JPS6333228A - Sealing device for plastic bag - Google Patents

Abstract

A plastic bag for retaining a content therein has a gathered throat portion (11) adjacent an end opening (13) thereof, the gathered throat portion (11) being formed by randomly disposed wall portions of the plastic material fused together by two or more rows of adjacent spaced apart fused zones (27) of plastic material disposed about a plurality of needle holes (25). Apparatus for forming the bag comprises at least one set of opposed gathering jaw plates (12, 12') for gathering, in a random fashion, a circumferential portion of the plastic bag adjacent the end opening (13) thereof to form a gathered throat portion (11). Two pressing plates (14) are disposed on a respective side of the gathered throat portion (11) and are each provided with two or more spaced apart rows of needle receiving bores (16) disposed adjacent one another in differing planes (21,21',21''). A needle support block (17) of heat conductive material has needles (18) secured thereto for conducting heat from the block (17). The block (17) is connected for movement to and away from one of the pressing plates (14) once the pressing plates (14) have moved to a pressing position so that the needles (18) will enter the bores (16) of both pressing plates (14) to puncture a press portion of the gathered throat portion (11) of the bag to fuse plastic material adjacent randomly disposed wall portions of the plastic material in the areas (26) of the penetrating needles (18) and in adjacent spaced apart planes (21,21',21'').

Description

DETAILED DESCRIPTION OF THE INVENTION A) Field of Industrial Application The present invention relates to an improved fused seal in a plastic bag and an apparatus for effecting the seal.

The seal comprises an irregularly pleated throat of a plastic bag, the throat having at least two or more rows of spaced apart thermally conductive conductors extending through the throat. fused together by a needle.

Mouth) Conventional Technology The opening of many plastic bags is usually collected by collecting a portion of the bag twisted around the pleated throat! Il
The wire may be wrapped or otherwise sealed using removable fastening tabs or other such elements.

Moreover, a disadvantage of such sealing elements is that they often do not securely secure the bag and easily loosen and crumble. Similarly, such elements require special machinery to use them in the throat of the filled bag. Additionally, it is often necessary to stop the bagging equipment to correct malfunctions in the strand or tab fasteners or to load sealing tape or tabs into the fasteners.

Such fastening devices are also time and labor consuming and often require adjustment or repair when parts become damaged or worn. The earliest sealing elements were not tamper-proof and could be easily removed from the bag.

The present invention overcomes the above disadvantages by providing a novel seal for plastic bags in which the throat is heat sealed using a heated piercing needle. It is known in the prior art to heat-seal plastic bags using heated piercing needles. British Patent No. 2,03
No. 4,278'a:', a method and apparatus for performing this type of heat sealing is disclosed. However, a drawback of this method and apparatus is that the plastic bag must be vertically oriented such that its open end is in a vertical position, and the bag is pierced with a hot needle. It is necessary to fold the open end 2 of the bag in a special zigzag manner beforehand. It is often difficult to accept the items in this bag of words. This is also time consuming and does not yet provide welded joints that are rigid and do not come undone suddenly.

To solve this problem'(!:'), the patentee proposes to fold the top end of the bag before the heat sealing is done, which adds even more time wastage to the sealing process. Incur difficulties and high costs.

...) PROBLEM SOLVED BY THE INVENTION A feature of the present invention is to provide a novel plastic bag seal, which does not require sealing elements and equipment for effecting the seal, thus reducing cost. reducing and substantially overcoming all the above-mentioned drawbacks of the prior art.

Another feature of the invention is the provision of a plastic bag seal having irregularly spaced fused areas.

Another feature of the invention is that the seal Z includes a plastic bag seal Z in which at least two or more rows of fusing needle holes are arranged offset from each other. )reactor.

According to the above characteristics, the present invention provides a plastic bag for holding the contents therein. The bag has a sealed, pleated throat proximate the open end.

The sealed, pleated throat is formed by an irregularly arranged wall of plastic material, the wall having two or more rows of plastic material arranged in place of a plurality of needle holes. fused together by spaced apart fused areas.

In another broad aspect of the invention, an apparatus is provided for fusing the pleated throat of a plastic bag. The device comprises a device 2 for gathering the circumference of the plastic bag close to the open end in an irregular manner to form a pleated throat.

A pressing device is provided for pressing together the randomly arranged plastic material of the pleated throat. The pusher has holes for receiving two or more rows of spaced apart needles arranged close to each other in different planes.

Is the fusing device adjacent to an irregularly arranged wall portion of plastic material within the area of the penetrated needle and in a closely spaced plane? two or more rows of thermally conductive needles movable in and out of the hole and fused across the pleated throat plastic material; has been done.

D) Example The present invention will be described in detail below with reference to the drawings.

In FIG. 1, a device for fusing the pleated throat 11' of the plastic bag 10 is shown.

The device is equipped with a gathering device forming two pairs of spaced apart jaw plates which gather together the circumferential portion 2 of the bag 10 adjacent to the open end 1 of the bag 10. Separated. A pair of pressing plates 14 are provided in a state where each plate is gathered together and placed on both sides of the pleated throat portion 110.

One or both plates move inwardly towards each other in the direction of arrow 15, thereby pressing against the pleated throat of adjacent irregularly arranged plastic wall sections? The surfaces of the folded press plate facing the Y row are brought into full contact. These pressing plates 14 have rows 2 of needle receiving holes 16 spaced apart by at least two or more rows.
1 (see FIG. 6).

The pressing plates 14 are also connected to the piston rods 9' of the piston cylinder 9, and they operate synchronously. The fusing device is in the form of a thermally conductive body or block having a plurality of needles 18 arranged in two or more rows and associated with respective holes 16, the pressure plate being arranged in the irregular shape of the bag. After pressing the pleated throat, it can be moved by the piston 8 towards one side of the pressing plate 14, thereby penetrating the bag material and removing the plastic material around the needle hole made by the heated needle. fused,
Thereby forming at least two rows of spaced apart fused areas of plastic material disposed in place of these needle holes.

As shown in FIG. 1, there are two sets of parallel oriented jumble jaw plates 12. However, a gathering device such as the jaw plate 12 may be provided with only an upper or a lower gathering device, and the bag material is moved into the fixed jaw member by shifting the upper jaw plate. It may be adapted to contact or be placed within the fixed jaw member thereby forming the throat 11 of the bag. As shown in Figure 2, the address of each group (]
1) The plates are opposite plates 12 and 12'l, each plate having a jaw-like cutout 19 at its end. The jaw-like cutout, as shown here, has a square cutout that tapers into a narrow section in which the bag is eventually brought together. This is accomplished by arranging each plate 12 and 12' in closely spaced parallel planes with the jaw-like cutouts 19 facing each other. A displacement device in the form of a piston rond 20 moves the jaw plates toward each other in the direction of arrow 21 so as to move the open end 16 of the bag as shown in FIG.
The surrounding parts of the throat are gathered together to form a constricted throat. After the throat has been formed, the jaw plate is moved between the pressure plates 14 or the pressure plates are moved into position. One of the jaw plates 12 or 121 may be replaced by a device for engaging with the other bag and transferred into the jaw-like cutout 19 of the bag material Y & plate in the area of the bag.

Referring to FIG. 4, the pleated throat 11 is shown relative to the pressure plate 14. As shown here (12), the throat portion 11 is formed by irregularly arranged wall portions of a plastic bag. By moving the pressing plate in the direction of arrow 15, the throat is compressed, thereby pressing the irregularly arranged wall sections of the bag material together so that adjacent wall sections are in full contact. . This is illustrated in FIG.

The pressing plate is clearly illustrated in FIG.
The rows or rows 21, 21' and 21" are provided with needle receiving holes. It is also understood that the holes in the outer rows or rows 21 and 21" are offset from the holes in the central row 21'. be done. This provides a stronger seal. If only one row of sealing holes is used, the seal may not be strong enough to cause sudden failure when the sealed bag is filled with goods and the seal is subjected to normal stress. I know. Similarly, needle 18
are arranged in the body block 17 which holds the needle in an arrangement similar to the arrangement of the needle holes 16.

Referring again to FIG. 5, the structure of the needle holding body or block 17 is shown diagrammatically. The block has a resistive element 22Y arranged within the block and connected to the power supply through a wire 23, thereby heating the block 17 and subsequently also the needle 18, which is made of a heat conductor. In a preferred embodiment, the emblem needle is made of tungsten steel while the block is made of bronze. However, other thermally conductive materials may also be used. To perform heat sealing, the block 17 is moved very close to one of the pressure plates 14 and immediately pulled back. This allows the pin 18 to penetrate the irregularly pleated throat 11 of the bag and melt the plastic around it to complete the closely spaced rows Z of pin seals. C with at least two rows of fused pin seals, thereby providing rigidity to the seal! This is an important thing to add. Although not essential, it is also preferred that pin seals in one row be offset from fused pin seals in adjacent rows. This provides greater strength to the seal as the pin seals support each other. If a single row of pin seals is used, only a very weak seal will be obtained as described above.

6 and 7 are enlarged views showing the structure of the pin seal 27 in the fused area. Figure 6 shows that the area is the needle hole 25.
One of the fused pin seals Z is shown as evidenced by the alternate cross-section "X". As shown here, the irregular flaps 11' of plastic material around the throat are fused to the needle hole 2.
forming a hard plastic wall 26 around 5.

FIG. 7 shows an array of six rows 27, 27' and 27" of fused pin seals extending across the throat 11 and located in the pressure plate 14 and block 17 in rows 21. and 27" of fused pin seals. 21' and 22'' match.

Any obvious modifications to the more preferred embodiments described herein are within the scope of the invention and such modifications are intended to be included within the scope of the following claims.
Let's go.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing the fusing device or the present invention, Fig. 2 is a perspective view showing an example of the structure of the collecting back plate, and Fig. 3 is the structure of the pressing plate and the heated needle block. FIG. 4 is a partially sectional plan view showing the position of the pleated bag portion relative to the pressing plate, and FIG. A fragmentary side view showing the location of the throat and needle holding block; Figure 6 is a partially enlarged sectional view showing the fused area at the bend of one needle hole; Figure 7 shows six rows of fused needles. FIG. 3 is an enlarged cross-sectional view of the fused throat showing the hole. 10 Niblastic bag 11: Folded throat 1
2: Jaw plate 16: Open end 14: Pressing plate 16: Needle hole 17 Body holding two needles 18: Heat conductive needle 19: Jaw-shaped notch 22:
Resistance element 26: Wall part (]6) 27: Pin seal

Claims (1)

[Claims] 1. In a plastic bag for holding contents,
The bag has a sealed and pleated throat proximate the open end of the bag, the sealed and pleated throat being made of molten plastic material arranged around a plurality of needle holes.
A plastic bag formed by irregularly arranged wall sections made of plastic material fused together by rows or more spaced apart fused pin seals. 2. The row of holes constitutes a tear line, and the top of the bag may be torn at the tear line to have an open end for removing the contents of the bag, according to claim 1. plastic bag. A plastic bag according to claim 2 having three or three rows of said holes. 4. The plastic bag of claim 2, wherein the needle holes in one of the rows are offset from the needle holes in an adjacent row. 5. In an apparatus for fusing the pleated throat of a plastic bag, the circumferential portion of the plastic bag near the open end is gathered together in an irregular manner to form the pleated throat. a gathering device and a pressing device for pressing together the irregularly arranged plastic material of said pleated throat, two or more rows arranged close to each other in different planes; a pressing device having needle-receiving holes spaced apart at two or more rows of thermally conductive wires movable into and out of the hole and across the plastic material of the pleated throat to fuse adjacent plastic material; Plastic bag sealing device with needle. 6. A plastic bag sealing device according to claim 5, wherein the hole in one of the planes is offset from the hole in an adjacent plane. 7. A plastic bag sealing device as claimed in claim 6, having three rows of spaced apart needle receiving holes and thermally conductive needles. 8. The gathering device comprises at least one pair of opposing gathering jaw plates, each having a tapered jaw-like notch at its end, the jaw plates disposed on the bag proximate to the open end of the bag. are extendable between the jaw-like cutouts and movable in directions facing each other in very close parallel planes with the jaw-like cutouts facing each other; 6. The plastic bag sealing device according to claim 5, wherein a portion of the plastic bag is gradually gathered together to form the pleated throat. 9. having two pairs of opposing collecting jaw plates, each pair disposed in a respective one of two spaced apart parallel planes, said pleated throat The part is 2
9. A plastic bag sealing device according to claim 8, which is defined as a portion of the gathered bag between a pair of jaw plates. 10. The pressing device is located between the two pairs of opposing collecting jaw plates and on either side of the pleated throat;
a plurality of pressing plates, the pressing plates being connected to a device for moving the pressing plates in a direction toward each other with the pressing surfaces of each of the plates parallel to each other, thereby making the pressing plates made of the thermoplastic material Pressing the irregularly arranged wall sections together, so that the irregularly arranged plastic materials are pressed together so that adjacent irregular wall sections made of plastic material are in full contact with each other. 9. The plastic bag sealing device according to claim 8, which is pressed together. 11. The fusing device comprises a body holding a needle made of a heat conductor and a resistive element disposed within the body for heating the body, the needle being secured within the body. and is made of a heat conductor to conduct heat from the body, and the body is connected to move toward or away from one of the pressure plates, once the pressure plate moves to the pressure position. , the needles enter the holes and penetrate the irregularly arranged wall portions made of the thermoplastic material, and fuse the material around each needle together to form the thermally conductive needles. 11. Apparatus for sealing a plastic bag as claimed in claim 10, forming at least two rows of spaced apart weld pin seals formed by melted plastic material around the molten plastic material. 12. The pressure plate has three rows of needle receiving holes spaced apart, the holding body has three rows of needles, and the outer needles and holes are in the three rows. 12. A plastic bag sealing device as claimed in claim 11, wherein the needles and holes are offset from the central row of needles and holes.