Air exhaust or air-and-smoke exhaust pipe for clean room and manufacturing method therefor

Abstract

The present invention provides an air exhaust or air-and-smoke exhaust pipe for a clean room and a manufacturing method thereof. The air exhaust or air-and-smoke exhaust pipe is a pipe that satisfies FM4922, FM4910, or another equivalent standard and that is used for exhausting nonflammable chemical gas and corrosive vapor or nonflammable chemical gas, corrosive vapor and smoke in fire. The manufacturing method for the air exhaust or air-and-smoke exhaust pipe is: coating an inner part of a pre-manufactured metal pipe with a liquid coating that can be initially dried at normal temperature or low temperature to obtain an inner coating pipe; and baking the inner coating pipe at a temperature not exceeding 250° C. after the coating is initially dried, thus the coating is completely dried to obtain a finished product.

Claims

1. A method for manufacturing an exhaust pipe for a clean room comprising the following steps: (i) preforming a metal into a pipe of a required shape or structure to define a preformed metal pipe, and carrying out surface treatment on the pipe; (ii) coating an inner part of the preformed metal pipe with a coating of a first component and a coating of a second component at a normal temperature, wherein the second component comprises a copolymer of a fluorinated alkene and vinyl ether and a homopolymer of fluorinated methyl acrylate as a second basic film former; (iii) allowing the pipe to remain in a natural state for a predetermined period of time, optionally irradiating the preformed pipe with ultraviolet light to make the coating touch-dry and hard-dry at a normal temperature to obtain an inner coated pipe; and (iv) allowing the pipe to remain in the natural state for another predetermined period of time at the normal temperature, optionally baking the inner coated pipe at a temperature not higher than 250° C. to cure the coatings to obtain a finished product.

2. The method for manufacturing the exhaust pipe for the clean room according to claim 1, wherein the coatings are liquid during coating construction, and the coating is a solution, an emulsion, a solvent-free liquid mixture, or a suspensoid containing solid powder.

3. The method for manufacturing the exhaust pipe for the clean room according to claim 1, wherein the coatings and touch-dry temperatures of the coatings are not greater than 35° C.

4. The method for manufacturing the exhaust pipe for the clean room according to claim 1, wherein a post-cure method in step (iv) includes placing the inner coated pipe into a baking oven or a baking room, or introducing air into an interior of the inner coated pipe.

5. The method for manufacturing the exhaust pipe for the clean room according to claim 1, wherein the fluorinated alkene is a fluorinated alkene selected from any one or more of chlorotrifluor ethylene, tetrafluoroethylene, polyvinylidene fluoride, vinyl fluoride, hexafluoropropylene, trifluoroethylene, trifluorobromoethylene, trifluoropropene, hexafluoroisobutene, and octafluoroisobutylene.

6. The method for manufacturing the exhaust pipe for the clean room according to claim 1, wherein the metal is iron, aluminum, copper, or an alloy thereof.

7. An exhaust pipe for a clean room, comprising a preformed metal pipe having a surface treatment, a coating of a first component, and a coating of a second component on an inner part, wherein the second component comprises a copolymer of a fluorinated alkene and vinyl ether and a homopolymer of fluorinated methyl acrylate as a second basic film former.

8. The exhaust pipe according to claim 7, wherein the first component comprises phenyl siloxane, methyl polysilicate methyl ester, a siloxane monomer, a homopolymer of perfluoroalkyl, and a copolymer of perfluoroalkyl, or a combination thereof as a first basic film former.

9. The exhaust pipe according to claim 7, wherein the fluorinated alkene of the second component further comprises a fluorinated alkene selected from any one or more of chlorotrifluor ethylene, tetrafluoroethylene, polyvinylidene fluoride, vinyl fluoride, hexafluoropropylene, trifluoroethylene, trifluorobromoethylene, trifluoropropene, hexafluoroisobutene, and octafluoroisobutylene.

10. The exhaust pipe according to claim 7, wherein the coating is liquid during coating construction, and the coating is a solution, an emulsion, a solvent-free liquid mixture, or a suspensoid containing solid powder.

11. The exhaust pipe according to claim 7, wherein the coating and a touch-dry temperature of the coating are not greater than 35° C.

12. The exhaust pipe according to claim 7, wherein a post-cure treatment is performed on the inner part including placing the inner coated preformed metal pipe into a baking oven or a baking room, or introducing hot air into an interior of the inner coated pipe.

13. The exhaust pipe according to claim 7, wherein the exhaust pipe satisfies a requirement of FM4922, FM4910.

14. The exhaust pipe according to claim 7, wherein the metal is iron, aluminum, copper, or an alloy thereof.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) The present invention is further described below in detail with reference to specific implementations. The “part” described in the embodiments of the present invention indicate mass fraction unless particularly specified.

Embodiment 1

(2) 100 parts of a 60% butanone solution (LUMIFLON® LF200MEK, purchased from Asahi in Japan) of a copolymer of fluorinated alkene and vinyl ether are taken, 1 part of a thixotropic agent (purchased from HDK® H18 in Wacker) is added, and the solution and the thixotropic agent are uniformly dispersed in a sand mill as component A. Polymeric MDI (purchased from Bayer 44V20) is component B.

(3) Degreasing and drying treatment are carried out on an inner part of a 304 stainless steel pipe of a specification required by a corrosion resistance test, a horizontal pipe combustion test, a vertical/horizontal pipe combustion test, and a vertical pipe combustion test, and then the pipe is prepared for use. The component A and the component B are taken and uniformly mixed by weight ratio of 100:7-8, and is sprayed on an inner wall of the 304 stainless steel pipe prepared for use. After a coating is touch-dry, the pipe is after treated in a baking oven of 80° C. for four hours and then is taken out. After the pipe is cooled down to a normal temperature, a chemical-corrosion resistance test and a fire resistance test are performed.

Embodiment 2

(4) 100 parts of an organic silicon resin (purchased from SILRES® MSE 100 in Wacker) are taken, 1 part of a thixotropic agent (purchased from HDK® H13L in Wacker) is added, and the organic silicon resin and the thixotropic agent are uniformly dispersed in a sand mill as component A of a coating. Tetrabutyl titanate is component B of the coating.

(5) Degreasing and drying treatment are carried out on an inner part of a 304 stainless steel pipe of a specification required by a corrosion resistance test, a horizontal pipe combustion test, a vertical/horizontal pipe combustion test, and a vertical pipe combustion test, and then the pipe is prepared for use. The component A and the component B of the coating are taken and uniformly mixed by weight ratio of 100:3-6, and is sprayed on an inner wall of the 304 stainless steel pipe prepared for use. After the coating is touch-dry, the pipe is aftertreated in a baking oven of 80° C. for four hours and then is taken out. After the pipe is cooled down to a normal temperature, a chemical-corrosion resistance test and a fire resistance test are performed.

Embodiment 3

(6) 100 parts of a 60% butanone solution (LUMIFLON® LF200MEK, purchased from Asahi in Japan) of a copolymer of fluorinated alkene and vinyl ether are taken, 20 parts of ECTFE powder (purchased from SOLVAY) are added, and the solution and the CTFE powder are uniformly dispersed in a sand mill as component A of a coating. Polymeric MDI (purchased from Bayer 44V20) is component B of the coating.

(7) Degreasing and drying treatment are carried out on an inner part of a 304 stainless steel pipe of a specification required by a corrosion resistance test, a horizontal pipe combustion test, a vertical/horizontal pipe combustion test, and a vertical pipe combustion test, and then the pipe is prepared for use. The component A and the component B of the coating are taken and uniformly mixed by weight ratio of 100:5-6, and is sprayed on an inner wall of the 304 stainless steel pipe prepared for use. After the coating is touch-dry, the pipe is after treated in a baking oven of 80° C. for four hours and then is taken out. Hot air of 250° C. is blew into the pipe for 20 minutes by using an air heater for further aftertreatment. After the pipe is cooled down to a normal temperature, a chemical-corrosion resistance test and a fire resistance test are performed.

Embodiment 4

(8) 100 parts of an organic silicon resin (purchased from SILRES® MSE 100 in Wacker) are taken, 20 parts of ECTFE powder (purchased from SOLVAY) are added, and the organic silicon resin and the ECTFE powder are uniformly dispersed in a sand mill as component A of a coating. Tetrabutyl titanate is component B of the coating.

(9) Degreasing and drying treatment are carried out on an inner part of a 304 stainless steel pipe of a specification required by a corrosion resistance test, a horizontal pipe combustion test, a vertical/horizontal pipe combustion test, and a vertical pipe combustion test, and then the pipe is prepared for use. The component A and the component B of the coating are taken and uniformly mixed by weight ratio of 100:2.5-5, and is sprayed on an inner wall of the 304 stainless steel pipe prepared for use. After the coating is touch-dry, the pipe is after treated in a baking oven of 80° C. for four hours and then is taken out. Hot air of 250° C. is blew into the pipe for 20 minutes by using an air heater for further aftertreatment. After the pipe is cooled down to a normal temperature, a chemical-corrosion resistance test and a fire resistance test are performed.

(10) Chemical-corrosion resistance test:

(11) At 25° C., an inner surface of the pipe prepared in each of the foregoing embodiments is immersed in each the following media for eight hours, and then is removed and cleaned.

(12) 1 #medium: 75% sulfuric acid

(13) 2 #medium: 30% hydrochloric acid

(14) 3 #medium: a mixture of 30% hydrochloric acid and 30% hydrogen peroxide whose volume ratio is 1:1

(15) 4 #medium: saturated ammonia

(16) After the foregoing reagents are treated, disadvantages and destruction are tested by using a microscope, and it is detected, by using an electrospark tester, whether there is leakage on a coating on the inner surface of the pipe.

(17) Testing results are as follows:

(18) TABLE-US-00001 Sample name 1# medium 2# medium 3# medium 4# medium Embodiment 1 Coating Coating Coating Coating completed completed completed completed and no and no and no and no leakage leakage leakage leakage Embodiment 2 Coating Coating Coating Coating completed completed completed completed and no and no and no and no leakage leakage leakage leakage Embodiment 3 Coating Coating Coating Coating completed completed completed completed and no and no and no and no leakage leakage leakage leakage Embodiment 4 Coating Coating Coating Coating completed completed completed completed and no and no and no and no leakage leakage leakage leakage

(19) Fire resistance test:

(20) The fire resistance test is performed according to the FM 4922 Certification Standards of Air Exhaust Pipe or Air-and-Smoke Exhaust Pipe.

(21) In the horizontal pipe combustion test, a straight pipe whose diameter is 12 inches and horizontal length is 24 feet is placed on a testing apparatus. A combustion source is placed on one end of the pipe, a fan is mounted on the other end of the pipe, and flame is lit up and is sucked into the pipe. If all the following conditions are satisfied in a testing process for 15 minutes, the product performance is considered as being qualified:

(22) 1. Flame in the pipe cannot extend to a place away from a flame exposure end by 23 ft (7.0 m).

(23) 2. A temperature at a place of 23 ft (7.0 m) inside the pipe cannot exceed 1000° F. (538° C.).

(24) 3. If the pipe and/or a mounting connector cannot maintain a complete structure, there is no burny or glowing particle after a dropped, dripped, or a melted pipe part or connector material gets into contact with the floor.

(25) 4. No external burning is caused due to autoignition or temperature transfer inside the pipe. When burning of an external surface is caused during exposure to external flame, the flame should intermittently appear and cannot spread outside a range of the first connector that is away from the exposure end by 4 ft (1.2 m).

(26) In the horizontal/vertical pipe combustion test, a 90° bent pipe whose diameter is 12 inches, vertical length is 15 feet, and horizontal length is 24 feet is placed on a testing apparatus. A combustion source is placed on one end of the pipe, a fan is mounted on the other end of the pipe, and flame is lit up and is sucked into the pipe. If all the following conditions are satisfied in a testing process for 15 minutes, the product performance is considered as being qualified:

(27) 1. Flame in the pipe cannot spread to a place on a horizontal pipe segment away from a flame exposure end by 23 ft (7.0 m).

(28) 2. Flame outside the pipe should be limited to a vertical pipe segment, and cannot spread to an external surface on the horizontal pipe segment.

(29) 3. A temperature at a place of 23 ft (7.0 m) inside the pipe cannot exceed 1000° F. (538° C.).

(30) 4. If the pipe and/or a mounting connector cannot maintain a complete structure, there is no burny or glowing particle after a dropped, dripped, or a melted pipe part or connector material gets into contact with the floor.

(31) In the vertical pipe combustion test, a straight pipe whose diameter is 12 inches and vertical length is 15 feet is placed on a testing apparatus. A combustion source is placed on one end of the pipe, a fan is mounted on the other end of the pipe, and flame is lit up and is sucked into the pipe. If all the following conditions are satisfied in a testing process for 15 minutes, the product performance is considered as being qualified:

(32) 1. Flame in the pipe cannot spread to a range within 10 ft (3.1 m) from a top end of the pipe.

(33) 2. Flame outside the pipe cannot spread to a range within 5 ft (1.6 m) from the top end of the pipe.

(34) 3. A temperature inside the pipe measured at a place away from the top end of the pipe by 1 ft (0.3 m) cannot exceed 1000° F. (538° C.).

(35) 4. If the pipe and/or a mounting connector cannot maintain a complete structure, there is no burny or glowing particle after a dropped, dripped, or a melted pipe part or connector material gets into contact with the floor.

(36) Testing results are as follows:

(37) TABLE-US-00002 Horizontal/ Horizontal vertical Vertical Sample name pipe test pipe test pipe test Embodiment 1 Qualified Qualified Qualified Embodiment 2 Qualified Qualified Qualified Embodiment 3 Qualified Qualified Qualified Embodiment 4 Qualified Qualified Qualified

(38) Although the implementations of the present invention are described in this specification, these implementations are merely used as presentations and should not limit the protection scope of the present invention. Various omissions, replacements, and changes made without departing from the scope of the present invention should all fall within the protection scope of the present invention.