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Custom Industrial Liquid Paint Spray Systems

Application of Liquid Paint Spray Services
Application of Liquid Paint Spray Services

Liquid coatings use liquid as the medium to deliver paint solids to the product surface. The liquid is then evaporated in the curing process resulting in an adhered paint film. In response to increased environmental concerns, paint suppliers have developed a wide variety of compliant coating chemistries including epoxies, alkyds, polyesters, acrylics, urethanes, and waterbase. The biggest advantages of liquid coatings is the ability to efficiently mix and match a wide variety of colors at your facility and then easily change colors during production runs. In addition, many varieties of liquid paint dry in ambient or low temperature heated air which permits temperature sensitive parts such as plastic or wood to be coated.

Liquid coatings are applied by spray, dip, or flow coat application. The optimal application method will depend on the part to be painted, its configuration, its performance requirements and production rate.

Click Here (PDF - 70KB) to view our Coatings Comparison Table.

Liquid Spray Application

Spray application is the most common method of liquid painting and can be applied manually for low production or automatically with reciprocators or robots for high production rates. Several types of spray systems are available such as, "airless", where paint is sprayed under high pressure without atomizing air or, "air spray" including air-assisted airless, high volume low pressure (HVLP) and conventional high pressure air spray. Typically, spray is the least transfer efficient application method and can range from 25% to 50% for non-electrostatic guns and 45% to 70% for electrostatic spray. Electrostatic application electrically charges the paint particles that are then attracted to a grounded, conductive part, usually metal. HERR works closely with your local preferred spray equipment supplier to provide up-front "buy-in" from a local source to insure continuing support for equipment adjustment and use as well as replacement parts.

While paint can be sprayed in an open area if proper health and safety precautions are taken, most sprayed liquid paints are applied in a paint "booth" or enclosure that contains the overspray and fumes. A booth also limits dirt or other outside contaminants from being introduced to the paint operation. Paint spray booths are designed to meet requirements of the National Fire Protection Association (NFPA 33) and other codes that dictate criteria such as air flow, materials of construction, safety equipment, isolation among others. HERR designs a wide variety of booths and booth features as listed below. The booth selection will be based upon your specific application and goals.

  • Down, Side or Cross Draft Air Flow
  • Continuous and Batch (truck)
  • Waterwash or Dry-Filter Exhaust
  • Paint Sludge Removal Systems
  • Automatic Dry-Filter Change
  • Fire Protection
  • Exhaust Cascade for VOC Abatement
  • Multi-Level and Manlifts for Access
  • Roof Slots and "Pop-Top" for Crane
  • Air Make-Up with Filtration, Conditioning
  • Cure Cycle
  • Automatic Doors

Dip Coating

Dip coating, as the name implies, coats parts by dipping them directly into a paint tank. Except for batch operations, parts are typically transported into and out of the tank on an overhead conveyor or flat line belt conveyor. The paint is usually circulated and filtered to maintain its quality and may require some degree of bath temperature control. This type of application is considered 100% transfer efficient by regulatory agencies and enables coating inside as well as outside part surfaces. However, care must be taken with respect to the part design and hanging arrangement to insure that the part drains efficiently and does not trap air and create a paint void. A drip recovery system is also recommended to return and reuse the paint. HERR incorporates a number of features into our dip tanks including the following:

  • HRS, Stainless or Plastic Construction
  • Automatic Paint Addition
  • Hinged or Removable Lids
  • Drip Recovery and Return
  • Paint Circulation and Filtration
  • Water Jacket Cooling System

Flow Coating

Flow coating involves flowing paint over parts as they pass by a series of low pressure paint nozzles in an enclosed housing similar in configuration to a spray washer. Like dip coating, flow coating is considered 100% transfer efficient capturing run-off paint in a tank beneath the housing and re-applying it. Also like dip coating, the part geometry and hanging arrangement must be considered to drain paint carry-out in recesses and prevent voids beneath tabs or ledges. HERR's flow coaters incorporate a number of features including the following:

  • HRS, Stainless or Plastic Construction
  • Automatic Paint Addition
  • Non-Shear Pumps
  • Automatic Paint Viscosity Management
  • Paint Circulation and Filtration
  • Even, Gravity-Pressure Paint Flow

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