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Finishing Workshop Columbus, Ohio May 16-17, 2017

Design & Maintenance of Pretreatment Washers for Non-Ferrous

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Types of Multi- Stage Washers Pretreatment washers are designed and built to meet specification requirements produced in collaboration between chemical experts, finishing coaters and experience of the equipment builder.

Tank 2 Return Pump Tank 1 Return Pump

Multi- Stage Washer

1 Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Types of Multi-Stage Washers Various designs of washers with different types of application methods are available. The most common are: Spray – (Vertical, Horizontal, Chain Drive, Other.)

Tank 2 Return Pump Tank 1 Return Pump

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Types of Multi-Stage Washers Various designs of washers with different types of application methods are available. The most common are: Immersion – Dip Tanks

Tank 2 Return Pump Tank 1 Return Pump

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Application Methods for Multi-Stage Pretreatment Washer

• Spray • Immersion • Waterfall • Combined

Each method can be supplied by the equipment manufacturer and each has some advantages and disadvantages. The type of application typically chosen by the paint shop is based on many factors such as type of parts to be processed, throughput required, available space, project cost, etc..

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Application Methods for Multi-Stage Pretreatment Washer

Spray Immersion

Waterfall

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Types of Application: Listed below are a few advantages and disadvantages of different types of application methods of pretreatment:

Type Advantages Disadvantages Impingement (Spray) Aggressive cleaning Atomization can Good coverage facilitate: Control of flow Cross contamination (Direction & Target Areas) between stages. Heat loss of solution.

Part movement .

Increased maintenance.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Types of Application: (Continued)

Type Advantages Disadvantages

Immersion (Dip) Very good coverage Possible air entrapment in part voids.

No aggression (Must add agitation to facilitate cleaning.)

Solution entrapment in part.

Reduced production throughput.

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Types of Application: (Continued)

Type Advantages Disadvantages

Waterfall Good coverage. Low aggression.

Low cross contamination Geometry and between stages. orientation dependent. Low solution heat loss .

Lower power required for pumping.

Low maintenance.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Pretreating or (Preparing The Surface) Application Types:

While there are different methods of surface cleaning and application of solutions, there is no perfect process. Any process has limitations. This is why this type of equipment must be evaluated and chosen based on important considerations.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Washers Functions

Typically the pretreatment washer performs multiple processes to prepare the parts for receiving the finish :

• Proper Cleaning

• Proper Metal Treatment

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Washers Functions

Proper Cleaning – Removing unwanted contaminants from the part to prepare the substrate for Metal Treatment.

Proper Metal Treatment - Application of chemicals designed to provide: 1. Effective adhesion of the applied finish coating. 2. Protection of the substrate under the finish coating.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning The first stage of the pretreat process is to prepare the surface of the metal for acceptance of the metal treatment.

THE FOUNDATION

This cleaning process is the most important step of the pretreatment.

It is similar to the foundation of a building, everything is supported here. This is why the washer contains many tools and features to provide consistent repetitive results if operated and maintained properly.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Types of Washers

Since time is limited we will focus on spray.

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Types of Layouts for Spray Washers

Courtesy of Amchem Products, Inc.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Proper Cleaning requires:

Scrubbing or work by means of aggression on the part for removal of dirt, chips and debris.

Chemical Reaction on the part for conditioning contaminants such as oils and other unwanted substances to be removed.

Rinsing the parts for removal of excess chemicals and contaminates in solution.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray Typical 4 Stage Pretreatment Washer Schedule

Stage Time Temperature Length

Entrance 9’ –0” Dwell times and 1st -Cleaner 90 sec. 130 F 30’ –0” stage Drain 13’ – 0” lengths base on a 2nd -Rinse 30 sec. Ambient 10’ –0” conveyor Drain 13’ – 0” speed of 20 FPM. 3rd –Rinse 30 sec. Ambient 10’ –0”

Drain 13 ’-0”

4th –Treat 45 sec. Ambient 15’ –0”

Exit 9’ –0”

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Proper Cleaning - Spray Chemical experts have designed these processes for proper performance based on the chemical makeup of the solutions and the amount of contact time (dwell time) to the work piece.

Changing the conveyor speed changes the dwell time of the parts in the washer along with the scrubbing, chemical reaction, rinsing & draining times.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray Scrubbing – Stage 1 Cleaning Force

Using impingement energy of spray helps to “Knock-Off” unwanted chips and debris.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Chemical Reaction – Stage 1 Application of the Chemical Solution Spray Nozzle technology can be flexible to apply the solution to the perimeter of the part utilizing various spray patterns and nozzle arrangements.

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Proper Cleaning - Spray

Rinsing – Stage 2 and or 3 Rinsing the parts is an important stage of the cleaning process!

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Rinsing – After Cleaning or Metal Treatment For proper rinsing the design of the washer should have:

• Good spray coverage of the part with some impingent to properly clean away excess chemicals and debris after cleaning.

• Proper overflow of the rinse tank to keep the rinse water clean.

• Proper drainage of the parts to reduce drag out of cleaning chemicals into rinse tank.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Rinsing – After Cleaning or Metal Treatment For proper rinsing the design of the washer should have:

• Proper pitch the floor drain boards to reduce chemical and contaminant drag out.

Note: Typically drain boards between stages are pitched at a minimum of ¼” per foot and divided so that two- thirds of the length flows back to the preceding stage and one-third drains to the next stage.

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Proper Cleaning - Spray

Door at apex. Typically drains boards are split 2/3 length to preceding stage and 1/3 length to next stage. Pitched drain boards between stages.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Rinsing – After Cleaning or Metal Treatment For proper rinsing the design of the washer should have:

Proper pitch of the floor to reduce chemical and contaminant drag out. Tank 2 Return Pump Tank 1 Return Pump WARNING: “Oil Canning” can occur in drain areas from foot traffic causing improper drainage of solutions.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Rinsing – After Cleaning or Metal Treatment For proper rinsing the design of the washer should have:

Tank 2 Return Pump• Proper Tank 1 Return Pump containment of over spray with silhouettes.

• Proper control of overspray with spray riser orientation.

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Proper Cleaning - Spray

Rinsing – After Cleaning or Metal Treatment For proper rinsing the design of the washer should have:

• Good spray coverage of the part perimeter. • Quality of the rinse water using good automatic overflow and water makeup designs.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Cleaning - Spray

Install limiting orifice to maintain proper water volume and Remove valve avoid excess handle to overflow. avoid accidental closure but keep in area for maintenance.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Metal Treatment - Spray

Most of the same design principals for spray cleaning apply to the spray application of chemical solutions on the part for creating a protective coating. • This stage, after the cleaning process may or may not require a heated chemical solution. • If heated, the solution bath temperature should be properly maintained for consistent reaction properties. • Nozzle spray patterns may or may not be different. Many styles are available and can be recommended by the chemical company for the type of metal treatment being performed. • Lower spray pressure for less impingement energy on the treated surface.

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Proper Metal Treatment – Spray Rinse

For chemistry requiring a rinse stage after coating:

• Flat “V” spray pattern for rinsing off excess chemicals and stopping the chemical reaction after the pretreatment process. • Lower impingement pressure to prevent disturbance of the formed treatment protection barrier.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Metal Treatment – Spray Rinse

For chemistry requiring a rinse stage after metal treatment:

Good over flow control by draining from the tank gutter just above the solution level and replenishing fresh clean water to the tank by use of a controlled fill line or introducing city or DI water into a set of risers at the end of the rinse stage as a final rinse.

Note: Additional rinse stages may be required depending on the chemistry and downstream requirements.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Proper Design (Non Ferrous Substrates) In order for the pretreat process to perform correctly the washer should have certain design features of the :

• Tanks

• Tunnel

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Tank Design – Construction

Courtesy of Amchem Products, Inc.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Construction

• Tanks should be constructed of materials that are compatible with the chemicals used in the process to maintain integrity and reliability of the equipment.

• Tanks are typically made from mild for higher pH or alkali based solutions and stainless steel 304 or 316 for low pH or acid solutions or where DI or RO water is being used.

Note: Today, more of the market is demanding all SS for flexibility of the chemical technology that may require this compatibility.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Construction

Good fabrication techniques are essential for: • Structural integrity. • Chemical containment. When fabricating components • Chemical compatibility. of Stainless Steel by welding a different of low carbon content may be used to increase weldibility – Designated as in 304L or Tanks should be welded inside 316L. and out to prevent leaks

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Tank Design – Size L x W x D • The Length of the tank is typically based on volume of the solution required or the amount of heat coil required in heated stages. • The Total capacity of the tank should be 2-3 times the

total volume Courtesy of Amchem Products, Inc. pumped.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Size L x W x D • The Width of the tank typically extends 30-40” beyond the tunnel for maintenance (cleaning filters, tank access and pump maintenance).

• The Depth of the tank is typically 36-42” to keep the pumps properly submerged in the solution at all times while maintaining clearance from the floor.

Courtesy of Amchem Products, Inc.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Drainage

Tanks should have proper slope to facilitate draining of solution and sludge.

• Tank bottom should be sloped 1” of drop per 5’ of tank width.

• Tank drain line should be sized for 4” diameter and flush mounted to allow discharge of sediment from the bottom of tank.

.

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Tank Design – Fill Tanks should have: • 1-1/2” lines for quick fill. • ¾” lines for level control.

Tank Design – Fill Fill tube should extend below surface of solution to avoid splashing and creating foam.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Fill Tanks should have:

Tank Design – Fill Provide a gap between fill line and fill tube for a visual inspection of water flow and anti- siphon.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Fill Tanks should have:

Proper level control is required for loss of solution from drag out and loss if overflowing is required. • The tank should contain automatic level control to: • Maintain proper volume. • Maintain proper overflow, if required. • Protect pumps from cavitation. • Protect heat sources from over heating.

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Tank Design – Heated Solution

• Tanks using heated serpentine tubes are installed a minimum of 6” from floor for good fluid circulation to maintain good heat transfer from the tube to the solution.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Heated Solution Tanks should have:

• If tubes are heated from direct combustion: • Tubes are typically fabricated using stainless steel for chemical compatibility and longer life. • Tube to tank connections are welded inside and out to prevent solution leakage. Heat tube attached to tank . Inside

Outside

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Heated Solution Tanks should have:

If tubes are heated from direct combustion:

• Keep combustion systems properly tuned to: • Maintain uptime with reliable heating. • Maintain maximum burner efficiency. • Prevent rich flame with unburned gas that results in sooting.

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Tank Design – Maintenance Tanks should have: • Easy open tank lids for regular maintenance and inspection.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Maintenance Tanks should have: Large pump screens to isolate the pump inlet from large particulate that could cause pump damage or clog lines and nozzles.

Double screens so screens can be cleaned one at a time without allowing debris from entering pump.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Maintenance Tanks should have:

Removable sludge dams to keep heavy sludge and debris away from pump suction and removed during major maintenance for easier cleaning.

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Tank Design – Maintenance Tanks should have: Gutters the length of the tank ahead of screens for trapping oils and floating debris .

Gutter the length of the tank. Drain lines.

Overflow drain lines fed from gutters extending out of the tank to main drain (downstream of the main valve).

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Maintenance Tanks should have: Properly designed compartment for easy pump removal and maintenance.

Pump Compartment

Inside

Outside

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tank Design – Maintenance Tanks should have: Pressure gauges for monitoring pump delivery.

To prevent damage to gauges from pressure spikes, use liquid filled type.

Label operating pressure range for good maintenance.

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Tunnel Design – Exhaust Tunnel should have: • Exhaust at entrance and exit of washer to reduce chemicals exposure in the plant area from being carried out through steam and mist.

Shields below exhaust reduce dripping of solution on the parts while entering and exiting the washer.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tunnel Design – Drains

Tunnel should have: Pitched drain decks on the entrance and exit of the washer draining back to the tanks to reduce solution outside the washer. Pitched to tank.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tunnel Design

Tunnel should have: Shrouds on the entrance and exit walls and between stages to reduce over spray. Shrouds to reduce over spray.

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Tunnel Maintenance

Riser & Nozzle Maintenance Installing manual valves on the bottom of risers allow for fast and frequent dumping of sludge that accumulates at the bottom. Typical on all risers.

Always use components compatible with the chemicals used.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tunnel Maintenance

Riser & Nozzle Maintenance Installing quick disconnects between the risers and headers can decrease maintenance time if the riser has to be removed.

Typical on all Tank 1 Return Pumprisers.

Use metal risers, and quick disconnects where hot solution is being pumped

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Tunnel Maintenance Riser & Nozzle Maintenance Installing snap on nozzles on all risers to decrease maintenance time when checking for plugged or worn nozzles.

Tank 2 turn Pump Tank 1 Return PumpTypical on all risers.

Guard risers and nozzles from contact with hanging parts.

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Washer Safety

Safety Grating Safety gratingTank should 2 Return be installed Pump over tanks for personnel to safely perform maintenance. On catwalks and landings. Tank 1 Return Pump

Over tank openings.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Washer Safety

Safety Grating Safety gratingTank should 2 Return be installed Pump over tanks for personnel to safely perform maintenance. Grating should extend to within 6” Tank 1 Return Pump from walls to prevent personnel from stepping off the edge into the tank.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Washer Safety

Guarding Guarding should be in place to protect personnel from harm.

Moving shaft. Tank 2 Return Pump

Hot exhaust flue pipe.

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Washer Safety

Ladders and Landings Ladders are required for personnel to have access to areas.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal

Washer Safety Newly Ladders and designed lift Landings system for Safe access is safe and required for efficient personnel to nozzle have access maintenance to higher . areas.

Courtesy of Belco Industries, Inc.

Design & Maintenance of Pretreatment Washers for Non-Ferrous Metal Thank You and Please Operate Your Die Cleaning

Process

Belco Industries Inc. 9138 W. Belding Rd. Belding, Michigan 48809 USA

Phone: 616-794-0410 Fax: 616-794-3424 Web: www.belcoind.com

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