JPS59187507A - Heat seal method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-sealing method that enables accurate pitch alignment of containers and lids in an integrated production system for molding plastic containers, filling articles, and heat-sealing lids. Sur.

In conventional tray forming, filling, and sealing continuous packaging machines, the lid material is marked with predetermined marks for registration at regular intervals, and generally has a lid material temporary stop mechanism.
It was based on the so-called brake method. In this method, one pitch should be set to an error of 0.05 τ or less, so printing accuracy is extremely strict. Another method, as shown in Fig. 1, is to sandwich the lid material between two sets (7) of pinch rollers for registration. ! If the cover material with a length of 11250 rmn was printed with an accuracy of within 4rM1, it was possible to register the main valve. However, in this method, it is difficult to match the pitch by stretching the lid material, but it is difficult to register unless the lid material is made of a material similar to single aluminum, which has low resilience after stretching, and it is difficult to achieve registration unless the lid material is made of a material similar to single aluminum, which has low resilience after stretching. It could not be used with a lid material made of a multilayer film.

In this method, the lid material is stretched in a predetermined manner between a preheating area by opening for preheating and the above two sets of pinch rollers before passing through a cooling area. This method heat-seals the lid to the container by minimizing elongation and accurately registering (pitch matching) marks on the lid. According to this method, adhesive lacquer is applied to conventional aluminum foil. Previously, only coated aluminum foil could be used alone, but now it is now possible to use aluminum foil as a lid material laminated with other plastic films, or even plastic film as a lid material. 0 Even though the plastic film stretches, it returns to its original shape as soon as the tension is removed (between the pinch rollers), so the marks are not aligned when sealing the lid material.

In addition, with the normal brake method, the pitch accuracy is often forced to pull the cover material with the brake method, so the pitch accuracy must be extremely strict as mentioned above, and the pitch accuracy is usually 10.05 frames. It is the rank. After sealing again,
Because the lid material is forcibly stretched, the periphery of the lid material may curl upward while the lid material is sealed, causing the lid material to curl upwards, and the tray to be deformed. Accidents may also occur in which the curled portion or deformation damages the seal portion of other sealed containers. In addition, wrinkles occur on the lid material, making it unsightly and impairing printability.

FIG. 1 is an explanatory diagram of the conventional method, in which 1 is a stock roll of lid material a, 2.3 is a pair of pinch rolls, and 2.
Hold the lid material A between the rolls of books, for example with a pinch roller.
The pinch roller 3 remains fixed at 2, and the support rod 4 of the roll opens from the axis at a predetermined angle in order to obtain a predetermined stretching. Passing through the guide roll 5 in the stretched state,
A container (tray) is formed on another line, filled with the stored items B, and inserted under the lid material. 6 is a heat sealing zone, and 7 is a trimming zone, where the products are cut at alignment marks and sent out on a conveyor as individual products C. Step 8 checks the register mark with a phototube.

FIG. 2 is an explanatory diagram of the heat sealing method of the present invention. The lid material a fed from the stock roll 1 shown in FIG. The time is about 5 seconds at 6CI' to 80°C. Next, the lid material is fed between pinch rolls 2 and 3, and when stretching is completed, it is cooled in a cooling zone by a cooling air blower 10.

Figures 3 and 4 show the results of tests on the elongation of various aluminum and plastic film laminates due to preheating and cooling. (throat) shows the elongation (vertical axis) when leaving the pinch roller.

In the case of , PET is polyethylene terephthalate, A!
is aluminum and PE is polyethylene.

(Foundation) has a preheating temperature of 25°C, and ca2 is the same <40°C.
, H is the same at 60°C1 ■ is the same <800C1 The dotted line (to) is preheated to 40°C and then cooled, (
7) shows the case where it was preheated to 60'C and cooled as it was after stretching L1, and 7 shows the case where it was preheated and stretched to 80'C and directly cooled in the trench.

(6) is preheated to 25°C, (6) is preheated to 400°C, and (Foundation) is preheated to 60°C. This figure shows the state of residual elongation when using a laminated material containing aluminum foil.

Furthermore, in the method of the present invention, the lid material of plastic film or laminated film containing aluminum foil of 30μ or less is once preheated, stretched with a pinch roller, cooled, and then heat-sealed to the container, so that the sealing register can be adjusted. However, even if the lid material is stretched using two sets of pinch rollers, the restoration of the lid material is small, so it is easy to match the appearance.

In addition, a container that is heat-sealed by filling the contents made by the method of this invention solves the conventional problem of turning up, and is free from pinholes caused by piercing from the turned up part from the outside. There is no occurrence of wrinkles on the surface, the problem of corrosion of the aluminum foil caused by the noise of the contents, etc. is solved, and the printability is good as well as the occurrence of wrinkles on the surface.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the conventional forming, filling, and heat sealing method, Fig. 2 is an explanatory diagram of the method of the present invention in the sealing process, and Figs. 3 and 4 are illustrations of the stretching and pinch roller of plastic laminated aluminum foil. It is a graph showing the relationship between residual elongation immediately after release. 1...Stock roll for lid material, 2.3...
...One pair of pinch rollers 14...Pinch roller support rod, 5...Guide roll, 6...Heat seal zone, 7... Trimming zone, 8...Phototube, 9...Preheating zone, 10...Cooling near blower, A...Preheater, B...Filled contents , C...Product, a... Laminated aluminum foil or plastic snack film. Patent applicant: Toppan Printing Co., Ltd.

Claims (1)

[Claims] In an integrated production system that covers everything from forming containers to filling and heat-sealing lids made of plastic film or plastic film-laminated aluminum foil, the lids before heat-sealing are passed through a preheating area and then stretched with two sets of pinch rollers. This heat sealing method is characterized in that the lid material is immediately cooled to stop the elongation of the lid material, thereby making it possible to accurately match the pitch of the lid material.