A new revolution has begun in filling of high value liquids in rigid containers (bottles or jerry cans) across Asia, with the market leaders moving to “Net weight filling” technology over other volumetric fillers.
What is Net weight filling technology?
Net-weight filling technology is amongst a host of filling systems available in the market, along with level, volumetric, piston and gravity fillers. What makes Net-weight filling systems different from the rest is the fact that it doses the quantity of liquid being filled by measure of weight. Using a load cell mounted directly underneath the loading plate, net-weight filling system guarantees the highest accuracy of filling vis-à-vis other filling systems in the market today.
Which products are best suited for this technology?
The net-weight filler is particularly apt for markets where the product is expensive, delicate, abrasive or aggressive in nature. Such products in the food & beverage market would include edible oils, sauces, syrups, dressings, dairy products, and flat alcohol drinks to name a few. It is the filling system to give the fastest return on investments.
How does this technology work?
Essentially, the way net-weight filling works is like having an advanced electronic weighing scale underneath the bottle to tell you how much product you have filled into the bottle. Firstly, the load-cell is controlled by an electronic card which would feedback each filling cycle. This feedback is used to auto-correct itself using a well designed algorithm for the next cycle. This is critical because product properties change due to change in temperature and pressure, which could directly affect the ‘in-flight’ product and hence the final weight. Moreover, this ensures that each filling cycle is independent to the next. Therefore, the filler is constantly adjusting itself to attain the highest accuracy for the specified weight to be filled.
When an empty bottle is transferred onto the load-plate of the filler, the first step of the filler is to measure the empty bottle weight, also known as tare weight. The filler will record this tare weight and measure whether it is within the expected tolerance defined in the recipe. If the tare weight is outside of the tolerance, a signal is sent to that particular filling station not to fill the bottle for that cycle, and thereby reject it.
Once the tare weight is recorded and accepted by the filler, the nozzle is then actuated to fill the product into the bottle. The bottle is filled with a laminar flow. Laminar flow ensures that there is a constant flow with little turbulence during filling, which helps to avoid or reduce foaming due to product characteristics. Due to constant monitoring of filling process against a filling graph, this is also the stage where the filler is able to detect if product is leaking out of the bottle (due to leak in bottle or improper positioning of bottle). In such a case the filling graph deviates from standard. When this happens, filling is stopped and bottle reject at end of the cycle.
At the next stage after filling the bottles are measured for the final weight once the nozzle has been closed. This is the final stage of measuring the weight of the bottle with the product settled. The filler simply subtracts the tare weight from the final weight of the bottle to get the net-weight of the liquid. The filler will record the weight and calculate several data such as tolerance of the final weight and standard deviation. While the bottle proceeds to the capping station, the filling carousel continues to complete the cycle and accept the next bottle. In this process, the load cell is zero-set before receiving the next bottle.
What are the advantages of this technology?
• One big advantage of the net weight filler is that it can provide statistical data of every filling station of every cycle for information tracking & analysis such as standard deviation, mean and median weight of the bottle, or performance of every nozzle can be derived.
• Net-weight fillers are also easy to maintain, even during real-time production. If for some reason, there is a faulty load cell or a recurring issue with a particular filling head, it is actually very easy to shut-off that particular head to prevent it from filling. This can easily be done through the touch-screen panel.
• Net-weight fillers are also built to be clean and hygienic in design due to its numerous food applications. There is no contact between the nozzle and the bottle, and the filler is designed to prevent product-stagnation for hygienic reasons. It is easy to run CIP (clean-In place) and SIP (sanitize in place) cycles on the net weight filler to ensure hygienic filling.
• Ultimately, netweight filling provides greater savings for the manufacturer, which can be passed onto to the end customer in an increasingly competitive market.
Piyush Bhandari I Director
Clearpack Singapore Pte Ltd
Tel: +65 6741 4077 Fax: + 65 6741 3286
E mail: firstname.lastname@example.org