JPH0212189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a vibration-damping steel plate, and more particularly, a vibration-absorbing steel plywood material having a sandwich structure in which a viscoelastic substance is sandwiched between two steel plates. It is something.

A vibration-damping steel plate is made by laminating two thin steel plates with a thickness of 1 mm or less with a thin viscoelastic material layer (approximately 0.1 to 0.6 mm thick) such as plastic in between, and absorbs the vibration energy applied to it by shearing the viscoelastic material layer. It has the function of rapidly damping vibrations through deformation and converting them into thermal energy, thereby effectively damping vibrations. For this reason, damping steel plates are mainly used for vibration prevention and noise prevention.For example, vibration damping steel plates are used for the floors, walls, and ceilings of the cabins of ships to improve livability, and for automobile oil pans and other applications. It has come to be used for a variety of purposes, such as making various parts made of damping steel plates to reduce automobile noise, and even general building materials such as partitions being made of damping steel plates to prevent noise. There is. Various configurations of vibration damping steel plates have been proposed,
Some vibration damping steel plates have been put into practical use and are on the market, but vibration damping steel plates with a sandwich sandwich of plastic film between two thin steel plates are expected to be low in price due to their ease of manufacture. To date, it has been difficult to commercialize this material because it still has problems such as not having very high vibration damping performance and being easy to peel off. According to the studies conducted by the present inventors, the cause of this problem lies in the air bubbles remaining at the boundary between the film and the steel plate. ) increases, the vibration damping performance also decreases and peeling becomes more likely. The conventional manufacturing method of damping steel plates by sandwich-chunching a film is to stack the film on top of the lower steel plate, then stack the upper steel plate on top of that to form a laminate, which is then hot-pressed to form a laminate. It is heat-pressed and then cooled. Therefore, the air that enters between the film and the steel plate during the formation of the laminate is trapped in the surface layer of the film, which becomes molten when heated by the hot press, and is cooled while remaining at the boundary between the film and the steel plate. Therefore, air bubbles are left in the resulting product as described above. The presence of these bubbles makes the damping performance of the damping steel plate lower than the damping performance of the film itself (the efficiency of converting vibration energy into thermal energy), and also reduces the adhesion between the film and the steel plate. This makes it easy to peel off, and furthermore, during bending, a rice-grain-like depression is formed on the surface of a bent portion with a small radius of curvature due to depression of the portion corresponding to the internal air bubbles, which impairs the appearance of the molded product.

The present invention has been made based on the above-mentioned findings, and provides a continuous manufacturing method and manufacturing apparatus that hardly causes the aforementioned bubbles to remain in the manufacturing of a damping steel plate having a structure in which a film is used as a sandwich sandwich. The purpose is to

That is, in the manufacturing method of the damping steel plate of the present invention, first, a self-adhesive thermoplastic resin film, a so-called hot melt type plastic film, is generally placed between the first and second steel plates at room temperature. preheating the laminate to a temperature range such that the film has a Young's modulus of 10 ⁷ to 10 ⁹ dyn/cm ² ,
The laminated body within this temperature range is transferred while being pressed against the outer surface of both steel plates with a roll, and the air bubbles between the inner film and the inner surface of the steel plate are pushed out backwards using a so-called squeezing roll method, and the air is removed and heated rapidly. While doing so, the film is immediately thermocompressed using a hot roll at a temperature higher than its melting point, and then cooled in a cooling zone in a restrained state.

The vibration damping steel plate manufacturing apparatus of the present invention used in this manufacturing method includes a preheating device for preheating the laminate to a temperature range such that the Young's modulus of the film is 10 ⁷ to ^{10 9} dyn/cm ² , and a A press roll, preferably made of an elastic material, is provided on the exit side of the apparatus and presses the laminate heated to within the temperature range from the outer surface of both steel plates and removes air bubbles while transferring the same. The present invention includes a combination of a hot roll and a rapid heating device for thermocompression bonding the laminate under conditions where the film is at a temperature higher than its melting point.

In this way, the laminate in which the film is sandwiched between two steel plates is preheated to a temperature at which the film is easily deformed, and air bubbles are removed by transferring the film while pressing it with rolls. According to the present invention, the film and the steel plate are brought into close contact with each other by removing air bubbles, and immediately after the film is rolled, the film and the steel plate are bonded under heat using a hot roll immediately after the film is rolled. There are no air bubbles entering the product, and the resulting vibration-damping steel plate is of high quality and free of air bubbles. In addition, since the manufacturing process of this invention forms a continuous flow, it can be applied to both cut plates and coiled materials.In particular, for cut plates, high-speed continuous processing can be achieved compared to the conventional hot press method, resulting in high efficiency. becomes.

In this invention, the heating in the preheating device is performed within the temperature range where the Young's modulus of the film is 10 ⁷ - ^{10 9} dyn/cm ² . ), when the Young's modulus of the film exceeds 10 ⁹ dyn/cm ² , the film becomes rigid and does not conform well to the surface shape of the steel plate, making it easy for gaps to form between the film and the steel plate. This is because when the film is transferred under pressure, air is drawn in, causing the generation of bubbles.Furthermore, if the Young's modulus of the film is less than 10 ⁷ , the film becomes sticky, trapping the bubbles and making it difficult to remove them. In this case, since the thickness of the film is usually about 0.1 to 0.6 mm for this type of damping steel plate, it hardly affects the preheating temperature range.

In this invention, the self-adhesive thermoplastic resin film is made of, for example, polypropylene, polyethylene, ethylene acrylic acid copolymer, or a mixture of these with various components added, and has the desired vibration damping performance in the operating temperature range. The ingredients are adjusted to achieve the following. However, in the present invention, since the bubble ratio can be reduced to almost zero, it is possible to manufacture a vibration damping steel plate that effectively utilizes the vibration damping performance of the film itself without impairing it.

In addition, in this invention, it is preferable that the time interval from the time of removing air bubbles with the pressure roll to the time of thermocompression bonding with the hot roll is as short as possible. Therefore, a gap may be formed between the film and the steel plate in the peripheral area, and the steel plate is tightly attached to the film by pressure welding by the pressure roll, and while the suction force at the mating surfaces in a vacuum state is superior to the stress, It is best to heat and press it into a hot roll before deformation occurs. in this case,
Since heating with a hot roll only makes linear contact with the steel plate, it may not be sufficient depending on the product specifications such as the thickness of the steel plate, so a rapid heating device is combined with the hot roll immediately before heating. This rapid heating device heats the laminate, which has been preheated by the preheating device described above, within a short period of time as described above, and therefore, depending on the line speed, within a short gap between the pressure roll and the hot roll. The heating capacity of the film is used to rapidly heat the film to a temperature higher than its melting point. Specifically, an induction heating device or a near-infrared heating device is used.

Thermocompression bonding using hot rolls is carried out in a state in which the film is heated above its melting point, and is then cooled while being transferred under restraint using pinch rolls or the like.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing the line arrangement of a vibration-damping steel plate manufacturing apparatus according to an embodiment of the present invention, and the steel plate that has been pretreated such as degreasing is the first steel plate that is the lower steel plate in the figure. 1 and a second steel plate 2 serving as the upper steel plate. The first steel plates 1 are placed one by one on an idle roller table 3 and fed into a film laminator 4, where a self-adhesive thermoplastic resin film 5 is uniformly applied over the entire width of the first steel plates. Spread it out and cover it.
Once the entire length of the first steel plate is covered, the film is cut. At this time, it is preferable that the film 5 be lightly brought into close contact with the first steel plate 1 by, for example, charging the film. The second steel plate 2 is stacked on the first steel plate 1 with the film 5 on top, and in this way a laminate 6 is prepared in which the film 5 is sandwiched between the two steel plates 1 and 2. . This stacked body 6 is started to be transferred downstream of the line by a pinch roller 7, and is first fed into a preheating device 8 such as an infrared heater. This preheating device 8 heats the laminated body 6 that has been sent in to a temperature range such that the Young's modulus of the film 5 is 10 ⁷ to 10 ⁹ dyn/cm ² . The laminate 6 preheated in this way is transferred while being pressed from the lower surface side while it is within the temperature range by a pressure contact roll 9 made of a rubber roll provided on the exit side of the preheating device 8. Air bubbles are removed. Bubble removed laminate 6
are in close contact with each other on the entire surface, and immediately after leaving the pressure roll 9, the hot roll 1 is heated through a rapid heating device 10.
Bitten by 1. The time from when the steel sheet leaves the pressure roll 9 until it is bitten by the hot roll 11 is, for example, several seconds to more than ten seconds, depending on the thickness of the steel sheet.
The rapid heating device 10 is, for example, an induction heating device using an induction coil, and the laminate is heated by the rapid heating device and a hot roll to a temperature above the melting point of the film, and is then pressed by the hot roll and bonded by thermocompression. . hot troll 1
1, a pinch roll with a built-in heater may be used; the thermocompression-bonded laminate leaving the hot roll 11 immediately enters the cooling zone 12, where it is cooled while being restrained from above and below by the pinch rolls 13 there. , after the necessary post-treatment, vibration damping steel plate 1
It becomes 4.

In the present invention, the film 5 as a viscoelastic substance has various components adjusted to obtain the desired vibration damping performance depending on the temperature range in which the damping steel plate is used. Naturally, the temperature characteristics of Young's modulus of bass also change, so
When setting the temperature in the preheating device 8, the type of film should be taken into consideration as well as the dimensions and material of the steel plate used and the film thickness.

For example, the temperature characteristics of the Young's modulus of a polypropylene film whose composition has been adjusted to a melting point of 140°C for high-temperature applications are shown in Figure 2.
It can be seen that in this case, it is necessary to heat the film using the preheating device 8 so that the film temperature becomes 85° C. or higher. Similar characteristics of a three-component film whose main component is ethylene acrylic acid copolymer (EAA) whose melting point is adjusted to 100°C for use in the normal temperature range of 20°C to 60°C are shown in Figure 3. As shown in Figure 2, it is clear that it is necessary to preheat the film to a temperature of 20°C or higher. moreover
Melting point 105℃ for use in medium temperature range from 60℃ to 90℃
The temperature characteristics of Young's modulus in an EAA film whose composition has been adjusted are shown in FIG. 4, and it can be seen that it is necessary to preheat the film to a temperature of 53° C. or higher.

In one embodiment of this invention, the first and second steel plates have a thickness of 0.4 mm, a width of 1250 mm, and a length of
A vibration-damping steel plate was manufactured using a polypropylene resin film (thickness: 0.15 mm) having the properties shown in Figure 2, using a 2500 mm film.
In this case, the film temperature in the preheating device is 95-100℃
While the temperature is within this range, remove air bubbles with a rubber pressure roll and insert it into a hot roll located 1.8m downstream of the pressure roll, during which time a 1m long induction heating Rapid heating was performed using a coil to further raise the film temperature by 50°C, and supplementary heating was performed using a hot roll to finally raise the film to above its melting point temperature and bond it under thermocompression. The induction heating coil used at this time had an output of 100 kW, and it was confirmed that it was capable of rapid heating at about 20°C/sec, and the line speed could be increased to about 20 m/min. The attached reference photo 1 shows the film surface of a sample cut from the damping steel plate obtained at this time after forcibly peeling it off, and it can be seen that there are almost no bubbles at all. For comparison, reference photo 2 shows the peeled surface of a sample obtained in the same manner without removing air bubbles with a rubber pressure roll, and clearly shows that there are many air bubbles on the film. There is.

As described above, according to the present invention, when producing a damping steel plate having a structure in which a film is sandwiched, no air bubbles are generated at the boundary between the film and the steel plate, and the production can be performed in a continuous flow. Therefore, it is possible to manufacture high-quality film sandwich type vibration damping steel plates with high efficiency, which greatly contributes to lower prices.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the line arrangement of a vibration damping steel plate manufacturing apparatus according to an embodiment of the present invention, and FIGS. 2, 3, and 4 show the temperature characteristics of Young's modulus of different types of films. FIG. 1: First steel plate, 2: Second steel plate, 4: Film laminator, 5: Film, 6: Laminated body, 7: Pinch roll, 8: Preheating device, 9: Pressure roll, 1
0: Rapid heating device, 11: Hottrol, 12:
Cooling zone, 13: pinch roll, 14: vibration damping steel plate.

Claims (1)

[Claims] 1. A self-adhesive thermoplastic resin film is sandwiched between a first steel plate and a second steel plate, and these films have a Young's modulus of 10 ⁷ to ^{10 9} dyn/cm ^{2 .} At this temperature, both steel plates are transferred from their outer surfaces while being pressed together with a roll to remove air bubbles, and while being rapidly heated, they are immediately thermocompressed with a hot roll at a temperature higher than the melting point of the film, A method for manufacturing a damping steel plate, which comprises cooling the plate after that. 2 Preheating a laminate in which a self-adhesive thermoplastic resin film is sandwiched between a first steel plate and a second steel plate to a temperature such that the Young's modulus of the film is 10 ⁷ to 10 ⁹ dyn/cm ² a press roll that is provided on the exit side of the preheating device and presses the laminate heated to the temperature from the outer surface of both steel plates and removes air bubbles while transferring the laminate; and immediately after the press roll, the laminate is 1. An apparatus for manufacturing a damping steel plate, comprising a combination of a rapid heating device and a hot roll for thermocompression bonding at a temperature higher than the melting point of the film.