A coating system can be broken down into several discreet subsystems that include surface preparation, application, curing and material handling. The equipment used in these processes depends on the type of coating used, the volume and size of products and several other variables.
Each stage in the coating process and each independent piece of equipment can be further divided by function and design. Times, pressures, temperatures, physical dimensions and many other design variables will impact the success or failure of the coating system. Success at its peak is a high-quality finish that meets or exceeds customer expectations and is produced consistently at the lowest possible cost. Failure is not satisfying customers and producing parts with a coating that does not look like it should or perform as it should. Failure of the finishing system increases cost and reduces production capacity.
Each component in the system is critical if the system is going to be a success. Knowing this, it is logical to think that most systems are designed and built with features that accurately fit the parts to be run, and that they are compatible with the expectations of the company that is purchasing the system. Alas, nothing could be further from the truth. In fact, many systems are not a good fit for the parts they are intended to run, they often do not meet the minimum production needs of the company, and they may not be able to produce the level of quality needed.
To avoid serious deficiencies, a company needs to work closely with the supplier to construct accurate design specifications. A good supplier will diligently collect the necessary design information and help provide the buyer with a specification for procurement of the system that considers each component in each piece of equipment and satisfies their needs.
Finishing systems are built at many different levels, from a simple batch operation to a large conveyorized line. Some lines are simple enough that a company can acquire the equipment and install it themselves. Most of the larger coating lines are built by companies that specialize in designing and building complete “turnkey” finishing systems.
Turnkey methodology
These “system houses” often use a standard format to develop the design information and prepare a proposal. KMI Systems Inc. (Crystal Lake, IL) has developed an aid to this purpose that they title “Generic Procurement for a New Powder Coating System.” While the document is created for powder systems, the same framework can be adapted to any other coating technology.“We wanted to create a method we could use to help out customers accurately outline their needs,” says Kevin Coursin, president of KMI. “They often have different levels of understanding of systems and they do not always have a firm grasp of what it takes to meet their goals.” He indicated that an initially poor definition of the system requirements might lead to inequalities, such as bids with different items and big price differences, in the resulting bids. The specification document helps level the playing field and ensure that the customer has a clearly defined set of goals for system design and performance.
George Koch Sons (Evansville, IN) has a similar document it uses for putting together a proposal, its five-page “Koch RFQ.” “It’s extremely valuable,” says Don Miller, regional sales manager at George Koch Sons. “It’s a vehicle for transferring information from sales into our estimating department so that they have all the tools and information they need to do a job.”
As with KMI’s form, George Koch Sons’ form goes into lengthy detail about everything from all aspects of the building in which the system will be installed to all the details about the products to be coated and the coatings to be used. Production rates, insurance information and chemical and paint suppliers are other critical pieces of the puzzle.
“We find out who their current or proposed chemical supplier is and determine what the washer schedule is going to be,” Miller says. “That includes how long the wash stage should be, how many rinses, whether zinc or iron phosphate will be used, whether a sealer is needed, whether a DI or RO system will be used and what kind of heating system is needed. There are associated costs and benefits with those things.”
“If someone doesn’t know what the washer schedule is, we’ll assist in locating one or two or three chemical companies for them to talk to,” Miller says. “We have a good idea of what is needed in most cases, but it’s really dictated by the chemical peoplewhat they want for the kind of finish the customer needs.”
Klaus Lachmann, sales manager, Eisenmann Corp. (Crystal Lake, IL) agrees about the importance of the chemical supplier. “Turnkey system builders are equipment builders; we’re not paint or chemical people. That part of the equation has to come from the customer for from suppliers. We’re smart enough to know what a typical process would be but, to be sure, you need the interaction of the chemical and paint people.”
But when it comes to forms, “Every company operates differently,” Lachmann says. Eisenmann doesn’t use a single, lengthy, formal report but rather less-formal, internal forms that are usually system-specific.
The use of forms “is really up to the individual,” Lachmann says. “After you’ve done it 30 years, you know what you need. There’s no form that’s going to take you to the point of developing the optimum systemyou have to have the knowledge.”
Either way, the important considerations seem to be basically the same. In some cases, however, there is less choice in what a finished system will look like. For example, automakers will provide specifications to their suppliers of what is required.
Pulling it all together
Documentation is designed to identify the needs of a particular company and define the processes that will be necessary to meet the product goals. It begins with a project overview to describe the basic features of the equipment that will make up the system and then breaks each piece of equipment down into a specification. Each major piece of equipment is listed with the data that will govern the overall design. An example of an initial list is shown in Figure 1.A similar list is constructed that includes all of the customer-supplied features for the system. This could include concrete work, utility requirements, building modifications, waste-treatment equipment, racks and hangers, water, chemicals and other materials needed to get the system operational.
With these two lists, the provider of the system and the customer have clearly defined responsibilities, and both of them can refer to the list to plan the project and organize the installation.
After the overview is developed, it is time to identify the specific design parameters that will be used for sizing the system. This list will include:
- Production days per year
- Production minutes per shift
- Design hook centers
- Hooks per minute
- Design conveyor speed in fpm
- Maximum part or rack height
- Maximum part width across the rail
- Maximum part length in the direction of travel
- Size of product opening
- Design part weight per hook
- Design rack weight per hook
- Total conveyor load per foot
Insurance standards (Standard, Factory Mutual, Industrial Risk Insurers) and utility requirements (water, natural gas, electricity, compressed air) are also listed.
After the background design information is complete, the designer can begin to create specifications for each piece of equipment. This will include physical dimensions, metal gauges, number of nozzles, Btu, pressures, CFM and other data that define the specific piece of equipment and its features. It also includes a list of valves, filters, gauges and other devices that will provide functions for the equipment and describe how they will work.
The equipment specification is an in-depth description of what features the system will have and how they will work. It is critical to provide detail in this section, which covers every function of the system. Figure 2 is an example of the kind of information listed in this specification to show metal gauges and materials of construction for the spray washer.
In the next section of the specification, the supplier provides a list of the documentation that will be provided with the system. This includes a concept drawing, project schedule, electrical and mechanical approval drawings, service manual and, finally, “as built” drawings at the end of the project.
In the KMI specification, the information developed in the specification is used to prepare the system proposal, and the prices are added at the end. A list of possible options is also added with the itemized cost for each option.
This is one organized method of developing a well-constructed specification and bid package. A company that is in the market for a coating system needs to be sure that they are working with sound information on the parts, production requirements and quality goals to make the system specification accurate. With accurate input information, they should be in a good position to ask for bids and receive comparable proposals that reflect the standards established. This can make it a lot easier to review bids from different companies and make a fair comparison.
