Automatic quantitative packaging scales are core equipment in modern industrial production, enabling accurate material measurement and automated packaging. Widely used in food, chemical, pharmaceutical, and grain industries, they significantly improve production efficiency, reduce labor costs, and ensure consistent product quality.
I. Basic Working Principle of Quantitative Packaging Scales
The working principle of quantitative packaging scales is based on dynamic weighing control technology, achieving high-precision measurement through a three-stage feeding mechanism (fast, medium, and slow). When the equipment enters automatic operation, the weighing control system opens the feeding gate to begin feeding. When the material weight reaches the fast feeding set value, fast feeding stops, and medium feeding is maintained. When the material weight reaches the final set value, the feeding gate closes, completing the dynamic weighing process. Subsequently, the system detects the bag clamping device status. After confirming that the packaging bag is clamped, the weighing hopper discharge gate opens, and the material enters the packaging bag. After discharge, the discharge gate automatically closes. After emptying the material, the bag clamping device is released, the packaging bag automatically falls and is sewn, then conveyed to the next workstation. This cycle repeats automatically.
II. Main Types of Quantitative Packaging Scales
1. Classification by Weighing Method
- Hopper Type (Net Weight Scale): Quantitative feeding is achieved through a central weighing hopper. The discharge gate is closed first, then the upper feeding port is opened for fixed-value feeding. Once the target value is reached, the feeding port is closed, and the discharge port is reopened to load the material into the container. Features include integrated structure, high precision, and high speed; suitable for dedicated production lines for granules and powders.
- Hopperless Type (Gross Weight Scale): The items to be packaged are directly loaded into containers or bags for weighing. Quantitative control is achieved by adjusting the opening size of the discharge port. Features include simple structure and high precision; often used for liquid fixed-value filling.
2. Classification by Feeding Mechanism
- Gravity Feeding Packaging Scale: Suitable for granular materials such as feed, fertilizer, rice, beans, and seeds. Typically uses a gate-type or vibrating feeder.
- Screw Feeding Packaging Scale: Suitable for powdery materials such as cement, putty powder, and chemical powder. Requires a screw feeder and vacuum degassing device to ensure airtight packaging.
- Belt Feeder Packaging Scale: Suitable for sheet-like, block-like, mixed, and irregularly shaped materials, such as organic fertilizer, compost, aggregate, gravel, sand, and soil.
III. Core Components of a Quantitative Packaging Scale
1. Weighing Unit (Key Component)
- Storage Bin: A buffer bin used for material storage and providing a near-uniform material flow.
- Gate: Located at the bottom of the storage bin, used to contain material within the bin during equipment maintenance or malfunction.
- Cutting Device: Composed of a cutting hopper, cutting gate, pneumatic components, and air supply valve, providing fast and slow feeding stages; the material flow can be adjusted independently.
- Scale Body: Composed of a weighing hopper, load-bearing bracket, and load cell, converting weight into an electrical signal.
- Bag Clamping Device: Composed of a bag clamping mechanism and pneumatic components, its function is to clamp the packaging bag, ensuring that all weighed material falls into the bag.
- Electrical Control Device: Composed of a weighing display controller, electrical components, and a control cabinet. The control system operates in an orderly manner according to a predetermined program.
2. Auxiliary Systems
- Pneumatic System: Provides power to the cylinders, controlling bag clamping, material feeding, and other actions.
- Dust Removal System: Reduces dust emissions and improves the working environment, especially suitable for powdery materials.
- Sewing and Conveying Device: Completes bag sewing and conveys the bags to the next workstation.
- Control System: Uses a PLC or dedicated controller to achieve automated process control and data management.
IV. Selection Considerations for Quantitative Packaging Scales
1. Selection Based on Material Characteristics
- Powdered Materials: Prioritize models equipped with screw feeders, such as flour, seasoning powder, and chemical powder.
- Granular Materials: Select gate feeders, such as rice, beans, and seeds.
- Strip-shaped/Irregular Materials: Select belt feeders, such as compost, aggregates, and tea leaves.
2. Model Selection Based on Production Scale
- Slow Speed/No Weighing Hopper: Approximately 120-180 bags/hour
- Medium Speed/Single Weighing Hopper: Approximately 240-480 bags/hour
- Fast Speed/Dual Weighing Hopper: Approximately 500-800 bags/hour
- High Speed/Servo Feeding: >900 bags/hour
Selection Recommendations:
When choosing a quantitative packaging scale, companies should first clarify their own needs, including material characteristics, packaging weight, accuracy requirements, and production scale. Then, choose a brand with technical expertise and application cases in the corresponding industry. Simultaneously, attention should be paid to the maintainability and after-sales service of the equipment to ensure long-term stable operation. For industries with high precision requirements, it is recommended to choose equipment with independent dual-station weighing and dual-speed (fast and slow) feeding functions to improve packaging efficiency and accuracy.
Muniu Machinery Equipment provides you with professional quantitative packaging equipment and one-stop packaging solutions, giving you peace of mind in your packaging needs.
https://www.muniupack.com/5-50kg-Granule-Quantitative-Packaging-Scale
Muniu Machinery Equipment
0
0 
