stack 20 and the clamping assembly 60. A pair of sealing jaws 44 having sealing edges 82 are movable relative to each other between an open position and a closed position. In the open position, the sealing edges 82 are spaced apart from each other between which the pouch 10 and the probe 70 can be placed. In the closed position, the sealing edge 82 is in contact with the pouch 10, and heat can be applied to heat bond the unfixed end of the pouch 10. Conventional actuating means, such as a pneumatic actuator 38, can be used to move the sealing jaws 44 between the open and closed positions. When moving the sealing jaws to the closed position, one of the sealing jaws may hold the pouch and only the other may be moved,
Those skilled in the art will appreciate that both sealing jaws may be moved. The sealing jaws 44 can be of any length provided they have at least the length of the free ends of the pouch 10 for sealing.

Various forms of sealing jaws are known to those skilled in the art. For example, the sealing jaws 44 may include a thermal conductor, such as nickel (and chrome) containing NICHROME (Driver-Harri).
s), a heat insulating material, a supporting member (for example, aluminum), and a temperature sensor (for example, thermocouple 86).
And an elastic member (for example, a rubber material) that gives flexibility for sealing. 0.34 to 0.69 MPa (50 to 100 ps) to mechanically seal between the sealing jaws 44 and the pouch 10.
sealing pressure in the range of i), preferably 0.55M
A sealing pressure of Pa (80 psi) is suitable.

Clamp assembly 60 includes seal assembly 58.
Are arranged transversely to the support surface 60 such that the stacks are arranged between the stack 20 and the clamp assembly 60. 4, 5
As shown, the clamp assembly 60 includes two clamping jaws 50. Each of the clamping jaws 50 has a clamping edge 90. The clamping jaws 50 move relative to each other between the open and closed positions. In the open position, the clamping edges 90 are spaced apart from each other between which the pouch 10 and the probe guide member 68 can be arranged. In the closed position, the clamping edges 90 press against each other and engage and pinch the pouch 10 around the probe guide member 68 to clamp the clamping edge 90 and the probe guide member 6 together.
Mechanically seal between 8 and pouch 10. Conventional actuating means, such as a pneumatic actuator 38, can be used to move the clamping jaws 50 between the open and closed positions. It will be appreciated by those skilled in the art that when moving the clamping jaws to the closed position, one of the clamping jaws may be stationary and the pouch may be retained and only the other may be moved, or both clamping jaws may be moved. Will be understood. The clamping jaws 50 may be of any length as long as they have at least the length of the free end of the pouch 10 to clamp it.

Clamping jaw 50 engages and clamps probe guide member 68 around pouch 10 between clamping edge 90 and pouch 10, and between pouch 10 and probe guide member 68. , Side wall 1 of pouch 10
Mechanically seal between 2 and 14. The clamping jaws 50 may be of various configurations to mechanically seal and facilitate evacuation as described above. In the first embodiment shown in FIG. 4, each of the clamping edges 90 comprises an elastic layer 52, and in the second embodiment shown in FIG. 5, each of the clamping edges 90 forms a notch 9 forming an opening 98.
Four. The opening 98 may have a shape similar to the outer shape of the probe guide member 68, for example. In this case, the probe guide member 68 is positioned within the opening 98 (ie, the notch 94) when the clamping jaws 50 are in the closed position. FIG. 8 shows the clamping jaw 50 in the closed position, with the notch 94 engaging the probe guide member 68 and the pouch 10. A high clamping pressure ensures a mechanical seal and allows for precise control in the vacuum pumping process.

The probe guide member 68 (hence the opening 98)
And the notch 94) can be of various shapes, for example semi-circular, elliptical, oval or rhombic. FIG.
Indicates that the probe guide member 68 has a diamond shape and the inside angle is 60
1 illustrates one embodiment for the diamonds of degrees and 120 degrees. Similarly, the probe 70 and the first and second channels 7
The circular cross sections 4 and 76 are also shown, but they can have various shapes. The probe guide member 68 and the probe 70 can be formed from conventional materials such as Delrin or aluminum or stainless steel.

Clamping jaws 50 can be formed from conventional materials such as aluminum and steel. The clamping edge 90 is also made of the same material as the clamping jaw 50. When the clamping edge 90 includes the elastic layer 52, the elastic layer 52 is formed of an elastic material such as foamed rubber. Alternatively, as shown in FIG. 5, one of the clamping edges 90 has one elastic layer 62, eg, 30 to 7.
It may have an elastic layer 52 of polyurethane having a hardness of 0 durometer, preferably 40 durometer, with the other being an edge of a harder material. An appropriate clamping pressure is 0.
Pressures in the range of 69 to 1.38 MPa (100 to 200 psi).

Referring to FIGS. 1-9, the probe assembly 62 is attached to the mounting portion 64. Mounting part 64
Is a flexible coupling 100, for example a rubber coupling, and a mounting bracket 1 for mounting to the frame 54.
02 and a probe holder 104. The mount 64 does not necessarily require the flexible coupling 100, but some flexibility is preferred as it increases system flexibility. For example, the connector 100 provides flexibility when the pouch 10 is clamped between the notches 94 around the probe guide member 68. Other mounting means for mounting the probe assembly 62 are known to those skilled in the art.

Attached to the probe assembly 62 is a tube 106 or similar means for passing air. A vacuum source or vacuum generator 108 is connected to the tube 106 and evacuates air from the pouch 10 to create a vacuum. Vacuum sensor 110 detects the level of vacuum within tube 106, or pouch 10. A programmable logic controller (hereinafter, simply referred to as PLC (Programmable Logic Controller)) 112 converts a vacuum level detected by the vacuum sensor 110 into an electric signal via a converter (transducer or converter) 113. And transmits it to the vacuum generator 108.

The operation of the apparatus will be described with reference to the flowchart shown in FIG. The clamping jaws 50 and the sealing jaws 44 are moved to the open position to effect the wrapping action (step 114). The probe assembly 62 is located approximately on the centerline of the open opening 18 of the pouch 10,
It is preferably arranged parallel to the support surface 56. The probe 70 can extend and retract with respect to the probe guide member 68. Similarly, when the probe guide member 68 can move relative to the probe support member 66, the probe guide member 68 can extend and retract with respect to the probe support member 66. In this embodiment, the probe guide member 68 does not move relative to the probe support member 66, the probe 70 is in the extended position (step 114), and the pouch 10 inserts the opening 18 into the probe assembly 62. Support, holding frame 5
6 and the upper frame 54 (step 116). Probe guide member 68 and probe 70
Is inserted into the opening 18 of the pouch 10. The positioning of the pouch 10 depends on the application, but the seal assembly 58
And clamp assembly 60 are arranged to be engaged. The relative position of the probe assembly 62 with respect to the pouch 10 depends on the application. That is, it differs depending on the size of the pouch 10 and the arrangement of the stack 20 within the pouch 10. For example, as shown in FIG. 1, when the stack 20 is placed on the right side of the pouch 10, the probe assembly 62 is placed on the left side of the pouch 10. The probe assembly 20 may be located above the stack 20. The notch 94 engages with the probe guide member 68 and the pouch 10,
The probe assembly 62 is positioned within the pouch 10 so that it does not engage the probe support 66 or the probe 70. The sealing edge 82 must not interact with either the probe support member 66 or the probe guide member 68 when in the closed position. Furthermore, the sealing edge 82 must also not interact with the inserted probe 70 in the extended or retracted position when in the closed position. The probe 70 must extend within a few millimeters of the stack 20. Preferably, the distance from the probe tip 72 to the deposit 20 is
About 1 of the thickness of the stack 20 (that is, the object to be packaged)
/ 2. The above arrangement prevents the probe 70 from being blocked during vacuum pumping (ie, does not become clogged with the deposit 20 or the pouch 10 or the pouch does not collapse around the probe 70). .

At step 118, parameters such as time, temperature and vacuum level settings are initialized. These parameters can either be manually initialized or the PLC can be run as a full process controller while the device is operating.
It can be set by providing a central device such as 112. Such a central device includes a menu 119 (FIG. 9) that allows a user to select a preset parameter stored for a specific shape of an object or pouch and recall the setting with one selection. An interface can be provided. This makes it possible to instantly set up established, variable and repeatable results, independent of human error.
It is then possible to diagnose the process and establish product quality standards.

The clamping jaws 50 are moved to the closed position and the notches 94 are provided on the pouch 1 around the probe guide member 68.
It engages with 0 and clamps it (step 120). A vacuum is applied (step 122) and maintained (step 124) until it is determined that the desired vacuum level has been reached (step 126). The probe 70 is retracted while maintaining the vacuum (step 128). Sealing jaw 44
Moves to the closed position, engages pouch 10 and presses it (step 130). The vacuum is shut off when the sealing jaws 44 are closed (step 132). Alternatively, the application of vacuum may be maintained until the heat seal is made. When the sealing jaws 44 are closed, heat is applied to the sealing jaws 44 to heat seal the pouch 10 (step 13).
4). The application of heat is stopped when the desired seal is obtained, but the sealing jaws 44 are cooled while still held in the closed position (step 136). The sealing jaws 44 are then moved to the open position (step 13
8) The clamping jaws 50 are opened and the pouch 10 is released (step 140). The sealed pouch 10 is then removed by conventional means (step 14).
2). The probe 70 is then extended and ready to wrap the next pouch (step 144). If the next pouch is to be packaged (Y in step 146), the process is repeated from step 116. At this time, depending on the application example, it may not be necessary to initialize the parameters in step 118. If the next pouch is not packaged (N in step 146), the process stops (step 14).
8).

The parameters initialized in step 118, which can be set using the menu 119,
For example, it contains the following items: -The desired temperature T which is the set temperature for sealing the pouch 10.
D (° C) -used as the baseline temperature in the heating process,
Adjusted temperature TR (° C) which is a temperature level for adjusting the amount of heat applied to the sealing jaw-Vacuum level to be applied to the pouch (mmHg) -Proceeding before PLC detects the vacuum level by the vacuum sensor 110 Standby time (seconds) -Vacuum boost, which is an optional setting for powerful evacuation in the initial stage of the vacuum process when evacuating a large pouch-Heating time, which is the total time for heating the sealing jaws 44
(Sec) -Cooling time, which is the total time that heating is stopped after the sealing jaws 44 are heated and heat is dissipated from the sealing jaws.
(Seconds)

The other parameters are, for example, typically set in a menu for each device (thus, it is not necessary to set them in individual packaging processes) and include the following items. -Time increments or intervals during which individual operations are carried out in the packaging process CTI (seconds) -minimum time MIN (seconds) for heating the sealing jaws at individual cycle time increments-when the sealing jaws have not reached said baseline temperature Maximum heating time for sealing jaws in individual cycle time increments MAX (seconds)

The time increment CTI is a constant K (second) in the maximum time.
Is equal to the time added. That is, CTI = MAX + K
Is. The constant K can be set to MIN or any number. Alternatively, MAX and MIN can be set as a percentage of CTI.

Referring to FIG. 9, the PLC 112 converts the vacuum level detected by the vacuum sensor 110 into the converter 11.
3 to the vacuum generator 108. Preferably, the signal from PLC 112 is a DC voltage between 0 and 10V and is converted by converter 113 to 0 to 762mmH.
g (0 to 30 inchHg). The signal from the vacuum sensor 110 is a DC voltage between 0 and 5V. When the vacuum is applied in step 122, PLC 112 delays detection until the waiting time has elapsed. Due to this waiting time, it is possible to read an appropriate vacuum level even if a sudden change in the vacuum level occurs due to the start of application of the vacuum. When the waiting time has elapsed, the PLC 112 commands the vacuum sensor 110 to detect the vacuum level once during each cycle time increment. When the desired vacuum level is reached, the PLC 112 will generate a signal for the next step to be performed. If the desired vacuum level is not reached, an error signal is generated. Once the sealing jaws 44 are closed, the PLC 112 stops applying vacuum at step 132. A closed loop vacuum level control system is thus constructed. A time control function can also be used when controlling the vacuum to a very low level, such as removing excess air.

Although various methods of controlling the heat of the sealing jaws are well known to those skilled in the art, the present invention employs a closed loop temperature control system for impulse sealing.
The PLC 112 executes temperature control. The actual temperature TA of the sealing jaws is sensed by thermocouple 86 and compared to the desired temperature TD (which may use multiple thermocouples). PLC1
12 calculates the difference (DIFF) between the two temperature values (that is, DIFF = TD-TA). Then, logic is provided to set the heating time to provide a pulse width modulated input to the semiconductor relay at each cycle time increment. This relay allows low voltage, high current alternating current to each heat conductor. This pulse width modulation is based on DIFF for each cycle time increment based on the heating time (HON) and heating stop time (HOF).
It is achieved by dividing into F) and. That is, D
If the value of IFF is small, then the value of HON is reduced to reduce the time that heat is applied to the sealing jaws.

Sealing jaw heating process (step 1
34) and the cooling process (step 136) are shown in FIGS. Once the parameters have been selected (step 150), the actual temperature T of the sealing jaws 44
A is sensed using, for example, thermocouple 86 (step 152). Next, the difference DIF between the desired temperature TD and the actual temperature TA
F is calculated (step 154), and DIFF is adjusted temperature T.
It is determined whether it is larger than R (step 156).
If DIFF is higher than the adjusted temperature TR (Y in step 156), the value of MAX is set in HON,
The value of CTI-MAX is set in HOFF (step 158). If DIFF is not higher than the adjustment temperature TR (N in step 156), it is determined whether DIFF is lower than the adjustment temperature TR and is a positive value (step 160). If 0 <DIFF <TR, Z is calculated (step 162). Z
Is smaller than MIN (Y in step 164), the MIN value is set in HON and the CTI-MIN value is set in HOFF in step 166. If Z is greater than MIN (step 164
In the case of N), the value of Z is set in HON and the value of CTI-Z is set in HOFF in step 168. D
When IFF is not between TR and 0 (that is, when DIFF becomes a negative value and becomes N in step 160), HON is set to 0.0 and HOFF is set to CTI in step 170. . Under this set point, the sealing jaws are heated during HON and stopped during HOFF (step 174). Steps 152 to 174 are repeated until the heating time is reached (step 178).
And N). When the heating time is reached (Y in step 178), heating of the sealing jaws is stopped in step 180. At this time, the cooling timer starts. During the cooling time, the condition is maintained, that is, the sealing and clamping jaws are held in the closed position (step 182).
This properly forms the seal. This is because there are materials, such as monomeric polyurethanes, that must be pressed and cooled for consistent results. With such materials, heat must be dissipated in the area of the sealing jaws, requiring complex cooling methods such as water cooling. When the cooling time has elapsed, the PLC 112 commands the sealing jaws to open (step 138).
If the process did not run as described above,
PLC 112 displays an error condition.

An example of the process outlined in FIGS. 11 and 12 is shown in FIGS. 13 and 14 and Table 1. 13 and 14, the time increment is rounded to 0.01 second. The set parameters are as follows. MIN = 0.02 seconds MAX = 0.08 seconds K = 0.02 CTI = MAX + K = 0.1 seconds TR = 15.6 ° C. (60 ° F.) TD = 48.9 ° C. (120 ° F.) Heating Time = 1.0 seconds

FIG. 13 shows the temperature change with time for heating the sealing jaw, and FIG. 14 shows the heating pattern of the sealing jaw with time.

For example, at time 0.1 second, the temperature TA in FIG. 13 is about -3.9 ° C (25 ° F), and therefore DIFF = TA-TD = 48.9-(-3.9). ) = 5
2.8 ° C (120-25 = 95 ° F). DIFF = 52.8 ° C. (95 ° F.)> TR =
Since it is 15.6 ° C (60 ° F), HON is set to 0.08, and HOFF = CTI-MAX = 0.1-0.0.
8 = 0.02 is calculated. As shown in FIG. 14, the sealing jaws are heated for 0.08 seconds and stopped for 0.02 seconds.

At time 0.5 seconds, the temperature TA in FIG. 13 becomes about 43.3 ° C. (110 ° F.), and 0 <DIFF =
5.5 ° C (10 ° F) <TR = 15.6 ° C (60 °
Since it is F), Z is calculated to be 0.013. Z = 0.0
Since 13 <MIN = 0.02 seconds, HON is set to 0.02 and HOFF = 0.08 is calculated. As shown in FIG. 14, the sealing jaws are heated for 0.02 seconds and stopped for 0.08 seconds.

Table 1 Time TA DIFF ZZ <MIN HON HOFF ───────────────────────────────────── 0 O 120 − − 0.08 0.02 0.1 25 95 − − 0.08 0.02 0.2 45 74 − − 0.08 0.02 0.3 65 55 0.073 N 0.07 * 0.03 0.4 90 30 0.04 N 0.04 0.06 0.5 110 10 0.013 Y 0.02 0.08 0.6 125 -5 − − 0.00 0.10 0.7 115 5 0.006 Y 0.02 0.08 0.8 115 5 0.006 Y 0.02 0.08 0.9 115 5 0.006 Y 0.02 0.08 1.0 121 -1 − − 0.00 0.10 * This value is a value rounded with a time increment of 0.01 seconds

The method described above is a heating control method suitable for various pouch materials. This method is suitable for temperature-sensitive products, where the desired temperature rises too high to cause product fires, and for processes where cycle time is important. As described above, the heat control depends on the set values of the parameters input by the user in the menu 119.

In a system in which a predetermined amount of heat is applied during a preset time, a heat control method of turning on and off with time is also possible. With such a control method, especially in high speed applications, heat is applied and absorbed over time.

[0041]

According to the present invention, the vacuum level of the packaged object can be kept accurate and constant, and a high vacuum level can be achieved during the vacuum sealing process.

[Brief description of drawings]

FIG. 1 is a plan view of a packaging device of the present invention.

FIG. 2 is a side view of the probe assembly of the present invention.

3 is an enlarged end view of the probe assembly, not seen from the right in FIG.

4 is a cross-sectional view of the device according to the first embodiment of the present invention, taken along the line 7-7 in FIG.

5 is a sectional view of the device according to the second embodiment of the present invention, which is a sectional view taken along the line 7-7 in FIG.

6 is a cross-sectional view of the device of the present invention taken along the line 8-8 of FIG.

7 is a cross-sectional view of the device of the present invention taken along the line 9-9 of FIG.

8 is an end view of the clamping jaw shown in FIG. 5 in the closed position.

FIG. 9 is a schematic side view of a probe assembly and a mounting portion.

FIG. 10 is a flow chart of the method of the present invention.

FIG. 11 is a flow chart of the method of the present invention.

FIG. 12 is a flow chart of the method of the present invention.

FIG. 13 is a graph showing an example of temperature change when the sealing jaw of the present invention is heated.

FIG. 14 is a graph corresponding to FIG. 13, showing an example of a heat pattern applied when heating the sealing jaw of the present invention.

FIG. 15 is a schematic perspective view of a pouch and an object known in the prior art and usable in the present invention.

FIG. 16 is a schematic perspective view of a completed package of the type that is closed and sealed by the device of the present invention.

FIG. 17 closes a pouch of the type shown in FIGS.
1 is a cross-sectional view of a prior art device for sealing.

[Explanation of symbols]

 10 ... Pouch 16 ... Seal 20 ... Object 44 ... Sealing jaw 50 ... Clamping jaw 54 ... Frame 58 ... Seal assembly 60 ... Clamp assembly 66 ... Probe support member 68 ... Probe guide member 70 ... Probe 72 ... Probe tip

 ─────────────────────────────────────────────────── --Continued Front Page (72) Inventor James Bradley Roy USA, New York 14519, Ontario, Rosemary Lane 2778

Claims (4)

[Claims] 1. A packaging device for packaging an object in a pouch, that is, a pouch having side walls fixed to each other and having openings opened, and a frame having a support surface for supporting the pouch, and a frame supported by the frame. A probe assembly having a probe and a probe guide member that telescopically extends and surrounds the probe, wherein the probe is provided so as to be movable in the axial direction relative to the probe guide member. ,
And a probe assembly having an end portion that is inserted into the pouch through the opened opening and further has an axial channel through which air flows, and the probe is inserted into the pouch. Means for moving between an advanced position and a retracted position, a means for applying a vacuum to the axial channel to remove air from the pouch, and a clamp mounted relative to the probe assembly. An assembly, ie, a first clamping jaw movably mounted with respect to a second clamping jaw between an open position and a closed position, the first and second clamping jaws comprising: A clamp assembly that engages and clamps the pouch around the probe guide member when in the closed position; and an eye in the pouch that is mounted relative to the probe assembly. A seal assembly disposed between a target object and the clamp assembly, the seal assembly being moveable relative to a second sealing jaw between an open position and a closed position. The first position in the closed position
And a second sealing jaw between them to engage the pouch to form a seal in the open opening. 2. The first and second clamping jaws each have an opening that is the same as the outer shape of the probe guide member,
The packaging device according to claim 1, wherein the pouch is engaged with and sandwiched around the probe guide member in the opening. 3. The probe assembly further comprises a probe support member which telescopically extends and contracts to surround the probe guide member, and the probe guide member is movable relative to the probe support member. The packaging device according to claim 1, wherein the packaging device is provided in. 4. A method of selectively applying heat to a sealing jaw to heat seal an open opening of a pouch, wherein a total thermal cycle time for applying heat to the pouch by the sealing jaw is selected. Selecting a cycle time increment that is less than the total thermal cycle time, and selecting a maximum time increment that is less than the time increment, i.e., a maximum time increment during which heat can be applied to the sealing jaws. Selecting a desired temperature, i.e. the temperature at which the sealing jaws are heated and heat-sealed to this temperature, and a baseline temperature lower than the desired temperature, i.e.
Selecting a baseline temperature at which the application of heat to the sealing jaws is adjusted by the baseline temperature; and a step of calculating a heating time, that is, detecting the actual temperature of the sealing jaws, the desired temperature and the If the difference from the actual temperature is determined and the difference is equal to or higher than the baseline temperature, the heating time is set to the maximum time, and the difference is larger than 0 and smaller than the baseline temperature. A step of calculating a heating time by setting the heating time to a value smaller than the maximum time, and setting the heating time to 0 when the difference is 0 or less; Heating the sealing jaws for a heating time and cooling the sealing jaws by not heating the sealing jaws for the remaining time of the cycle time increment; Until the thermal cycle time, In each cycle time increment, the method comprising said calculating step, and a step of repeating the heating and cooling steps.