JPS60141337A - Production of fin for heat exchanger - Google Patents

Abstract

PURPOSE:To eliminate deterioration in corrosion resistance and heat exchangeability of heat exchanging fins by coating a lubricating material consisting of a base material composed of paraffinic and naphthenic hydrocarbons on an aluminum sheet having an org. or inorg. film, activating the same by heating and pressing the aluminum sheet. CONSTITUTION:A mixture composed essentially of paraffinic hydrocarbon and naphthenic hydrocarbon having 15-20 average number of carbon atoms and 200-350 average mol.wt. is coated on the surface of an expanded aluminum or aliminum alloy sheet having an org. or inorg. film at 1-8mg/dm<2> coating amt., <=150ppm moisture concn. and 5-10cst viscosity. The aluminum sheet is heated to 50-200 deg.C surface temp. to activate the lubricating material then the aluminum sheet is pressed. Flare drop-out and flare crack are thus prevented and the deterioration in the corrosion resistance and heat exchangeability of the heat exchanging fins is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a fin material for a heat exchanger (hereinafter simply referred to as a fin manufacturing method) for use in heat exchanger fins for household cooling and heating equipment, automobiles, etc. Yes, after providing an inorganic or organic film or a composite film of these on the surface of an aluminum or aluminum alloy plate (hereinafter simply referred to as an aluminum plate), the formability is improved when the plate is subjected to drawless press processing. The present invention relates to a method for manufacturing fins for heat exchangers, which provides a large quantity of fins for heat exchangers that have good corrosion resistance, excellent heat exchange efficiency, and excellent heat exchange efficiency.

Conventionally, aluminum plates have been subjected to surface treatment as described above, and then subjected to drawless press processing to produce heat exchanger fins 1. However, during press processing, an accident called flare flying or flare cracking often occurs. Performance as a heat exchange member such as corrosion resistance and heat exchange rate deteriorates, and in extreme cases, it may become unusable.

The inventors of the present invention were at the stage of various studies regarding the above-mentioned defects, and as a result of further research into hydrocarbon compounds adhering to the surface of an aluminum plate, they arrived at the present invention. t Id, a boehmite film, a chromate film, an anodized film, an inorganic film chemically formed by other means, an organic polymer, or an inorganic-organic polymer, etc. on the surface that has been previously formed with a protective film. Paraffinic in aliphatic hydrocarbons prior to pressing 4! F# -, - hydrocarbon (CnHzn+2), naphthenic hydrocarbon type.By heating the plate □ with hot air, steam heating, etc. immediately before pressing, the applied paraffin type Or naphthenic hydrocarbons are activated.

When press work is performed in this state, the surface of the aluminum, ram, plate, etc. is activated, so boundary lubrication is good, and good fins can be obtained without accidents such as flare flying and flare cracking. .

Note that this activation method is not limited to the method using heating. In addition, the composition of the lubricant used in the present invention is mainly composed of aliphatic hydrocarbons, but the composition and average molecular weight may differ slightly depending on the raw materials, etc., but the main component is paraffin as described above. The composition is mainly composed of naphthenic hydrocarbons and naphthenic hydrocarbons. That is, the ratio of these main components may be, for example, 50:50, 30:0, or vice versa, and is not particularly limited, but the average molecular weight is 20:0.
0 to 350, and preferably has an average carbon number (n) of 15 to 25. Also, the viscosity varies depending on the usage conditions, but under normal usage conditions, the viscosity at 40°C is 5 to 10 es.
A range of t is used. In addition, the lubricant in this column may contain up to 5 parts of wear-resistant additives, and the water content should be kept to 156 ppm or less in view of storage stability and corrosion resistance of treated plates.

The reasons for the limitations of the present invention will be described below.

The main components of the lubricant used in the treatment method of the present invention are paraffinic and naphthenic hydrocarbons with an average molecular weight of 200 to 3.
The reason why the average carbon number is 15 to 25 is that if the lubricant is less than that, the lubricant will run off when heated immediately before the molding press, and if it is more than that, the fluidity after heating will be lacking.

It is preferable to apply the lubricant in an amount of 1 to 8 inches per dtl because if it is less than 1 g/dtl, the coating will not be effective, and if it exceeds 8 g/dtl, the winding may become misaligned during winding. Powerful.

The temperature of hot air heating immediately before the forming press is not desirable because if the surface temperature of the aluminum plate is below 50°C, the heating effect will be small, and if it is heated above 200°C, the lubricant will change in quality or the fluidity will be too strong. .

The suitable range is 50°C to 200°C in terms of the surface temperature of the treated plate.

Specific examples of the present invention will be described below.

Example work.

JIS1200-H26 aluminum plate (thickness 0.11
1 '5, RL] 1000 tnwt, length 600
0m)'(mImmersion treatment in triethanolamine aqueous solution (triethanol concentration 3000ppm, PH10) at approximately 95°C for 3 minutes to reduce film thickness* 10 my/'drrt
After that, it was washed with shower water and dried at about 150° C. for 15 seconds.

After drying the aluminum grade on which the water conservation oxidation film has been formed, press oil [Shell Petrochemical] Provided by: Paraffin-based average molecular weight 270-300, average carbon number (n)
19-22, kinematic viscosity 6-9 cst (40°C)] at about 5 mg/di and then wound up. Thereafter, it was heated in an atmosphere of 70° C. immediately before the forming press of a drawless press, and then punched and molded into a predetermined shape to obtain fins. This product was in good condition with no part of the flare flying off or cracking.

Example 2゜Example 1. The surface of an aluminum plate of the same type as Alodine I
Chromate film 3m after treatment with 'tkxt 200
q/dm+ was formed and dried for 150°05 seconds.

1 m9/dm of press oil (supplied by Shell Oil) was applied to the surface of the aluminum plate 1ρ, and the plate was rolled up.

The aluminum plate was heated in an atmosphere of 70° C. for several seconds immediately before forming and pressing, and a predetermined fin was obtained after drawless pressing. This fin was in good condition with no part of the flare flying or cracking.

Example: 3 JI81.2QQH, 267 aluminum plate surface thickness 0
．． 115 strokes, width 1000mm, length: 6000m)? :
Degreased hindlimb surface K by etching, e.g. ASM41
55 Kai (Kansai Paint Co., Ltd.: water-dispersed silica-acrylic composite-melamine resin type paint) was applied using a reverse roll method, and after application, it was dried at a metal temperature of 200 to 220°C for 20 seconds and rolled up. The amount of coating formed on the surface of this material was 15~/di.

Pressing oil [(provided by Shell Petrochemical ■) average molecular weight: 200, average carbon number (n) was applied to the aluminum plate.
: 15, Kinematic viscosity: 5cst (40℃) Moisture content: 1
00111 m or less] was applied in an amount of about 3 m9/dm7 and wound up. The plate was held in an atmosphere at 150° C. for 5 seconds immediately before a forming press, and then a fin of a predetermined shape was obtained using a drawless press. This fin maintained a good shape and did not cause any damage to part of the flare.9 Example: 4, T18120+0+H26 aluminum plate (H
．． l 4 i5mtx, I 1000 rr, *,
The surface of the length: 6000 m) was coated with an aqueous hypohalite solution (
Hypohalite ion concentration: 1000 times, PH10.5
) in C (, 95°C for 3 minutes to obtain an oxide film of about 12~/dn-).

The surface of the aluminum plate was soaked in a 93°C water glass aqueous solution (1
No.3 water glass, concentration 5 o 9 /iJ, PH12,4)
After treatment for 30 seconds, it was dried. Next, press oil (supplied by Shell Petrochemical ■) 5 mq was applied to the surface of the aluminum plate.
After that, the aluminum clay shingle plate was heated to 120" O in front of a forming press 1α, and a fin of a predetermined shape was obtained using a drawless press.

This fin had a good shape with no damage to the flare part.

Comparative Example-1 The aluminum plate was processed into a fin by a drawless press without applying lubricant or JJN heat after surface treatment to remove the oxide film and gold film in the same manner as in Example-1, but the flare was partially damaged but was not good. It was not a good product.

Comparative Example 2 After surface treatment was performed to form an oxide film in the same manner as in Example 1, a lubricant was applied. Next, a pressure fin was processed using the normal processing method without heating, but cracks occurred in a portion of the flare and the product was not good.

When fins for heat exchangers are formed using the method described above, there will be no cracking in the flare part during processing, so the processing yield will not only increase, but the molding will be reliable, resulting in high precision fins. By assembling the heat exchanger, it is now possible to obtain a high quality heat exchanger with consistent heat exchange efficiency.

Claims (1)

[Claims] 1) In the process of forming an organic film or an inorganic film on the surface of a wrought aluminum or aluminum alloy material and press-working the wrought material, a heat exchange fin is produced from K. Before winding up the wrought material in the manufacturing process, there is a step of applying a lubricant based on paraffinic and naphthenic hydrocarbons; number axis) is 15 to 25 and the average molecular weight is 2
Paraffinic hydrocarbons consisting of 00 to 350 (CnHz
2. The method for producing a soft heat exchanger fin as set forth in claim 1, characterized in that the main component is a mixture of Cn+2) and naphthenic hydrocarbon (CnHgn). 3) Coating amount is 1-8m! The heat exchanger fin according to claims 1 and 2, characterized in that a lubricant having a water concentration of 1501 f or less and a viscosity of 5 to 10 c'5tVc is used. manufacturing method. 4) Immediately before the forming press, the interface temperature of the fin material is 5.
A method for manufacturing a heat exchanger fin according to claims 1 to 3, wherein the fin is activated by heating to 0'' to 7200°C.