JPS60129170A - Method for coating hot-melt resin on synthetic resin film - Google Patents

Abstract

PURPOSE:To enable high-speed coating without wrinkle, deformation, etc. by supplying a synthetic resin film in a tense state to adsorption regions provided to a cooling roll and coating and cooling simultaneously a hot-melt resin in the attraction regions. CONSTITUTION:The device is provided with a cooling roll 4 having attraction regions 2, 3 of the area approximately the same or properly larger than the region to be coated of a synthetic resin film 1. The roll 4 is disposed in such a way as to position level the axial center of the roll and is circulated internally with cooling water for cooling the surface. The film 1 is continuously supplied to the surface of the roll 4 in the prescribed tense state in the longitudinal and transverse directions via a guide roll 5, a pair of tension rolls 6, a driving roll 7 and a pinch roll 8. While the film 1 is attracted in the regions 2, 3, a hot-melt resin is coated thereto from a nozzle head 10 disposed to face the film and is cooled simultaneously during the transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of applying a hot melt resin to a synthetic resin film, and more specifically, for example, a method of applying a hot melt resin to a thermoplastic synthetic resin film for reinforcing a thermoplastic synthetic resin film as a back sheet of a disposable diaper. This invention relates to a method of applying melt resin.

Ultra-thin polyethylene film is generally used as the back sheet of disposable diapers, and a pressure-sensitive adhesive tape is fixed to the film to tighten it when the diaper is worn. It is known to apply hot melt resin to the area. Conventionally, such coating has been generally carried out by transferring the hot melt resin from a storage tank to the film via a multi-stage coating roll, but this may result in uneven coating or shrinkage and deformation of the coated surface, resulting in film damage. There were drawbacks such as the width changing. These drawbacks may be solved to some extent by reducing the coating speed, but this is not efficient.

The purpose of the present invention is to provide a coating method that can solve the above-mentioned drawbacks, and the method of the present invention for achieving that purpose will be explained as follows with reference to the drawings. .

FIG. 1 schematically shows an apparatus for carrying out the method of the invention.

The apparatus includes a cooling roll 4 having an adsorption area 2°3 having an area approximately equal to or suitably larger than the area to be coated with the synthetic resin film 1, and the cooling roll 4 is arranged so that the roll axis is horizontal. , so that cooling water circulates inside it to cool its surface. The film 1 is continuously supplied to the surface of the cooling roll 4 under a predetermined tension in the length and width directions via a guide roll 5 , a pair of tension rolls 6 , a drive roll 7 , and a pinch roll 8 . Transferred to the next process. During the transfer, the film 1 is attracted by the attraction areas 2 and 3 and cooled at the same time as it is coated with hot melt resin which is ejected from the nozzle head 1O disposed opposite thereto.

The tip 10a of the nozzle head 10 is preferably placed at a predetermined height H from the central horizontal line 15 that equally divides the cooling roll 4, and is parallel and horizontal to the surface of the cooling roll 4. If the height H is lower than a predetermined value, the film 1 may be braked due to the resin pressure during application of the hot melt resin, causing wrinkles, or the resin pool may become smaller, resulting in uneven application. Sometimes. If the height H is higher than a predetermined value, the resin layer may not spread well and the resin may have tails and may not be applied neatly. In a preferred embodiment, the height H is 5
~15 mn. Furthermore, if the nozzle head 10 is not parallel and horizontal to the surface of the cooling roll 4, wrinkles and uneven coating will occur in the film 1 when applying the hot melt resin.

As shown in FIG. 4, when the suction area 16 has a flat surface 16a and a concave surface 16b, the hot melt resin layer applied to the film 1 is formed in a pattern corresponding to the flat surface and the concave surface.

Note that the pinch roll 8 can be adjusted toward and away from the surface of the cooling roll 3 using an air cylinder (not shown). As shown in FIG. 3, the pair of tension rolls 6 are arranged on both sides of the film 1 so that the film 1 is pulled in the widthwise direction. The nozzle head 10 is
It has a valve control cylinder 11 that adjusts the amount of hot melt resin ejected, and is supported by an arm 13 of a slider 12. The slider 12 is supported by a frame 15 so as to be moved forward and backward by an air cylinder 14.

According to the method of the present invention, the film 1 is supplied to the surface of the cooling roll 4 under a predetermined tension in both the length and width directions, and the area to be coated of the film 1 is suctioned by the suction areas 2 and 3 while the area to be coated is Since a method is adopted in which hot melt resin is applied to the film and cooled at the same time, unlike conventional methods, the film 1 does not wrinkle before and after being supplied to the surface of the cooling roll 4, and The area coated with hot melt resin does not shrink or deform due to heating of the resin, its width changes, or uneven coating occurs, and it can be coated at a higher speed than conventional methods. can do. therefore,
This method is extremely useful as a method of applying a hot melt resin to a thermoplastic synthetic resin film, especially a low-melt material such as polyethylene, to reinforce the area concerned.

[Brief explanation of drawings]

Fig. 1 is a schematic side view of an apparatus for carrying out the method of the present invention, Fig. 2 is a side view showing the main steps of the method of the present invention in the same apparatus, and Fig. 3 is a drawing in which the film is stretched in the width direction by a tension roll. FIG. 4 is a plan view showing the process, and is a plan view showing an example in which the suction area of the cooling roll has an uneven surface. ■...Film, 2, 3...Adsorption area 4...Cooling roll 5...Guide roll 6...Tension roll 7...Drive roll 8...Pinch roll 10
... Nozzle head 15 ... Center horizon Yoshiharu Shirahama Patent attorney 1st figure 2nd figure 3rd figure

Claims (4)

[Claims] (1) A synthetic resin film is continuously supplied under tension in both its length and width to the surface of a cooling roll having an adsorption area on the surface, and while adsorbing the applied area of the film to the adsorption area, The method is characterized in that hot melt resin is ejected from coating nozzles disposed opposite to each other in the adsorption area and applied to the area to be coated, and at the same time is cooled by the cooling roll. A method of applying hot melt resin to synthetic resin film. (2) At least, the film is tensioned in the width direction by tension rolls arranged on both sides thereof diagonally with respect to the transport direction, and the film is tensioned in the width direction by means of pinch rolls arranged opposite to the surface of the cooling roll. A method of applying a hot melt resin to a synthetic resin film according to claim 1, wherein the hot melt resin is supplied while being pressed against the surface of the synthetic resin film. (3) The film is supplied from above to below the cooling roll arranged horizontally, and the film is supplied to the cooling roll at a predetermined height position from a center horizontal line that equally divides the cooling roll in the vertical direction. A method for applying a hot melt resin to a synthetic resin film according to claim 1, wherein the hot melt resin is ejected from the application nozzles arranged parallel and horizontally opposite to each other. (4) The adsorption area is formed on an uneven surface, and the hot melt resin is applied to this while adsorbing the film to the uneven surface, so that the applied hot melt resin surface is shaped into a pattern corresponding to the uneven surface. A method of applying a hot melt resin to a synthetic resin film according to claim 1 to be formed.