Equipment Introduction

The Powder Fertilizer Packing Machine, also known as an automatic quantitative packaging machine for powdered fertilizers, is an automated metering and filling packaging device specifically designed for powdered and powdery fertilizers. It is the core equipment at the end of the entire organic fertilizer, compound fertilizer, and water-soluble fertilizer production line, responsible for automatically weighing, filling, sealing, and conveying the finished fertilizer to a set weight, completing the final transformation from bulk material to commercially packaged bagged product.

This equipment uses electronic weighing principles to weigh and package materials, typically equipped with a three-speed screw feeding system (fast, medium, and slow), featuring high precision, high speed, and no dust pollution. The powder fertilizer packaging machine is the final piece of equipment in the complete process of “fermentation—pretreatment—crushing—screening—packaging” in a powdered organic fertilizer production line.

Unlike granular fertilizer packaging machines, powder fertilizer packaging machines need to specifically address the special problems of poor powder flowability, easy dust generation, and easy moisture absorption and clumping. Therefore, it has specialized designs in feeding, dust removal, and sealing.

Equipment Structure and Composition

The powder fertilizer packaging machine mainly consists of four core parts and several auxiliary equipment:

(I) Feeding and Weighing System

1. Silo (Transfer Silo)

Used for temporarily storing powder fertilizer to be packaged. The silo is usually made of 304 stainless steel and equipped with a forced feeding device (vibrator or arch breaker) to prevent powder from clumping and becoming loose inside the silo. The silo is connected to the upstream equipment with a soft, moisture-proof, and sealed design.

2. Screw Feeding Mechanism

The core feeding component of the powder fertilizer packaging machine. It adopts a single or double screw feeding method, and the screw speed is controlled by a variable frequency motor. Common feeding methods are fast, medium, and slow three-speed graded feeding:

Fast feeding: large flow rate coarse feeding, quickly filling most of the weight

Medium feeding: transition stage, reducing the impulse

Slow feeding: fine feeding, ensuring final accuracy

3. Weighing Device

Uses an independently suspended weighing sensor (such as a Mettler Toledo high-precision sensor), ensuring stable signal transmission. The sensor transmits the weight signal to the instrument for data processing, enabling automatic tare, zeroing, and measurement.

4. Control System

Based on a PLC (Programmable Logic Controller), and equipped with a high-brightness LED display window, it allows independent input of packaging weight and displays the weighing value. It has automatic storage functions for shift production, daily production, and cumulative production.

(II) Bag Clamping and Filling System

Pneumatic Bag Clamping Device: After manual bagging, a light touch of a microswitch activates the bag clamping cylinder to grip the packaging bag. The equipment has automatic detection functions for each action state: fast filling, medium filling, slow filling, weighing, stabilization, bag clamping, unloading, and bag dropping.

(III) Conveying and Sealing System

1. Conveying Device

Typically, an idler roller belt conveyor is used. The conveyor belt is wear-resistant and corrosion-resistant, and the continuous idler roller structure ensures that material does not accumulate under the conveyor belt and that slippage does not occur.

2. Sealing Device

Selectable based on packaging bag type:

Sewing device: Suitable for woven bags, automatic sewing

Heat sealing machine: Suitable for composite film inner bags, sealing temperature and speed adjustable

(IV) Auxiliary Systems

Dust removal system: Air intake, dust collector, controls dust overflow

Feeder: Lifts materials to the packaging machine’s hopper

Air supply system: Provides compressed air (usually 0.4-0.6 MPa) required for pneumatic actuators

Arch breaking technology: Prevents material from clumping and bridging during screw feeding

Working Principle of the Equipment

The working process of the powder fertilizer packaging machine is an automated closed-loop control process:

Step 1: Manual Bagging

The operator places an empty bag over the discharge port, triggering a bag clamping signal.

Step 2: Pneumatic Bag Clamping and Automatic Tare

The bag clamping cylinder actuates to grip the bag, the discharge gate automatically closes, and the weighing system automatically tares and zeros the scale.

Step 3: Graded Feeding

The feeding mechanism feeds material into the weighing hopper (or directly into the packaging bag) sequentially at three flow rates: fast, medium, and slow.

Initially, fast feeding quickly fills most of the weight.

When the weight approaches the target value, it switches to medium-speed feeding.

When the precise measurement value is reached, it switches to slow feeding to accurately replenish the material to the target value.

Step 4: Weighing Judgment

The pressure sensor converts the weight into an electrical signal and transmits it to the instrument for data processing. Once the set target weight is reached, the feeding process ends, and the weighing success indicator light illuminates.

Step 5: Material Discharge and Bag Drop

After the feeding cylinder closes, the discharging cylinder at the bottom of the metering hopper activates, opening the discharging gate. Material fills the packaging bag by its own weight. After discharging, the discharging gate closes, and the bag clamping mechanism automatically opens to unload the bag.

Step 6: Conveying and Sealing

The packaging bag automatically falls onto the conveyor belt and is sent to the sewing machine or heat sealing machine for sealing. At the end of one work cycle, the control instruments automatically enter the next work cycle.

Applications of the Equipment

The powder fertilizer packaging machine is mainly used in the following fields:

1. Production of Powdered Organic Fertilizer

For packaging powdered organic fertilizers such as humic acid powder, bone meal, fish meal, rapeseed cake powder, earthworm castings powder, and compost powder.

2. Water-soluble Fertilizer, Fertilizer for Drip Application, and Foliar Fertilizer

Automatic metering and packaging of powdered water-soluble fertilizers, macro-element water-soluble fertilizers, and humic acid water-soluble fertilizers.

3. Compound Fertilizer and Blended Fertilizer

Packaging of compound fertilizer powders and blended fertilizer powders.

4. Fertilizer Raw Materials

Ammonium sulfate, ammonium bicarbonate crystals, phosphate fertilizers, potash fertilizers, BB fertilizers, formulated fertilizers, and micronutrient fertilizers.

5. Other Powdered Materials

Quantitative packaging of powdered materials such as pesticide powder, additives, flour, feed, and chemical raw materials.

Application of Powdered Fertilizer Packaging Machines in Production Lines

Complete Powdered Fertilizer Process Flow:

Raw Material Crushing → Batching and Mixing → Drum Screening (Fine Powder Purification) → Finished Product Silo → Powdered Fertilizer Packaging Machine → Conveying and Sewing → Palletizing and Warehousing

Section Support Logic:

1. Qualified fine powder after screening is stored in a high-level silo and conveyed to the packaging machine’s buffer silo via bucket elevator, achieving continuous and uninterrupted packaging;
2. Fine powder recovered from dust removal during filling is returned to the silo, resulting in zero raw material loss;
3. A single machine can be used independently or combined with automatic bagging, checkweighing, metal detection, and robotic palletizing to form a fully automated packaging line;
4. Multiple units can be connected in parallel to adapt to large-capacity fertilizer bases, meeting the needs of batch outbound shipments.

Common Faults, Causes, and Standardized Solutions

Standard Operating Procedures and Full-Cycle Maintenance Methods

(I) Standard Start-up and Shutdown Procedures

Start-up

1. Check that the hopper and screw conveyor are free of clumps, the dust collector filter is intact, the sensors are free of powder accumulation, and the equipment is reliably grounded;
2. First, start the dust collector and vibratory arch-breaking motor, run the screw conveyor unloaded for 3 minutes, and confirm that the rotation direction is correct;
3. Call up the corresponding fertilizer formula on the touch screen, complete the zero-point calibration, and then begin bagging production.

Shutdown

1. Stop the front-end feeding and wait for all material in the hopper and screw conveyor to be emptied;
2. Sequentially shut down the screw conveyor, dust collector, and conveying equipment, and clean any residual powder from the weighing hopper and bag clamping area;
3. For long-term shutdowns, loosen the bag clamping cylinder and protect the sealing dustproof skirt.

(II) Graded Maintenance Standards

1. Wipe the load cell and clean the dust from the bag daily; check the dust collector pressure differential; calibrate the zero point every shift.
2. Disassemble the auger weekly to clean the adhering material, check the wear of the auger blades, and add grease to the cylinder.
3. Replace the dust collector filter element monthly; tighten the drive chain and motor bolts; clean the dust from the electrical control box.
4. Replace all gear oil in the reducer every 4 months; replace aged sealing skirts and air pipe joints.

(III) List of Vulnerable Parts

Auger blades, load cell, dust collector filter bag, dustproof sealing skirt, cylinder seal ring, V-belt, solenoid valve.

Target Customers for this Equipment:

1. Powdered Organic Fertilizer Manufacturers: Powdered organic fertilizer production lines have a simple configuration (compost turner + crusher + screening machine + packaging machine), with the packaging machine being an essential component. Suitable for small and medium-sized organic fertilizer processing plants handling livestock and poultry manure, straw, biogas residue, and other waste.
2. Water-soluble Fertilizer, Fertigation Fertilizer, and Foliar Fertilizer Manufacturers: The core packaging equipment in a fully automated powdered water-soluble fertilizer batching and packaging production line. Suitable for packaging products such as macro-element water-soluble fertilizers, humic acid water-soluble fertilizers, and potassium humate.
3. Compound Fertilizer and Blended Fertilizer Manufacturers: Packaging needs for compound fertilizer powders and blended fertilizer powders.
4. BB Fertilizer, Formula Fertilizer, and Micronutrient Fertilizer Manufacturers: Packaging of BB fertilizers, formula fertilizers, micronutrient fertilizers, boric acid, boron fertilizers, and other fertilizers.
5. Enterprises Building or Expanding Fertilizer Production Lines: Fertilizer production projects requiring a complete packaging system.

Key Selection Considerations:

Material Characteristics Priority: Choose screw feeders for free-flowing powders; select models with anti-bridging devices for sticky or easily arched materials.

Accuracy Requirements: Select ±0.5% for general fertilizers; ±0.2% for high-end products.

Capacity Matching: Calculate the required packaging speed based on daily output, allowing for a 10%-20% margin.

Environmental Requirements: Prioritize models equipped with dust removal systems.

Material Requirements: Prefer 304 stainless steel for corrosive materials.