WASTE REDUCTION - POLLUTION PREVENTION IN THE FURNITURE INDUSTRY POLLUTION PREVENTION WASTE REDUCTION FOR INDUSTRIAL AIR TOXIC EMISSIONS APRIL 24-25, 1989 FOUR SEASONS HOLIDAY INN GREENSBORO, NC BY VINCENT R. ROSS, PRESIDENT ROSS ASSOCIATES, INC. 33 MINERAL SPRINGS ROAD ASHEVILLE, NC 28805
WASTE REDUCTION-POLLUTION PREVENTION IN THE FURNITURE INDUSTRY: NEW TECHNOLOGIES FOR REDUCING FINISHING WASTES AND VOC EMISSIONS Because furniture finishing products have been traditionally solvent-based, the issue of reducing wastes from finishing products is bound up with the issue of reducing volatile organic compound (VOC) emissions. Currently, it is VOC emission regulation, much more than a concern about reducing wastes, that is driving whatever movement there is in the industry toward substitute finishing products and technologies. Furniture finishing, as it relates to high quality residential furniture, involves a process which may consist of 30-35 steps. The process may iklude application of various kinds of stains, fillers, glazes sealers, wash coats, and top coats which are used to achieve a specific and distinctive final appearance. It is this distinctive appearance that the furniture maker is selling, and the process used to achieve this look is crucial. In many cases, the individual finishing processes have evolved over long periods, perhaps 50 years, and represent substantial investments on the part of the manufacturers in time and process research. The processes were developed using very specific finishing products, and while some modern finishing products-- stains, for instance--may be acceptable substitutes for older ones, in many cases substitutions dramatically alter the appearance of the finished product. This is particularly true in the case of top coatings: substituting the more recently developed water-based coatings for organic solvent-borne coatings upon which the processes were originally based may change the entire process and alter the distinctive appearance of the final product. Although some of the major finishing product manufacturers have worked on developing water-based top coats, they have been unable to achieve the clarity that many furniture manufacturers need.
i. Some Segments of the Furniture Industry Can Take Advantage of Alternative Coating Technologies Manufacturers of contemporary furniture--particularly contemporary furniture with high-gloss finishes, which is essentially constructed from panels that lend themselves to flat-line finishing, can now rely on largely non-polluting finishing processes such as ultraviolet curing and/or electron beam curing. These processes can help certain segments of the furniture industry reduce finishing wastes because they use high-solid materials and very little solvent to produce almost instantaneous cures. These processes are not suitable, however, for finishing carved furniture such as the Chippendale style. Metal furniture can be finished using powder coating and electrostatic application techniques, which again use very little solvent. Many manufacturers of juvenile furniture also successfully use electrostatic finishing. In juvenile furniture, the concern is not so much with the quality of the finish as with its non-toxicity. These processes, however, are not applicable to high-quality, fashion furniture. So, some segments of the furniture industry can significantly reduce their use of solvents and therefore their generation Of solvent waste. However, there are few substitute products or techniques manufacturers of high-quality residential and office furniture can take advantage of, and there seems to little cooperation between the furniture makers and the manufacturers Of finishing products to develop acceptable substitutes. The furniture makers take the position that when something satisfactory is available, they will use it, and the finishing products manufacturers take the position that it is not reasonable to expect them to make the entire investment in research and development since they can sell their current products with no problem.
Breaking out of this stand-off may require that furniture industry associations, such as the American Furniture Manufacc turers Association or the National Kitchen Cabinet Association, # get out front and take a proactive position on the waste reduction issue. The industry may also need help in encouraging wider adoption of the available successful techniques from universities, where a lot of the technology resides but has not been transferred. The cause of waste reduction needs to be given impetus in the furniture industry because it is going to become necessary, and there is no use in waiting until our backs are against the wall to respond.. Waste Disposal Problems Can Create Unexpected Crises for Manufacturers Recently I visited a furniture plant which had just received word that the supplier of the rags used in the company's wiping stain process is going out of business. The rag supplier had also been laundering the rags and had been told that their waste water treatment plant can no longer comply with EPA regulations. The furniture manufacturer was faced with re-evaluating its entire finishing process, which it had been using for many years, in two weeks. Another substance that the furniture industry is going to have to deal with soon is urea formaldehyde. Most of the glue that is used in production gluing such as veneer or plastic lamination, is based on urea formaldehyde. Regulations regarding this substance have become very stringent, about one part per million, and that's almost zero. Furniture manufacturers are going to have to address both the emission of VOCs from finishing products and glues they use and the disposal of wastes form these products. Still, no one has taken the initiative to aggressively address the issue. 3
Some processes that are beginning to offer partial solutions to VOC and waste problems for furniture manufacturers are the new high-tech coating methods, some of which I referred to earlier. AS I have explained, these new methods are excellent for some uses but totally inadequate for others, so they are not a cureall. However, solving the problems we can solve is a first Step, and more widespread adoption of these processes would certainly have benefits. The coating methods to which I refer are as follows: 0 Electrostatic spray coating uses the attractive force between materials of opposite electrical charge to aid in applying a uniform coating to various surfaces. This method reduces overspray and waste, thus improving application efficiency over ordinary spray coating processes. Organic emissions are reduced because of this efficient procedure. For solvent and water-borne coatings, the amount of coating solids and corresponding solvent carrier needed for a specific coating job are also reduced. Electrostatic spray coating is used to apply solvent-borne, water-borne, or powder coatings. 0 Hot melt formulations are applied in a molten state. There is no solvent to evaporate so about 100 percent of the materials that are deposited remain as a solid part of the coating. Hot melt coatings are most often applied to paper, paperboard, cloth, and plastic. Because hot melts work only for certain purposes, they cannot be judged universally applicable in the paper and fabric coating industry. 0 High-solids coatings reduce solvent emissions. The basic ingredient in an organic coating is the binder or 4
resin, which is a film-forming organic polymer with glassy, plastic, or rubbery properties in the dried state. There are two categories of high solids resins: two component ambient temperature cured, and single component heat converted. High-solids coatings can be used to reduce solvent emissions in a variety of industrial coating processes. 0 Electron beam curing is a process in which high energy electrons are used to cure electron beam-curable coatings. Electrons bombard a coating and produce free radicals throughout the coating, thus initiating a cross-linking reaction that continues until the coating is cured. This process is most effective on flat surfaces where the electron beam strikes the surface vertically. If the beam strikes the surface at an angle closer to horizontal, the amount of absorbed energy is too small and causes the coating to cure improperly. 0 Ultraviolet curing is a process in which ultraviolet light reacts with photosensitizers in the coating to initiate cross-linking to form a solid film. The main components of an ultraviolet curable coating are an ultraviolet-curable base polymer, diluent monomers, and ultraviolet photochemical initiators. Ultraviolet light for curing is useful and effective on flat surfaces where the light reaches the surface vertically. When the ultraviolet light strikes a surface at an angle closer to the horizontal, the amount of absorbed light is too small for effective curing. 5