JPH0739153B2 - Hot plate for corrugator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating box for corrugators for producing corrugated board, and more particularly to a hot plate on the upper surface of the heating box.

[0002]

2. Description of the Related Art A double facer, as shown in FIG.
A starch-based adhesive is applied to the center core 2 of the single-faced cardboard 1 at the gluing station 3, and the liner 4 supplied from the side facing the single-faced cardboard 1 and the heating box 5 and the belt 6 are pressure bonded. Further, the belt 6 and the belt 7 are sandwiched and conveyed to the rear to complete the bonding.

Through the above steps, the outer surface of the liner 4 is
While it comes into sliding contact with the heating plate on the upper surface of the heating box 5, an adhesive or the like is easily attached and solidified on the heating plate, so that the liner 4 may be scratched or sometimes damaged.

In order to prevent this, frequent cleaning is required, which requires manpower and also reduces the operating rate of the corrugator.

[0005]

DISCLOSURE OF THE INVENTION Therefore, for example, Japanese Utility Model Laid-Open No. 58-64429.
As disclosed in the publication, it has been proposed to apply a low friction material such as a fluororesin to a hot plate.

The above-mentioned polymer materials have low surface wettability, so that it is difficult for an adhesive to adhere to them and they also have good slipperiness, but there is a major defect that they are inferior in wear resistance. It will be worn by contact and cannot be expected to operate without maintenance for a long time.

Therefore, it is conceivable to select a material that is harder and has better wear resistance than the above-mentioned fluororesin, but the problem of adhesiveness of the adhesive is still unsolved.

An object of the present invention is to provide a hot plate which is excellent in abrasion resistance, and at the same time, is hard to be adhered with the adhesive and is easy to peel off the adhesive.

[0009]

In order to solve the above problems, in the present invention, the surface of the corrugator hot plate in contact with the corrugated cardboard liner has a minute hardness of 500 _{HV 0.3} or more and a surface roughness of 0.1 to 3 μmRa. That is, the porous layer is provided.

The above-mentioned porous layer has a cross-section porosity of 0.3.
It is good to keep ~ 15%.

[0011]

[Function] Since the porous layer has the specific surface roughness as described above, it is suitable for a surface shape that gives a contact angle at which the water-soluble adhesive is difficult to wet, and it is , Water as a solvent is easily trapped at the adhesive interface between the adhesive and the surface of the hot plate, and the water trapped in the minute irregularities or the porous space has a surface temperature of the hot plate, for example, 160 to 180 ° C.
Boiling or bumping is caused by the expansion action, and the expansion action destroys the adhesive interface formed between the adhesive and the porous layer. Therefore, the product after the adhesive adhered to the hot plate is solidified or carbonized,
It is easily peeled off by the rubbing force of the liner, and does not aggregate or accumulate.

Further, since the surface hardness of the porous layer is a specific value or more, it is excellent in wear resistance.

[0013]

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

As shown in FIG. 1, the heating box 10 has a hollow chamber 11 for passing a heating fluid, and a heating plate 12 on the upper surface thereof is provided with a porous layer 13.

The porous layer 13 is made of a metal such as high carbon steel, stainless steel or molybdenum, an alloy such as a cobalt base alloy, a self-fluxing alloy or a nickel base alloy, Al ₂ O ₃ (alumina), Al ₂ O _3-. TiO ₂ (alumina-titania),
Stabilized zirconia _{(ZrO 2 -Y 2 O 3,} ZrO 2 -C
aO), zircon (ZrSiO ₄ ), titania (T
iO ₂ ), chromium oxide (Cr ₂ O ₃ ), chromium carbide (C
r ₃ C ₂₎ and the like ceramics, WC based cemented carbide (WC
Co, WC-NiCr, WC- Ni), Cr 3 C 2 group cemented carbide _{(Cr 3 C 2 -NiCr, Cr} 3 C 2 -Co),
TiC-based cemented carbide (TiC-NiCr, TiC-Co)
Composed of a thermal spray coating of carbide cermet.

The method of forming the sprayed coating may be any of a gas spraying method, an electric arc spraying method, a plasma spraying method, a flame spraying method and the like.

When the thermal spray coating is formed in this way, as shown in FIG. 2, fine irregularities 14 are formed on the surface and pores 15 are formed inside.
To form the porous layer 13. The fine irregularities 14 on the surface are adjusted by a means such as grinding to adjust the surface roughness so that the center line average roughness value (μmRa) falls within the range of 0.1 to 3 is the non-adhesiveness of the adhesive. From the viewpoint of peelability and slipperiness of the liner, it is most preferable.

Similarly, from the viewpoint of the peelability of the adhesive, it is preferable that the cross-section porosity of the pores 15 is 0.3 to 15%.
If it is 0.3% or less, there are few voids in the porous layer 13 and there is almost no effect of evaporating the water which is the solvent of the water-soluble adhesive to destroy the adhesive interface, and if it is 15% or more, the voids are formed. This is because there is a risk that the adhesive itself will penetrate if it becomes too large.

The surface roughness and the cross-sectional porosity of the porous layer 13 largely depend on the particle size of the hard particles forming the layer 13. Therefore, it is preferable to keep the particle size in the range of several μm to several tens of μm.

The microhardness of the porous layer 13 is 500 or more, preferably 600 to 130, in _{terms of} micro-Vickers, 300 g weight (H _V0.3 ) in consideration of wear resistance.
It is 0.

Further, the thickness of the porous layer 13 is required to be a certain amount or more, and if it is too thin, the layer 13 itself peels off or the durability is impaired. A good thickness is 0.05 mm or more. Moreover, 3 mm or more is not economical.

The optimum adhesive for the hot plate of the present invention is
Although it is a starch-based adhesive such as cornstarch, it is needless to say that a predetermined effect can be obtained by using other water-soluble adhesives.

Next, experimental examples and comparative examples will be described.

Now, the porous layer shown in FIG. 3 is formed on the hot plate made of cast iron by various thermal spraying methods, the corn starch adhesive is applied to the surface of the porous layer, and the corn starch adhesive is placed in an electric furnace at 180 ° C. for 30 minutes. After being left for a minute, the removability (peelability) and abrasion resistance of the applied adhesive were examined. The wear resistance was obtained as a weight loss with respect to the forced wear history using an accelerated wear tester. The evaluation results are shown in FIG. In the figure, in the peelability column, double circles indicate extremely easy peeling, single circle marks indicate easy peeling, cross marks indicate difficult peeling, and double circle marks indicate abrasion resistance in steel materials. In comparison, the single circle mark is extremely excellent, the cross mark is relatively excellent, and the cross mark is almost the same.

The self-fluxing alloys of Experimental Examples 3 and 4 were JI
S, H8303-1989.

[0026]

According to the present invention, as described above, since the hard porous layer having fine irregularities is provided on the surface of the heating plate,
While the surface wettability is controlled by the minute irregularities,
The moisture of the water-soluble adhesive captured by the minute irregularities and pores evaporates and expands due to the heat of the heating box, destroying the adhesive interface between the adhesive and the porous layer, and easily peeling off the adhered adhesive. As a result, the adhesive does not aggregate or accumulate, and is removed together with the rubbing of the liner, and the surface of the hot plate is maintained smoothly for a long period of time, which can significantly reduce labor and improve productivity. .

Further, the surface of the porous layer has a high hardness and therefore has excellent wear resistance.

[Brief description of drawings]

FIG. 1 is a transverse sectional view showing an embodiment of a hot plate according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view of the above.

FIG. 3 is a table showing the results of experimental examples and comparative examples.

FIG. 4 is a side view showing the main part of the double facer.

[Explanation of symbols]

 1 Single-sided Corrugated Cardboard 2 Core 3 Gluing Station 4 Liner 5 Heating Box 6 Belt 7 Belt 10 Heating Box 11 Hollow Chamber 12 Heat Plate 13 Porous Layer 14 Micro Asperity 15 Pore

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Hiro ▼ Yukihiko Oka 663 at 734 Kobayashi, Bessho Town, Miki City, Hyogo Prefecture (663) Inventor Tetsuya Doi 1-11-19 Fukaehoncho, Higashinada-ku, Kobe City, Hyogo Prefecture -C number

Claims (2)

[Claims] 1. A hot plate for a corrugator, which is provided with a porous layer having a microhardness of 500 _{HV 0.3} or more and a surface roughness of 0.1 to 3 μmRa on the surface of the corrugated board in contact with the liner. 2. The cross-sectional porosity of the porous layer is 0.3 to 15
% Is the hot plate for corrugator according to claim 1.