JB/T 7217-1994 General technical requirements for coating of separation machinery
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Machinery Industry Standard of the People's Republic of ChinabZxz.net
JB/T7217-94
General Technical Conditions for Separation Machinery Coating
Published on July 18, 1994
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1995
Machinery Industry Standard of the People's Republic of China
General Technical Conditions for Separation Machinery Coating
Subject Content and Scope of Application
This standard specifies the terminology, technical requirements, inspection items and inspection methods for the coating of separation machinery products. This standard is only applicable to the paint coating of separation machinery products. 2 Terminology
2.1 Coating
JB/T7217-94
The process of applying paint to the surface of a substrate to form a protective, decorative or special functional coating is also called coating construction. 2.2 Adhesion
The sum of the bonding forces between the coating and the substrate.
2.3 Brush marks
Stripe-like folding after the brush coating dries. 2.4 Blistering
The phenomenon of the coating film peeling off into an arch or bubble shape.
2.5 Color change
The phenomenon of paint film discoloration caused by the migration of color between coatings. 2.6 Whitening
The phenomenon of organic coating film whitening or losing its luster, generally caused by moisture and frost. 2.7 Orange peel
The wrinkled surface similar to orange peel on the coating. 2.8 Wrinkling
The phenomenon of the coating film folding up during the drying process, usually caused by drying too quickly. 2.9 Pinholes
The phenomenon of small holes in the coating film during the coating and drying process. 2.10 Peeling
The phenomenon of spontaneous detachment of the coating film.
2.11 Sagging
The phenomenon that the lower edge of the coating is thicker during the coating and curing period. 2.12 Gloss
An optical property of the coating surface characterized by its ability to reflect light. 3 Technical requirements
3.1 General requirements
3.1.1 Painting should be carried out in a clean and dry place. When working in the sky, strong winds, dust, rain, snow, fog, the paint film cannot dry, and direct sunlight causes the temperature of the parts to exceed 50C, painting cannot be done. Approved by the Ministry of Machinery Industry on July 18, 1994
Implementation on July 1, 1995
JB/T 721794
3.1.2 Painting should be carried out in an environment with a relative humidity not exceeding 85% and an ambient temperature not lower than 5℃. 3.1.3 All non-processed surfaces of easily rusted metals and surfaces with special requirements of separation machine parts and components should be painted. Surfaces that are not easy to paint after assembly can be painted before assembly.
3.1.4 When the surfaces of separation machine parts have special requirements such as heat resistance, corrosion resistance, and oil resistance, corresponding heat-resistant, corrosion-resistant, and oil-resistant paints should be used for painting.
3.2 Surface requirements before product painting
3.2.1 Before painting, the surface of parts must be free of protrusions, welding slag, spatter, sprue mouth flash, and meat. Burrs, sharp edges, iron filings, oil stains, etc. are not allowed on the surface.
3.2.2 Before painting, welded parts should be pre-processed to different quality levels according to different rust levels (A, B, C, D) by manual rust removal or surface spray rust removal. When manual rust removal is used, it should comply with the provisions of Article A2.1. When surface spray rust removal is used, it should comply with the provisions of Article A2.2 [see Appendix A (Supplement)].
3.2.3 Before painting, the casting surface shall be pre-processed by mechanical cleaning, sandblasting or shot blasting to remove surface rust, sand, paint and other attachments, so that the casting surface is gray and natural.
3.2.4 When painting heat-resistant paint, corrosion-resistant paint, paint-resistant paint and other paints with special requirements, the surface pre-processing must be done to see the original color of the metal before painting.
3.3 Painting requirements
3.3.1 The interval between the metal surface after rust removal and the primer shall not be greater than 8h, but no matter how much the interval is, the surface shall not be rusted or contaminated before painting.
3.3.2 Primer, putty and topcoat shall be used in accordance with relevant regulations. 3.3.3 Uneven parts of the surface may be filled with putty. Putty is applied and scraped, and each layer shall not exceed 0.5mm. If multiple layers are required, the last layer must be applied after the previous layer is completely dry and polished. The polished surface should be flat, smooth, hard and matte. The total thickness of putty should generally not exceed 2mm.
3.3.4 The primer should be controlled to a certain film thickness. The primer damaged by processing or welding should be repainted. The primer should be firmly bonded to the metal surface.
3.3.5 The topcoat should be no less than two layers, and the last layer should be applied after the product performance test is qualified. 3.3.6 Parts where the coating film is easy to become thin, such as edges, ends, welds, etc., should be painted locally to obtain a uniform film thickness. 3.3.7 The coating should be uniform and continuous, and there should be no defects such as roughness, unevenness, missing coating, brush marks, blistering, color bleeding, orange peel, wrinkling, pinholes, peeling, whitening, sagging, uneven gloss, etc. If the above defects occur, they should be repaired. 3.3.8 After painting, attention should be paid to protecting the paint film, keeping the paint film surface clean, and preventing oil pollution and mechanical damage. If the paint film is damaged, the damaged part should be removed, cleaned and repainted. When painting, protective measures should be taken for the unpainted surface. 3.3.9
3.3.10 The boundary between the two colors of paint should be clear. 3.3.11
The joints of parts should be painted smoothly and with clear boundaries. 3.3.12 The color of the topcoat can be determined by the manufacturer or according to user requirements. 3.3.13 Purchased accessories that have been painted do not need to be painted again. When there is a requirement in the order, they can be painted according to user requirements. 4 Inspection items and methods
4.1 The surface treatment quality shall be inspected according to the requirements of Appendix A. 4.2 The appearance quality of the primer, intermediate paint layer and face collar layer shall be inspected by visual method and shall comply with the provisions of Article 3.3.7. 4.3 Coating Adhesion Test
Use a 200mm×200mm steel plate test piece, which has been surface treated and coated according to the requirements of the production process. Use a sharp blade to draw a cross with an angle of 60* on the surface of the test piece. The knife mark should reach the steel plate. Then apply the tape so that it is close to the paint film. Then quickly pull up the tape by hand. The total width of the coating on both sides of the knife mark does not exceed 2mm. It is qualified. 2
JB/T 7217-94
Appendix A
Quality grades of rust removal on steel surfaces before painting
(Supplement)
The original rust degree of steel surfaces is classified in Table A1.A
Rust degree grades
The steel surface has almost no rust and is completely covered with oxide scaleThe steel surface has begun to rust, and the oxide scale has begun to fall offThe oxide scale on the steel surface has been rusted or can be scraped off, but there are no visible pittingThe oxide scale on the steel surface has been rusted and left, and there are quite a few visible pittingMethods and quality grades of rust removal on steel surfacesA2
A2.1 Manual rust removal
Manual rust removal (including rust removal using tools such as scrapers, wire ropes, mechanical wire ropes, grinding wheels, etc.) is divided into two grades, A1 and A2, according to the rust removal quality requirements.
Grade A1: Thoroughly remove loose oxide scale, rust and dirt. Finally, use a vacuum cleaner, clean and dry compressed air or a clean brush to clean the surface. The cleaned surface should show a light metallic luster. b. Grade A2: The surface rust removal requirements are the same as those of Grade A1, but more thorough. The cleaned surface should have a clear metallic luster. A2.2 Surface spray rust removal is divided into four levels: B1, B2, B3 and B4 according to the rust removal quality requirements. a. Grade B1; light spray rust removal. Loose oxide scale, rust and dirt should be removed. b. Grade B2: Thorough spray rust removal. All oxide scale, rust and dirt should be removed. Finally, use a vacuum cleaner, clean and dry compressed air or a clean brush to clean the surface. The surface should be slightly gray. Grade B3: Very thorough spray rust removal. Oxide scale, rust and dirt should be removed to the extent that only slight dot or streak traces remain. Finally, the surface is cleaned with a vacuum cleaner, clean and dry compressed air or a clean dustpan. d.B4 level: blasting to white. Oxide scale, rust and dirt should be completely removed. Finally, the surface is cleaned with a vacuum cleaner, clean and dry compressed air or a clean dustpan. The surface should present a uniform metallic luster. Additional remarks:
This standard was proposed by the National Technical Committee for Standardization of Separation Machinery. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Hangzhou Chemical Machinery Factory. The main drafter of this standard is Ding Haoquan.
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