PLURAL COMPONENT PROPORTIONING SYSTEM FOR EPOXY PAINTS
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| Overview: | Plural component proportioning
systems are self-contained epoxy paint proportioning and mixing systems.
These systems provide proper mixing and precise generation of the paint
required by an application and consequently generates minimal waste.
Epoxy paint mixtures are prepared by premixing a base and a catalyst, and combining them in appropriate proportions in a separate container. After mixing and waiting the specified time, application of the paint to the workpiece may proceed. Epoxy paint ingredients have a limited pot life once mixed, which cannot be exceeded without affecting the characteristics of the paint. If the pot life is exceeded, the mixture must be disposed and the application equipment must be cleaned with a solvent. Under conventional methods, the mixture is prepared by hand. This frequently results in the generation of excess paint, which requires solvent cleanup and disposal of the paint and solvent as a hazardous waste. Proportional paint systems are also suitable for polyurethane paints and should have many of the same benefits of epoxy paint mixtures. An additional benefit is that since the mixing is automated it also tends to be more accurate and consistent than conventional mixing systems. Plural component proportioning systems are used in conjunction with application devices. The proportioning and application system layout typically includes the following components: 1) proportioning pump module, 2) mix manifold, 3) mixer, 4) application device, 5) material supply module, and 6) purge or flush module. These systems optimize painting operations by maximizing efficiency and minimizing waste generated. The plural component proportioning system for epoxy paints provides total control of materials from container(s) to the application. They are accurate and can provide more consistent material quality than hand mixing. These systems can also keep pace with higher production requirements. They mix on demand (i.e. as the gun is triggered), which results in no significant quantities of wasted materials. Material cleanup requires less labor and maintenance, and generates less waste because the mixed material can be purged with solvent from the mix manifold, mixer, hose, and applicator before it cures. The plural component proportioning system is a closed system and as a result, there are fewer spills, less contamination or waste to clean up, and less contact between personnel and potentially hazardous materials. In addition, the proportioning system makes bulk purchase of material practical. If an epoxy paint requires a significant induction time (15 minutes or longer) the plural component proportioning system can still be used, provided that the mixed paint is allowed to stand in a separate container prior to application. A PrecisionMixTM (P-Mix) controller for the plural component proportioning system may also be implemented. The P-Mix controller is an electronic system that continuously mixes resin and catalyst at a pre-selected ratio in small batches, delivering the mixed material on command. The P-Mix can detect ratio problems and prevents off-ratio coatings from being applied. This often results in a significant reduction in rejection rates. The P-Mix system also reduces the time required for color changes, because the required mix ratios are entered electronically. All materials are contained in the system; the electronic control allows color changes and flushing to take place without exposing the operator to hazardous materials. The P-Mix system can also generate hard copy reports for environmental and product usage information. Some of the operating parameters reported are flow rate, mix ratio, resin usage, catalyst usage, and solvent usage. No new waste streams are generated using
Plural Component Proportioning Systems as compared to conventional methods.
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| Compliance Benefit: | Use of an automated process
to mix epoxy paint immediately prior to using the plural component proportioning
system reduces the volume of chemicals used and waste generated. The process
provides for the following compliance benefits:
The compliance benefits listed here are only meant to be used as a general guideline and are not meant to be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g. the amount of workload involved.
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| Materials Compatibility: | Material specification data for the epoxy paint materials needs to be evaluated, with respect to the proportioning and application system components, prior to specification of the actual system to ensure material compatibility. The materials used for the pumps and packings need to be evaluated on a case-by-case basis. Stainless steel and Teflon® components do not pose compatibility problems with most materials used in epoxy paint operations. |
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| Safety and Health: | Health concerns depend on
the variety of paint that is used. The use of polyurethane paints requires
implementation of precautions associated with isocyanates. Inhalation of
lead- and zinc chromate-based paints can lead to irritation of the respiratory
system. Some lead compounds are carcinogenic. Solvent-based paints can irritate
the lungs and mucous membranes. Prolonged exposure can affect respiration
and the central nervous system. Proper personal protective (PPE) equipment
should be used. These safety and health issues are also applicable when
using conventional methods.
Consult your local industrial health specialist,
your local health and safety personnel, and the appropriate MSDS prior
to implementing this technology. |
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| Benefits: |
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| Disadvantages: |
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| Economic Analysis: | Capital costs for plural component
proportioning systems can range from $50,000 to $70,000 for systems that
mix multiple materials or $6,000 to $7,000 for basic units that mix two
materials. Application systems are additional and their capital costs can
range from $500 to $5,000. Each application needs to be evaluated on a case-by-case
basis with respect to material and labor costs and savings.
The following is an example of the replacement
of a hand-mixing paint operation with a relatively simple Plural Component
Proportioning System. |
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| Assumptions: |
Annual Operating Cost Comparison for Plural Component Proportioning System and Hand Mixing System
Click Here to View an Active Spreadsheet for this Economic Analysis and Enter Your Own Values. To return from the Active Spreadsheet, click the reverse arrow in the Tool Bar. |
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| NSNs: |
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| Approving Authority: | Approval is controlled locally
and should be implemented only after engineering approval has been granted.
Major claimant approval is not required.
In the Air Force, approval authority is
local and does not require engineering approval. The authorization for
use of this equipment is being added to T.O.1-1-8. |
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| Points of Contact: | Navy: Mr. Scott Mauro Naval Facilities Engineering Service Center, Code 423 1100 23rd Avenue Port Hueneme, CA 93043-4370 Phone: (805) 982-4889, DSN: 551-4889 FAX: (805) 982-4832 Email: maurosm@nfesc.navy.mil Air Force: Mr. John Lindsay |
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| Vendor: | The following is a list of
plural component proportioning system manufacturers. This is not meant to
be a complete list, as there may be other manufacturers of this type of
equipment.
Graco Inc. Binks Manufacturing Company Fluid Air Products (Government Distributor) |
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| Source(s): | Mr. Jeff Smith, DeVilbiss
Ransburg Industrial Liquid Systems, Toledo, OH Mr. Carl Springer, Binks Manufacturing Company, Franklin Park, IL. Mr. Vern Novstrup, NFESC, 11/99. |
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