JPH03184838A - Manufacture of pcm damping steel sheet - Google Patents

Abstract

PURPOSE:To prevent appearance failure of a product based on deterioration of color such as hue and glossiness and generation of dulling by sandwiching a resin layer between the steel sheets, heating and contact-bonding the steel sheets to form a damping steel sheet and thereafter applying coating for PCM thereto and baking the coating. CONSTITUTION:Two sheets of steel sheets 1a, 1b are supplied from an uncoiler and a resin layer 2 is sandwiched between these steel sheets. This resin layer 2 is formed by uniformly applying liquid resin to a downside steel sheet 1b or a topside steel sheet 1a and drying the liquid resin and thereafter laminating both steel sheets 1a, 1b. Further the resin layer 2 is formed by sandwiching a resin film between both steel sheets. The above-mentioned application of liquid resin is performed by roll coating and spray coating, etc. The resin layer 2 is heated together with both steel sheets and also pressed by a pair of contact-bonding rolls 3. Both steel sheets 1a, 1b and the resin layer 2 are mutually contact-bonded and integrated to form one sheet of damping steel sheet 1. Thereafter a chemical conversion film 4 is preferably formed. Then resin 5 for coating which is solid and excellent in corrosion resistance and resistance to stain e.g. such as unsaturated polyester resin, is applied to the steel sheet 1a becoming the upper face of the damping steel sheet 1 and also baking treatment of coating is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of manufacturing a PCM vibration damping mesh plate that prevents appearance defects due to deterioration of coating color, cloudiness, etc. that occur during the manufacturing process.

[Conventional technology]

Recently, vibration damping mesh plates have been used for washing machine outer panels and the like for the purpose of reducing noise in home appliances and the like. These manufacturing methods use laminated steel plates with resin sandwiched between the steel plates, and after processing and assembly, they are painted and baked, and the damping steel plates are used in the post-painting process (bost coat) to make the product. On the other hand, it is a well-known fact that home appliance manufacturers use PCM steel sheets that are painted before processing due to the inefficiency of painting processed products or problems with appearance.

In order to eliminate the painting process at the home appliance manufacturer, the finished product is delivered as a coil or sheet, and after being processed and assembled by the home appliance manufacturer, it is directly made into a product without painting. It is called PCM (pre-coated metal) steel plate because it has a painted finish.

As a further need, the demand for PCM damping steel plates is increasing, and in order to meet this demand, two PC
It is conceivable to manufacture M steel plates and use them to sandwich resin.

[Problem to be solved by the invention]

However, in the conventional manufacturing method as described above, there is a waste of manufacturing two painted steel plates for bonding the upper and lower plates together, and the painted surface of the steel plate, which is already a PCM steel plate, is wasteful. Since the coating is heated to, for example, about 120° C. to 200° C. and pressed with a pressure roll, there are problems in that the coating film changes in color and becomes cloudy, resulting in poor appearance.

This invention has been made in view of these conventional problems, and it solves the above problems by forming a damping steel plate before painting the surface of the steel plate and then applying PCM coating. It aims to solve the problem.

[Means to solve the problem]

This invention is a method of manufacturing a PCM damping steel plate by sandwiching a resin layer between steel plates and heat-pressing them to form a damping steel plate, and then painting and baking a PCM paint.

[Effect]

This invention has the above-mentioned configuration, and includes, for example, two
At the time when a resin layer is interposed between two steel plates and the resin layer is heat-pressed to form a damping steel plate, the surface of the steel plate has not yet been painted. The above-mentioned vibration-damping steel plates are coated, and then, in order to improve the coating adhesion and corrosion resistance of the front and back surfaces after lamination, the base of the steel plates is preferably chemically treated, i.e., for boat fishing, chromate or After the phosphate conversion coating treatment is applied, the paint baking process is completed. Therefore, since the process order of the forced steel plate forming process and the painting process is reversed, instead of preparing two coils of coated steel plate for the front and back sides, after forming the damping steel plate, the front and back sides are manufactured in the same chance painting baking process. Moreover, since the painted surface is not subjected to heat-pressing processing, no appearance defects such as color deterioration or cloudiness occur on the painted surface.

〔Example〕

Hereinafter, the present invention will be explained with reference to the drawings. Figure 1 is a partial conceptual diagram showing the manufacturing method in the order of steps;
As shown in FIG. 1, first, two steel plates 1a and lb are supplied from an uncoiler (not shown), and a resin layer 2 is sandwiched between them. This resin layer 2 is made by uniformly coating liquid resin on the lower steel plate lb or also on the upper steel plate 1a, and drying it.
Both steel plates 1a.

1b, or by sandwiching a resin film between both steel plates. The liquid resin is applied by roll coating, spray coating, or the like. Next, the resin layer 2 is made of both steel plates,
While being heated, as shown in FIG. 1(b), the steel plates 1a and 1b and the resin layer 2 are pressed together and integrated by a pair of pressure rolls 3 to form one damping steel plate 1. becomes.

After that, preferably after applying a chemical conversion coating 4, the steel plate 1a which becomes the upper surface of the vibration damping steel plate 1 is coated with hard, corrosion-resistant and anti-corrosive material such as unsaturated polyester resin (as shown in FIG. 1(C)). A paint resin 5 with excellent stain resistance is applied and the paint is baked.

In this example, the coating layer was dried at a high temperature (
In the example, it is placed at a temperature of 180 to 200″C for a predetermined time,
We performed so-called baking drying, which forcibly causes chemical changes such as oxidation and polymerization. Hot air, infrared rays, etc. are used as a heat source. Similarly, a paint 5 such as alkyd resin or vinyl resin is applied and baked on the steel plate 1b, which is the lower surface, at the same time for the sole purpose of corrosion resistance.

The following table shows changes in the coating color of the PCM damping steel plate obtained by the above method.

Table 2 In the table, the comparative example shows that the first
Between the steps in Figures (a) and (c), Figure 1 (d) and (e)
This is a vibration-damping steel plate in which a resin is heat-pressed after being painted on a steel plate, that is, after it is made into a PCM steel plate.In the example, a damping steel plate is formed by heat-pressing a steel plate before painting. It was then painted with PCM.

Tables 1a and 1b show the evaluation when comparing the hue and gloss of a normal PCM coated steel plate (without vibration damping resin) painted and baked with the same paint, and as shown in Table 2, In both cases, the inventive examples show good values with little change in hue and glossiness, whereas the PCM
After laminating, the change is large and it cannot be used as a PCMI mounting.

〔Effect of the invention〕

As explained above, according to the present invention, by applying PCM coating after forming the vibration damping rope plate, it is possible to prevent deterioration of colors such as hue and glossiness and poor appearance of the product due to occurrence of cloudiness, etc. .

[Brief explanation of drawings]

FIG. 1(a) shows the process order of the manufacturing method according to the present invention.
, (b), and (C), and the process order of the comparative example is shown in (a), (d), (e), and (c).

Claims (1)

[Claims] (1) A method for manufacturing a PCM vibration-damping steel plate, which comprises sandwiching a resin layer between steel plates and heat-pressing them to form a vibration-damping steel plate, and then applying a PCM paint and performing a baking process.