『Low Flow Meter For Adhesive Dispensing Viscosity Limits』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)
Low Flow Meter For Adhesive Dispensing Viscosity Limits
Quick Answer: For most adhesive dispensing applications with very low flow, you face two practical viscosity limits. An oval gear meter works reliably up to about 50,000 cP without heating, while a Coriolis mass flow meter reads from 0.05 kg/h with no upper viscosity cap in real terms. If your process runs hot melt adhesives above 100,000 cP or demands shot accuracy under 0.1 ml, choose a micro Coriolis meter from Silver Instruments instead of a gear meter.
We have seen this on customer sites many times. A gear meter set to dispense UV glue at 80,000 cP without a jacket starts slipping 3 to 5 percent within two weeks. In practice, engineers skip the gear option once they cross 30,000 cP at room temperature.
Why Viscosity Decides the Meter Choice for Low Flow Adhesive
Adhesive viscosity changes the Reynolds number and the pressure drop inside a flow meter. An oval gear meter counts discrete pockets of liquid. When the fluid is too thick, the meter needs extra inlet pressure to fill the pockets fully. Below a certain pipe velocity, the gear pair can spin without a complete fill, so the output signal drifts low by 0.5 to 2 percent. That error is painful in SEM glue or a two part epoxy bead line where a 15 gram shot must stay within 0.1 gram repeatability.
Coriolis mass flow meters behave differently. The micro bend tubes oscillate and sense mass directly. They do not need viscosity compensation tables. A Silver Instruments micro Coriolis model like the SI-CMF010 measures 0.05 kg/h to 30 kg/h across a viscosity range of 0 to 100,000 cP with the same ±0.2 percent accuracy. You can switch from a 2,000 cP acrylic adhesive to a 70,000 cP silicone sealant and keep the same setpoint on the 4-20 mA HART output. No recalibration.
Real Viscosity Limits and What They Look Like in Numbers
Oval gear meters we supply, such as the SI-OG004 DN4, handle 0.1 L/h to 20 L/h with a factory accuracy of ±0.5 percent for adhesives between 5 and 50,000 cP. Once you push past 50,000 cP, the pressure loss jumps. At 100,000 cP, the pressure drop across a DN4 oval gear meter can exceed 4 bar, which collapses flexible adhesive feed lines. You add a heating jacket, drop viscosity to 15,000 cP at 45 °C, and the meter runs within spec again.
A Coriolis tube does not mind that range. Our SI-CMF015 runs from 0.1 kg/h up to 60 kg/h. We have tested it with a hot melt polyurethane adhesive at 180 °C and 220,000 cP, feeding a robot head in a car window bonding
_600x400.jpg)
How to Avoid Pressure Drop and Cavitation in Thick Adhesive Lines
Most engineers skip this part. Low flow dispensing with high viscosity needs a short, straight pipe run and a flow conditioner if you use a Coriolis meter. Oval gear meters prefer a Y strainer upstream because cured adhesive flakes destroy gear tips within days. Keep the meter body warm. A 50 watt heating band on a DN6 oval gear meter body prevents cold spots that raise viscosity locally and slow the gears. The Coriolis SI-CMF010 has an integrated PT100 for temperature monitoring so your PLC can alarm before the adhesive gels inside the tubes.
For very low flows under 0.01 kg/h, even micro Coriolis tubes face a signal to noise issue. Here is the thing. You can pulse dose and average the mass totalizer over 10 cycles. A sealant plant in Indonesia runs that method with our SI-CMF010 at 0.008 kg/h and holds shot mass variation under 0.5 percent.
Frequent Questions About Low Flow Meters for Adhesive Viscosity
What is the lowest flow rate a Silver Instruments oval gear meter can measure for high viscosity glue? The SI-OG004 DN4 records from 0.1 L/h with a minimum viscosity of 10 cP and a maximum of 50,000 cP without heating. Below 0.1 L/h, slip becomes too large.
Can a Coriolis meter handle hot melt adhesives above 200,000 cP? Yes. Our SI-CMF020 is rated for media temperature up to 200 °C and tested with viscosity up to 500,000 cP. The flow range starts at 0.2 kg/h.
Do I need a flow straightener for an oval gear meter on adhesive? Not normally because positive displacement meters are insensitive to flow profile. But you must install a 100 mesh strainer before the gear pair. Hard particles score the chamber and ruin accuracy.
Which meter gives a 4-20 mA mass flow and density output in one device? Only the Coriolis meter. The SI-CMF010 outputs mass flow, density, and temperature over a single HART loop. This helps you catch wrong mixing ratios in two part adhesives fast.
What information do you need to quote a low flow adhesive meter? Send us your adhesive type, operating viscosity in cP at working temperature, pipe size (DN), flow range in kg/h or mL/min, and process pressure in bar. Our team will propose an SI-OG or SI-CMF model with a price within one working day.
Hot Blog
Related AD
