Powder Coating Plant for Power Transformer

Powder coating has today established itself because the best means of metal surface finishing. It has replaced liquid painting and various methods of electroplating thanks to the various advantages this process offers …

1.  Substantial improvement to chemical corrosion
2. Substantially improved resistance to mechanical abuse – better scratch resistance, abrasion resistance and mechanical wear and tear
   

•  Cleaner process for improved environment 
•  Faster process for better productivity through the paint-shop 
• Requires less skills for top quality coatings 
• Guarantees uniform and consistent results 
• Substantially improved aesthetics for higher sales value of the finished product 
• Requires lower energy per Meter2 of surface coated 
• Requires lesser care in storing and packing thanks to the toughness of the coat 
• Is cost-effective
  

Powder coating may be a simple process requiring minimal skills and training. The articles to be coated are first cleaned of all foreign matter from the surface. low-carbon steel components got to undergo a phosphate conversion coating. Aluminum components undergo a chromate conversion coating. 

This, known as pretreatment, is used for improved bonding of the powder coat to the fabric being coated to supply a longer life to the coat. the tactic employed usually may be a dip in chemicals and water in various tanks. Occasionally, the method could also be automated through a sprig pretreatment process.

A batch powder coating system:

The ‘pretreated’ articles are jigged and bulk amount into the coating booth on a hard and fast or rotatable jig-holder. The manual coater coats the components from all sides. The articles are then removed onto an oven trolley (or directly into the oven). 

The trolley, if used, is rolled into the oven when full. within the oven, at a temperature of 180-220oC, in 10-15 minutes, the powder melts, polymerizes fuses and cures into the ultimate tough uniform and consistent powder coat that has high aesthetic value. 

At the top of the curing schedule, the trolley is unrolled of the oven and allowed to chill down. The articles are then removed out from the paint-shop.

A Batch Powder Coating System

A Conveyor powder coating system:

The ‘pretreated’ articles are jigged and loaded onto the continuously moving overhead conveyor. because the conveyor moves the articles through the coating booth, they're coated on all sides by manual and/or automated spray guns. 

The conveyor then carries the articles into the tunnel oven (or during a semi-automated version, the articles are offloaded for off-line curing). within the oven, at a skin temperature of 180-220oC, in 10-15 minutes, the powder melts, polymerizes, fuses and cures into the tough uniform and consistent powder coat that has high aesthetic value. 



 Automatic Powder Coating Plant
At the top of the curing schedule, the article moves out of the oven (or the trolley is unrolled of the oven) and allowed to chill down through a cool-off zone. The articles are then removed off the conveyor and brought out of the paint-shop.

The Powder Coating System

Complete powder coating systems are available two versions – a batch system and a conveyorized system. The primary difference is that the mode of cloth movement from operation to operation. Powder coating itself could also be by manually held spray guns or by automated guns fixed-mounted or reciprocator - mounted.

A complete powder coating system requires the next components:
PRE-TREATMENT SYSTEM – consisting of tanks or tubs containing chemicals or water during which the articles are dipped to scrub and prepare the surface for powder coating. the dimensions of the tanks depends on the dimensions and quantity of articles to be coated. the precise process depends on the metal make-up of the article.

Videos For Automatic Plant of Powder Coating Plant

AIR COMPRESSOR – fitted with appropriate filters provides clean and dry gas to the powder coating system. A 3HP or a 5HP compressor is usually adequate for a batch coating system using 1 coating machine. Conveyorized systems with multi-gun application may require a much bigger capacity compressor .

POWDER SPRAY SYSTEM (also referred to as the powder coating machine) – is taken into account the guts of the powder paint shop. Normally an electrostatic powder spray system is employed . This sprays electrostatically charged powder into the spray booth where the articles to be coated are hung. Electrostatic forces provide a consistent and
consistent coating quality.

 

Chemical Treatment or Pre-Treatment of Products


POWDER COATING BOOTH WITH RECOVERY SYSTEM – during which the actual powder coating is run . The efficiency of backup of over sprayed powder for reuse decides the economics of powder coating. The efficiency of overall retention of over sprayed powder decides the pollution-free worthiness of the system. 

There are two kinds of powder recovery booths – Filter Cartridge type and thus the Hyper Cyclone type.

CURING OVEN – during which the powder coated articles are placed for 10 to fifteen minutes at the recommended temperature for the powder to melt, polymerize, fuse and cure into the last word finish of high aesthetic appeal with strong mechanical and chemical properties.

IRON & STEEL:
      Fair:
          3-in-1 chemical (FRP lined)

Good: 
          De-rusting /descaling (FRP lined)           Water rinse           3-in-1 chemical (FRP lined)
Excellent:

          De-greasing          Water rinse
          De-rusting (FRP lined)          Water rinse (FRP lined)
          Activation (FRP lined) – optional
          Phosphating* (FRP lined)
          Passivating
* A fine crystalline zinc phosphate coat of 1-2 gms/M2 is Water rinse recommended for optimum results 

ALUMINUM:
Fair:
De-greasing
Water rinse (check with Chemical supplier)
Good:
De-greasing
Water rinse
Chromate conversion* (FRP lined)
Excellent:
the ‘good’ process plus nitric acid etching prior to chromate conversion

* Chromate conversion coat of 0.1-0.5 gm/M2 is recommended.
Note: Anodized aluminum surfaces need to be only de-greased.



The Powder Spray System
All electrostatic powder spray systems use only the in-built 100 kV technology – benchmark technology in powder coating today – worldwide. The 100 kV integrated applicator improves transfer efficiencies, productivity and powder consumption substantially in comparison to other less-than- 100 kV technologies.
The Powder Recovery Booth
The equipment that decides the economical viability of your powder coating paint-shop is that the powder recovery
booth. The economies of your paint-shop depend upon the real recovery of over sprayed powder for reuse.
If you an end-user or using only a couple of colors (maybe 1 to 3), you would like to closely study the likelihood of using
the DSP powder recovery booth because it offers advantages to you.

DELTA Series Filter Cartridge type:
RED LINE DELTA Series (DSP) recovery systems are the newest generation state-of-art filter cartridge type powder recovery systems. With effective cartridge type recovery system just like the DSP booth, you're assured of a minimum of 98+% (and virtually 100%) of recovery of powder. Conventional and sometimes poorly executed recovery booths might not be ready to offer quite 75-80% of recovery of reuse while making tall claims of 85 or maybe 95% recovery efficiencies. this is often often the case with poorly designed and copycat cartridge type powder recovery booths.

How the DSP powder recovery system function:
The powder over spray recovery system is found within the rear section of the powder spray booth (on the face opposite to the sprayer). The front section is that the coating booth. The workpieces, duly jigged are persisted the jig-holder within the coating booth (manually or on a conveyor) and sprayed with powder. 

A specially designed low-pressure, high capacity fan sucks air and therefore the powder overspray through the coating booth to the recovery system during a horizontal flat airflow pattern. The specially designed PTFE coated polyester-based filter cartridges entrap virtually all the powder particles. 

The remaining powder particles, if any, are trapped within the final filters (if installed – optional), allowing virtually clean air to the shop-floor atmosphere through the fan system. Electronically controlled high-pressure reverse pulse air jets located above each filter cartridge regularly and automatically clean the powder-laden filter cartridges. This throws the powder from the filter cartridges back to the powder spray booth and is collected within the powder bin located under the booth. This process, referred to as cartridge scavenging may be a continuous and on-line process. The collected powder are often manually (or automated) sieved and reused.

Why the DSP booth:

• Highest recovery efficiency – lowest powder cost 
• Quick color change – save time in color change 
• Neat & compact – utilizes lowest foot-print on the shop-floor 
• Easy-to-maintain 
• Healthy and pollution-free environment 

The Powder Recovery Booth 

The equipment that decides the economical viability of your powder coating paint-shop is that the powder recovery booth. The economies of your paint-shop depend upon the real recovery of over sprayed powder for reuse. The Powder Curing 

Oven Powder curing ovens whether fuel-fired or electrical – are extremely energy efficient, lowering the facility bills also as saving scarce fossil fuels. 

Uniform temperatures throughout the whole internal working area of the oven ensure uniform powder curing.

This becomes a really critical think about powder coating. less than required temperatures may mean an incomplete powder curing process, resulting in the powder coat shedding (and the merchandise suffers unnecessarily). above stated temperatures could lead on to the powders’ important resistance to chemical corrosion and mechanical abuse components burning off. this is able to translate into a lower life to the merchandise being coated.