JPS63147629A - Plastic sheet having many projecting air rooms, manufacture thereof and apparatus therefor - Google Patents

Abstract

PURPOSE:To prepare a plastic sheet having excellent cushioning, soundproof, heat insulating characteristics and so on, by adhering protecting sheets to one or both faces of the plastic sheet having a number of projecting air rooms. CONSTITUTION:Two plastic films 6 and 6 are passed through rotating drums 16 and projecting parts 18 surrounding the recessed parts and the contact parts are subjected to heat fusion to be welded together to prepare a plastic sheet having a number of projecting air rooms. The projecting parts of the sheet are coated with a paste by means of a paste coating roll 2 and a protecting film is adhered to one or both sides of the sheet to make them in a body. As the surface is covered with the protecting film 4, the sheet has excellent cushioning, soundproof and sound insulating characteristics, strength and so on, and it is useful for a cushioning material and so on.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention relates to a plastic sheet having a large number of convex air chambers used as cushioning, packaging, soundproofing, heat insulation, heat-retaining materials, etc., and a method and apparatus for producing the same. Regarding improvements.

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. This is a so-called air cap (registered trademark), and air sealed in convex portions that are separated and sealed from each other serves as an air cushion and is used for packaging articles.

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 Camp (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, the applicant previously proposed in Japanese Patent Application No. 61-1) 992 a pair of rotary cylinders 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. We proposed a method for producing a material using a drum, as shown in Figure 5, in which two plastic films 1 bulge outward through a crimped part 3 and have air chambers 2 with convex surfaces on both sides. .

C8 Problems to be Solved by the Invention In the material having the air chambers 2 having convex shapes on both sides, since the plastic film 1 constituting the air chambers is exposed, it may be torn by vibrations during packaging or transportation, causing the material to become a shock absorber. There is a risk that it will become useless. Further, when used as a soundproofing material or a heat insulating material, the effect is low because air flow paths are formed because there are depressions between the convex air chambers.

For this reason, it is desired to develop a plastic film with high strength (and excellent heat insulation and heat retention effect), as well as its manufacturing method and equipment, in which an air chamber with convex shapes on both sides is sandwiched between protective films in a sandwich-like manner. Ta.

Means for Solving Problem D3 In order to solve the problems of the prior art described above, the plastic sheet having a large number of convex air chambers of the present invention is provided by forming a predetermined portion of two overlapping thermoplastic plastic films. It is an air chamber formed by closely contacting the inside of which is filled with gas, and two thermoplastic plastic films bulge outward to form a convex shape. Multiple bags are connected in a plane direction with a common contact part. Additionally, a convex protective film is attached to one or both sides of the formed convex air chamber.

This method of manufacturing a plastic sheet uses two rotating drums each 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, and the protrusions engage with each other. a step of supplying a thermoplastic film to the cylindrical surface of each of the rotating drums that is rotating in a state of
a step of heating the thermoplastic plastic film to a softening point; a step of winding the two thermoplastic plastic films into the engaging portions of the two rotating drums and applying pressure with the convex portions to bond them by thermocompression; A step of removing the thermoplastic film molded product by cutting off the suction force acting on it, a step of gluing it on both sides of the thermoplastic film molded product, and a step of applying a protective film to both sides of the pasted molded product. It is characterized in that it consists of a step of pasting.

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;
A guide roll that supplies a thermoplastic film to the cylindrical surface of each of the rotating drums, and a guide roll that is inscribed in the cylinder of the rotating drum and that engages with the suction hole after the thermoplastic film is wound around the rotating drum. A thermoplastic film formed by a fixed vacuum roll that applies suction force while being sandwiched between mating convex parts and thermocompression bonded, a heater for temporarily heating the thermoplastic film to a softening point, and the rotating drum. It is characterized by comprising means for pasting the thermoplastic film on both sides of the molded product, and means for pasting a protective film on both sides of the thermoplastic film molded product.

88 Effect According to the method and apparatus of the present invention, after the thermocompression bonding process of two plastic films having concave portions and convex portions formed thereon by a pair of rotating drums and the molded product removal process by cutting off the suction force, the process shown in FIG. By adhering the protective film 4 from both sides as shown in , H, a double-sided protective plastic sheet with high strength can be manufactured, and existing equipment can be used as is to provide an inexpensive product.

In the plastic sheet of the present invention, a new air chamber 2 is formed between the protective film 4 and the recessed crimp portion 3, so that the cushioning force is further enhanced.

Furthermore, since the air in the air chamber 2.2' is completely isolated from the outside by the protective film 4, it is effective as a heat insulating material.

F. Examples Hereinafter, preferred embodiments of the method and apparatus for manufacturing the plastic sheet of the present invention will be explained in detail based on the drawings. 1st
The figure is an overall configuration diagram of the apparatus of the present invention, FIGS. 2A and 2B are a front view and a side view of an embossing roll that constitutes a part of the apparatus of the present invention, and FIG. 3 is a plan view of the rotating drum.

In the figure, 5 is a raw material roll, which is a two-ply thermoplastic plastic film 6 [e.g. polyethylene film (LDPE, LLDPE, HDPE)]
, polypropylene film, a composite film made of nylon and polyethylene bonded together using Surlyn adhesive] are wound up. In this example, we use two layers of polyethylene film (
Hereinafter, it will simply be abbreviated as film. ) is used. The two-ply film 6 is separated into single films 6' by a separating roll 7, guided by a guide roll 8, and supplied to an embossing roll 9 and a rotating drum 16.

Two embossing rolls 9 and two rotating drums 16 are prepared, and the winter 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 drums 16 are arranged so that their circumferential surfaces are in contact with each other, and serve to attach the wound veneer films 6' together into a predetermined shape while rotating them.

The embossing roll 9 is provided with a cylindrical outer ring 10, as shown in FIGS. 2A and 2B. On the outer peripheral surface of the outer ring 10, a plurality of embossed teeth 1) are attached at predetermined angular intervals so as to be slidable in the circumferential direction by means of relief grooves 10a and 10b, and on the inner peripheral surface, embossed teeth 1) are provided at predetermined angular intervals. multiple heaters 12
and a roll telescopically attached via a spring 14a to an arm cylinder 14 radially provided at a predetermined angle (in this example, 45° intervals from the axis O of an eccentric shaft 15, which will be described later) on the inner ring 13. 14b is inscribed.

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 O' 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 1) a of the embossed tooth 1) is imaginary centered on the point 0'. Different trajectories are drawn with respect to the circle P, and the protrusion length of each tooth surface 1) a from the virtual circle P differs depending on the direction in which each arm cylinder 14 is protruded. In this example, the deviation between axis 0' and center 0 is set to 5
By setting it to the fin, the length that the tooth surfaces of the embossed tooth 1) A on the right side and the embossed tooth 1) B on the left side in the figure on the horizontal axis protrude from the virtual circle is set to 10.20 m, respectively. A difference of lON in the depth of engagement with the recess 17 of the rotating drum 16, which will be described later.

This is so that it occurs.

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 8o x 8
The bottom of cIl and 2C! A recess shape with a thickness of l 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 individual concave 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. Menschukizami is applied to the top surface of the convex part to strengthen the adhesion.

Additionally, a melamine resin coating is applied to the surface of the Methushukizami 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 1) that mesh with the embossed teeth 1),
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
According to the rotation of the 6-rotation drum 16, which is always in a negative pressure state, the suction hole 19 of a specific recess temporarily engages the suction hole 21 with the suction hole 21, and a suction force is generated in the suction hole 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 is in the range of 200°C, and when polyethylene is used as the material as in this example, the temperature is preferably about 90°C.

Next, the two veneer films 6', which have been molded by the engagement of the embossed teeth 1) and the recesses 17 and are held by suction in the recesses 17, are held between the projections 18 of the rotating drum 16 that engage with each other. and 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 horizontal axis '1jAL of the eccentric shaft 15 of the embossing roll 9 and the rotating drum 1 shown in FIG.
By changing the setting angle made with 6, the rotating drum 16
Since the depth of engagement with the embossed tooth 1) that meshes with the concave portion 17 of the embossed tooth 1) changes (for example, there is a difference of 1Q mm between the embossed tooth 1) A and IIB), as shown in Fig. 4A and B, the air chamber Plus snack sheet 24 where the thickness h of 3 differs by up to 20 mm
．． 24' is obtained.

Returning to FIG. 1 again, the plastic sheet 24 (24'), which has convex air chambers formed on both sides, receives the glue from the transfer roll 26 immersed in the glue tank 25 and rotates. The glue is sent between rolls 27.27,
A pair of pressure bonding rolls 30 that rewind and rotate the protective film 4 wound around the sub-raw material roll 28 via a guide roll 29 after being pasted on the surface of the convex air chamber.
The protective film 4 is attached to the surfaces of the convex air chambers on both sides to form a finished product, which is then carried on a belt conveyor 31.

G1 Effects of the Invention According to the present invention, the existing production equipment for plastic sheets having convex air chambers on both sides can be used as is, and the surface gluing process (equipment) and the process (equipment) for applying protective films on both sides can be performed. ), you can obtain a product with great buffering power, soundproofing, heat insulation, heat retention, and strength, with the air chamber surface sandwiched between protective films.

[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 figure is also a plan view of the rotating drum, and FIGS. 4A and 4B are plan views (A) of the plastic sheet manufactured by the present invention.
5 and 6 are cross-sectional views of conventional plastic sheets. 5-raw material roll, 7-separation roll 8-guide roll, 9-embossing roll 10--outer ring,
1) - Embossed teeth 12 - Heater, 13 -...
Internal 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) Old

Claims (3)

[Claims] (1) An air chamber formed by closely adhering a predetermined portion of two stacked thermoplastic films.The inside of the chamber is filled with gas, and the two thermoplastic films bulge outward to form a convex shape. A plastic sheet having a large number of convex air chambers made by connecting a plurality of eggplant bags in a plane direction with a common contact part, and pasting a protective film on one or both sides of the formed 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 step of supplying a thermoplastic film to each cylindrical surface of the rotating drum; a step of holding the supplied thermoplastic film along the recessed portion by suction force generated in the suction hole; and a step of holding the supplied thermoplastic film along the recessed portion; The two thermoplastic films are heated to the softening point, the two thermoplastic films are rolled into the engaging portions of the two rotating drums, and the convex portions are pressed to bond them under heat, and the suction force acting on the suction holes is A step of taking out the thermoplastic film molded product that has been sealed and thermocompressed, a step of gluing it on both sides of the thermoplastic film molded product, and a step of attaching a protective film to both sides of the glued molded product. A method for manufacturing a plastic sheet having a large number of convex air chambers. (3) 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, a guide roll for supplying a thermoplastic film to the cylindrical surface of each of the rotating drums, a thermoplastic film inscribed in the cylinder of the rotating drum and for the suction hole; a fixed vacuum roll that applies suction force while the thermoplastic film is rolled up on a rotating drum and then sandwiched between mutually engaging convex parts and thermocompressed; a heater that temporarily heats the thermoplastic film to its softening point; A number of methods comprising means for pasting a protective film on both sides of a thermoplastic film molded product formed by a drum, and means for pasting a protective film on both sides of the pasted thermoplastic film molded product. Equipment for manufacturing plastic sheets with convex air chambers.