Process Control: The Role of Technology
Adopting new production technologies may also require substantial changes in other parts of the manufacturing process. For example, installation of automated pressure casting will probably require tighter control of raw materials, possibly the development of new casting slip formulations, and tighter control of casting slip properties.
The BenefitsNew technologies can result in increased production rates, lower labor input, improved product properties and performance, lower unit costs, lower scrap rates, and improved yields in downstream processing. Pressure casting can, for example, result in lower firing losses if properly used. Such technologies may or may not simplify the lives of the process control personnel, but they certainly can-and should-result in better and more consistent control.
A partial list of some of these technologies is included below. As you read through it, note how well (or not) your company performs in each area, and how processing and control might be improved. (Obviously, not all of these technologies are applicable to every situation.)
- Very tight control of raw materials. Working with vendors is critical, and new instrumentation aids in routine evaluation. Asking for both tighter control and lower costs is probably counterproductive.
- Computer-controlled automated batching. Precision batching is indispensable in keeping body composition consistent.
- Tightly controlled spray drying.Spray drying allows the production of free-flowing powder, which is important for controlling automated pressure fabrication processes.
- High-intensity mixing. This can speed production and produce more consistent material. It can sometimes be used to "mimic" the spray drying process to produce free-flowing powder.
- Isostatic pressing. Originally used for advanced ceramics, this process is now used to produce conventional products like tableware, speeding production and minimizing drying.
- Automated high-pressure slip casting. Not only can this reduce labor costs, it can speed throughput and improve uniformity.
- Automated, high-volume hydraulic presses for pressure fabrication. Higher production rates and more uniform pressed ware can result.
- Modern drying technology, perhaps including microwave drying. Throughput can be improved, energy use decreased, and losses at this and subsequent production steps reduced.
- High-volume, versatile roller decoration. Not only does this improve throughput and quality, it offers great latitude in the marketplace.
- Robotic glaze application. This replaces a tedious, potentially hazardous operation and can improve uniformity and lower labor costs.
- Pulse firing systems. Kiln control and uniformity are improved and energy consumption decreased. More control zones are easy to incorporate, and these zones can be much more easily changed.
- Computer-based kiln monitoring and control. The computer offers the ability to monitor and control many points and functions in real time, as well as to maintain a database of information.
- Kiln temperature profile monitoring using undercar sensors. This provides an independent method of monitoring the temperature profile and especially the temperature uniformity at the ware being fired.
- Fiber-lined kilns, including tunnel kilns. Such kilns are more versatile and potentially more uniform, resulting in better control, lower energy consumption and greater firing flexibility.
- Roller hearth kilns. For certain types of ware, these kilns improve efficiency by removing kiln furniture and shortening the firing cycle.
- Fast firing schedules. Faster firing can improve throughput, but it requires much tighter control of the upstream processing, as well as the firing process. New body and glaze compositions and/or changes in ware geometry may be needed.
- Automated kiln loading and unloading. This can decrease labor costs, reduce physical stress or injuries to workers, and lower ware losses.
- Modern test instruments. Instrumentation is available for slip viscosity, surface area determination, particle size distribution measurement, moisture content, non-destructive testing, chemical analysis and dimensional evaluation. Testing can substantially tighten process control, make data more timely and reduce control-related labor costs.
- Sophisticated database logging. Today's technology enables the tracking of production and process control data at all production steps, as well as the generation of control charts and reports. This can be the heart of a much more sophisticated statistical process control capability.
- The Internet. The Internet offers a wealth of opportunities for personnel training, keeping abreast of technology, communicating with vendors and customers, etc.
Maintaining an EdgeIf you've been following industry news, you've realized that manufacturers in low-cost-labor countries like China, Thailand, Indonesia, South America and others are building new facilities or upgrading older ones with the most modern equipment and technologies from Italy, Germany, the U.S. and elsewhere. The combination of the best technologies with low labor costs is potent, to say the least.
New technologies can result in improved processing and tighter process control, but they require financial investment, time, planning, training, thought and careful integration. However, in this highly competitive global economy, companies that do not continually upgrade to the most appropriate new technologies will eventually cease to exist. That's the most negative form of process control there is!