Weighing is an essential component, if not the heart, of any process line. Heat and Control’s business team manager packaging Robert Marguccio writes about four key things that count when weighing. This article first appeared in the March edition of Food & Drink Business.
Weighing is a crucial part of any food or beverage production line. With this equipment it is imperative that performance and reliability remains at optimal levels, in order to protect brand names, reputation and ensure product quality while optimising profitability.
Ishida built the very first multihead weigher in the early 70s, and it was designed to weigh whole capsicums. Since then, there have been many technical developments and learnings that have led to this equipment being able to portion out faster and more accurately, while also taking into consideration the specific characteristics of each product.
In consideration of computer combination weighing (CCW), i.e. multihead weighing, these four important factors need to be considered when weighing anything from food and non-food consumer goods to pharmaceutical products.
1. Accurate efficiency
Multihead weighing technology has advanced significantly, offering greater accuracy and efficiency due to software improvements, faster digital filtering, anti-floor vibration, faster processing, and precise feeder control.
Some models also offer auto adjust feeder controls that remove the need for operator intervention in system optimisation. These Control systems provide optimal product feeding and external vibration control for more accurate weighing.
New algorithms can calculate three optimal weight combinations, double-check them, and then select the one nearest to the target weight all in a single cycle, minimising error discharges, increasing efficiency, while also enhancing weighing accuracy and consistency. Fast data transmission now enables the weigher to respond more quickly to control inputs, while enhanced automatic filters and faster filtering of the weigh signal from the load cells speeds up stabilisation.
Because of the reduced settling time, more heads are now available for inclusion in the combination calculation thus increasing the range of weight options and improving accuracy. All these advanced technologies increase performance speed, reduce giveaway, and offer maximum return on investment.
2. Weighing experience and expertise
To properly understand the multihead weighing function and the factors involved in the weigher decision making process, it is important to also include and understand the product characteristics, attention to detail of the process, multihead weigher choices along with up and downstream associated equipment. Configurations should be available to address a wide variety of elements/ challenges such as product integrity, capacity, and speed, including product feed/flow rates, package sizes, and packaging format.
For example, when a system requirement is to maintain product integrity of a fragile product (meaning, minimise breakage), the overall system stack-up height should be addressed along with each transition point, including infeed to scale, scale to vertical form fill seal, and discharge, in order to minimise breakage. Key weigher features need to also be included such as specially designed hoppers along with reduced hopper angles, which enable the product to slide rather than fall through the weigher. Further, by slowing down the speed of each weighment as it passes through the weigher, breakages are significantly reduced.
Weigher selection is also critical when one needs features such as a robust design capable of operating in harsh environments and tough products by providing resistance to wear and water ingress and improved hygiene and accessibility. Additionally, CCW weighers give greater access to product contact parts for more efficient high-pressure washdowns. These factors work to reduce cleaning time, to maximise weigher availability, and to maintain hygiene standards. All points needing consideration in weigher selection to reduce downtime and profitability.
3. Integration and automation
Machine networking, communication, and data management, coupled with automation, has become key to increasing total line performance. Processors now want more data and information, and modern systems are engineered to work and to communicate together, making it easier to obtain accurate production details in real time and to make quick calculated decisions, offering compounding benefits.
Today’s automation also shifts much of the complicated decision making away from the operators so they can focus on productivity and quality of the finished product. Unscheduled downtime due to decision making error can have significant impacts on performance, and if automated adjustments can be made in the packaging room as they occur without noticeable effects on operation, total line performance is improved. A single smart and simple user interface is also important so that operators can enter basic information for multiple machines quickly and easily.
Partnering with a company with experience is important in this respect as this saves money in the long term. There is no need to “reinvent the wheel” when experience through a large global install base is at hand. Being able to also integrate equipment up and down stream with the weigher also helps to reduce waste, giveaway and increase productivity and profitability. This total integration enables an operator to also bring automatic optimisation of the weigh signal filtration, product feeder vibration, and timing to ensure consistent high-performance weighing. An operator can control the weigher from practically any desktop, portable, or hand-held device. Diagnostics can be performed by wire or wirelessly to reduce the need for in-plant service calls.
Australia is a long way from everywhere, and in these times of COVID-19, local support is even more critical to ensuring productivity and profitability. Therefore, selecting the right partner is even more critical. For that reason, having an in-house network of engineers, technicians, skilled tradespeople, and support teams that has built an extensive knowledge bank and developed a wealth of experience and expertise is something that needs to be understood in the selection process, something that we think defines Heat and Control as an example.
Support should help optimise the production process at any stage, from design to implementation to application support. Hands-on expert knowledge, dependable equipment with the latest technology, service, and spare parts for the life of the equipment are a must.
Quality training also gives clients the ability to improve production output and efficiency. With operator turnover continuing to be one of the most challenging aspects of production, training is critical to improve and to maintain operator efficiency and identification of maintenance issues before problems occur.