JPS63147628A - Manufacture of plastic sheet having many projecting air rooms and device therefor - Google Patents

Abstract

PURPOSE:To make it possible to change easily the thickness (the height) of projecting air rooms, by meshing embossing gears whose meshing depths are variable with recessed parts of a rotating drum having a plurality of recessed parts and vacuum holes in its surface. CONSTITUTION:Films 6 and 6 are passed between a rotating drum 16 having a plurality of recessed parts 17, vacuum holes 19 and projecting parts 18 surrounding the recessed parts and an embossing roll 9 having embossing gears 11 meshing with the recessed parts 17, and are subjected to heat fusion to be welded together at their contact parts to prepare a plastic sheet having a number of projecting air rooms. The embossing roll 9 is held on an eccentric shaft. By changing a specified angle of the eccentric shaft to the rotating drum 16, the meshing depth between the embossing gear 11 and the recessed part of the rotating drum 16 can be changed, so that it is possible to change easily the thickness (the height) of the air rooms.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention is an improvement in a method and apparatus for manufacturing a plastic sheet having a large number of convex air chambers used as cushioning, packaging, soundproofing, heat insulation, heat-retaining materials, etc. Regarding.

B. Prior Art The following methods have been known as conventional methods for manufacturing cushioning materials. That is, this is a method in which one side of the polymer resin film has a plurality of uneven surfaces and the other side of the polymer resin film has a planar shape and are laminated together using an adhesive. The cross-sectional shape of the obtained cushioning material is shown in Fig. 6. It is a so-called air cap (registered trademark), and the air sealed in the convex parts that are separated and sealed from each other plays the role of an air cushion and is used for packaging goods. used.

However, when the conventional manufacturing method is used, the air cap (registered trademark) obtained has a convex shape with only one side inflated, so there is a problem that the volume ratio cannot be made large with respect to the overall weight of the air cap (registered trademark). was there. Cushioning materials for packaging are generally required to be lightweight and large in volume, but conventional manufacturing methods have not been able to effectively utilize the raw material polymer resin film.

Therefore, in Japanese Patent Application No. 61-11992, the applicant previously proposed a method using a pair of rotating drums having a plurality of recesses on the cylindrical surface, a protrusion surrounding the recesses, and a suction hole provided at the bottom of the recess. proposed a method for manufacturing a material having a structure in which two plastic films 1 bulge outward through a crimping part 3 and have air chambers 2 with convex surfaces on both sides, as shown in FIG.

C8 Problems to be Solved by the Invention When manufacturing a material having the air chambers 2 having convex shapes on both sides,
The thickness (height) h of the air chamber 2 is uniquely determined by the height of the convex portion on the surface of the rotating drum, so in order to obtain materials with different thicknesses, it is necessary to prepare several types of rotating drums.
Not only does this increase equipment costs, but it also takes time to replace the rotating drum and set operating conditions, resulting in low productivity.

For this reason, it has been desired to develop a manufacturing method and apparatus that can freely and easily change the thickness of the air chamber within a certain range without changing the rotating drum.

Means for Solving Problem D1 In order to solve the problems of the prior art described above, the method of manufacturing a plastic sheet having a large number of convex air chambers according to the present invention includes forming a plurality of recesses on the cylindrical surface and forming the recesses. In a method for manufacturing a plastic sheet having air chambers with convex surfaces on both sides by supplying two thermoplastic films between two rotating drums having a surrounding convex part and a suction hole provided at the bottom of the concave part. , characterized in that the thickness of the convex air chamber can be changed by engaging embossed teeth with variable engagement depth in the recessed portion of the rotating drum.

Further, the device for implementing this is two rotating drums having a plurality of recesses on the cylindrical surface, a protrusion surrounding the recesses, and a suction hole provided at the bottom of the recess. a pair of rotating drums rotating in engagement;
The pair of rotary drums each engage with an embossing roll, and the embossing roll includes an inner ring pivotally supported on an eccentric shaft, and the inner ring protrudes radially from the axis of the eccentric shaft. an outer ring that is inscribed with a plurality of roller bearings; and a plurality of embossing teeth that engage with the recesses of the rotating drum on the outer peripheral surface of the outer ring, changing the set angle of the embossing roll with respect to the rotating drum. This feature is characterized in that the depth of engagement between the recess and the stamped teeth changes.

E1 Effect According to the method and apparatus of the present invention, by changing the eccentric shaft of the embossing roll that engages with and follows the rotating drum at a predetermined angle with respect to the rotating drum, the embossing teeth and the rotating drum are Since the engagement depth of the recesses changes, the thickness of the air chamber can be changed very easily.

In other words, simply by installing a pair of embossing rolls on the existing rotating drum, it is possible to easily manufacture various plastic sheets with different thicknesses of air chambers (see Figure 4B), and this does not require excessive equipment. It is possible to provide low-cost products by significantly improving productivity.

F. Examples Hereinafter, preferred embodiments of the method and apparatus of the present invention will be explained in detail based on the drawings. Figure 1 is an overall configuration diagram of the apparatus of the present invention, Figures 2A and B are front and side views of an embossing roll that constitutes a part of the apparatus of the present invention, and Figure 3 is a plan view of the rotating drum. .

In the figure, reference numeral 5 denotes a raw material roll, in which a two-ply thermoplastic film 6 (e.g.
), polypropylene film, a composite film made of nylon and polyethylene bonded together using Surlyn adhesive] are wound up. In this example, a two-ply polyethylene film (hereinafter simply referred to as film) is used. The two-ply film 6 is separated into single films 6' by a separation roll 7, guided by a guide roll 8, and then embossed by a roll 9.
and is supplied to the rotating drum 16.

Two embossing rolls 9 and two rotating drums 16 are prepared, and each embossing roll 9 rotates following the rotation of the rotating drum 16 to determine the thickness of the air chamber of the plastic sheet. The rotating drum 16 is arranged with the circumferential surfaces of each film in contact with each other, and functions to attach the wound veneer film 6' into a predetermined shape while rotating it.

The embossing roll 9 is provided with a cylindrical outer ring 10, as shown in FIGS. 2A and 2B. On the outer circumferential surface of the outer ring 10, a plurality of embossed teeth 11 are attached at predetermined angular intervals so as to be slidable in the circumferential direction by ports 10b in relief grooves 10a, and on the inner circumferential surface, a plurality of embossed teeth 11 are mounted at predetermined angular intervals so as to be slidable in the circumferential direction. In addition to arranging the heater 12, arm cylinders 14 are provided radially at a predetermined angle (in this example, 45'' intervals from the axis O of the eccentric shaft 15, which will be described later) on the inner ring 13, and are extendable and retractable via springs 14a. The attached roll 14b is inscribed therein.

The inner ring 13 is a circular ring whose outer periphery is centered at a point O', and is supported by an eccentric shaft 15. That is, the axis 0 of the outer ring 10 and the center 0' of the inner ring 13 are offset in the horizontal axis (minor axis) L direction of the eccentric shaft 15, and the length of each arm cylinder 14 differs depending on the angle. Therefore, when the eccentric shaft 15 and the inner ring 13 are fixed and the outer ring 10 is rotated while being slid on the roll 14b, the tooth surface 11a of the embossed tooth 11 forms an imaginary circle P centered on point 0'. The protruding length of each tooth surface 11a from the virtual circle P differs depending on the protruding direction of each arm cylinder 14. In this example, by setting the deviation between axis 0 and center 0' to 5 points, the tooth surfaces of the embossed tooth 11A on the right side and the embossed tooth 11B on the left side in the diagram on the horizontal axis protrude from the virtual circle. The lengths are set to 10.2 On, respectively, so that a difference of 10 points occurs in the depth of engagement with a recess 17 of a rotating drum 16, which will be described later.

The cylindrical surface structure of the rotating drum 16 is shown in FIG.

Reference numeral 17 denotes a plurality of rectangular recesses separated from each other, which define the shape of the air chambers of the plastic sheet.

The shape and dimensions are appropriately selected depending on the purpose. For example, 8cm
A recess shape with a base of 8 cm and a thickness of 2C11 is chosen. Note that the dimensions and shape are not limited to these, and can be selected as appropriate. Reference numeral 18 denotes convex portions that separate the four individual portions from each other and are arranged in a grid pattern.

As shown in FIG. 1, the convex portions 18 of each rotating drum are accurately opposed and engaged with each other, and two sheets of veneer film 6' are sandwiched and bonded between the convex portions. Mesoshukizami is applied to the top surface of the convex part to strengthen the adhesion.

Additionally, the surface of the mesoshukizami is coated with melamine resin to protect the film from damage. A suction hole 19 is provided at the bottom of the recess 17 of the rotating drum, and has the function of temporarily applying suction to the film and holding the veneer film 6' in the recess 17 of the rotating drum 16.

Now, returning to FIG. 1, the manufacturing method will be explained again.

The veneer film 6' wound around the embossing roll 9 is heated by the heater 12 to around its softening point (100 to 250°C, depending on the material of the film), and the recesses 1
7 and the embossed teeth 11 that mesh with the embossed teeth 11,
It is held in the recess 17 by the suction force generated in the suction hole 19 .

The rotating drum 16 is made of a veneer film 6' that is stamped.
is held in the recess 17 and rotated around a fixed vacuum roll 20 at a rotation speed of 5 to 10 revolutions/rotation. This vacuum roll 20 is inscribed in the rotating drum 16. A lie 21 is partially provided on the cylindrical surface of the vacuum roll 20. A vacuum hose 22 is in communication with the slide 21. A vacuum pipe 23 passing through the central axis of the vacuum roll 20 communicates with the vacuum hose 22. Therefore vacuum roll 2
The zero sensor z1 is always placed in a negative pressure state. As the rotary drum 16 rotates, the suction holes 19 of specific recesses are temporarily held on the slide 21, and a suction force is generated in the suction holes 19. In this example, three rows of slides 21 are provided, and the rotating drum 16
The suction force is applied only until the veneer film 6' is wound around and held and bonded.

Further, the rotating drum 16 has a built-in heater (not shown), and has the ability to maintain the veneer film 6' heated by the heater 12 of the embossing roll 9 at that temperature. This temperature varies depending on the material of the film, but is usually 80~
The temperature range is 200°C, and when polyethylene is used as the material as in this example, about 90°C is preferable.

Next, the two veneer films 6', which have been molded by the engagement between the embossing teeth 11 and the recesses 17 and are held by suction in the recesses 17, are held between the protrusions 18 of the rotating drum 16 that engage with each other. They are heat fused together.

After heat fusion, the suction force of the suction hole 19 is cut off.

As a result, a plastic sheet 24 having convex air chambers 2 on both sides, as in the conventional example shown in FIG. 5, is formed.

In the above forming process, the embossing roll 9 shown in FIG.
By changing the set angle between the horizontal axis of the eccentric shaft 15 and the rotating drum 16, the depth of engagement with the embossed teeth 11 that mesh with the recesses 17 of the rotating drum 16 changes (for example, the depth of engagement between the embossed teeth 11A and 11B is As shown in FIGS. 4A and 4H, a plastic sheet 24.24' is obtained in which the thickness h of the air chamber 3 differs by up to 20 m1.

Returning to FIG. 1 again, the plastic sheet 24 (24') with convex air chambers formed on both sides can receive glue from the transfer roll 26 immersed in the glue tank 25 if necessary. The protective film 4 that is picked up and rotated is sent between the rolls 27 and 27 and pasted on the surface of the convex air chamber, and then wound onto the sub-raw material roll 28.
The product is fed between a pair of pressure rolls 30 and 30 that are rewound and rotated via a guide roll 29, where a protective film 4 is attached to the surface of the convex air chambers on both sides to form a finished product, and the product is transferred to a belt conveyor 31. It is carried on a .

G0 Effects of the Invention According to the present invention, the thickness of the air chambers can be changed within a certain range by simply using the existing production equipment for plastic sheets with convex air chambers on both sides and adding an embossing roll to it. Since different products can be obtained, excessive equipment costs can be avoided and inexpensive products can be provided. Also,
To change the thickness, all you have to do is change the angle of the embossing roll relative to the rotating drum, eliminating the hassle of replacing the rotating drum or adjusting operating conditions as in the past.
Productivity improves.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a plastic sheet manufacturing apparatus according to the present invention, and FIGS. 3
The figures are the same (a plan view of the rotating drum; FIGS. 4A and 4B are plan views (A) of the plastic sheet produced according to the present invention).
5 and 6 are cross-sectional views of conventional plastic sheets. 5- Raw material roll, 7- Separation roll 8- Guite roll, 9- Embossed roll 10-- External ring, 11- Embossed tooth 12... Heater,
13-Inner ring 14--Arm cylinder, 15
-Eccentric shaft 16--One rotation drum, 17--Concave portion 18-Convex portion, 25--Glue tank 27--Glue roll, 28--Sub raw material roll 30--Crimp roll. Patent registration applicant Kiyoshi Hosono - Figure 4 (A) (B)

Claims (2)

[Claims] (1) Two thermoplastic films are supplied between two rotating drums that have a plurality of recesses on the cylindrical surface, a convex part surrounding the recesses, and a suction hole provided at the bottom of the recess, so that both sides have convex surfaces. The method for manufacturing a plastic sheet having a shaped air chamber is characterized in that the thickness of the convex air chamber can be changed by engaging embossed teeth with variable engagement depth in the recessed portion of the rotating drum. A method for manufacturing a plastic sheet having a large number of convex air chambers. (2) Two rotating drums having a plurality of recesses on the cylindrical surface, a protrusion surrounding the recesses, and a suction hole provided at the bottom of the recess, which rotate with the protrusions engaging with each other. a set of rotating drums, and embossing rolls each engaged with the set of rotating drums; the embossing rolls each include an inner ring pivotally supported on an eccentric shaft; an outer ring that protrudes radially from the axis of the roller and is inscribed in a roll that is telescopically attached to a plurality of arm cylinders, and a plurality of embossed teeth that engage with the recess of the rotating drum on the outer peripheral surface of the outer ring. A plastic sheet having a large number of convex air chambers, characterized in that the depth of engagement between the recess and the embossing teeth is changed by changing the set angle of the embossing roll with respect to the rotating drum. Manufacturing equipment.