JPH0364367B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) A package is sandwiched between half-folded heat-shrinkable plastic films, the upper and lower filters are sealed and cut using a heated blade, and hot air is passed through the film to shrink the package. This relates to a sealer for packaging equipment that finishes the product into a shape that closely fits the outer shape.

(Prior Art) Conventionally, as shown in FIG.
Heated blades 11 and 12 assembled in an L shape cut the film 5 in a seal by pressing the overlapping portion of the upper and lower films. In other words, a rectangular film package slightly larger than the package 7 is produced, with one side folded and the opposite side and the front and back three sides sealed. Next, the package 7 is sent forward by the discharge conveyor, and at the same time, the package 7 is sent between the half-folded films whose front side is sealed by the supply conveyor again, and the opposite side and rear side of the folded side are sealed and cut.By repeating this process, a rectangular film is continuously formed. A package is made. By feeding this into a hot air tunnel by a discharge conveyor, the film is heat-shrinked and a film package that closely fits the outer shape of the package is completed.

(Problem to be solved by the invention) The sticker-cut film has one side folded back and 3
It has a substantially rectangular planar shape with one end sealed. If the package is rectangular, thin, and flat, when the film is heated, the shrinkage will be uniform throughout, making it easier to fit into the package and give a good finished product. However, if the package is rectangular and thick, the film will not shrink evenly as shown in Figure 4, and the corners will not shrink completely and remain as protrusions 15 and 16. In particular, the corners of the seal area will not be as protrusions. It is not aesthetically pleasing to leave it as it ages.

The object of the present invention is to solve the problem of the corners of the sealed portion of the film not shrinking completely and forming protrusions 15 and 16 that remain and spoil the aesthetic appearance.

(Means for Solving the Problems) The present invention solves the problem of remaining protrusions by making the corner portions rounded in advance. In the case of continuous sealing with rolled film, one end of the sheet cut blade installed in the same direction as the direction of travel of the packaged sealer for packaging using half-folded heat-shrinkable film is attached to the seal cut blade installed in the direction perpendicular to this. An R is provided at the contact point, and an R is provided on the preceding blade approximately symmetrically with this R. The tip of the R of the leading blade is Δl from the extension of the blade parallel to the package traveling direction.
The blade is provided so that it extends by the length of the blade, and the seal cut is made first on one side, and then the remaining two sides are surely cut with a seal. The sealed corners have a radius and are uniformly drawn by heat shrinkage so that no protrusions are produced.

(Example) An example of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining the main parts of the sealer of the present invention, and FIG. 2 is a diagram showing the sealing film being cut. For the blade 1 that is parallel to the package traveling direction A and the blade 2 that is perpendicular to the package, make a radius at the corner where the 1st blade and the 2nd blade touch, and symmetrically from the 2nd blade's contact with the 1st blade. R is provided in the .

In the conventional sealer, as shown in FIG. 3, the contact portion between the blade 11 parallel to the package traveling direction A and the blade 12 perpendicular to it is at a right angle, so the film corners 13 and 14 that are successively sealed are approximately at right angles. In the sealer according to the embodiment of the present invention, the blade 1 applies a rear radius, and the blade 2 applies a front radius to the next package.
As a result, the front and rear corners of the film that are continuously sealed become rounded. Also, when the blade 1 cuts the side seal, it is important that the preceding cut part 3 due to the already sealed front R intersects the seal cut line 4 of the side cut by Δl, including the variation in cut dimensions. The incomplete seal becomes a hole in the remaining film after it is heated and shrunk. Blade 2 extends by Δl on the extension line of blade 1, and the seals intersect.

Further, when the blades 1 and 2 are constructed separately, the contact between the blades 1 and 2 is incomplete and a gap is likely to occur, and in this case, the gap becomes incompletely sealed and becomes a hole after the film is heated and shrunk. Therefore, blade 1 and blade 2
are integral, or at least the tips of the blades in contact are connected. The sealer having the blades 1 and 2 described above feeds a substantially rectangular package 7, such as a videotape, between the half-folded films 5 from the supply conveyor 6 to the half-folding section 8, as in the conventional sealing process. Pre-cut part 3 with the back side aligned and sealed first
Stop it in a position opposite to , and then use blade 1 and blade 2 to seal-cut the remaining sides. The seal cutting temperature of the blade varies depending on the material of the film, but it is maintained at about 190°C, the temperature on the verge of fusing. Hot air is sent to the sealed package to shrink the film, so that the film can form a seal in close contact with the outer shape of the package without leaving any protrusions at the corners.

(Effects of the Invention) According to the present invention, when shrink-wrapping a thick package, it is possible to obtain a package with excellent appearance without leaving any protrusions at the corners where the seal is cut.

Also, as a result of experiments, when the film corner and the corner of the package are misaligned with the conventional method, wrinkles occur even in thin packages, but with this example, wrinkles are less likely to occur even if the film and the package are misaligned. Excellent in appearance. Therefore, regardless of whether the package is thin or thick, a package with good appearance can be obtained without replacing the package.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a cut-sealed state of the present invention. Third
FIG. 4 and FIG. 4 are diagrams showing a conventional example. DESCRIPTION OF SYMBOLS 1, 2...blade, 3...preceding cut section, 4...sticker cut line, 5...film, 6...supply conveyor, 7...package, 8...half-folding section.

Claims (1)

[Claims] 1. In a sealer for packaging using a heat-shrinkable film folded in half, an L-shaped first seal cut blade located in a direction perpendicular to the traveling direction of the package and whose corners are curved, and the first seal cut blade A second seal cut blade is provided at a position line symmetrical to the blade in the perpendicular direction, and the end of the second seal cut blade located in the packaging traveling direction is on an extension line of the first seal cutting blade in the packaging traveling direction. A sealer characterized in that two corner portions of the seal cut located further outward are formed in curved lines.