JPS58114943A - Manufacture of honeycomb sandwich panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a honeycomb sandwich panel using a powdered adhesive, in which a powdered adhesive is applied to the cell edges of a honeycomb core in advance, and after being fixed by heating and fusing, This invention relates to a method for manufacturing a honeycomb sandwich panel that is made by heat-bonding the panel with art materials.

Conventionally, honeycomb sandwich panels have been widely used in applications such as aircraft, railway vehicles, lumber, and office equipment due to their advantages such as light weight, flat surface properties, and excellent heat insulation properties.

41, it has major drawbacks in dentition speed and production cost. The main ones are listed below.

(1) Film adhesives are mainly used to bond honeycomb cores and art materials.

Because the film adhesive is in a film form, it also applies to unnecessary parts that are not involved in adhesion of honeycomb and mucoa.
The disadvantage is that adhesive is used unnecessarily and the light weight of the honeycomb sandwich panel results in an increase in weight which hinders the 51I/# length. In addition, the film is unavoidably expensive due to its high manufacturing cost, and it is often used together with release paper. It has disadvantages that lead to.

Further, in order to improve the adhesion between the film and the facing material, an autoclave is often used as part of the panel forming equipment, which complicates the process and reduces productivity.

(Paste adhesive is also often used instead of film adhesive to bond the honeycomb core and face material.)

Paste-type adhesives are also usually applied to the entire surface of the surface material, so they have the same disadvantage as film-type adhesives in that they are wasted and increase weight.

A paste adhesive can be applied to the honeycomb core cell edge, but if a misalignment occurs when the honeycomb core cell edge is fitted with the face material, the adhesive will be removed, causing a problem of adhesion defects.

(3) The honeycomb core is composed of an aggregate of tubular bodies with a hexagonal cross-section as shown in Figure 1, and the material used for the honeycomb core is generally extremely thin paper, plastic, metal foil, etc. The adhesive area at the point of contact with the art material is small, so sufficient adhesive strength can be obtained.In order to increase the strength, it is necessary to increase the amount of adhesive. Efforts are being made to increase the bonding and area by widening K (this phenomenon is called filleting, and refers to the state indicated by 2' in FIG. 3).

Therefore, for example, in the case of a film adhesive, a thickness of about 100μ is sufficient for normal surface bonding, whereas a thick film of 20U to 400μ is usually used for Nonikamsa/Deutsche Chibanel adhesive. It is being

This, in conjunction with the disadvantages mentioned in item 11 above, further impedes the weight reduction, which is the greatest feature of honeycomb sandwich panels, and leads to increased costs.Also, adhesive strength is required even though the adhesive area is small. Adhesives that can be used from the surface are also subject to severe limitations.

(4) In addition, when air permeability is required or when a perforated plate is used as a surface material, it is difficult to use a film adhesive, and there are many problems with construction methods if it is used forcibly. The following restrictions arise.

On the other hand, since powdered adhesives are in powder form, there are problems such as initial measures to control the powdery + β properties during construction and measures for recovery, but on the other hand, they can be produced at low cost and quality is It has the advantage of being small in the buff and can be applied to materials of various shapes. In particular, it is rapidly growing as an adhesive due to advances in application technology such as coating technology that uses static electricity. For example, powdered adhesives are the mainstream adhesive for clothing interlining, and are attracting attention in other technical fields as well, as they can comply with solvent regulations to prevent pollution.

However, powdered adhesives that are solid at room temperature i.

Normally, the molecular weight is high, so the viscosity when melting is high, and it is difficult to sufficiently wet the metal surface under no pressure. The cut surface of the cell edge of the 7-nicum core, which is about 100 μm in size, has a very small cross-sectional area, and the powdered adhesive applied only to the warp is extruded by the pressure applied during bonding, creating a so-called fillet property that covers the periphery of the edge. It is extremely difficult to achieve fillet properties. Fillet properties are a phenomenon that involves complex factors such as viscosity, surface tension, wetting, etc. mainly due to the properties of the adhesive, and many engineers are making efforts to improve the properties of honeycomb sandwich panels. This is an important problem in manufacturing, and the present inventors have also made extensive studies on this problem.As a result, we found that adhesive is applied to the cut surface of the honeycomb cell edge and in the direction perpendicular to the cut surface, that is, in the thickness direction of the honeycomb core. Alternatively, after applying the adhesive, a powdered adhesive is attached using a wrinkle adhesive or an adhesive, and then heat treatment is performed to melt the powdered adhesive and form a uniform film of powder particles. Later, it was discovered that a sufficient fillet could be obtained by forming panels, and the present invention was completed.

That is, the present invention applies an adhesive or an adhesive to the cell end face of a honeycomb core in the direction of the core thickness from one end to the other, and applies a powdered adhesive to the honeycomb core and the face material with the adhesive fixed to the adhesive or adhesive. This is a method for manufacturing a honeycomb sandwich panel characterized by the steps of laminating and heat bonding.

To explain the manufacturing method of the present invention in detail, it consists of the following steps (1) Coating the adhesive or adhesive on the cut surface of the I/nicumsel edge, and also coating it in the thickness direction of the nicums core from the K11m cut surface (7) 2) Process of fusing and fixing the powdered adhesive to the adhesive or adhesive application area (the powdered adhesive was fused and fixed) - Step 1 of combining Nikum core and art materials, heating and bonding, and making a panel As the powder adhesive used in the present invention, thermoplastic resins, thermosetting resins, and so-called composite resins that are a mixture of both can be used.

Thermoplastic resins include polyamide, polyester, ethylene-vinyl acetate, and saponified products thereof.

These resins include ethylene-ethyl acrylate copolymer melivinyl butyral, etc. These resins are obtained in powder form during polymerization9, pine mechanically crushed by freezing and crushing after polymerization, and powdered by precipitation from a solution, etc. can be converted into

Examples of thermosetting resins include epoxy resins, phenolic resin polyester resins, and acrylic resins.These resins mainly consist of a curing agent and a base resin, and they can be melt-blended together and then crushed, or they can be crushed separately and then crushed. It can be obtained by a method such as triblending.

A powder adhesive that is particularly effective in the manufacturing method of honeycomb φe sandwich panels is a so-called composite adhesive that is made of a mixture of a thermoplastic resin and a thermosetting resin.

Such adhesives include nylon-epoxy, nylon-
Examples include phenol, polyester-epoxy, silicone-epoxy, phenolic-vinyl, phenolic-nitrile rubber, and epoxy-phenolic. However, the best method may be selected in consideration of the required adhesive performance, adhesive conditions, etc., and the performance may not be fully expressed. In order to prevent this phenomenon,
It is necessary to control the temperature and heating time during fusion and fixation, and to set conditions that are milder than the bonding conditions. Example G
In the case of f-epoxy resin, strong adhesion can be obtained by setting it to B-stage under -deposition conditions, and
Advantages such as the ability to relax bonding conditions such as temperature and time can be obtained.

In the present invention, the following adhesives or adhesives can be used to attach the powdered adhesive to the nicum core. Various types of adhesives can be used, such as acrylic, vinyl, and rubber adhesives.Recently, hot melt type and reactive type adhesives have also been developed, and any of these can be used. The rubber adhesive is sticky. Acrylic adhesive has a carbon number of 2-1
Various products are commercially available, which mainly consist of acrylic acid ester polymers of aliphatic alcohols (2). Examples of hot-melt pressure-sensitive adhesives include those based on ethylene-vinyl acetate copolymers, styrene-block copolymers, polyamides, polyesters, and acrylic acid ester copolymers. In addition to these, urethane-based, silicon-based, polyvinylethyl ether-based, epoxy-based, etc. may also be mentioned. Adhesives are adhesives that have an appropriate level of tackiness because the powdered adhesive is applied while they remain tackified after application, and that maintain their tackiness to an appropriate level, i.e., do not rapidly lose their tackiness. things are suitable. As this adhesive, commercially available adhesives such as epoxy, urethane, silicone, rubber, polyamide, and acrylic adhesives can be used in the form of paste, solution, or emulsion.

Among these pressure-sensitive adhesives and adhesives, it is desirable to use one that does not inhibit the fillet properties of the molten powder adhesive when the adhered powder adhesive is fused and bonded by heating in the subsequent process. Adhesives made from pressure-sensitive adhesives or thermoplastic resins are preferred. Furthermore, since the adhesive always maintains its tackiness even if the solvent etc. evaporates after application, it is preferable to use a pressure-sensitive adhesive because there is a great deal of flexibility in combination with post-processing.

To explain the manufacturing method of the present invention, the pressure-sensitive adhesive or adhesive can be easily applied to the cell end face and in the thickness direction of the core by a roll coating method using a rubber roll or the like. A method of applying powdered adhesive to a honeycomb core coated with an adhesive or adhesive is to continuously apply powdered adhesive to a predetermined width from a mesh roll type spreader while the honeycomb core is conveyed through a guide in a flat manner. It can be made to adhere to the pressure-sensitive adhesive or the adhesive-applied area by spraying it on the adhesive. Further, honeycomb cores coated with an adhesive or adhesive are stacked on a flat plate coated with a powdered adhesive to a predetermined thickness, and the honeycomb core can be coated with uniform lateral pressure using the principle of transfer.

As a method for heating and fusing, a conventional hot air circulation furnace, a far-infrared heater, high-frequency induction heating, etc. can be used. It is preferable to form a film of powder by fusing, and reduce the tackiness to a negligible level -0 The coating thickness of the adhesive or adhesive is determined by the adhesion retention after fusion of the powdered adhesive, and the adhesion retention of the powdered adhesive after fusion. It is determined by considering the adhesion force of the adhesive and the strength of the panel after adhesion, but it is usually 11 to 100
μ is preferably 1 to 30 μ.

During the application of the pressure-sensitive adhesive or adhesive, it is desirable that the thickness be equal to or greater than the thickness of the foil constituting the honeycomb core; if the width is less than the thickness of the foil, sufficient fillet properties will not be obtained and the strength performance as a panel will deteriorate. Even if the adhesive is applied to a thickness 20 times or more thicker than the foil thickness, there will be no corresponding increase in strength, and the amount of adhesive used will simply increase, resulting in waste, increasing the weight of the panel and increasing costs.

The temperature conditions for heat-sealing the powder adhesive vary depending on the type of pressure-sensitive adhesive, adhesive, and powder adhesive used for attachment, but are usually 80 to 200°C. The conditions for combining the honeycomb core and face material to form a panel vary depending on the properties of the material and adhesive, but the temperature is 0.1-10K at 100-300η.
)/go under pressure conditions. As equipment for forming panels, a conventional multistage press equipped with heating equipment, an autoclave, a roll press, a belt press, etc. can be used depending on the purpose. - As stated above, the present invention begins with the combination of the above-mentioned steps (1) to (4), and it is necessary to satisfy all of them.

According to the present invention, the process of fusing and fixing the powdered adhesive without being affected by the material, shape, etc. of the honeycomb core and face material constituting the honeycomb core and face material in the generally used method for manufacturing honeycomb ΦΦ sandwich panels. This not only ensures the fillet properties of the adhesive, but also prevents the powder from falling off when forming panels, making handling easier and making it possible to form AK panels without adhesive defects.

In carrying out the present invention, it is preferable to spread the honeycomb core in advance and fix it by applying an adhesive, an adhesive, or a powdered adhesive.
There is a risk that troubles may occur, such as the strength of the adhesive itself making it impossible to spread, or the adhesive getting stuck between the cores and developing adhesive strength, making it impossible to spread.

By carrying out the process of the present invention after expansion, continuous production of honeycomb sandwich panels becomes possible without such troubles occurring.

Here, the features of the method for manufacturing a honeycomb sandwich panel of the present invention are summarized as follows.

(1) High-strength honeycomb sandwich panels can be manufactured with a small amount of adhesive, leading to weight and cost reductions.

Function: When the honeycomb core and face material are combined, it is possible to prevent adhesion defects from occurring due to misalignment between the core and the painting material.

(To) Applicable to perforated plates and surface materials that require breathability.

(4) Can be applied to transparent surface materials, and can be applied to application fields that require panel beauty-1) transparency and decorative properties.

(2) Since the amount of adhesive used is small, destruction of the core and dust particles due to pressure inside the core due to foaming and gas generation during heat bonding can be prevented.

(2) Since the powdered adhesive is fused and fixed to the core in advance, it is easy to position the art materials and the core when matching them, making it possible to perform continuous production using roll presses, belt presses, etc. that require automatic control, resulting in high productivity. A low mast can be secured.

(η High adhesion reliability and high performance in terms of durability, etc.

As is clear from the above description, the present invention provides a method for producing honeycomb sandwich panels at low cost and further promoting weight reduction, which is the greatest feature of honeycomb sandwich panels.

The present invention will be further explained below using Examples.

Example 1 Foil thickness 50μ1 Dimensions 400W x 600R x 10%, Core size 4/1 inch Material J I 8H 4000 people-50
5-Li-luminium honeycomb core was roll coated on both cell edge end surfaces and in the thickness direction of the honeycomb core (manufactured by Daiichi Kagaku Kogyo).

It was spread and adhered to the adhesive-applied area. The powdered adhesive adhered uniformly to the cell edge and did not fall off or fall due to vibration or impact during handling. Continuing, 150
℃ hot air circulation furnace +'l,','! , and the powdered adhesive was fused and fixed in place for 10 minutes. The thus obtained honeycomb core to which the powdered adhesive was fused and fixed had a good appearance, and the thickness of the adhesive layer was as shown in Table 1. /% It has been found that the adhesive does not fall off when the Nicum core is cut, the tackiness completely disappears, it is easy to handle such as stacking, and it is suitable for industrial production.

Aluminum with thickness α6% dimension 400X'SOO% @(
JI8H4000 people 1050F) on both sides of the core"1
Heat bonding was carried out for 5 minutes at a pressure of 5 k)/ai using a heat press set at 80°C.

After cooling, the panel had an attractive appearance.

When the panel was cut to a size of so'xso% and subjected to an EPO test, the strength shown in Table 1 was obtained.

Table 1 Experiment No. 1. 2. 3. 4 is an example of the present invention, and 5 is a comparative example with the present invention.

Example 2 In Example 1, nylon powder adhesive F8-17S
The same procedure as in Example 1 (experiment number 1) was carried out except that the epoxy powder adhesive Mu p-5oo (manufactured by Toagosei Chemical Industry Co., Ltd.) was used instead of P. As a result, the flatwise tensile strength was 5.
It was 2kl/-1.

Example 3 A solution epoxy adhesive 8-
20 (manufactured by Toagosei Chemical Industry Co., Ltd.) (■Shape: 30Wt*)
was coated with a film thickness (wet) of 10 μm using a roll coating method, and powdered adhesive F8-175P was coated on the adhesive coated area with a thickness of 400 μm without drying, and the adhesive was fused in a hot air oven at 150°C for 3 minutes. .

Glass plates with a thickness of 5% and dimensions of 50 x 50% were placed on both sides of the Nokuni cam core and pressed at a pressure of 1 kf/a1 at 180°C.
1 for 5 minutes, and then cooled in a water-cooled cold press for 5 minutes at a pressure of 1 k#1011 to obtain a Noricum Sundermanti panel using glass as an art material and having a good appearance. When a flatwise tear test was conducted in the same manner as in Example 1, a strength of 31 kf/- was obtained.

Example 4 and Comparative Example 1 Nylon-based Minato liquid adhesive FS-175SN (manufactured by Toagosei Chemical Industry Co., Ltd.) was dip-coated to a depth of 1000 μm on both sides of the cell edge of the same honeycomb core as in Example 1. Next, nylon powder adhesive F8- was applied in the same manner as in Example 1 without drying.
17SP (manufactured by Toagosei Chemical Industry Co., Ltd.) was coated and fused and fixed in various thicknesses. The same surface material as in Example 1 was bonded under the same conditions,
The results of a flatwise tensile test in the same manner were shown in the second
Table (Experiment numbers 1 to 3) K is shown.

On the other hand, the FS-17SP was uniformly spread and fused onto a flat Teflon sheet to obtain sheet adhesives having various stacking thicknesses. Using this sheet adhesive, the same honeycomb core and art materials as in Example 1 were adhered under the same conditions as in Example 1, and the results of a flatwise tensile test were reported in the second
Table (Experiment No. 4.5) K is shown. Experiment numbers 1 to 3 indicate examples of the present invention, and Experiment numbers 4 and 5 indicate comparative examples.

Table 2

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a honeycomb core. FIG. 2 is an AA' cross-sectional view of the honeycomb core to which the powdered adhesive has been fused. Figure 3 is a cross-sectional view of the adhesive laminated No. 1 Nikum core and painting materials. t Honeycomb Core 2, Powdered Adhesive 2.1 Powdered adhesive material showing sufficient fillet properties for heat bonding Name of patent applicant: Toagosei Chemical Industry Co., Ltd.

Claims (1)

[Claims] t Apply an adhesive or adhesive from the cell edges and end faces of the honeycomb core in the core thickness direction, apply powdered adhesive to the honeycomb core to which the adhesive is fixed with the adhesive or adhesive, and laminate the face material and heat. A method for manufacturing a honeycomb sandwich panel, which comprises the steps of gluing.