JPS5829216B2 - Manufacturing method of laminated spiral tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a spiral tube in which a belt-shaped polystyrene foam sheet is laminated with a belt-shaped sheet that can be adhered to the polystyrene foam sheet via an adhesive.

Conventionally, using a spiral paper tube machine (Langston machine),
It is already known to produce spiral tubes using paper.

However, it has been extremely difficult to manufacture a laminated spiral tube using a Langston machine using a polystyrene foam sheet and a sheet that can be bonded to the polystyrene foam sheet, for example, using an aqueous adhesive solution.

This is because polystyrene foam sheets and sheets that can be bonded to the polystyrene foam sheets to be laminated, such as synthetic resin films, have extremely low absorbency and permeability to adhesive solvents, so could not volatilize and therefore it was difficult to bond.

If a spiral tube is manufactured using a Langston machine under such conditions, the adhesive used will act as a lubricant between the laminated sheets during the backlash of the endless belt used in the Langston machine, causing the product to deteriorate. A slip phenomenon occurs, making it impossible to manufacture spiral tubes.

Furthermore, even if it were possible to manufacture a spiral tube, when cutting it, the wrapped product would come off due to insufficient adhesion (commonly known as dock ears), so high-speed production would be required. is extremely difficult.

When manufacturing a composite spiral tube made of highly water-absorbent paper and polystyrene foam sheet, bonding is possible because the paper absorbs a certain amount of solvent, but the bonding speed is slow, resulting in dog ears and making high-speed production difficult. .

The method using an organic solvent has the disadvantage that the resin is dissolved by the solvent and the thickness of the foam sheet is reduced.

The present inventor coated a polystyrene foam sheet with an adhesive that is liquid at room temperature and does not attack the polystyrene foam sheet, then laminated this and a sheet that can be adhered to the polystyrene foam sheet into a spiral shape, and then applied this adhesive to a polystyrene foam sheet with a wavelength of 2 to 20μ. An infrared heater having a temperature of 110~
When heated to 150°C, the polystyrene foam sheet and the solvent interposed between the sheet become vapor and dissipate to the outside of the polystyrene foam sheet, forming a polystyrene foam sheet and a sheet that can be adhered to the polystyrene foam sheet. The present invention has been completed based on the discovery that a polystyrene foam sheet can be firmly adhered and that a polystyrene foam sheet can be tertiary-foamed by the solvent of the adhesive to obtain a composite spiral tube with a high expansion ratio.

In the present invention, a strip-shaped sheet that can be bonded to a polystyrene foam sheet using an adhesive that is liquid at room temperature using a solvent that does not attack the polystyrene foam sheet is placed on a mandrel via the adhesive. This is heated with an infrared heater having a wavelength of 2 to 20μ to bond the band-shaped polystyrene foam sheet and a band-shaped sheet that can be adhered to the polystyrene foam sheet, and after cooling, a suitable The gist of this invention is a method for manufacturing a laminated spiral tube, which is characterized by cutting it into lengths.

The band-shaped polystyrene foam sheet used in the present invention is
Not only a styrene homopolymer but also a copolymer with a heptamer which can be copolymerized with styrene, containing 50% by weight of styrene.
The styrene copolymers containing the above can also be used as raw materials, and can be obtained by heating and melting these polymers in an extruder, adding a blowing agent such as an aliphatic hydrocarbon, and extruding and foaming them into a sheet. A sheet obtained by cutting a foamed sheet into strips having an appropriate width is used.

In the present invention, the polystyrene foam sheet is 0.4~:h
U+, especially one having a thickness of 1 to 2 mm, is preferably used.

In addition to the polystyrene foam sheet of the same quality as the polystyrene foam sheet, examples of the belt-shaped sheet that can be adhered to the polystyrene foam sheet include ordinary kraft paper, paper such as Hatron paper, thermoplastic resin film such as polyethylene, polypropylene, polystyrene, etc. A sheet obtained by cutting these resin foam sheets into strips having an appropriate width is used.

Additionally, metal foil such as aluminum foil can also be used.

When laminating a sheet that is not permeable to solvents, such as a thermoplastic resin film or metal foil, to a polystyrene foam sheet, a laminated spiral tube with good adhesion can be achieved by using the sheet that is not permeable to solvents as the inner layer. can be obtained.

In the method of the present invention, the sheets to be laminated are not limited to two layers, but can be a multilayer spiral tube with three or more layers as long as the sheets have good solvent permeability.

For adhesives that are liquid at room temperature and do not attack polystyrene foam sheets, lower aliphatic alcohols such as methanol, ethanol, propatool, or their aqueous solutions, or water are used as solvents, and modified polyvinyl alcohol, methyl cellulose, etc. are used as adhesive components. Carboxymethyl cellulose, polyvinyl acetate, ethylene vinyl acetate copolymer, vinyl acetate, acrylic acid ester and ethylene acetate copolymer, etc. are suitable, and are used in the form of a solution or emulsion, which have good initial adhesive strength. It is recommended to use a suitable adhesive.

Infrared rays can be divided into near-infrared, mid-infrared (ordinary) infrared, and far-infrared rays depending on their wavelength, but the boundaries between these are not always clear.

In the present invention, infrared radiation having a wavelength of 2 to 20 microns is used.

Heating with infrared rays is generally done by heating the surface of the heater to 300 to 700°C, adjusting the distance from the laminated spiral tube to 50 to 150° so that the surface of the polystyrene foam sheet is 110 to 1500°C, and ~24
Emits infrared light for seconds.

Specifically, the temperature on the surface of the infrared heater is approximately 4
At a temperature of 50°C, an adhesive using a solvent that is liquid at room temperature and does not attack polystyrene is applied to the polystyrene foam sheet at a distance of about 100 mm from the heater, and a sheet that can be bonded to the polystyrene foam sheet with the adhesive is laminated at a distance of about 100 mm from the heater. Adjust the laminated spiral tube so that it is heated for 4 to 24 seconds.

The heating temperature may be adjusted by adjusting the voltage.

The opposite side may also be heated using a reflector, but it is preferable to heat both sides in the same way using an infrared heater.

Therefore, the surface of the laminated spiral tube is 8 at 120 to 130℃.
It is most preferred to heat for around seconds.

Since the laminated spiral tube rotates and advances on the mandrel, the surface of the laminated spiral tube is uniformly heated by infrared rays.

Polystyrene has approximately 3-4μ, 6-7μ and 12-1
Since each has a maximum absorption at 5μ, when irradiated with infrared rays having a wavelength of 2 to 20μ, not only the surface but also the inside of the polystyrene foam sheet is sufficiently heated.

Water also has maximum absorption at 3μ and 6μ, and lower aliphatic alcohols also have maximum absorption at the same position, so we used a polystyrene foam sheet and a solvent that is liquid at room temperature and does not attack the polystyrene foam sheet. The solvent of the liquid adhesive interposed between the adhesive sheet and the adhesive sheet is vaporized by heating with an infrared heater.

Although the liquid permeability of the polystyrene foam sheet is extremely low, the vaporized solvent vapor is relatively easily permeable, so that the generated solvent vapor escapes from the surface of the polystyrene foam sheet to the outside.

At this time, the polystyrene foam sheet has its softening point temperature (90
-1400C), the generated steam causes tertiary foaming, and the thickness of the polystyrene foam sheet increases to about 2 to 4 times that of the initial sheet.

Heating with an infrared heater uniformly heats not only the surface of the polystyrene foam sheet, but also the inside and the solvent, so that only the surface is heated and does not turn into resin, which is the case with ordinary heating.

It is desirable that the polystyrene foam sheet is preheated with an infrared heater before being laminated with a belt-like sheet that can be adhered to the polystyrene foam sheet.

By preheating, the band-shaped polystyrene foam sheet undergoes secondary foaming and its strength increases, and preheating during adhesion has the effect of promoting tertiary foaming and drying.

When heating the stacked spiral tubes with infrared rays, or preheating the band-shaped polystyrene foam sheet, the ambient temperature between the infrared heater and the object to be heated is approximately 9
It is desirable to maintain the temperature at 0 to 110°C.

This is because if the object to be heated rises significantly, the surface of the polystyrene foam sheet will melt, making it impossible to obtain the desired laminated spiral tube.

In order to maintain such an ambient temperature, for example, in horizontal heating, if heating is performed using an open oven with both sides vented to the outside air, the above temperature can be maintained even without forced convection of heated air using a fan. It is possible to maintain an ambient temperature of

In addition, if the strip-shaped sheet that can be adhered to the strip-shaped polystyrene foam sheet does not absorb the solvent of the liquid adhesive, remove the excess solvent and apply the liquid adhesive to the surface to facilitate bonding with the polystyrene foam sheet. It is preferable to pre-dry it in advance to adjust the amount of solvent.

The adhesive solvent must not be completely dried during pre-drying.

The amount necessary for adhesion must remain.

Embodiments of the present invention will be described below with reference to the drawings.

1.2.3 is a polystyrene foam sheet in the form of a belt, each having a thickness of 1 mm, cut to a desired width, and used with its ends wound into a roll.

Polystyrene foam sheet 1 is the bottom layer, 2 is the upper layer, 3
is further laminated on top of the polystyrene foam sheets 2 and 3 to form a laminated spiral tube.
is guided to the upper surface of the adhesive tank 4, and the roll coater 5
Adhesive solution 6 is applied to the surfaces of polystyrene foam sheets 2 and 3 by.

This adhesive solution consists of vinyl acetate, acrylic ester,
It is an emulsion adhesive mainly composed of ethylene acetate copolymer, and is applied to the surfaces of polystyrene foam sheets 2 and 3 to a thickness of 0.1 to 0.2 Wm.

7 is a doctor for removing excess adhesive solution 6.

8 is an infrared heater for pre-drying polystyrene foam sheets 2 and 3, its surface temperature is 30
50-1501 from polystyrene foam sheets 2 and 3 heated to 0-700°C, preferably 400°C. t
, wrapping the polystyrene foam sheets 1 and 2 with an adhesive solution 6, preferably arranged at a distance of 100 mm and applied to the faces of the polystyrene foam sheets 2 and 3;
It is pre-dried to the extent that it can be bonded.

Note that this pre-drying must not completely dry the adhesive solution.

The polystyrene foam sheet 1 and the pre-dried polystyrene foam sheets 2 and 3 are wound around a mandrel 10 having a diameter of 76mm attached to the main body 9 of a Langston machine for obtaining a laminated spiral tube.
With the endless belt 12 stretched at , the windings are stacked and pushed forward.

13 is an infrared heater, which, like the infrared heater 8 described above, is placed at a distance of about 100 mm from a laminated spiral tube 20 in which polystyrene foam sheets 2 and 3 are spirally laminated on a polystyrene foam sheet 1; The spiral tube 20 is heated to 120-140°C.

By this heating, the moisture in the adhesive interposed in the middle turns into water vapor, which causes the polystyrene foam sheets 1, 2, and 3 to further foam (tertiary foaming), and evaporates from the surface of the sheets. The polystyrene foam sheets 2 and 3 are firmly adhered to form a laminated spiral tube 20 and extruded forward.

The product 21 is obtained by cutting this into a desired length.

The obtained laminated spiral tube product 21 has the polystyrene foam sheet 1 and the spirally laminated polystyrene foam sheets 2 and 3 adhered evenly and strongly over the entire surface, and has a smooth surface and can be processed quickly. The method of the present invention is extremely suitable as a high-magnification spiral lamination processing method for polystyrene foam sheets.

In the above example, the same polystyrene foam sheet was used as the belt-shaped sheet that can be adhered to the polystyrene foam sheet, but for example, polystyrene foam sheet 1 as the inner layer and/or polystyrene foam sheet 3 as the outer layer Paper such as kraft paper can also be used instead.

It is also possible to use a non-foamed thin thermoplastic resin sheet or film, or a metal foil such as aluminum foil for the inner layer.

The laminated spiral tube obtained by the method of the present invention is obtained by heating the polystyrene foam sheets 1, 2, 3 and the adhesive solvent by heating with an infrared heater 13,
Since the solvent dissipates to the outside of the laminated spiral tube, the laminated polystyrene foam sheets T-L2 and T-L3 are uniformly and firmly adhered to each other without causing uneven adhesion, and the heat dissipation of the solvent is prevented. As a result, tertiary foaming occurs and a spiral tube with high magnification can be obtained.

This tertiary foaming generates compression pressure and further improves adhesion.

In the method of the present invention, the amount and concentration of the adhesive is made appropriate by pre-drying the polystyrene foam sheets 2 and 3 coated with the adhesive solution 6, and also because the polystyrene foam sheets 2 and 3 are heated. , mandrel 10
When wrapped around the endless belt 12, it does not slip, so no defective products are produced.

In addition, since the obtained laminated spiral tube 20 is heat-formed and dried with the solvent of the adhesive dissipated, dog ears do not appear when it is cut.

As described above, the method of the present invention is capable of producing a laminated spiral tube 20 with extremely good adhesive properties with high efficiency, and is extremely useful as a method for manufacturing a laminated spiral tube using a polystyrene foam sheet.

According to the method of the present invention, laminated spiral tubes with large or small inner diameters can be freely obtained as desired.

The obtained laminated spiral tube can be suitably cut and used as a core, a container, especially a moisture-proof container for food, and many other uses.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing the method for manufacturing a laminated spiral tube of the present invention. The main symbols in the drawings are as follows. 1... Polystyrene foam sheet, 2... Polystyrene foam sheet, 3... Polystyrene foam sheet, 4...
・・Adhesive water tank 5・Roll coater 6・Adhesive solution 7・Doctor 8・Infrared heater
9... Langston machine body, 10... Mandrel,
11... Head, 12... Endless belt, 13.
...Infrared heater 20...Laminated spiral tube, 2
1...Product.

Claims (1)

[Scope of Claims] 1. A belt-shaped sheet that can be adhered to a polystyrene foam sheet with an adhesive that is liquid at room temperature and uses a solvent that does not attack the polystyrene foam sheet, is attached to the polystyrene foam sheet via the adhesive. , wound and laminated on a mandrel, heated with an infrared heater having a wavelength of 2 to 20μ to bond the band-shaped polystyrene foam sheet and a band-shaped sheet that can be adhered to the polystyrene foam sheet, and cooled. A method for manufacturing a laminated spiral tube, which comprises cutting it to an appropriate length. 2. Heat the surface of the spiral tube to 110=1 using an infrared heater.
Claim 1 characterized in that the heating is performed at 50°C.
A method for producing a laminated spiral tube as described in Section 1. 3. The method for manufacturing a spiral tube according to claim 1, which comprises preheating a band-shaped polystyrene foam sheet coated with an adhesive to a temperature at or below its softening temperature. 4 The thickness of the band-shaped polystyrene foam sheet is 0.4 ~
3. The method for manufacturing a laminated spiral pipe according to claim 1, which has a diameter of 0.00 mm. 5. The method for manufacturing a spiral tube according to claim 1, wherein the strip-shaped sheet that can be adhered to the strip-shaped polystyrene foam sheet is a thermoplastic resin sheet, paper, or metal foil. 6. The method for manufacturing a spiral tube according to claim 5, wherein the thermoplastic resin sheet is a sheet of polyethylene, polypropylene, or polystyrene. 7. The method for manufacturing a spiral tube according to claim 6, wherein the thermoplastic resin sheet is a foamed sheet of polystyrene, polyethylene, or polypropylene. 8. The method for manufacturing a spiral tube according to claim 1, wherein the solvent that does not attack the polystyrene foam sheet is water, a lower aliphatic alcohol, or an aqueous solution thereof.