EA033916B1 - Bag making method - Google Patents

Abstract

The invention relates to methods for manufacturing bags of spunbond with a rectangular bottom, using ultrasonic bonding. The technical problem is in non-uniform load distribution from the bag bottom along the seams resulting in seam tear on the bag bottom. The technical result of the suggested method consists in increased strength of produced bag due to location of seams on its sides with simplification of the method. The above technical result is achieved by the fact that the method of making a bag includes feeding the material from a roll, creasing the folding lines, cutting the material transversely to the direction of feeding from a roll for workpieces, folding a workpiece and fastening of the workpiece parts using seams formed by ultrasonic bonding; according to the claimed solution, a sheet of spunbond is selected as the material, after feeding the material from the roll, the edges of material located in parallel to the direction of material feed from the roll are roll inward to the backside, handles are manufactured along both rolled-in edges before creasing the lines, whereas folding of the workpiece includes the following: the material of workpiece along the edges located perpendicularly to the rolled-in edges, is to be rolled in at a right angle to the backside to form the sides of bag, the material of workpiece along the rolled-in edges is rolled inward at a right angle to the backside for formation the face walls of the bag, the parts of each side adjoining to the face walls of the bag are located on the outer side relatively to the part of side which remained in the initial position, the seams are formed on the sides of bag.

Description

The invention relates to methods for manufacturing spunbond bags with a rectangular bottom using ultrasonic welding.

A known method of manufacturing a plastic bag with a flat bottom (see patent for invention US4526565A, IPC B31B 35/00, publ. 02.07.1985). The method of continuous production of bags with a flat bottom, consisting of 4 side walls and a bottom attached from a plastic film, includes the following stages: forming a sleeve from a plastic film by blow extrusion, passing it between the pressure rollers to form a flat sleeve, passing it between hot knives to form several (at least two) continuous sleeves of smaller width, the formation of the side seam occurs due to the heating of the material with a hot knife, cutting I simultaneously weld the material, inflate the sleeve with air to form side folds, by passing the inflated sleeve through the bookmarks, which lay part of the sleeve inward, forming a pair of side folds located opposite each other, passing the folded sleeve through the welding shaft, forming diagonal on the sleeve seams and the bottom seam, to form a flat bottom, cutting off part of the sleeve of a given length below the bottom seam so that the part of the sleeve cut under the bottom seam becomes the upper neck the next bag.

The disadvantages of this method are the need to use the original billet in the form of a sleeve and the inability to use a sheet billet.

A known method of manufacturing a container with a square bottom (see patent for invention JPH01288428, IPC B31B 1/60, publ. 11/20/1989). The known method is intended for the production of bags of laminated materials (paper, plastic film, etc.) and includes the imposition of the edges of the rolled material on top of each other, subsequent bonding by heating (temperature welding), the formation of side tabs and the subsequent formation of a flat rectangular bottom.

The disadvantages of this method are the complexity and complexity.

Closest to the claimed solution is a method of manufacturing a folded bag (see patent for invention GB2330326, IPC B31B 29/60, publ. 12.12.2001). A method of forming a bag with side folds, which is a flat sleeve with embedded side folds and a bottom attached to this sleeve. The attachment of the bottom can occur both during the formation of the side folds, and after their formation. All parts of the bag are fastened together reliably enough to prevent the connection from breaking and the contents of the bag getting out. The parts of the bag are fastened with adhesive tapes, ultrasonic welding, glue, temperature welding, sewing.

The disadvantage of this method is the formation of fixing seams at the bottom of the bag, which reduces its strength and durability.

The objective of the invention is to develop a method for producing bags from sheet blanks of spunbond.

The technical problem is the uneven distribution of the load from the bottom of the bag along the seams, leading to rupture of the seams at the bottom of the bag.

The technical result of the proposed method is to increase the strength of the resulting bag by placing seams on its sidewalls while simplifying the method.

The specified technical result is achieved by the fact that the method of manufacturing a bag includes feeding material from a roll, scoring folding lines, cutting material transversely to the feed direction from a roll to workpieces, folding the workpiece and fastening parts of the workpiece using seams formed by ultrasonic welding, according to the claimed solution as the material choose a sheet of spunbond, after feeding the material from the roll, turn to the wrong side of the edges of the material, parallel to the direction of supply of materials ala from the roll, until the handle is made creasing lines along both tucked edges, wherein the folding blank comprises:

the workpiece material along the edges perpendicular to the turned edges is turned at right angles to the wrong side to form the sides of the bag, the workpiece material along the turned edges is turned at right angles to the wrong side to form the front walls of the bag, parts of each sidewall adjacent to the front walls of the bag, placed on the outside relative to the part of the sidewall remaining in the original position, the seams are formed on the sides of the bag.

When folding the workpiece, a tool is used that has the overall dimensions of the bag and is located on the wrong side of the workpiece. For the manufacture of handles on each of the rolled edges, both ends of the spunbond tape are fixed by ultrasonic welding or a hole is cut into

- 1,033916 material near the central part of each of the tucked edges.

The invention is illustrated by drawings, where in FIG. 1-13 shows the sequence of steps for implementing the proposed method, in FIG. 14 - finished bag, in FIG. 15 - scan bags. The positions in the drawings indicate:

- a roll of material;

- axis of the roll;

- spunbond sheet;

- direction of material supply;

- wrong side;

- scoring line;

- tucked edge;

- cut line;

- procurement;

- tape;

- hole;

- sidewall;

- front wall;

- bottom;

- the seam;

- equipment;

A is the width of the roll;

a - the width of the rolled edge;

In - the width of the workpiece;

b is the width of the sidewall;

D is the thickness of the bag;

H - bag height;

W is the width of the bag;

x is the width of the seam.

To implement the inventive method for the manufacture of bags carry out sequentially the operations shown in the following drawings.

FIG. 1 - rotate the roll 1 of a single layer of spanbond fabric of width A around its axis 2 to unwind and obtain a sheet of spunbond 3.

FIG. 2 - material (spunbond sheet 3) from a roll 1 is fed in a direction 4 perpendicular to the axis of rotation 2 of a roll 1 to a bag production line.

FIG. 3 - the edges 7 of the material with a width a, located parallel to the direction 4 of feeding the sheet of spunbond 3 from the roll 1, tucked on the wrong side 5.

FIG. 4 - tucked edge 7 is fixed by ultrasonic welding.

FIG. 5 and 6 - make at least one pair of pens of a certain type at the edges of the material opposite each other. For the manufacture of handles such as loops on each of the tucked edges 7 on the wrong side 5 fasten using ultrasonic welding both ends of the tape 10 from spunbond (Fig. 5). For the manufacture of pens such as holes, a hole 11 of an oval or other shape is cut out in the workpiece near the central part of each of the rolled edges 7 (Fig. 6).

FIG. 7 - to facilitate subsequent folding of the sides of the bag, scoring is carried out on the wrong side 5 of the spunbond sheet 3 along lines 6 located perpendicular to the feed direction 4 from roll 1 alternately at a distance of W and 2 (b + x), and scoring lines 6 are placed on sheet 3 so so that the handles are located in the center between a pair of scoring lines 6 located at a distance of W.

FIG. 8 - to obtain blanks 9 cut a sheet of spunbond 3 along lines 8 located perpendicular to the feed direction 4 from roll 1 at a distance B from each other, with each cut line 8 located in the center between a pair of scoring lines 6 located at a distance of 2 (b + x).

In FIG. 9 presents the workpiece 9.

FIG. 10 - the material of the workpiece 9 at a distance not exceeding b from the cut lines 8, rotate to a location at right angles to the wrong side 5 to form the sides 12 of the bag. Moreover, B-2b = W, where W is the width of the bag.

FIG. 11 - the material of the workpiece 9 at a distance not exceeding H from each of the rolled edges 7, is rotated to a location at right angles to the wrong side 5 to form the front walls 13 of the bag. The distance between the front walls D is the thickness of the bag. The material of the workpiece 9, remaining in the original plane, forms the bottom 14 of the bag. The parts of each sidewall 12 adjacent to the front walls 13 of the bag are arranged externally with respect to the part of the sidewall 12 adjacent to the bottom 14 of the bag and remained in the initial position, i.e., the position until the front walls 13 shown in FIG. 10. The size of the sidewalls and the thickness of the bag are related by the condition D = 2 (b-x) + x, where x is the width of the seam, that is, the edges of each sidewall when folding the bag

- 2 033916 have the ability to overlap themselves at a distance of not less than x. With this folding, a bag in the form of a rectangular parallelepiped with dimensions D / H / W is obtained from a sheet blank 9 with A / B dimensions.

FIG. 12 - the material of each sidewall 12 of the bag is compressed in one plane to form seams on the sides of the bag.

FIG. 13 - then fasten the seams 15 using ultrasonic welding. In addition, an additional seam is formed by ultrasonic welding on the sidewalls parallel to the bottom of the bag at a distance b from the bottom.

To ensure the operations shown in FIG. 10-13, the production line is equipped with a snap in the form of a rectangular parallelepiped with dimensions D / H / W corresponding to the dimensions of the bag being manufactured. Before the step of FIG. 10, the bottom of the tool with dimensions D / W is placed on / on the wrong side of the workpiece so that the sides of the bottom of the tool with size D are parallel to the sides of the workpiece with dimensions A, and accordingly, the sides of the bottom of the tool with size W are parallel to the sides of the workpiece with dimensions B. Then during the step of FIG. 10, press the central part of the sidewalls to the snap. Thereafter, during the step of FIG. 11, press the front walls to the snap. During the step of FIG. 12, the sidewalls are pressed to the snap-in so that at the places of the seam formation, the extreme parts of each sidewall 12 adjacent to the front walls 13 overlap with the central part of the same sidewall 12 adjacent to the bottom 14. After fastening the joints, the snap-out is removed from the bag (Fig. 14 )

Claims (4)

CLAIM 1. A method of manufacturing a bag, including feeding material from a roll, scoring folding lines, cutting the material transversely to the direction of supply from the roll to the workpieces, folding the workpiece and fastening parts of the workpiece using seams formed by ultrasonic welding, characterized in that a sheet of spanbond, after feeding the material from the roll, turn the edges of the material parallel to the direction of the material supply from the roll to the wrong side of the material; handles along the lines are scored both turned edges, scoring on the wrong side of the spunbond sheet along lines located perpendicular to the feed direction from the roll alternately at a distance of W and 2 (b + x), and the scoring lines are placed on the sheet so that the handles are located in the center between a pair of scoring lines, located at a distance W, where W is the width of the bag; b is the width of the sidewall; x is the width of the seam, while folding the workpiece includes the following: the workpiece material along the edges perpendicular to the turned edges are turned at right angles to the wrong side to form the sides of the bag, the workpiece material along the turned edges is turned at right angles to the wrong side to form the front walls bags, parts of each sidewall adjacent to the front walls of the bag are located on the outside relative to the part of the sidewall remaining in the original position, the seams are formed on CVID bags. 2. The method according to claim 1, characterized in that when folding the billet use a snap having the dimensions of the bag and located on the wrong side of the billet. 3. The method according to claim 1, characterized in that for the manufacture of handles on each of the rolled edges, both ends of the spunbond tape are fixed by ultrasonic welding. 4. The method according to claim 1, characterized in that for the manufacture of pens cut a hole in the material near the Central part of each of the tucked edges.