English

Company

  Xuzhou Xinxing Zinc/Chromate Coatings Co., Ltd. is a private ownedstock companyspecialized in DACROTIZED(Zinc/Chromate Coatings)rust prevention treatment for metals, and the first company introducing DACROTIZED(Zinc/Chromate Coatings) coating technology and modern productive equipment from Japan into xuzhou, provides clients with DACROTIZED(Zinc/Chromate Coatings)technology for rust prevention of standard parts, components, and other related metal products.

  With the policy of “Credit-oriented, Quality-oriented”, the company has won the credit from clients with high quality  services,

and has established sound relationship with many famous enterprises, home and abroad, in the field of aut omobile manufacture, home

appliances,communications, hardware and tools, outdoor construction engineering,and etc.

  Welcome clients, old and new, to our company to electroplate parts (nickel, zinc, and chromium-plating).


Samples

 

Difficulties: 

No fluid remaining in screw thread, no harm to screw tooth,pass ratio of finished products through go-no go gage ≥98%.

Procedures:

Degreasing--->Rinsing--->Drying--->Finishing--->Soaking --->Centrifu-gal--->Pre-heat--->Sintering--->Cooling--->Unload --->Repeating above steps--->Finish inspecting--->Storage

Quality requirements:

Corrosion resistance: ≥500hours

Adhesion: ≥3.5level (Japan STD) Surface: smooth and no fluid remaining, pass rate of finished

products ≥98% Coating thickness: 6-8um 

Difficulties:

Plastic spraying needed after DACROTIZED(Zinc/Chromate Coatings), the adhesion of the DACROTIZED(Zinc/Chromate Coatings)coating shall be above level 4.5 (Japan STD), good electric conduction.

Procedures: Degreasing--->Rinsing--->Rust resisting--->Drying--->Spray --->Pre-heat--->Sintering--->Cooling--->Process inspecting--->Plastic spraying--->Curing--->Unload--->Finish inspecting--->Storage Quality requirements of the DACROTIZED(Zinc/Chromate Coatings)coating:

Corrosion resistance: ≥240hours

Adhesion: ≥4.5level (Japan STD)

Surface: uniform coating and no omitted

Coating thickness: 4-6um

Electric conduction: nice

Bonding force: conform to State Adhesion STD level-0 after plastic spraying

Difficulties: 

 

No liquid remainder at inner walls, In. rust resisting time≥25days

Procedures:

Degreasing--->Rinsing--->Drying--->Finishing--->Ex. spray --->Pre-heat--->Sintering--->Cooling--->Unload--->In. rust resisting--->Finish inspecting--->Storage

Quality requirements:

Corrosion resistance: ≥168hours

Adhesion: ≥3.5level (Japan STD)

Surface: uniform, no coating omitted, inner rust resistant, no coating omitted no flowing fluid.

Coating thickness: 5-8um

  

Difficulties: 

Powder metallurgy substrate, rust resistance of 500hoursrequired, no liquids in tooth. 

Procedures: 

Degreasing--->Rinsing--->Drying--->Finishing--->Coating-->Pre-heat--->Sintering--->Cooling--->Unload--->Repeating above DACRO(Zinc/Chromate Coatings) procedures twice--->Finish inspecting--->Storage 

Quality requirements: 

Corrosion resistance: ≥500hours 

Adhesion: ≥3.5level (Japan STD) 

Surface: uniform appearance, no liquid remaining 

Coating thickness: 8-10um


Difficulties: 

Smooth and no liquid remaining , surpass three times of hardnessof the DACROTIZED(Zinc/Chromate Coatings)coating. 

Procedures: 

Degreasing--->Rinsing--->Drying--->Finishing--->Soaking--->Centrifugal--->Pre-heat--->Sintering--->Cooling--->Unload--->Repeating above DACRO(Zinc/Chromate Coatings) procedures once--->After coating--->

Finish inspecting--->Storage 

Quality requirements: 

Corrosion resistance: ≥1000hours 

Adhesion: ≥3.5level (Japan STD) 

Surface: uniform and flawless 

Coating thickness: 13-15um 

Difficulties: 

Highly bright surface, no abrasion at the point, no liquid remaining, after processing needed. 

Procedures: 

Degreasing--->Rinsing--->Rust resisting--->Drying--->Soaking--->Centrifugal --->Pre-heat--->Sintering--->Cooling--->After coating--->Drying--->Unload--->Finish inspecting--->Storage 

Requirements: 

Corrosion resistance: ≥500hours 

Adhesion: ≥3.5level (Japan STD) 

Surface: smooth and no liquid remaining 

Coating thickness: 5-7um 

Difficulties: 

No hydrogen brittleness to the DACROTIZED(Zinc/Chromate Coatings) finishedproducts,no effect on elasticity. 

Procedures: 

Degreasing--->Rinsing--->Rust resisting--->Drying--->Soaking --->Centrifugal--->Pre-heat--->Sintering--->Cooling--->Unload--->Finish inspecting--->Storage 

Requirements: 

Corrosion resistance: ≥240hours 

Adhesion: ≥3.5level (Japan STD) 

Surface: uniform coating and no neglect Coating thickness: 4-6um


Difficulties: 

In various colors, pass ratio of go-no go gage is over 98%. 

Procedures: 

Degreasing--->Rinsing--->Rust resisting--->Drying--->Soaking 

--->Centrifugal--->Pre-heat--->Sintering--->Cooling--->Unload-->Soaking (After coating)--->Curing--->Unload --->Finish inspecting--->Storage 

Quality requirements: 

Corrosion resistance of the DACROTIZED(Zinc/Chromate Coatings) 

coating: ≥240hours 

Adhesion of the DACROTIZED(Zinc/Chromate Coatings) coating: ≥3.5level (Japan STD) 

Surface: good appearance 

The DACROTIZED(Zinc/Chromate Coatings) coating thickness: 4-6um 

Bonding force: conform to state adhesion STD level-1 after treatment.

 

Difficulties:

The DACROTIZED(Zinc/Chromate Coatings) coating interior wall, no flowing liquid,no coating omitted

Procedures: 

Degreasing--->Rinsing--->Rust resisting--->Drying--->Finishing--->Spray--->Pre-heat--->Sintering--->Cooling--->Unload--->Finish inspecting


--->Storage Quality requirements: 

Corrosion resistance: ≥500hours 

Adhesion: ≥3.5level (Japan STD) 

Surface: smooth and no liquid remaining, no coating omitted,no liquid flowing (including interior wall) 

Coating thickness: 7-10um


Technology


I. What is DACRO(Zinc/Chromate Coatings)

DACRO(Zinc/Chromate Coatings) is derived from the pronunciation and abbreviation of DACROMET(Zinc/Chromate Coatings), is a representative hi-tech metal surface treatment in the world. The DACROTIZED (Zinc/Chromate Coatings)coating is an innovative patent control technology, developed by American and patented by Japanese, and then introduced to China . The whole set of equipment and procedures adopt total closed circulation, which innovates electro-galvanization and stops the generation of wastewater with acid, alkali, zinc and chromium etc., exhausted gas and pollution. The DACROTIZED(Zinc/Chromate Coatings) coating means the procedures of Degreasing–Finishing-Coating-Curing-Cooling-Finished product, which forms a silver-gray corrosion prevention coating film comprised of zinc, aluminum flakes and chrome compounds. Because the coating process generates only gasified water in the formation of the DACROTIZED(Zinc/Chromate Coatings) coating film; no any pollution and public harms is generated, therefore . It has been used widely in industrial developed countries and substitute gradually for traditional surface treatment generating serious pollution like electro-galvanization, hot-dip galvanization, hot-spray zinc, mechanical galvanization, zinc alloyed coating, oxidation and phosphoreted processing, and etc. and diminishes the production of pollution. The technology has been supported greatly by our government since the introduction into our country, and listed as state Emphasized popularization project on technology of environmental protection of 1999 (File-HF [1999] 185, Project No. 99B030).II. The structure and anti-corrosive mechanism of the DACRO(Zinc/Chromate Coatings) film 

The anti-corrosive mechanism of the DACROTIZED (Zinc/Chromate Coatings)coating film: 

The DACROTIZED (Zinc/Chromate Coatings)is an innovative rust prevention system for metals. The anti-corrosive mechanism of the DACROTIZED (Zinc/Chromate Coatings)coating film consists of the controlled galvanic protection action of zinc particles, the passivation of base metal by chromic acid and the mechanical barrier effect of zinc and aluminum flakes and chrome compounds, and elutriation effect of aluminum against zinc.


Structure of DACROTIZED(Zinc/Chromate Coatings) coating:Coating iron substrate with DACRODIP (a water-based dispersant containing metallic zinc and aluminum flakes at the size of 0.1-0.2×10×15μm, Cr2O3 andspecialized organic substances), and then heating the solution to approximately 300°C in an oven will reduce the hexavalent chromium to chromic to produce amorphous nCrO3.mCr2O3. The substance bonds with the metal surface, the zinc and aluminum flakes together with substrate; besides, the interior of zinc and aluminum flakes is filled with chromic anhydride. Therefore, the surface of metal is coated with a filmy silver-gray DACROTIZED? corrosion prevention coating after cooling.

III. Technical features of DACROTIZED(Zinc/Chromate Coatings)coating 

The DACROTIZEDcoating(Zinc/Chromate Coatings) is an advanced, integrated high-tech technology of surface treatment for metals and has superior advantages and features beyond others:


1?  Superior corrosion resistance 

The colored zinc-coating film in a good state shall be eaten off by thickness of 1μm~3μm ten hours later in salt spray test and penetrated 200 hours later. And the DACROTIZED coating(Zinc/Chromate Coatings) offers ten times corrosion resistance than that with traditional surface treatment by 1μm at the 100 th hour in the test, last over 1000 hours in the test; besides, its sulfur dioxide resistance offers a better rust prevention. (As shown is the electro-galvanizing part and DACROTIZED (Zinc/Chromate Coatings)part after 360 hours' salt spray testing.) 

2? Superior heat and corrosion resistance 

The surface with traditional zinc coating film will crack slightly at approximately 7 0°C , and the surface color will alter and corrosion resistance will diminish quickly at 200~ 300℃ . The DACROTIZED? coating forms at about 300℃ and will withstand high temperatures for extended periods of time. (As shown is the microstructures of electro-galvanizing part and DACROTIZED (Zinc/Chromate Coatings) part after 12 hours' heating at 300 ℃ ) 

(As shown is the microstructures of electro-galvanizing part < 240 hours' salt spray testing>and DACROTIZED (Zinc/Chromate Coatings) part<1000hours salt="" spray="" testing="">for 12 hours at 300 ℃ ) 

(As shown is the surface alteration of electro-galvanizing and DACROTIZED (Zinc/Chromate Coatings)part after 600hours salt spray testing for 8 hours at 300 ℃ ) 

3. Superior surface penetrability 

The film may be formed even in even slight space on the DACROTIZED(Zinc/Chromate Coatings) metal parts, offering a corrosion prevention coating film with nice penetrability. The ability coating inside and outside of pipe parts, uniformly and deeply, is far exceeding electro-galvanization. (As shown is the comparison of electro-galvanized and the DACROTIZED(Zinc/Chromate Coatings) parts after 240hours salt spray testing) 

4. Superior coating free of hydrogen brittleness Hydrogen brittleness is a disadvantage in traditional galvanization process. In the process of the DACROTIZED(Zinc/Chromate Coatings) coating, the shortage of acid treatment and hydrogen penetrating in galvanization, in combination with Curing at high temperature all contribute to the lack of hydrogen brittleness in the DACROTIZED coating(Zinc/Chromate Coatings), which is especially for corrosion prevention for high intensity parts with tensile strength Rm>1000N/sq.mm


Process

Duration

Acc.

Breakage


The DACROTIZED

<100hr>100hr

90 0

0 0

Galvanization 

(no Drying)

<100hr>100hr

0 0

90 90


5.Superior climate resistance. (As shown: hot-dip galvanized, phosphorated & powder coating and the DACROTIZED(Zinc/Chromate Coatings) parts after 1 year exposure on ship.) 

6. Optimized prevention mechanism of aluminum against electrochemistry corrosion 

In general, electrochemistry corrosion occurs once two metal or alloys with different electrode potentials contact. The corrosion prevention of galvanization depends on sacrifice of zinc; whereas the mechanism of the DACROTIZED(Zinc/Chromate Coatings) bases on the passivation of Cr acid and controlled sacrifice of zinc, which optimizes mechanism, controls the consumption of zinc, and increases safety of corrosion prevention by a large degree.

7. Beautiful matt silver-gray coating film 

The DACROTIZED(Zinc/Chromate Coatings) parts has beautiful and graceful matt silver-gray surface and the DACROTIZED coating(Zinc/Chromate Coatings) adhere firmly to colorful paints and dopes over-coated. 

IV. Analysis of inevitability, necessity and benefits of DACRO (Zinc/Chromate Coatings)

1. In terms of the serious air, soil and water pollution from galvanization, and harms toworkers, our country has stated repeatedly to develop a new green industry as a substitution ASAP. The end of galvanization is inevitable, whereas the DACROTIZED coating(Zinc/Chromate Coatings) is necessary. The later generates no any pollution and is a real green industry encouraged by our country. 

2. It is necessary for various metal surfaces to use the DACROTIZED(Zinc/Chromate Coatings) technology. On the one hand, galvanized parts feature on weak corrosion resistance, weak heat corrosion resistance and distortion, unstable coating film with hydrogen brittleness. On the other hand, the DACROTIZED coating(Zinc/Chromate Coatings) overcomes the said disadvantages and can last at least 10 years without corrosion, meeting the demands of clients and exportation. 

3. Tough the costs of DACRO(Zinc/Chromate Coatings) is more than galvanization, a deeply economic analysis proves its cost efficiency. Take hot-dip zinc plating for example, the processing price is 1800 Yuan/ton whereas the processing cost of DACRO(Zinc/Chromate Coatings) will be higher by 20%~30% , but the rejected percentage from hydrogen brittleness and distortion in the former is as highly as 10%, so the cost from both processing and materials far exceeds the excessive part in DACRO. As for medium and small parts, the processing charges in DACRO(Zinc/Chromate Coatings) will be higher by 30%~50% , the life of the DACROTIZED(Zinc/Chromate Coatings) parts will be increased by 3 or 5 times, or above, which saves not only a vast of maintenance expenses but materials. As for the parts with critical requirements, like the parts of automobiles, motorcycles, aviation and space, brides and roads and electronics, galvanization is far from satisfaction, the DACRO is optimum, no costs consideration, therefore, exists. For example, the DACROTIZED coating(Zinc/Chromate Coatings) to some auto components costs 5000~8000Yuan/ton (5~8 Yuan/kg), which is unparalleled as for galvanization. 

All in all, the DACROTIZED(Zinc/Chromate Coatings) technology, the high-tech in surface treatment in the world, has been praised as innovative product and green engineering in international metal surface treatment. She will service for any industry internationally.


Scope

The materials that can be coated with DACROTIZED(Zinc/Chromate Coatings) include a wide range of metals such as steel, iron, alloys, non-ferrous metals like aluminum and copper, cast and forging pieces, and also sintered metals with special methods, and other special surface treatment. The industries involving in or under development of DACROTIZED(Zinc/Chromate Coatings) are numerous, and the industries our company has engaged in are as follows:

1.Automobiles and motorcycles industries. Being high-speed vehicles, their components are required by better stability, heat, and humidity and corrosion resistance. In the past, many Chinese automobile components relied on importation, but now many components of auto manufacturers like CSVW, DPCA, are processed with DACRO(Zinc/Chromate Coatings) in our company.

2.Subways, tunnels and light track engineering. The pre-covered and of subways, tunnels and light-track engineering must of extremely high corrosive resistant, and treatment with the DACROTIZED coating(Zinc/Chromate Coatings) might be the best method. Now the subway and tunnels in Shanghai has taken this technology 

3.Sewage treatment facilities. A vast of corrosive substances in sewage will erode steel structures of sewage treatment easily, so most steel structures and rails in sewage treatment plants and pumping station applies DACROTIZED(Zinc/Chromate Coatings).

4.Wave railings along the road. Railings of separated strip was originally painted or electro-galvanized, the failure of beauty, erodible and expensive maintenance may be resolved by DACROTIZED(Zinc/Chromate Coatings) which can last at least 20 years free of maintenance, once for all, and the engineering involved is the railings and glistening sign posts etc. on Luoshan Road, and that of Exterior-Ring Road is under design. 

5.Bridges, viaducts and highways. Being a permanent construction, especially, the metal steel structures shall affect the life of the whole bridge once rusted, and the extensive connecting cement and rubber shall produce unconceivable result once broken. The absence of hydrogen brittleness, good climate resistance and wearability resolve the said weaknesses. Therefore, the new bridges and highways all use the metal structures DACROTIZED(Zinc/Chromate Coatings) by our company. 

6.Ocean engineering. The corrosion against vessels, navigation marks from salt in seawater may be readily solved by DACROTIZED(Zinc/Chromate Coatings). 

7.Power supply industry. In the transmission and distribution of high-voltage electricity and power supper in a city, naked red wires, besides cables and wires, are all exposed outdoors enduring sunshine, drenching and pollution, involving in expensive maintenance cost. If DACRO(Zinc/Chromate Coatings) is applied in the iron towers of wires, horizontal rails, support clips, elbows and screw caps, natures of beauty, duration and savings in maintenance expenses annually in a large amount shall compensate original high costs. 

8. Small hardware and standardized parts . Consumptive small hardware, manual tools, screws, screw caps and washers with originally electro-galvanization treatment will be corrosive in one or two years and have to be handled at a discount, which can be resolved by DACRO(Zinc/Chromate Coatings) at lower cost. With the beauty and duration natures and rust prevention, the parts are satisfied with client at a higher price. 

Small hardware and standardized parts . Consumptive small hardware, manual tools, screws, screw caps and washers with originally electro-galvanization treatment will be corrosive in one or two years and have to be handled at a discount, which can be resolved by DACRO(Zinc/Chromate Coatings) at lower cost. With the beauty and duration natures and rust prevention, the parts are satisfied with client at a higher price.


Other examples:

Contact us

Xuzhou Xinxing Zinc/Chromate Coatings Co., Ltd

Add: Mengjiagou.Northern Suburbs.(No.204 Fuxing Road N.)Xuzhou.Jiangsu Province.China

Mobile: 13705211630 

Tel: +86-516-87766900 

Mob:(0)13705211630

Fax: +86-516-87766548

http: www.xzdkl.com

E-mail: sales@ xzdkl.com