JPH1190313A - Acceleration of curing of outside surface coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the peeling of a coating agent and the paper washing of a solvent and to cure the coating agent in a short period of time by directly heating once the entire outer peripheral surface of a steel pipe to a specific temp. or above, then applying the coating agent on the steel pipe where the outer peripheral surface temp. is at a specific temp. range during transportation. SOLUTION: The entire outer peripheral surface of the steel pipe 2 transported in an axial direction at a speed of, for example, 60 to 90 m/min on a roller table 1 is directly heated by the burner flames of ring burners 3 until a temp. above 100 deg.C is once attained. The outer peripheral surface temp. of the once heated steel pipe 2 falls in the process that the steel pipe is transported on the roller table 1, where the outer peripheral surface temp. attains 50 to 70 deg.C, then the coating agent 5 is sprayed to the steel pipe from a coating agent spraying device 4 installed downstream of the ring burners 3. As a result, the factors to adversely influence the coating, such as moisture and dust, are removed by the burner flames and the peeling of the coating agent 5 is eliminated. The drying time of the coating agent 5 is thus shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for accelerating the curing of a coating agent, for example, at the time of rust prevention of a steel pipe.

[0002]

2. Description of the Related Art Conventionally, when packing a steel pipe as a product, a coating agent such as a rust inhibitor is directly applied to the surface of the steel pipe at room temperature, and then dried or allowed to cool naturally, or
After applying the coating agent, they were immediately bound and packed.

[0003]

However, in the above-described conventional coating method, when the coating agent is applied, since the water or oils and fats adhere to the surface of the steel pipe, the coating agent is peeled off or the solvent is removed. , And it was difficult to form a uniform coating layer.

In addition, since it took a long time for the coating agent to cure and dry, even if the coating could be performed well, if it was tied immediately after the application of the coating agent, it would not be possible to bind or pack it. There was a problem that the coating agent peeled off. On the other hand, in the case of binding after drying completely, the above-described problem does not occur, but a space for drying is required, and there is a problem that it takes time to pack.

The present invention has been made in view of the above-mentioned conventional problems, and prevents the coating agent from peeling off due to moisture and oils and fats adhering to the surface of a steel pipe and prevents vapor washing of a solvent. It is another object of the present invention to provide a method for accelerating the curing of an external coating agent that can cure the coating agent in a short time.

[0006]

In order to achieve the above-mentioned object, in the method for accelerating the curing of an outer coating agent according to the present invention, the entire outer peripheral surface of a steel pipe is directly heated by a burner flame until the temperature reaches 100 ° C. or higher. Later, during transport, the outer peripheral surface temperature becomes 50
When the temperature reaches ７０70 ° C., a coating agent is applied to the steel pipe. By doing so, excess moisture, dust, oils and fats attached to the surface of the steel pipe are burned and removed, and the curing of the coating agent is promoted.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The method for accelerating the curing of an outer surface coating agent according to the present invention comprises the steps of:
On the roller before the coating agent is applied, which transports the steel pipe in the axial direction, the entire outer peripheral surface of the steel pipe is once heated to 100 ° C by a burner flame.
After heating directly to the above, the coating agent is applied to the steel pipe when the outer peripheral surface temperature reaches 50 to 70 ° C. during the transportation.

[0008] According to the method for accelerating the curing of the outer surface coating agent of the present invention, the entire outer peripheral surface of the steel pipe is once exposed to a burner flame.
Since it is directly heated to 0 ° C or more, excess water, dust, and grease adhering to the surface of the steel pipe are burned and removed, and when the outer peripheral surface temperature reaches 50 to 70 ° C during transportation, the steel pipe is heated. Even if the coating agent is applied, once the outer peripheral surface
Since the temperature is raised to not less than ° C. and the inner surface is sufficiently kept warm, the temperature of the coating does not drop suddenly, and the curing of the coating agent is promoted.

In the method for accelerating hardening of an external coating agent according to the present invention, the entire outer peripheral surface of a steel pipe is once exposed to a burner flame for 10 times.
The reason why the heating is performed directly until the temperature becomes 0 ° C. or more is to burn and remove excess moisture, dust, and fats and oils adhered to the surface of the steel pipe and to sufficiently keep the inner surface portion warm.

In the method for accelerating curing of an outer coating agent according to the present invention, the coating agent is applied to a steel pipe when the outer peripheral surface temperature reaches 50 to 70 ° C.
According to experiments by the present inventors, if the temperature is lower than 50 ° C., there is no effect of promoting the curing of the coating agent. On the other hand, if the temperature exceeds 70 ° C., the coating agent is deteriorated, and after drying, the coating agent is easily peeled off.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for accelerating the curing of an external coating agent according to the present invention will be described below with reference to an embodiment shown in FIGS. FIG. 1 is an explanatory view of the method for accelerating the curing of the outer surface coating agent of the present invention, and FIG. 2 shows the transition of the outer surface temperature of the steel tube when the outer surface of the steel tube is heated by the method for accelerating the external surface coating agent of the present invention. FIG.

In FIG. 1, reference numeral 1 denotes a roller table on which a number of rollers 1a for transporting a steel pipe 2 in an axial direction are provided.
In the middle of the roller table 1, for example, the heating amount is 30 × 1
Six ring burners 3 of 0 ³ (kcal / H · P) are arranged in each zone, and nine zones are arranged at intervals of 0.15 m.

Then, the above-described ring burner 3 moves the roller table 1 on the roller table 1 for example at 60 to 90 m / min.
The entire outer peripheral surface of the steel pipe 2 which is conveyed in the axial direction at the speed described above is directly heated by a burner flame until it once reaches 100 ° C. or more.

FIG. 2 shows an example of a temperature decrease rate due to a temporal transition of the outer surface temperature of the directly heated steel pipe 2. FIG. 2 is a graph showing the temperature of the outer peripheral surface of the steel pipe 2 when applying a coating agent. For example, the installation position of the coating agent spraying device 4 described later and the conveying speed of the steel pipe 2 on the roller table 1 are determined so that the temperature is 50 to 70 ° C.

When the outer surface temperature is 1 using the ring burner 3
The outer surface temperature of the steel pipe 2 once heated so as to be equal to or higher than 00 ° C. is reduced downstream of the ring burner 3 when the outer surface temperature is reduced to 50 to 70 ° C. in the process of being transported on the roller table 1. Coating agent spraying device 4 installed in
The coating agent 5 can be sprayed from.

Incidentally, a steel pipe having an outer diameter of 114.3 mm and a total length of 12 m is temporarily heated at a conveying speed of 70 m / min using the above-mentioned ring burner 3 so that the outer surface temperature becomes 100 ° C. or higher. After that, when the outer peripheral surface temperature reached 60 ° C. during the transportation, the alkyd resin-based rust inhibitor was coated from the coating agent spraying device 4.
The rust inhibitor dried in 3 minutes. On the other hand, if the same rust inhibitor is coated without heating,
It took 0 minutes. In addition, according to the present invention, the rust preventive did not peel off.

[0017]

As described above, the method of accelerating the curing of the outer coating agent according to the present invention, when coating the outer surface of the steel pipe, applies the outer surface on a roller for transporting the steel pipe in the axial direction before applying the coating agent. The entire outer peripheral surface of the steel pipe is once directly heated with a burner flame so that the temperature becomes 100 ° C. or more, and when the outer peripheral surface temperature reaches 50 to 70 ° C. during transportation, a coating agent is applied to the steel pipe. The burner flame can remove factors that have an adverse effect on the coating, such as moisture, dust, and oils, preventing the coating agent from peeling off and accelerating the curing of the coating agent. Can be shortened.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a method for accelerating the curing of an outer surface coating agent of the present invention.

FIG. 2 is a diagram showing transition of the outer surface temperature of a steel pipe when the outer surface of the steel pipe is heated by the method for accelerating the curing of an outer coating agent of the present invention.

[Explanation of symbols]

 2 Steel pipe 3 Ring burner 4 Coating agent spraying device 5 Coating agent

Claims (1)

[Claims] 1. When coating the outer surface of a steel pipe,
On the roller before applying the coating agent, which transports the steel pipe in the axial direction, the entire outer peripheral surface of the steel pipe is once heated to 100 ° C. with a burner flame.
A method for accelerating the curing of an external coating agent, comprising applying a coating agent to a steel pipe when the temperature of the outer peripheral surface reaches 50 to 70 ° C. during transportation after directly heating until the above.