Paint formulation is tricky business. While much of a paint mixture may be of one particular color (generally white), the colored pigments must be added in precisely. Miscalculations could potentially turn a turquoise paint into an aqua paint, disappointing customers and costing the manufacturer money, not to mention tarnishing their reputation for consistency. It’s extremely important that a high precision, high resolution scale is used when measuring the components for the final paint color.
Arlyn Scales can give you the precision and resolution you need and at higher capacities than traditionally offered. We have been a leader in the scale manufacturing business for the past thirty years. Our scales offer a combination of affordability, accuracy, and durability. Our scales are made in our factory located next to our business in Long Island, New York. This situation allows us to ship factory direct to our clients, thereby saving them money since there are no markups from distributors. This arrangement also saves us money that we put back into our manufacturing process, enabling our customers to get an even higher quality scale at a price that our competition can’t match, let alone beat.
Surface Acoustic Wave (SAW) Technology and Precision Accuracy
Prior to the invention of SAW technology and the SAW load cells, the most accurate and affordable technological component of a scale was the strain gauge load cell. The load cell is attached to the scale between the platform and the bottom of the scale. Within the load cell is something called a spring element, which you can compare to a diving board. Attached to the spring element are four thin sections called flexures. Attached to these flexures are strain gages. When a load is placed on the platform, the spring element bends, which causes the flexures to bend and the resistance of the gauges to change. Since the gauges are wired together to form a Wheatstone’s bridge, there is a voltage output that changes with the resistance of the gauges. This voltage is sent through an Analog to Digital Signal Converter and is then sent to the scale’s indicator where the weight displayed.
The problem with most strain gage load cells is the material used during the manufacturing process. Many manufacturers and distributors use aluminum when constructing the load cell. However, the spring element must bend significantly to produce an accurate measurement. This combination leaves the load cell vulnerable to damage from shock and overloading as well as drifts in accuracy from temperature. While we manufacture our load cells in-house using a special stainless steel alloy, they still do not provide the extremely high resolutions required by the paint manufacturing industry.
SAW load cells are inherently better than strain gage load cells because
- An Analog to Digital conversion is not necessary
- They are less subject to distortion as the spring element is thicker
- SAW load cells are more stable over time
- They provide higher resolution and accuracy
While they feature a spring element in the load cell, there are two surface acoustic wave transducers attached, rather than flexures and strain gages. One is a transmitter while the other is a receiver. The receiver detects the SAW wave being sent by the transmitter, which is then amplified by an amplifier and sent back to the transmitter. This happens continuously to create a frequency. When a load is applied to the scale’s platform, this frequency changes. By digitally measuring the frequency, we’re able to determine the weight of the load.
High Resolution for Paint Accuracy
The high resolution of the SAW scales allows for greater accuracy in formulation, especially paint mixing. As previously mentioned, often the base paint makes up a significant amount of paint in the color formula, but in order to achieve the desired color, the colored pigments must be added. These pigments may be very small amounts, but should the wrong amounts be poured into the base due to inaccurate weighing, the final color may not be the precise shade it should be. And once, you have added the pigments, you cannot take them back. The only thing to do at this point is start all over.
Our SAW scales have a much greater resolution that a strain gauge scale. For example, a 100 lb. strain gauge scale has a resolution of 0.02 lb., but a 100 lb. SAW scale has a resolution of 0.001. If you were trying to add 0.2 lbs. of red pigment to a base paint, the strain gauge scale can only provide 10% accuracy, whereas the SAW scale can give you accuracy of half of 1% for the same pigment. The highest capacity of a Ultra Precision SAW scale is 500 pounds with a .005 pound resolution and offer a maximum resolution of .0001 at the ten pound capacity.
Automated Weight Value Triggers
Arlyn can also provide you with a setpoint controller with your SAW scale to help automate your precision paint mixing. Our optional setpoint controller enables the user to enter up to eight weight values. Once one of the weight values has been read by the scale indicator, the controller can send an electronic notification to the scale user, or a signal can be sent via a solid state relay to turn on/off equipment, such as a dispensing pump. With paint mixing, you could set up a drum on the scale container that holds the required amount of base paint. You could then enter a target weight value equaling the first pigment weight plus the base weight. We advise the weight value to be just shy of the actual target since the dispensing pump will trickle for a moment after it is shut off. You can then repeat the process for each additional pigment required. By doing this, you will be able to refine the formula and automate it, thus reducing human error and increasing consistent production of that paint color.
Precise Customer Service
We also have one of the greatest customer support staffs in the scale industry. Not only are our associates highly knowledgeable about the entire Arlyn Scales product line, but they have many years of experience in industries that use scales as well. Should you have any more detailed questions regarding SAW scales or any of our other scales for your paint formulation needs, our courteous representatives will be happy to help you. Call us today at (800) 645-4301 for more information!