CN114670460A

CN114670460A - Paper feeding unit, cutting unit and single-sheet plastic packaging device

Info

Publication number: CN114670460A
Application number: CN202210186749.4A
Authority: CN
Inventors: 李守祥; 杨佩林; 孟建民; 李双川
Original assignee: Beijing Ico Science & Technology Co ltd
Current assignee: Beijing Ico Science & Technology Co ltd
Priority date: 2022-02-28
Filing date: 2022-02-28
Publication date: 2022-06-28
Anticipated expiration: 2042-02-28
Also published as: CN114670460B

Abstract

The invention relates to a paper feeding unit, a cutting unit and a single-sheet plastic packaging device. The unit of form advancing is arranged in the device of plastic envelope sola, and this unit of form advancing includes: a base (12) comprising a chassis (121) and a support bracket (122) movably connected to the chassis (121), the support bracket (122) being adjustable in spacing from the chassis (121) based on a load; and the paper guide mechanism (14) is arranged on the support frame (122) and comprises a pair of guide plates (141) which are oppositely arranged and limit a containing space (143) and a push plate (144) which is arranged between the pair of guide plates (141) and can move along the feeding direction of the single sheets to be plastically packaged.

Description

Paper feeding unit, cutting unit and single-sheet plastic packaging device

Technical Field

The invention relates to the technical field of plastic packaging machinery, in particular to a paper feeding unit, a cutting unit and a single-sheet plastic packaging device.

Background

In the plastic packaging industry, the consumables used for plastic packaging can be basically divided into two types, namely, coiled materials and sheets. During sheet plastic packaging, a manufacturer of consumable materials needs to pre-cut and pre-bond the consumable materials. An operator needs to place a single sheet to be subjected to plastic packaging into the plastic packaging film one by one and then perform plastic packaging one by one. When batch operation is performed, a large amount of manpower is occupied by sheet plastic package, so that the efficiency is low and the cost is difficult to reduce. Therefore, coil plastic packaging becomes a priority for batch operations.

For the plastic package of the coiled material, the plastic package film is in a whole reel state as the name implies. The plastic packaging film does not need to be pre-cut and pre-bonded one by one before plastic packaging of the coiled material. An operator needs to put the single sheets to be subjected to plastic packaging into the plastic packaging machine one by one. After the plastic package is finished, the plastic package film packages a whole of a plurality of single sheets which are spaced side by side, and the whole state is also presented. And then, cutting the whole plastic packaging film by an operator according to the requirement to obtain single plastic packaged sheets. This operation has certain drawbacks. For example, a certain requirement is imposed on an operator in a paper feeding stage of feeding the sheet to be plastic-sealed into the plastic sealing machine, the operator needs to keep high concentration of energy when feeding the sheet to be plastic-sealed, otherwise a large amount of plastic sealing films are wasted.

At present, a paper feeding mechanism replacing manpower is developed, for example, a Chinese patent with the publication number of CN202967626U provides a paper feeding mechanism of a laminating machine paper feeder. However, in the preparation stage, the existing paper feeding mechanism usually needs to consume about 1 meter of plastic packaging film for preparation, and in the stage of waiting for the depletion of the single plastic packaging film and the paper supplement, the paper feeding mechanism needs to be stopped and restarted, and the preparation stage is repeated. The above-mentioned steps are repeated, so that the construction period is prolonged and the plastic-sealed coiled material has a large amount of loss. For another example, the whole plastic film after plastic packaging is either rolled into a cylinder or repeatedly folded, or laid flat. The former option results in the flatness of the plastic film together with the enclosed sheet being affected, while the latter option requires a sufficiently large field and keeps the field clean. When the whole plastic packaging film is cut, due to uncertainty (such as space size) of the single packaged film, manual cutting is usually used for final cutting, and consistency and stability of manual cutting are difficult to guarantee, and the requirement for manpower cannot be reduced. Automatic cutting designs have also been proposed, for example, chinese patent publication No. CN215399762U provides a cutting device for a plastic packaging press, but the conventional cutting device generally cannot cope with plastic packaging films of various specifications, and particularly cannot cut small (e.g., less than 80mic) roll plastic packaging films.

Disclosure of Invention

The present invention is directed to a paper feeding unit that solves at least some of the above problems.

The present invention also aims to provide a cutting unit that solves at least some of the above mentioned technical problems.

The invention also aims to provide a single-sheet plastic packaging device applying the improved paper feeding unit and the improved cutting unit.

According to an aspect of the present invention, there is provided a paper feeding unit for a sheet-fed plastic package apparatus, comprising: a base including an undercarriage and a support bracket movably connected to the undercarriage, the support bracket adjustable in spacing from the undercarriage based on a load; and the paper guide mechanism is arranged on the support frame and comprises a pair of guide plates which are oppositely arranged and limit a containing space and a push plate which is arranged between the pair of guide plates and can move along the feeding direction of the single paper to be sealed and sealed.

In some embodiments, an elastic member is connected between the push plate and the at least one guide plate, and the elastic member applies a force to the push plate to make the push plate approach the single sheet to be sealed and sealed along the feeding direction.

In some embodiments, the support frame is hinged to the base frame and an elastic support is connected between the support frame and the base frame, the elastic support applying a force to the support frame that moves the support frame away from the base frame.

In some embodiments, the pair of guide plates is adjustably disposed at an interval to the support frame, and the support frame is further provided with an interval adjusting mechanism connected to the pair of guide plates, the interval adjusting mechanism including: the pair of racks are arranged in parallel and at intervals and are connected with the pair of guide plates in a one-to-one correspondence manner; the gear is rotatably arranged on the support frame and positioned between the pair of racks, and the gear is meshed with the pair of racks respectively.

In some embodiments, the support frame is provided with a cam mechanism selectively drivingly engageable with the pair of guide plates, wherein during driving engagement of the cam mechanism with the pair of guide plates, the pair of guide plates together with the push plate move in a direction away from the support frame, and during disengagement of the cam mechanism from the pair of guide plates, the pair of guide plates together with the push plate move in a direction towards the support frame.

In some embodiments, the paper feeding unit further comprises a paper feeding mechanism, and the paper feeding mechanism comprises: the paper rolling wheel is rotatably arranged on one side of the supporting frame, which is back to the bottom frame, and the peripheral surface of the paper rolling wheel defines a contact surface which can be abutted against a single sheet to be plastic sealed and borne by the supporting frame; and the pair of paper feeding wheels are positioned at the downstream of the paper twisting wheel along the feeding direction, and rotate oppositely to each other and limit a paper feeding gap for receiving the single paper to be plastically packaged sent out by the paper twisting wheel between the paper feeding wheels.

In some embodiments, a gap adjustment mechanism is coupled to at least one of the pair of feed rollers, the gap adjustment mechanism comprising: a bracket rotatably disposed about a pivot axis fixedly disposed relative to the chassis of the base, the at least one feed roller being connected to the bracket; a guide plate fixedly disposed with respect to a chassis of the base; a first elastic adjusting member connected between the bracket and the guide plate and applying a first adjusting force to the bracket; and the second elastic adjusting piece is connected between the bracket and the guide plate and applies a second adjusting force to the bracket, wherein the directions of the first adjusting force and the second adjusting force are opposite.

According to another aspect of the present invention, there is provided a cutting unit for an apparatus for sheet plastic packaging, comprising: a frame; the transverse cutting mechanism is movably arranged on the rack transversely to the feeding direction of the packaged single sheet and comprises a transverse cutter capable of rolling transversely to the feeding direction; a cross cutting guide rail arranged on the frame transversely to the feeding direction of the wrapped single sheets and abutting against the cross cutting knife; and the paired longitudinal cutting mechanisms are arranged on two opposite sides of the machine frame along the transverse direction.

In some embodiments, the lateral cutting mechanism comprises: a carriage movably mounted to the frame transverse to the feed direction; the cutter shaft is arranged on the bracket and extends along the feeding direction; the bottom support is sleeved on the cutter shaft and is provided with a conical surface; the spring is abutted against the side surface of the bottom support, which is back to the conical surface; the transverse cutting knife is sleeved on the knife shaft and attached to the conical surface of the bottom support in a taper matched with the conical surface, under the thrust of the spring, the knife edge part of the outer periphery of the transverse cutting knife is attached to the transverse cutting guide rail, and a gap exists between the part outside the knife edge part of the transverse cutting knife and the transverse cutting guide rail.

According to another aspect of the invention, a single-sheet plastic packaging device is provided, which comprises a paper feeding unit, a plastic packaging unit, a cutting unit and a material collecting unit which are sequentially arranged along the feeding direction of a single sheet to be plastic packaged, and is characterized in that the paper feeding unit is the paper feeding unit, and the cutting unit is the cutting unit.

Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following, or may be learned from the practice of the invention.

Drawings

Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:

fig. 1 is a schematic diagram of a plastic encapsulation apparatus according to an embodiment of the present invention;

fig. 2 is a schematic view of a paper feeding unit according to an embodiment of the present invention;

fig. 3 is a schematic view of a paper feeding cassette in a paper feeding unit according to an embodiment of the present invention;

FIG. 4 is a schematic view of another angle of the embodiment of FIG. 3;

FIG. 5 is a schematic view of a spacing adjustment mechanism;

FIG. 6 is a schematic view of another embodiment of a paper guide mechanism;

FIG. 7 is a schematic view of a paper feeding cassette according to another embodiment of the present invention;

FIG. 8 is a schematic view of another angle of the embodiment of FIG. 7;

FIG. 9 is a schematic view of the embodiment of FIGS. 7 and 8 with the base omitted;

FIG. 10 is a schematic view of the paper feeding cassette of the embodiment of FIG. 7 engaged with a pickup roller;

fig. 11 is a schematic diagram of a sensor in the paper feeding unit according to an embodiment of the present invention;

FIG. 12 is a schematic view of a paper feeding unit according to an embodiment of the present invention, in which a part of the structure is omitted to expose a paper pickup mechanism and a gap adjustment mechanism;

FIG. 13 is a front view of the paper pickup mechanism and the gap adjustment mechanism;

FIG. 14 is a sectional view taken along line A-A of FIG. 13;

FIG. 15 is a left side view of FIG. 13;

FIG. 16 is a schematic view of a cutting unit according to an embodiment of the invention;

FIG. 17 is a schematic view of the cutting unit of FIG. 16 with portions of the structure omitted to expose a lateral cutting mechanism and a longitudinal cutting mechanism;

fig. 18 is a schematic view of a lateral cutting mechanism;

FIG. 19 is a schematic view of the transverse cutting mechanism of FIG. 17 from another perspective with portions omitted for clarity in showing the relationship of the transverse cutter to the transverse cutting rail;

fig. 20 shows a detailed view of the lateral cutting mechanism;

fig. 21 is a longitudinal sectional view of the transverse cutting mechanism;

FIG. 22 shows the relationship of the cross cut knife with the cross rail from a top view;

fig. 23 is a schematic view of a longitudinal cutting mechanism; and

fig. 24 shows a detailed view of the longitudinal cutting mechanism.

Description of reference numerals:

1. a paper feeding unit; 11. a frame; 12. a base; 121. a chassis; 1211. a positioning sleeve; 122. a support frame; 1221. a positioning claw; 1222. a guide groove; 123. an elastic support member; 13. an actuation mechanism; 131. hooking and locking; 133. actuating an electromagnetic mechanism; 134. swinging arms; 135. a limiting hook; 136. limiting the opening; 137. a magnetic attraction mechanism; 14. a paper guide mechanism; 141. a guide plate; 1411. a stop projection; 142. a support plate; 143. an accommodating space; 144. pushing the plate; 145. an elastic member; 146. a guide plate; 147. inserting plates; 15. a spacing adjustment mechanism; 151. a gear; 152. a rack; 153. a spring plate; 154. an L-shaped plate; 16. a paper rubbing mechanism; 161. a paper rolling wheel; 162. a paper feeding wheel; 17. a gap adjustment mechanism; 171. a support; 172. a guide plate; 173. a first elastic adjustment member; 174. a guide bar; 175. a second elastic adjustment member; 18. a cam mechanism; 181. a first camshaft; 182. a second camshaft; 183. a first cam; 184. a second cam; 185. a third cam; 186. a fourth cam; 187. an actuating lever; 188. a first link; 189. a second link; 191. a first set of sensors; 1911. a single sensor; 192. a second set of sensors; 1921. a single sensor; 2. a plastic package unit; 3. a cutting unit; 31. a frame; 311. a cross bar; 32. a transverse cutting mechanism; 321. a support; 322. a cutter shaft; 323. a transverse cutter; 3231. a blade tip portion; 324. a bottom support; 3241. a plane; 3242. a conical surface; 325. a spring; 326. a locking sleeve; 327. transversely cutting the guide rail; 33. a hold-down mechanism; 331. an upper pressure plate; 332. a lower pressing plate; 3321. teeth; 333. a bolt; 34. a synchronous belt; 35. a turntable; 36. a longitudinal cutting mechanism; 361. a support; 362. a cross bar; 363. a longitudinal cutter; 4. material receiving unit

Detailed Description

Referring now to the drawings, a schematic diagram of a disclosed apparatus for plastic encapsulation of single sheets will be described in detail. Although the drawings are provided to present some embodiments of the invention, the drawings are not necessarily to scale of particular embodiments, and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present disclosure. The position of some components in the drawings can be adjusted according to actual requirements on the premise of not influencing the technical effect. The appearances of the phrase "in the drawings" or similar language in the specification are not necessarily referring to all drawings or examples.

Certain directional terms used hereinafter to describe the drawings, such as "inner", "outer", "above", "below", and other directional terms, will be understood to have their normal meaning and refer to those directions as they normally relate to when viewing the drawings. Unless otherwise indicated, the directional terms described herein are generally in accordance with conventional directions as understood by those skilled in the art.

The terms "first," "second," and the like, as used herein, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

In the present invention, the term "paper" refers to a sheet-like individual material to be sealed, including but not limited to photographs, postcards, promotional sheets, bills, securities, and the like.

Fig. 1 shows an embodiment of a molding apparatus according to the present invention. As shown in fig. 1, the plastic packaging device integrally includes a paper feeding unit 1, a plastic packaging unit 2, a cutting unit 3, and a material receiving unit 4, which are sequentially arranged along a feeding direction of a single sheet to be plastic packaged. After the grouped (piled) single sheets to be subjected to plastic packaging are fed to the plastic packaging unit 2 one by the paper feeding unit 1, the single sheets are packaged in the plastic packaging unit 2 by the whole plastic packaging film, then the packaged single sheets are fed to the cutting unit 3, and the transverse edge and the longitudinal edge are cut on the whole plastic packaging film by the cutting knife, so that the plastic packaging is finished, and the final plastic packaging product is obtained. The plastic packaged products are fed to a feeding unit 4. The cut transverse edges are typically transverse edges of the plastic film in which the individual sheets are enclosed, the transverse edges of the plastic film typically being a certain length, e.g., 0.5 cm, 1 cm to 3 cm, etc., from the transverse edges of the enclosed individual sheets as desired. Similarly, the cut longitudinal edges are typically the longitudinal edges of the plastic film in which the individual sheets are encapsulated, and the longitudinal edges of the plastic film are typically a certain length, e.g., 0.5 cm, 1 cm to 3 cm, etc., from the longitudinal edges of the encapsulated individual sheets as desired. The plastic film is a whole coiled material.

The above-described respective units are described in detail in turn below.

Fig. 2 shows an embodiment of the paper feed unit 1. The paper feeding unit 1 includes a frame 11 and a paper feeding cassette and a paper twisting mechanism 16 mounted on the frame 11, wherein the paper feeding cassette includes a base 12 and a paper guide mechanism 14 mounted on the base 12.

Fig. 3 to 5 show one embodiment of a paper feeding cassette. As shown in the figure, the base 12 comprises a base frame 121 mounted on the frame 11 and a support frame 122 hinged on the base frame 121 by a pivot shaft, one side of the support frame 122 away from the pivot shaft is supported by an elastic support 123 (e.g. a spring) between the support frame 122 and the base frame 121, and the elastic support 123 always applies a pushing force to the support frame 122 to make it depart from the base frame 121, so that the support frame 122 is inclined and angled relative to the base frame 121. To facilitate the installation of the elastic support 123, a positioning sleeve 1211 is provided on the base frame 121 to receive one end of the elastic support 123, and a positioning claw 1221 is provided on the supporting frame 122 to install the other end of the elastic support 123. In the illustrated embodiment, the locating sleeve projects from the base frame 121 in a direction away from the support bracket 122 and defines an internal bore that receives the resilient support 123. Preferably, two positioning sleeves 1211 are arranged on the base frame 121 transversely to the feeding direction of the single sheets to be sealed, and two positioning claws 1221 are correspondingly arranged on the supporting frame 122, so that the two elastic supporting members 123 can give more stable and balanced support to the supporting frame 122.

The paper guide 14 is mounted on the support frame 122 of the base 12 and defines a receiving space 143 for receiving individual sheets to be sealed. In the embodiment shown in fig. 3 and 4, the paper guide mechanism 14 includes two guide plates 141 disposed opposite to each other, and a push plate 144 disposed between the two guide plates 141 so as to be reciprocally movable in the feeding direction of the single sheet to be die-sealed. The receiving space 143 is defined by the two guide plates 141. An elastic member 145 (such as a tension spring) is connected to the push plate 144 and always applies a force to the push plate 144 to make it close to the downstream-located paper pickup mechanism. The elastic member 145 may have one end fixed to the guide plate 141 and the other end connected to the push plate 144. Alternatively, in the case where the supporting plate 142 is disposed between the two guide plates 141, one end of the elastic member 145 may be fixed to the supporting plate 142, and the other end thereof may be coupled to the push plate 144. By means of the action of the elastic member 145 on the pushing plate 144, the pushing plate 144 can push the grouped (stacked) single sheets to be plastic-sealed, which are preset in the accommodating space 143, to the downstream paper twisting mechanism to realize paper feeding/supplementing.

For automation of the sheet replenishment process, an actuating mechanism 13 may be provided for the pusher plate 144. As shown in fig. 3 and 4, a magnetic attraction mechanism 137 is disposed on a side of the push plate 144 opposite to the paper pickup mechanism, and the magnetic attraction mechanism 137 may be installed between two opposite guide plates 141 and attract the push plate 144. For this purpose, the push plate 144 may be integrally formed of a material capable of forming a magnetic attraction fit with the magnetic attraction mechanism 137, or a magnetic attraction member made of such a material may be disposed on the push plate 144. A hook 131, which may be a flexible or rigid rope or a rigid hook with a sliding groove, is mounted on the support frame 122 of the paper feeding cassette. A rotatable swing arm 134 is arranged on the side of the base frame 121 facing away from the support frame 122. The hook latch 131 is coupled to the swing arm 134 through an opening of the base frame 121 and can be pulled by the rotation of the swing arm 134. In one embodiment, the rotation of the swing arm 134 is driven by an electromagnetic actuating mechanism 133 arranged on the side of the chassis 121 facing away from the support frame 122, the swing arm 134 being pivotably mounted on e.g. a housing of the electromagnetic actuating mechanism 133. Multiple groups (stacks) of single sheets to be plastically packaged can be arranged in the accommodating space 143 in advance, and at this time, the magnetic attraction mechanism 137 is in a normally open state and adsorbs the push plate 144 thereon. When a group (stack) of single sheets to be plastic-sealed at the forefront (closest to the plastic sealing unit 2) is exhausted or is about to be exhausted due to being fed to the plastic sealing unit 2 one by one, a sensor (such as a reflective sensor) arranged at the end part of the paper guide mechanism close to the paper twisting mechanism sends a signal to a processor, the processor controls an electromagnetic actuating mechanism 133 to drive a swing arm 134 to rotate, and then the support frame 122 is pulled to rotate in a direction close to the bottom frame 121 through a hook lock 131. When the supporting frame 122 rotates to the position, the sensor sends a signal to the processor again, the processor controls the magnetic attraction mechanism 137 to be disconnected, and the magnetic attraction mechanism loses the magnetic attraction force to release the push plate 144. Under the driving of the elastic member 145, the push plate 144 moves forward to a proper position rapidly and pushes a next group (stack) of single sheets to be plastic-sealed forward to automatically replenish the sheets to the proper position, then the push plate 144 is driven to be close to the magnetic attraction mechanism 137, and the magnetic attraction mechanism 137 enters a normal open state again and attracts the push plate 144, thereby completing one paper replenishing action. A new group (stack) of single sheets to be plastic-sealed is fed to the plastic sealing unit 2 one by one, and then the automatic paper supplementing action is repeated to automatically supplement the next group (stack) of single sheets to be plastic-sealed in place, and so on. The process of supplementing the single sheet to be plastic-sealed is smooth and continuous automatically, and before the single sheet to be plastic-sealed is completely exhausted, an operator can pull the push plate to supplement the single sheet to be plastic-sealed into the accommodating space 143 at any time without stopping the machine during supplementing the single sheet to be plastic-sealed, so that the delay of the construction period caused by repeated stopping and the material waste caused by multiple starting preparations are avoided. The paper supplementing process also allows enough time for operators, and the operators do not need to keep high concentration all the time, so that the operators can easily operate two or more plastic packaging devices at the same time.

In the embodiment shown in fig. 3 to 5, the distance between the two guide plates 141 is adjustable, so that the single sheets to be sealed by plastic can be adapted to different sizes. As shown in fig. 4, the supporting frame 122 is provided with a spacing adjustment mechanism 15, wherein two mutually parallel racks 152 are correspondingly connected to the two guiding plates 141, and each rack 152 extends transversely to the feeding direction of the sheet to be sealed. A gear 151 is rotatably mounted on the support frame 122 between the two racks 152. The rotation of the gear 151 drives the two racks 152 engaged therewith to move in opposite directions to each other, thereby moving the two guide plates 141 away from or close to each other. A guide groove 1222 may be formed on the support bracket 122 transversely to the mold feeding direction, and a bolt 333 for connecting the corresponding rack 152 and the guide plate 141 is inserted into the guide groove 1222 and can move along the guide groove 1222. Here, there may be a plurality of push plates 144 of different sizes grouped in a kit to accommodate varying widths between the guide plates 141.

As shown in fig. 4 and 5, considering that the racks 152 are in the form of long strips and are connected to the corresponding guide plates 141 only at one end, and the other end has a configuration of a free end, a spring plate 153 for urging the free end of each rack 152 to abut against the gear 151 is provided on the support frame 122. The spring 153 is mounted on the support 122, for example by means of an L-shaped plate 154, and with its elastic portion (for example, the arc-shaped convex area of the arc-shaped spring 153) abuts against the free end of the rack 152 from the side of the rack 152 facing away from the gear. Thereby, the rack 152 can be tightly engaged on the gear 151.

Although FIG. 3 illustrates the process of automatically replenishing paper via the cooperation of the spring 145, the actuator 13, and the pusher 144, those skilled in the art will appreciate that the motion of the pusher 144 may be via other forms other than a spring. For example, in the embodiment shown in fig. 6, the elastic member, the actuating mechanism 13, etc. are omitted, so that after the previous group (stack) of single sheets to be plastic-sealed is about to be fed out, the next group (stack) of single sheets to be plastic-sealed can be replenished in place by manually pushing the push plate 144, and the continuous replenishment of the single sheets to be plastic-sealed in place can also be realized, and the paper can be replenished at any time without stopping the machine.

Fig. 7 to 9 show another embodiment of a paper feeding cassette that can realize continuous paper feeding and replenishment without stopping. As shown in the figure, the main difference between this embodiment and the embodiment shown in fig. 3 to 5 is the arrangement of the paper guide 14 and the paper feeding. In this embodiment, the supporting frame 122 of the base 12 is rotatably disposed around a pivot shaft fixed to the base frame 121, and a pair of elongated slots extending in the feeding direction of the sheet to be sealed are formed in the supporting frame 122, and the two

guide plates

141, 146 are respectively inserted into the two elongated slots and can move up and down. Each

guide plate

141, 146 is also formed with a long groove extending along the feeding direction of the individual sheets to be plastic-sealed, both sides of the insertion plate 147 are respectively inserted into and can move along the long grooves of the

corresponding guide plates

141, 146, and the push plate 144 is formed on the end of the insertion plate 147. For example, the push plate and the insert plate may be formed integrally by bending a plate material. The up and down movement of the two

guide plates

141, 146 is driven and controlled by the cam mechanism 18 mounted on the support frame 122.

As shown in fig. 9, two cam shafts of the cam mechanism 18, i.e., a first cam shaft 181 and a second cam shaft 182, are mounted on the support frame 122 in parallel with each other and transversely to the feeding direction of the sheet to be sealed, and the first cam shaft 181 and the second cam shaft 182 are each rotatable about their own central axes. A first cam 183 rotatable with the first cam shaft 181 is mounted to the first cam shaft 181 at a position corresponding to the guide plate 141, and a second cam 184 rotatable with the first cam shaft 181 is mounted to the second cam shaft 182 at a position corresponding to the guide plate 146, and a third cam 185 rotatable with the second cam shaft 182 is mounted to the second cam shaft 182 at a position corresponding to the guide plate 141, and a fourth cam 186 rotatable with the second cam shaft 182 is mounted to the second cam shaft 182 at a position corresponding to the guide plate 146. Rotation of the first cam shaft 181 drives rotation of the first and

second cams

183, 184, and rotation of the second cam shaft 182 drives rotation of the third and

fourth cams

185, 186, which in turn drives upward movement of the guide plate 141. The guide plate 141 is formed with two stopper projections 1411 corresponding to the first cam 183 and the third cam 185, and the guide plate 146 is formed with two stopper projections (not shown) corresponding to the second cam 184 and the fourth cam 186. An actuating lever 187 is drivingly connected to the second cam shaft 182, and a first link 188 and a second link 189, which are hinged to each other, are connected between the first cam shaft 181 and the actuating lever 187.

Referring to fig. 10, when a part of the sheet to be sealed is still left between the inserting plate 147 and the paper feeding wheel(s) 161 of the paper feeding mechanism, the actuating rod 187 is controlled to rotate (e.g. driven by an operator), so as to drive the second cam shaft 182 to rotate, and the rotation of the second cam shaft 182 drives the third cam 185 and the fourth cam 186 to rotate synchronously. At the same time, the rotation of the actuating lever 187 also drives the first cam shaft 181 to rotate through the first link 188 and the second link 189, and the rotation of the first cam shaft 181 in turn drives the synchronous rotation of the first cam 183 and the second cam 184. Thereby, the first cam 183 and the third cam 185 apply a force to the guide plate 141 to move it upward, and the second cam 184 and the fourth cam 186 also apply a force to the guide plate 146 to move it upward. At this time, a part of the sheet to be plastic-sealed is thrown between the insert plate 147 and the downstream (two) pickup roller 161, and the support frame 122 is rotated around the pivot shaft in a direction approaching the base frame 121 (downward) under the reaction force, so that a space is formed between the insert plate 147 and the support frame 122. After the single sheets to be plastic-sealed are inserted into the space, the inserting plate is moved to the position in the direction far away from the paper rubbing mechanism 16 (backwards) by pulling the push plate 144, and at the moment, the inserting plate is separated from the group (stack) of the single sheets to be plastic-sealed, which is formed by combining the part of the single sheets to be plastic-sealed and the single sheets to be plastic-sealed inserted into the space. The actuating lever 187 is then controlled in the reverse direction to disengage the four

cams

183 and 186 from the

guide plates

141 and 146, allowing the

guide plates

141 and 146 together with the insert plate 147 to fall back to the initial position. The push plate 144 is pushed to move the inserting plate 147 towards the direction (forward) close to the paper twisting wheel 161 to the lower part of the group (stack) of single sheets to be sealed by plastic, thereby completing one-time paper supplement. Here, the forward movement of the pushing plate 144 may also be realized by an elastic member connected between the pushing plate and the guiding plate, and such a cycle is repeated, so that the paper feeding of the plastic packaging device is realized without stopping the machine, and uninterrupted plastic packaging is achieved.

By means of the embodiments shown in fig. 7 to 9, paper can be supplemented without stopping the machine before each group (stack) of single sheets to be plastic-sealed is exhausted, the paper supplementing operation can be performed at any time, the time is sufficient and controllable, and the continuous plastic-sealing operation is facilitated. The scheme is particularly suitable for operating two or more plastic packaging machines simultaneously, and greatly improves the efficiency. The whole paper supplementing process is stable and reliable, the operation is simple, and inconvenience brought to the subsequent processes such as cutting due to misoperation is avoided.

Those skilled in the art will appreciate that the embodiments shown in fig. 3 to 5 and the embodiments shown in fig. 7 to 9 can be combined with each other, for example, in a non-illustrated embodiment, a spacing adjustment mechanism 15 can be provided to adjust the spacing between the two guide plates to accommodate single sheets to be sealed with different sizes, and a cam mechanism 18 is provided to manually control the paper feeding process.

According to the embodiment of the invention, the single sheets to be plastic-sealed are fed from the paper feeding unit 1 to the plastic sealing unit 2 one by the paper twisting mechanism 16. Fig. 12 to 15 show an example of the pickup mechanism 16 in detail. As shown, the paper feeding mechanism 16 includes a paper feeding wheel 162 and a paper feeding wheel 161 arranged along the feeding direction of the single sheets to be sealed. The pickup roller 161 is located above the supporting frame 122, or above a group of sheets to be sealed and fed. The number of the paper pickup wheels 161 can be two, and they are arranged transversely to the feeding direction of the single sheet to be plastic-sealed and rotatably sleeved on a rotating shaft arranged on the frame. As mentioned above, the supporting frame 122 of the base 12 is supported by the elastic supporting member 123 between the bottom frame 121 and the supporting frame 122, after carrying the sheet to be plastic-sealed, the supporting frame 122 is pressed or has a tendency to be pressed downward, but the elastic supporting member 123 also supports the supporting frame 122 in the opposite direction against the downward pressure, at this time, a group (stack) of the sheet to be plastic-sealed to be fed is pushed right under the paper twisting wheel 161, and the uppermost sheet of the sheet to be plastic-sealed is pressed against the surface of the paper twisting wheel 161 by the elastic supporting member 123. The surface of the pickup wheel 161 is preferably designed as a soft friction surface with a certain roughness, and the rotation direction is designed to move the uppermost sheet to be sealed in contact toward the downstream sealing unit 2. The pickup roller 161 moves in the counterclockwise direction with reference to the angle shown in fig. 12. The uppermost sheet to be plastic-sealed subsequently enters the gap between the pair of sheet feeding wheels 162, and is fed to the downstream plastic sealing unit 2 by the pair of sheet feeding wheels 162. The pair of paper feeding wheels 162 are arranged on the frame transversely to the feeding direction of the single paper to be sealed and rotate in opposite directions. With reference to the angle shown in fig. 12, the paper feed roller 162 positioned above rotates in the counterclockwise direction, and the paper feed roller 162 positioned below rotates in the clockwise direction. Once the uppermost sheet to be plastic-sealed in the group (stack) of the sheet to be plastic-sealed being fed is twisted out by the paper twisting wheel 161 and delivered to the downstream pair of paper feeding wheels 162, the sheet to be plastic-sealed below the sheet to be plastic-sealed is converted into a new uppermost sheet to be plastic-sealed and abuts against the paper twisting wheel 161 under the action of the elastic support 123 to wait for being twisted out by the paper twisting wheel 161 and delivered to the downstream pair of paper feeding wheels 162. The above steps are repeated until the group (stack) of single sheets to be sealed by plastic is exhausted, and the next group (stack) is replenished in place by the push plate 144.

By means of the paper rolling wheel 161 and the pair of paper feeding wheels 162, accurate delivery of a single sheet to be plastically packaged can be achieved, and double or multiple sheet wrong delivery is avoided.

Considering that the sheets to be sealed have different thickness or size standards, e.g. 80-250g/m²The gap adjusting mechanism 17 is provided to adjust the gap between the pair of feeding rollers 162 to allow a single sheet to be sealed and sealed with different thickness or size to pass through while prohibiting two or more sheets to pass through.

In the embodiment shown in fig. 12 to 15, of the pair of feeding rollers 162, the upper feeding roller 162 is sleeved on a rotating shaft mounted on the frame 11, and the lower feeding roller 162 is mounted on a bracket 171 of the gap adjusting mechanism 17, and the bracket 171 is hinged on the rotating shaft mounted on the frame 11. The frame 11 is also provided with a guide plate 172. The first elastic adjustment member 173, for example, a tension spring, is coupled between the bracket 171 and the guide plate 172 and applies a first adjustment force of a tension form. One end of the guide rod 174 is mounted on the bracket 171, and the other end is movably inserted into the opening of the guide plate 172, and a second elastic adjusting member 175, such as a compression spring, is fitted over the guide rod 174, and the second elastic adjusting member 175 is pressed between the guide plate 172 and the bracket 171 and applies a second adjusting force in the form of a pushing force. The presence of the first elastic adjusting member 173 and the second elastic adjusting member 175 enables the gap between the two feeding rollers 162 to be dynamically adjusted, so that even if sheets to be plastic-sealed with different thicknesses or sizes continuously pass through the gap, the gap width can be automatically adjusted by the first elastic adjusting member 173 and the second elastic adjusting member 175 to adapt to the thickness of the sheets to be plastic-sealed, and the sheets to be plastic-sealed passing through the gap can be clamped to be accurately delivered to the designated position of the plastic sealing unit 2 without manual adjustment and stopping. After the single sheet to be sealed by plastic package passes through the gap, the two feeding rollers 162 can be automatically reset under the action of the first elastic adjusting member 173 and the second elastic adjusting member 175. At least one of the pair of feed rollers 162 is preferably a soft-surfaced roller.

In order to ensure that the sheets to be packaged are delivered one by one at uniform intervals, a plurality of sensors, for example photoelectric sensors, may be arranged upstream of the feed roller 161, which sensors are arranged at uniform intervals in the direction of feed of the sheets to be packaged. The sensor may be mounted on the supporting bracket 122 of the paper feeding cassette and disposed adjacent to the pickup roller 161. In one embodiment, a set of sensors may be disposed on each of opposite sides of the support frame 122, wherein each set of sensors includes a plurality of sensors arranged along a feeding direction of the sheet to be overmolded. A plurality of through holes may be formed in the supporting frame 122 corresponding to the number of sensors and arranged at regular intervals in the feeding direction of the single sheet to be plastic-sealed, and a plurality of sensors installed at each side of the supporting frame 122 may be aligned with the through holes one by one. Thus, the sensors on opposite sides of the support frame 122 are aligned two-by-two up and down. An example of two sets of sensors that are opposed to each other is shown in fig. 11, in which the supporting frame 122 of the paper feed cassette sandwiched between the two sets of sensors is omitted for clarity. The first group 191 and the second group 192 of sensors are respectively disposed on the upper and lower sides of the supporting frame 122 and each consists of a plurality of

sensors

1911 and 1921, and each sensor 1911/1921 is aligned with one sensor 1921/1911 on the other side through a through hole at a corresponding position on the supporting frame 122. During the period that the paper pickup wheel 161 picks up the topmost single sheet to be plastic-sealed from a group (stack) of single sheets to be plastic-sealed, the sensors respectively send detection signals to the processor when detecting the single sheet to be plastic-sealed. Through the detection signals of the sensors, the processor can accurately obtain the position of the single sheet and send an instruction to the paper twisting mechanism at a proper time, and the paper twisting wheel 161 twists out the next single sheet to be plastic-sealed. Therefore, the paper feeding interval can be ensured to be accurate and stable, and the subsequent processes such as cutting can be conveniently and smoothly carried out.

The plastic packaging unit 2 is positioned at the downstream of the paper feeding unit 1. The plastic packaging unit 2 sets and selects operation parameters such as temperature, speed, language, length unit, margin size and the like through a touch screen of a man-machine conversation. The plastic packaging unit 2 can be made of the existing plastic packaging technology, and is not described herein.

The cutting unit 3 is arranged at the downstream of the plastic packaging unit 2 and is used for cutting a plurality of single sheets which are wrapped by the whole plastic packaging film one by one to obtain plastic packaging products with required sizes. Fig. 16 shows an embodiment of a cutting unit 3 according to the invention. As shown in the figure, the cutting unit 3 includes a frame 31, and a lateral cutting mechanism 32 and a longitudinal cutting mechanism 36 mounted on the frame 31.

Fig. 17 to 22 show an example of the lateral cutting mechanism 32. The lateral cutting mechanism 32 includes a support 321 and a lateral cutter 323 mounted on the support 321. A transverse bar 311 is arranged on the machine frame 31 transversely to the feed direction of the individual sheets to be sealed, and a support 321 is mounted on the transverse bar 311 and can be displaced along the transverse bar 311. In consideration of the stability of the movement of the support 321, two parallel cross bars 311 are provided, and the two cross bars 311 are respectively disposed through the support 321. The horizontal cutter 323 is formed in a disc shape and is preferably rotatably provided on a cutter shaft 322 attached to the holder 321. In the transverse cutting mechanism 32, as shown in detail in fig. 21, the shoe 324 has a hollow sleeve section and a carrier section connected to the sleeve section, the knife shaft 322 is mounted on the support 321 transversely to the feed direction of the enclosed individual through the hollow inner bore of the sleeve section, and the cross-cutter 323 is fitted over the outer circumference of the sleeve section of the shoe 324 and abuts against the carrier section of the shoe 324. The locking sleeve 326 is fitted over the sleeve section of the shoe 324 from the side of the cross cutter 323 facing away from the bracket section to position the cross cutter 323 on the shoe 324. The sleeve portion of the collet 324 and the locking sleeve 326 may be threaded, a tight fit, or alternatively, may be relatively fixedly attached. One end of a spring 325 (e.g., a compression spring) is pressed against the bottom support 324 from the side of the bottom support 324 facing away from the cross-cut knife 323, and the other end of the spring 325 can be pressed against a bearing 328 mounted on the knife shaft 322 or can be pressed against a bracket. On the frame 31 of the cutting unit 3, a crosscutting rail 327 (also referred to as a crosscutting straight knife) is arranged transversely to the direction of feed of the wrapped sheet, which crosscutting rail 327 is arranged on the side of the crosscutting knife 323 facing away from the shoe 324, while the spring 325 always exerts a force on the shoe 324 together with the crosscutting knife 323 directed toward this crosscutting rail 327. Referring to fig. 19, the cross-cut rail 327 has upper and lower surfaces that are opposed and both extend transverse to the feed direction of the wrapped sheet, and two opposed side surfaces connected between the upper and lower surfaces and both extend transverse to the feed direction. The knife shaft 322 is located above the cross cutting rail 327, and the cross cutter 323 faces one side of the cross cutting rail 327. The cross cutter 323 abuts against the side of the cross cutting rail 327 by the urging force of the spring 325.

As shown in fig. 21 and 22, in one embodiment, the bracket section of the shoe 324 has a flat surface 3241 facing the spring 325 and a tapered surface 3242 facing the cross-cut knife 323, wherein the tapered surface 3242 is concave in a direction toward the flat surface 3241. The taper of the tapered surface 3242 is represented by α, and α is 1 ° to 3 °, preferably 2 °. Accordingly, the disk-shaped face of the cross cutter 323 is formed with the same taper, when viewed in an axial direction perpendicular to the knife axis 322, so that the cross cutter 323 can abut against the tapered surface 3242 of the shoe 324. Thus, when the cross cutter 323 abuts against the side of the cross cutting rail 327 by the urging force of the spring 325, since the cross cutter 323 has a taper and the side of the cross cutting rail 327 is flat, only the blade portion 3231 at the outer periphery of the cross cutter closely contacts the cross cutting rail 327, and a gap exists between the portion other than the blade portion 3231 and the cross cutting rail 327, as shown in fig. 22. The horizontal round cutter is transversely and reciprocally cut along the horizontal cutting guide rail, and the conical design of the round cutter is matched, so that the cutting is more light, fast and accurate, the problem of burrs which easily appear during cutting is solved, and the problem that the plastic packaging film which is lower than 80mic cannot be automatically cut in the small-sized cutting unit 3 is solved.

In addition, the cross cutting knife 323 and the cross cutting guide 327 may have different hardness or be made of materials with different hardness, so that the circular knife may also have an effect of automatically sharpening the knife during the reciprocating cutting and the knife tip portion contacting the cross cutting guide.

In the illustrated embodiment, the movement of the lateral cutting mechanism 32 is driven by a timing belt 34. A pressing mechanism 33 for engaging the timing belt 34 is provided on the support of the lateral cutting mechanism 32, and includes an upper pressing plate 331 and a lower pressing plate 332 connected together by a bolt 333. The upper press plate 331 is a flat plate, and the side of the lower press plate 332 facing the upper press plate 331 is formed with a plurality of teeth arranged at intervals, and the timing belt 34 clamped between the upper press plate 331 and the lower press plate 332 has a plurality of tooth structures adapted to the teeth of the lower press plate 332, which are arranged along the entire length direction of the timing belt 34. The timing belt 34 is wound around two rotary discs arranged on both sides of the frame of the cutting unit 3 transversely to the feed direction of the wrapped sheet, one of the rotary discs 35 having a tooth structure adapted to the teeth of the timing belt 34, and the rotation of the rotary disc 35 can be driven by a motor controlled by a processor. When the turntable 35 with teeth rotates, the timing belt 34 is driven to move, and the teeth of the timing belt 34 are inserted into the teeth on the lower pressing plate 332, so that the bracket 321 of the transverse cutting mechanism 32 is driven to move synchronously, and the reciprocating cutting action of the transverse cutting knife 323 transverse to the feeding direction of the wrapped single sheet is realized. Of course, in other embodiments, the lower pressing plate 332 of the pressing mechanism 33 may be designed as a flat plate, and the upper pressing plate 331 may be designed to have a tooth structure adapted to the teeth of the timing belt 34. Further, the members for clamping the upper and lower press plates may be replaced with clamps such as jaws from bolts.

The reciprocating motion time of the transverse cutting knife 323 can be detected by means of an integrated multi-sensor edge detection technology, and the precision of the transverse cutting position is ensured by matching fuzzy positioning calculation and position compensation calculation of a specific curve. In one embodiment, at least two sensors, such as photosensors, are provided upstream of the transverse cutting mechanism 32, and are aligned in the feed direction of the wrapped sheet. When the sensor positioned at the most upstream of the sensors detects the passing of the single wrapped sheet, for example, the leading edge of the single wrapped sheet in the feeding direction, the sensor at the most upstream sends a signal to the processor, and the processor controls the speed of the single wrapped sheet to be reduced based on the signal. When a downstream sensor of these sensors detects the passage of the wrapped sheet, for example, the passage of the leading edge of the decelerated wrapped sheet, then the downstream sensor sends a signal to the processor, and the processor calculates the position of the wrapped sheet by the fuzzy positioning algorithm based on the signal and sends an action command to start cutting to the transverse cutting mechanism 32, and the transverse cutting knife 323 starts cutting. By means of the multi-sensor detection, the speed reduction and the positioning calculation, the cutting precision of the encapsulated single sheet can be improved, and the size of the plastic package product is in a controllable range. And

In addition to the transverse cutting mechanism 32, a pair of longitudinal cutting mechanisms 36 are provided on the frame 31 of the cutting unit 3, which are disposed on opposite sides of the frame 31 transversely to the feeding direction of the wrapped sheet. Fig. 20 shows a pair of longitudinal cutting mechanisms 36, and fig. 21 shows a partial example of one of the longitudinal cutting mechanisms 36. As shown in the figure, the longitudinal cutters 363 of the two longitudinal cutting mechanisms 36 are both disposed on a support 361, two parallel cross bars 362 are mounted on the support 361, and a rotatable longitudinal cutter 363 is respectively sleeved on the same side of the two cross bars 362. Referring to fig. 21, two longitudinal cutters 363 on the same side constitute a double reamer structure of the longitudinal cutting mechanism 36. In the projection transverse to the feeding direction of the enclosed single sheet, the edges of the two longitudinal cutters 363 in the double reamer structure are partially overlapped, and in the projection along the feeding direction of the enclosed single sheet, the two longitudinal cutters 363 are attached to each other or only have a slight gap. In addition, according to the illustrated embodiment, the two bars 362 mounting the twin reamer structure may be vertically offset from each other. The double-reamer structure is applied to the field of plastic package, so that the problems that less than 80mic plastic package film cannot be cut and excessive waste materials are caused by large cutting residual edges are solved by longitudinal cutting. The transverse cutting mechanism 32 and the longitudinal cutting mechanism 36 are matched, so that the whole plastic packaging film can be directly converted into a finished product after plastic packaging is finished, and the problem that the finished product is bent or the cleanliness is reduced easily due to plastic packaging of coiled materials is solved.

The cut plastic-sealed product can be directly delivered to a downstream receiving unit 4. The material receiving unit 4 may be a tray, which is not described in detail herein.

According to the plastic packaging device, all units are cooperatively matched and cooperatively controlled by the processor, so that the plastic packaging efficiency is remarkably improved compared with that of the traditional plastic packaging device, and the manual participation degree is greatly reduced.

It should be understood that although the description is in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent alterations, modifications and combinations can be made by those skilled in the art without departing from the spirit and principles of the invention.

Claims

1. The utility model provides a form advancing unit that is used for device of plastic envelope soliton which characterized in that includes:

A base (12) comprising a chassis (121) and a support bracket (122) movably connected to the chassis (121), the support bracket (122) being adjustable in distance from the chassis (121) based on a load; and

the paper guide mechanism (14) is arranged on the supporting frame (122) and comprises a pair of guide plates (141; 141,146) which are oppositely arranged and limit a containing space (143) and a push plate (144) which is arranged between the pair of guide plates (141; 141,146) and can move along the feeding direction of the single paper to be sealed.

2. The paper feeding unit of claim 1, wherein an elastic member (145) is coupled between the push plate (144) and the at least one guide plate (141; 141,146), the elastic member (145) applying a force to the push plate (144) to urge the push plate (144) toward the sheet to be sealed in the feeding direction.

3. The paper feeding unit as claimed in claim 1, wherein the supporting bracket (122) is hinged to the base frame (121), and an elastic support (123) is connected between the supporting bracket (122) and the base frame (121), the elastic support (123) applying a force to the supporting bracket (122) to move the supporting bracket (122) away from the base frame (121).

4. The paper feeding unit according to any one of claims 1 to 3, wherein the pair of guide plates (141; 141,146) are provided to the supporting frame (122) with an adjustable interval, the supporting frame (122) is further provided with an interval adjusting mechanism (15) connected to the pair of guide plates (141; 141,146), the interval adjusting mechanism (15) includes:

A pair of racks (152) provided in parallel and spaced apart, the pair of racks (152) being connected to the pair of guide plates (141) in a one-to-one correspondence;

and the gear (151) is rotatably arranged on the support frame (122) and is positioned between the pair of racks (152), and the gear (151) is respectively meshed with the pair of racks (152).

5. The paper feeding unit according to any one of claims 1 to 3, wherein the supporting frame (122) is provided with a cam mechanism (18) selectively drivingly engageable with the pair of guide plates (141; 141,146), wherein the pair of guide plates (141; 141,146) together with the push plate (144) move in a direction away from the supporting frame (122) during the driving engagement of the cam mechanism (18) with the pair of guide plates (141; 141,146), and the pair of guide plates (141; 141,146) together with the push plate (144) move in a direction closer to the supporting frame (122) during the disengagement of the cam mechanism (18) from the pair of guide plates (141; 141,146).

6. The paper feeding unit according to any one of claims 1 to 5, wherein the paper feeding unit (1) further comprises a paper pickup mechanism (16), the paper pickup mechanism (16) comprising:

the paper rolling wheel (161) is rotatably arranged on one side, back to the bottom frame (121), of the supporting frame (122), and the peripheral surface of the paper rolling wheel (161) defines a contact surface which can be abutted against a single sheet to be subjected to plastic packaging and borne by the supporting frame (122); and

And the pair of paper feeding wheels (162) are positioned at the downstream of the paper twisting wheel (161) along the feeding direction, and the pair of paper feeding wheels (162) rotate oppositely to each other and define a paper feeding gap for receiving the single paper to be plastically packaged sent by the paper twisting wheel (161) between the paper feeding wheels.

7. The paper feeding unit as claimed in claim 6, wherein at least one paper feeding roller (162) of the pair of paper feeding rollers (162) is connected with a gap adjusting mechanism (17), the gap adjusting mechanism (17) comprising:

a bracket (171) rotatably disposed about a pivot axis fixedly disposed relative to a chassis (121) of the base (12), the at least one feed roller (162) being coupled to the bracket (171);

a guide plate (172) fixedly provided with respect to a chassis (121) of the base (12);

a first elastic adjusting member (173) connected between the bracket (171) and the guide plate (172) and applying a first adjusting force to the bracket (171);

a second elastic adjusting member (175) connected between the bracket (171) and the guide plate (172) and applying a second adjusting force to the bracket (171), wherein the first and second adjusting forces are directed in opposite directions.

8. The utility model provides a cut unit that is used for device of plastic envelope sola which characterized in that includes:

A chassis (31);

a transverse cutting mechanism (32) movably arranged on the frame (31) and transverse to the feeding direction of the enveloped single sheets, wherein the transverse cutting mechanism (32) comprises a transverse cutter (323) capable of rolling in the direction transverse to the feeding direction;

-a cross-cutting guide (327) arranged on said frame (31) transversely to the feeding direction of said wrapped single sheet and abutting against said cross-cutter (323);

a pair of longitudinal cutting mechanisms (36) arranged on opposite sides of the frame (31) in the transverse direction.

9. The cutting unit according to claim 8, wherein the lateral cutting mechanism (32) comprises:

a carriage (321) mounted to the frame (31) movably transverse to the feed direction;

a cutter shaft (322) provided to the holder (321) and extending in the feeding direction;

the bottom support (324) is sleeved on the cutter shaft (322) and is provided with a conical surface (3242);

a spring (325) that rests on the side of the base (324) facing away from the conical surface (3242);

the transverse cutting knife (323) is sleeved on the knife shaft (322) and abuts against the conical surface (3242) of the bottom support (324) in a conical degree matched with the conical surface (3242), under the thrust of the spring (325), the knife point part (3231) at the outer periphery of the transverse cutting knife (323) is tightly attached to the transverse cutting guide rail (327), and a gap exists between the part outside the knife point part (3231) of the transverse cutting knife (323) and the transverse cutting guide rail (327).

10. A single-sheet plastic packaging device, comprising a paper feeding unit (1), a plastic packaging unit (2), a cutting unit (3) and a material collecting unit (4) which are sequentially arranged along the feeding direction of a single sheet to be plastic packaged, wherein the paper feeding unit (1) is the paper feeding unit as claimed in any one of claims 1 to 7, and the cutting unit (3) is the cutting unit as claimed in any one of claims 8 to 9.