Weighing processes are integral to a food processing plant. They ensure ingredients meet recipe specifications and quality compliance requirements.
The most common weighing technology uses a spring scale to measure mass (or weight). The spring extends or compresses according to Hooke’s law.
Automated weighing systems eliminate the need for manual handling, reducing contamination and human errors. They can also reduce downtime due to a lack of manpower.
Accuracy
Accurate weighing saves cash by decreasing overfilling and waste, optimizing resources and reducing material costs. It also reduces production downtime and allows for increased profitability. In addition, a precise filling process ensures compliance with regulatory standards and minimizes the risk of costly recalls.
The best way to ensure accurate weighing is by using an OIML or NTEP certified scale with the appropriate sensitivity weights. The sensitivity weights should be equal to or less than the number of balance divisions. This method, known as comparison weighing or substitution weighing, eliminates errors caused by built-in weigh-in weights and reduces disturbances during the measurement cycle.
Inaccurate weighing is often due to a malfunctioning load cell. The correct choice of a high-quality, durable load cell will result in consistent and accurate measurements. Incorrect operation of the balance may also contribute to inaccuracy. Other factors that contribute to inaccurate weighing include environmental influences and sample characteristics (e.g., evaporation of liquids or hygroscopic/hydrophobic solid materials that gain or lose weight).
Reliability
For processes that rely on weighing, reliability is crucial. Even the smallest deviations can result in an entire batch failing quality checks or not meeting production deadlines. Luckily, automated weighing systems can reduce the likelihood of human error and provide a more consistent, reliable process.
To achieve high reliability, ensure that the weighing system is correctly installed and calibrated. For example, if the hoppers are suspended from a set of load cells, ensure that those load cell supports can support the total weight of the hopper and its contents without flexing. In addition, be sure to address any pressure differences that could impact the system. Also, be sure that the weighing system has been thoroughly tested and cleaned prior to use to minimize the possibility of contamination. This will prevent the accumulation of debris on the weighing pan that can impact accuracy. Finally, always use gloves and tongs when handling the weighing equipment to avoid adding mass to the weighing pan.
Efficiency
An efficient product-weighing process is one of the cornerstones of quality in manufacturing. A slight deviation in the process can result in expensive losses or compromised products. To ensure optimal weighing processes, the equipment must be properly maintained and calibrated. This includes selecting the right scales for specific applications and establishing standard operating procedures (SOPs).
Unnecessary motion waste is one of the biggest obstacles to efficiency in the manufacturing industry. This is created by extra movements by the operator that are not needed to complete a task. Eliminating these wasteful movements can go a long way to increasing productivity, reducing labor costs and reducing injuries.
Many automated weighing systems come with built-in features that eliminate these unnecessary motions and streamline the overall process. Additionally, modern weighing systems provide robust data capture and analysis. This enables businesses to better understand their production and identify areas that need improvement. This enables businesses to maintain high standards of accuracy and efficiency across all production processes.
Safety
Weighing dangerous chemicals requires the right precautions to protect workers, ensure product quality and comply with regulations. Mishandling of corrosive substances can result in expensive clean-ups, fines and reputational damage for businesses.
Environmental considerations must also be taken into account. A weighing room should be free from vibrations, temperature changes and drafts. It should be located away from larger laboratory equipment, air conditioning vents and doors that can cause temperature gradients that affect measurements. The weighing environment should also be free from magnetic materials that can interfere with key balance components that enable precise measurements.
Weighing in hazardous environments involves additional safety measures like risk assessments and zone classifications that identify areas where explosive gases, vapors or dust might exist. These areas must be designated as areas classified under standards like ATEX or NFPA, and the weighing equipment used in these areas should be specially designed to operate safely with flammable materials. This includes using devices with intrinsically safe circuits to prevent sparks.