In Loss-in-Weight Feeding
22.214.171.124 – Photo 126.96.36.199 – Suspension/Platform ArtThe need to accurately and continuously weigh in a process environment presents specific challenges to a loss-in-weight feeder.
In Weigh Belt Feeding
188.8.131.52 – Photo 184.108.40.206 – Thru the Belt Schematic 220.127.116.11 – Auto Tare SchematicThe need to accurately and continuously weigh in a process environment presents specific challenges to a weigh belt feeder.
Key to gravimetric feeding, weight measurement provides the means to "close the loop" on feed rate control. This section details the unique challenges faced in precision weighing in the process environment, and profiles the technologies and application considerations surrounding this crucially important contributor to feeder performance.
The second leg of the gravimetric feeding triangle, weighing, refers to a feeder’s on-board measurement of this crucially important variable, essential to the accurate determination and control of gravimetric feed rate.
This section begins with the core challenges faced in the weighing operation. Next, the three most prevalent current technologies in weighing are introduced: the vibrating wire, the strain gauge, and the linear variable differential transformer, or LVDT.
And in the last three sections, weighing issues are detailed for each type of feeder operating principle (loss-in-weight, weigh belt and weigh meter) commonly employed in plastics processing.