In a complete packaging production line, the checkweigher is generally installed after filling and sealing and before case packing and palletizing. This layout makes it the final quality inspection checkpoint, as well as a cost-saving node to prevent non-conforming products from entering the subsequent high-cost packaging processes. As an original manufacturer with full-line manufacturing capacity, Marchi Packaging Equipment can provide a full set of connected equipment ranging from electronic checkweighers and large-bag checkweighers to automatic feeding, case erecting, case packing and high-level palletizing systems.
I. Model Selection and Core Configuration
For bagged products with a net weight ranging from 100g to 500g, Marchi recommends the MCZX240 electronic checkweigher, which has a weighing range of 100g to 500g, a division value of 0.2g and sorting accuracy of ±0.2g. For large-bag or carton-packed products between 25kg and 50kg, Marchi provides large-bag checkweighers with sensor measuring range expanded to 100kg, a division value of 10g and accuracy of ±10g. Both models adopt fully imported high-precision sensors together with automatic dynamic zero-tracking technology, so daily calibration is not required during long-term continuous operation. Optional reject mechanisms include pusher type, air-blow type and lever type according to product features. The touch screen HMI supports multi-language operation and multi-formula storage.
II. Detailed Packaging Process
Taking a medium-speed packaging line for the snack food industry as an example, the complete workflow is as follows:
Feeding and Filling: Granular materials such as peanuts, broad beans and green peas are transported via a Z-type elevator to the multi-head combination weigher, which completes high-precision weighing at the target weight of 150g. Materials fall into the former of the vertical packaging machine. After bag forming, longitudinal sealing, transverse sealing and cutting, independent small finished bags are produced.
Weight Re-inspection: Finished bags are delivered to the MCZX240 electronic checkweigher by conveyor belts. Sensors collect weight signals, and the control system judges products based on the preset upper limit of 150.2g and lower limit of 149.8g. Qualified products are conveyed forward continuously, while unqualified products are pushed into the collecting bin by the lever-type reject mechanism.
Material Sorting and Arrangement: Qualified bags are spaced apart by acceleration conveyors and sent to the sorting turntable or storage chute. The sorting system counts and arranges bags into groups of 40 bags per carton.
Case Erecting and Packing: The automatic case erector picks up carton blanks, shapes the cartons and seals the bottom flaps before conveying them to the packing station. The servo pushing device steadily pushes the sorted bag groups into cartons.
Case Sealing and Conveying: Filled cartons go through the flap folding and tape sealing machine, then are diverted and transported to the palletizing area via roller conveyor lines.
High-level Palletizing: A carton turning mechanism is arranged at the inlet of the palletizer to adjust carton orientation according to the required stacking pattern. Palletizing manipulators or lifting platforms stack cartons layer by layer onto pallets, with 12 cartons (3×4) per layer and 5 layers (60 cartons) per pallet, and the total height of each pallet shall not exceed 1.8 meters. Finished pallets are automatically output by chain conveyors and transported to warehouses by forklifts.
III. Process Details and Key Parameters
Three details of the weight inspection process directly affect the overall production efficiency: first, speed matching between the feeding section and the weighing section to avoid incomplete weighing caused by too small spacing between bags; second, the response time of the rejecting action, and the time from detecting unqualified products to sending out reject signals of MCZX240 is controlled within 50 milliseconds; third, the surface material of the conveyor belt. White anti-sticking belts equipped with cleaning brushes are adopted for materials prone to powder adhesion.
Key parameters are summarized as follows: weighing range 100g to 500g, division value 0.2g, sorting accuracy ±0.2g, sorting speed 155 times per minute, conveyor belt speed 70 meters per minute. The equipment adopts 220V AC power supply with an overall protection grade of IP54, which is suitable for ordinary food workshop environments.
IV. Customer Pain Points and Marchi Solutions
Based on surveys of hundreds of customers, the Marchi technical team has summarized three core pain points:
Pain Point 1: Gradually declining weight detection accuracy leads to false rejection of qualified products or missed inspection of unqualified products.
Solution: Fully imported high-precision sensors are equipped together with automatic dynamic zero-tracking technology, which realizes zero calibration after each weighing to ensure stable accuracy during long-term operation. After one month of continuous operation, the measured accuracy is still kept within ±0.2g without daily calibration.
Pain Point 2: Cumbersome and error-prone parameter adjustment during product switching.
Solution: The full-color touch screen is embedded with a formula management system. Users can store parameters such as upper and lower weight limits, reject modes and conveyor speeds of each product as independent formulas. When switching products, operators only need to select the corresponding formula name, and all parameters can be automatically called within 30 seconds.
Pain Point 3: Inability to link weight detection data with upstream packaging machines to realize closed-loop control.
Solution: Marchi equipment is equipped with standard MODBUS TCP communication interfaces for data exchange with any packaging machine controller supporting this protocol. When the checkweigher detects continuous batches of packaging products with weight deviation in the same direction, it will automatically send correction instructions to the packaging machine to adjust the filling volume or bag length, realizing closed-loop optimization from inspection to production control.
V. Brand Strength
Specializing in packaging machinery manufacturing for many years, Marchi Packaging Equipment has independent capabilities in R&D, production, installation and commissioning from single machines to full production lines. The company has built an equipment demonstration center to receive customers for material trial tests. Marchi electronic checkweighers, large-bag checkweighers, weight detectors and supporting case erectors, case packers, case sealers and high-level palletizers have been widely used in food, chemical, pharmaceutical, hardware and other industries nationwide. Marchi always marks equipment parameters truthfully without exaggerated labeling, and wins customer trust through actual operating data. For customers with full-line procurement demands, Marchi can provide one-stop services including scheme design, equipment manufacturing and on-site installation and commissioning.
Marchi Service Cases
Marchi Packaging Equipment Factory owns 27 years of experience in the packaging machinery industry, more than 5,000 cooperative customer cases and exports to over 50 countries. It is a long-term supplier to Fortune Global 500 enterprises, supporting whole factory scheme design and non-standard customization. It can package powder, granule, liquid and other materials, and has cooperated with many large food, pharmaceutical and chemical enterprises.
Food Industry: PepsiCo, Yili, Uni-President Enterprises, YumChina, Little Sheep, Tastien, By-health, Nam Soon Group, Five Grains Mill, Yan Gufang, SEAMILD, Qiandao Bee Garden, Sanjiu Group, Puratos, Guangxi Nongken Mingyang Starch, Dong'e Ejiao, Wen's Group, Amway, etc.
Pharmaceutical Industry: Tianjin Hongri, Weigao Group, Dong'e Ejiao, Xiuzheng Pharmaceutical, Yibai Pharmaceutical, Lukang Pharmaceutical, Taihang Pharmaceutical, Niscon, Jinkun, Hubei Gongtong Pharmaceutical, Fuhe Group, Infinitus, Zhejiang Medicine, Zhejiang Guobang Pharmaceutical, etc.
Veterinary Drug Industry: Longxiang Pharmaceutical, Jizhong Pharmaceutical, China Animal Husbandry Industry, Cheng Bixin, Houyi Group, Ramical, Twins Group, Yuehai Group, Haid Group, Wen's Group, Zhengbang Group, etc.
Food Additive Industry: Xinghu Technology, Xintuyang Biology, Muen Biology, Yinong, Puratos, Sanjiu Group, Ajinomoto, Meihua Group, Chenguang Biology, Rhine Biology, Jinhe Biology.
Chemical and Daily Chemical Industry: New energy, new material, mineral, chemical and other industries; Liby, P&G, Yongxin Chemical, Shengtai Chemical Technology, Guangzhou Hekang, Forster, Sanrun, Sany Group, CATL.
