Following are specific recommendations for preventing pollution in your fiberglass operations. You can also view common pollution prevention methods that apply to all types of business by clicking on the category "hyper links" further down this page.


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Good Housekeeping (Click here for common p2 methods that apply to all types of business)


Use recyclable floor sweeping compound reduces amount of resin and solvent contaminated floor sweeping


Maintenance (Click here for common p2 methods that apply to all types of business)


Purchase and Inventory (Click here for common p2 methods that apply to all types of business)


To reduce rejected and/or excess raw materials: improve inventory control purchase materials in smaller containers return unused materials to suppliers


Material and Waste Storage (Click here for common p2 methods that apply to all types of business)


Cover solvent containers reduces air emissions prevents contamination with water

Segregate wastes such as chlorinated from non-chlorinated solvent, aliphatic from aromatic solvent, wastewater from flammables. makes solvent waste easier to recycle


Basic Operations (Click here for common p2 methods that apply to all types of business)


To reduce equipment cleaning wastes:

  • place the solvent container near the resin spray area
    • prevent drippage and spills when cleaning tools
  • clean equipment before resin dries
  • restrict solvent use by limiting the quantity issued each shift
  • schedule production runs together and schedule families of products in sequence
    • minimizes cleaning between batches
  • store and reuse solvents until the high concentration of resin contamination prevents effective cleaning
  • reduce solvent rinse usage
    • use small lab-type wash bottles for treater pan cleanouts
    • use squeegee tools for treater and vessel cleanouts and press the squeegee against the vessel walls to force the remaining resin to the bottom for collection
    • use a two-stage cleaning process where dirty equipment of tools are first cleaned in dirty solvent, followed by a clean rinse with a smaller volume of fresh solvent. Recycle the dirty solvent when it reaches the maximum level of contamination and replace with the accumulated "clean" rinse solvent.

Limit quantities of raw materials and products for testing and analysis reduces laboratory and research wastes


Equipment Changes (Click here for common p2 methods that apply to all types of business)


To reduce scrap solvated and partially cured resins:

  • Modify resin pan geometry
    • Pan widths should be no more than 10 inches wider than the fabric. If a narrow width fabric is run in an unnecessarily wide pan, additional solvated resin is wasted. Install adjusting devices made to fit into treater pan to reduce its volume and occupy the treater pan volume when coating narrow fabric.
  • reduce transfer pipe size
    • reduces the amount of resin discarded from the pipe connecting the mix tank to the treater tank.
    • disadvantage: requires detailed hydraulic analysis and possibly pump modifications to ensure that an acceptable flow rate is maintained.


Material Substitution (Click here for common p2 methods that apply to all types of business)


Use less toxic and volatile solvent substitutes in the curing process and/or for cleaning. There are commercially available substitutes that are biodegradable, water-soluble, resin bed compatible and recoverable. reduces air emissions

Replace organic solvents with emulsifiers. The emulsifier is an alkaline mixture of surfactants, wetting agents, and various proprietary ingredients which can often be disposed of in the sanitary sewer. virtually no air emissions biodegradable non-flammable there are claims that emulsifiers last twice as long as solvents disadvantages: some emulsifier concentrates may contain solvents, dissolved metals, silicates, and phosphates that make them unacceptable in some sewage systems. Different cleaning techniques must be employed when using emulsifiers, so adequate instruction of both management and workers is essential.

Resin formulation can be modified to reduce the VOC emissions. In general a resin with lower monomer content should produce lower emissions. Vapor suppressions agents (e.g. paraffin waxes) also are sometimes added to resins to reduce VOC emissions.


Process Change (Click here for common p2 methods that apply to all types of business)


Employ alternate material application and fabrication techniques reduces solvent and resin spillage and oversprays

Change spray design to reduce gelcoat and solvent oversprays.

Optimizing the material application process reduces overspray and air emissions. Overspray can be eliminated or reduced greatly through simple techniques such as spray orientation and advanced measures such as equipment modification. Lower operating pressures for spray delivery systems reduces cost and maintenance of pressure lines, pumps, controls, and fittings as well as frequency and difficulty of routine cleanup of work areas. Non-spray resin application methods reduce material waste and other expenses, in particular energy purchase cost.

  • Spray Orientation- waste often accumulates around the bottom of sprayed objects because the tip of the spray gun is directed down toward the bottom of the object, rather than horizontally. Likewise, it may be difficult for the operator to shoot the top of high objects. If spraying is directed vertically instead of horizontally to the top of the object, the spray dissipates as a fine mist up to several feet away from the object. Hence, depending upon the shape of the objects, appropriate spray orientations may be developed.
  • Spray Delivery Systems - The atomization and spray patterns become more efficient, reducing excessive fogging, overspray, and bounceback for the delivery systems listed below:
    • high-pressure air system - practically obsolete due to large amounts of expensive high pressure air required. Low styrene emissions limits generally can't be met.
    • airless method - pressurized resin stream is electrostatically atomized through a nozzle with variable orifice size and spray angle. Considered to be very efficient in delivering resins to the work surface, although excessive fogging, overspray and bounceback may occur.
    • air-assisted technology - modifies the airless gun by introducing pressurized air on the outer edge of the resin stream as it exits the pressure nozzle. The air stream forms an envelope that forces the resin to follow a controllable, less dispersed spray pattern. Lower resin delivery pressure can be used since the air assist helps distribute the resin. Low delivery pressure also reduces fogging, overspray, and bounceback, which in turn reduces raw material waste. Since more resin ends up on the product, the amount of spraying is reduced, leading to a reduction in styrene air emissions.
  • Non-Spray Application Methods - although non-spray application techniques could be messy or even impossible in some cases, they merit consideration in other circumstances. The various non-spray application methods are as follows:
    • prespray fiber reinforcing (prepregs) - resin-to-fiber ratios can be strictly controlled, atomization of pollutants is practically eliminated, and cleanup and disposal problems are greatly reduced. Disadvantages are higher raw materials cost, energy requirements for curing, and the refrigerated storage needs of prepregs.
    • in-house resin impregnators appear to have considerable potential for reducing pollution associated with open molding operations. Use lower-cost polyester resins and fiberglass materials than prepregs. Can be mounted in lamination area of plant to feed resin-saturated reinforcing materials directly at the molding operations.
    • resin roller dispensers can reduce material losses due to excessive fogging, overspray, turbulence, and bounceback. Low delivery pressures help maintain a cleaner work area. External emissions and the need for high levels of make-up air are reduced. Very often existing spray gun equipment can be adapted to resin rollers.
    • vacuum bag molding allows resin delivery without atomization, with the exception of the gelcoat. Vapor emissions and odor are greatly reduced. Excess resin can be trapped and dust-generating operations are minimized.
    • closed molding systems practically eliminate requirements for atomization of resins and may offer a number of production advantages over conventional approaches to molding. Eliminates fogging, bounceback, and overspray and reduces vapor emissions and odor. There is little, if any, waste resin. Dust-producing operations are reduced.


Recycling & Waste Exchange (Click here for common p2 methods that apply to all types of business)


Minimize solids concentrations to allow for efficient solvent reclamation.

Have you looked into purchasing your own solvent distillation unit?

  • Commercial solvent recovery units are available in various sizes. Most pay for themselves in less than 2 years.
  • reduces solvent purchases.
  • reduce the amount of waste that has to be managed.

If you don't reclaim solvent through distillation, does your hazardous waste handler reclaim solvent?

  • Contract with a solvent tank maintenance service to come to your business periodically. They will remove the solvent and sludge from your tank and replace it with clean solvent.
  • Or, spent solvents can be sent off-site to a commercial recycler.

Waste exchange scrap solvated and partially cured resins


 




The majority of information in this section comes from Guides to Pollution Prevention: The Fiberglass-Reinforced and Composite Plastics Industry, EPA Office of Research and Development, October 1991, EPA/625/7-91/014
University Outreach

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Office of Waste Management
Marie Steinwachs, owm@missouri.edu

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