Big Bag Filling and Unloading Systems
Safe Raw Material Management for Plastic Granules, Crushed Materials, Powders, and PET Flakes
In the plastics industry, Big Bags are widely used for the storage, transportation, and dispatch of granular, regranular, crushed materials, plastic flakes, and powder raw materials within the plant. However, the safe and controlled unloading of materials with different flow characteristics from Big Bags requires more than a standard conveyor construction.
Big Bag filling and unloading systems are designed taking into account the characteristics of free-flowing, restricted-flowing, or difficult-to-flow bulk raw materials. Thanks to their modular system structure, stations can be configured according to material type, Big Bag dimensions, process capacity, unloading method, and plant automation.
The product range offers solutions for processing the following materials:
* Plastic granules
* Regranulates
* Plastic crushed material
* PET flakes and plastic pellets
* Masterbatch
* Additives
* Mineral fillers
* Free-flowing or slow-flowing powders
* Compounds and recycled products
Modular Big Bag Systems
Big Bag stations have a modular construction that can be adapted to different applications encountered in the plastics industry.
Depending on the intended use, the systems can be equipped with the following equipment:
* Big Bag loading with forklift or electric chain hoist
* Lifting traverse
* Big Bag outlet clamping system
* Dust-free clamping device
* Iris cuff closing system
* Intermediate storage hopper
* Suction boxes and suction pipes
* Rotary valve
* Vacuum raw material conveying
* Pneumatic pressure conveying
* Cyclone separator
* Vibration or shaking system
* Fluidization system
* Rotary base unloader
* Level sensors
* Weighing and dosing system
* Dust collection connection
* Safety fence and light curtain
* PLC control and central automation connection
This structure facilitates the integration of Big Bag stations into an existing production line or a central raw material conveying system.
Big Bag Unloading Systems
Big Bag Unloading Stations for Granules
Big Bag unloading stations developed for free-flowing plastic granules offer various intermediate hopper options from 60 liters to 2,000 liters.
Material can be transferred from the hopper to the production line using two different methods:
* Vacuum conveying system
* Pneumatic pressure conveying using a rotary valve
Hoppers can be manufactured from aluminum or stainless steel depending on the capacity and application.
60 and 70 Liter Granule Discharge Stations
The 60 and 70 liter systems are designed for applications where the total system height needs to be kept as low as possible.
In the 70-liter model, the granules are transferred to the vacuum conveying system from suction points located on the side of the hopper. In the 60-liter model, the material is discharged through a DN200 or DN250 outlet at the bottom of the hopper.
A suction box or rotary valve can be connected to the lower section. In applications using a rotary valve, a discharge capacity of approximately 3-6 tons/hour can be achieved, depending on the material and process conditions.
Main Features
* Compact system height
* Stainless steel intermediate hopper
* Loading with forklift or electric chain hoist
* Maximum lifting capacity of 2,000 kg
* 450 mm inlet opening
* Side vacuum suction or bottom discharge
* DN200 and DN250 outlet options
* Suction boxes with one, two or four outlets
* Rotary valve connection
* Waste material discharge hatch
550 Liter Granule Discharge Station
The 550-liter Big Bag discharge system is suitable for production facilities with low to medium raw material consumption.
Free-flowing granules can be taken from the suction points next to the hopper or from the suction box connected to the bottom outlet. Pneumatic pressure conveying can be achieved using a rotary valve in models with a DN200 outlet.
Main Features
* 550-liter intermediate storage volume
* Aluminum or stainless steel hopper
* Big Bag loading with forklift or electric hoist
* Vacuum or pressure conveying
* Multiple suction point options
* Rotary valve capacity of approximately 3-6 tons/hour
* Level sensor and filter connections
* Easy control and cleaning
1,000 Liter Granule Discharge Station
The 1,000-liter model can be used for buffer storage and continuous material feeding in plastic processing lines with higher raw material consumption.
The product can be conveyed by vacuum via a DN100 outlet or by pressure via a DN200 outlet and rotary valve. Using different suction boxes, material can be sent from the same hopper to multiple production machines.
Main Features
* 1,000 liter intermediate tank
* Aluminum or stainless steel options
* Forklift or electric hoist operation
* Vacuum and pneumatic pressure conveying
* One, two, four or six suction points
* Approximately 3-6 tons/hour rotary valve capacity
* Maximum and minimum level sensor connections
* Inspection opening with sight glass
* Filter connection
1,450 and 1,500 Liter Granule Discharge Stations
1,450 and 1,500 liter intermediate tank
These systems are designed for plastic production facilities with high raw material consumption. The large buffer volume helps ensure continuous material supply to the production line during Big Bag changes.
Different numbers of suction points can be used for vacuum conveying. In systems with a DN250 outlet, pneumatic conveying can be achieved with a rotary valve at a capacity of approximately 6-10 tons/hour.
2,000 Liter Granule Discharge Station
The 2,000-liter Big Bag discharge station is designed to take the entire raw material from a Big Bag into the intermediate hopper.
Discharging the Big Bag in a single operation reduces operator intervention and Big Bag dwell time in the system. The granules in the hopper can be transferred to the production line via a vacuum or pressure conveying system.
Main Features
* 2,000-liter hopper capable of holding one Big Bag
* Aluminum or stainless steel construction
* Loading with electric chain hoist
* Side suction connections
* Suction boxes in different capacities
* DN250 rotary valve connection
* Approximate conveying capacity of 6-10 tons/hour
* Level and filter connections
* Integration into central conveying systems
# Big Bag Discharge Systems for Crushed Material
Crushed plastic material may have a more irregular particle geometry and lower fluidity compared to granules. Therefore, crushed material applications require a steeper outlet geometry and suitable discharge equipment that facilitates flow.
Big Bag discharge systems for crushed material typically use a 60° outlet hopper. The systems are suitable for free-flowing crushed material and granules.
600 Liter Crushed Material Station
The 600-liter model is suitable for recycling and plastic processing lines with low or medium material consumption.
In the side-suction model, raw materials are fed into the vacuum conveying system via suction pipes. In the DN200 outlet model, pressurized conveying can be achieved by connecting a rotary valve.
The rotary valve discharge capacity can be approximately 3-6 tons/hour depending on the application.
1,000 Liter Crushing Material Station
The 1,000-liter system provides a larger buffer volume. The hopper can be manufactured in aluminum or stainless steel.
The side-suction model can work with central vacuum raw material conveying systems. The DN200 outlet model is suitable for rotary valve connection.
1,550 Liter Crushing Material Station
The 1,550-liter model is designed for plastic recycling and compounding plants with high material consumption.
Side-suction or DN250 rotary valve outlet options are offered. In applications using a rotary valve, a discharge capacity of approximately 6-10 tons/hour can be achieved.
2,000 Liter Crushing Material Station
The 2,000-liter system features a large intermediate hopper capable of holding the entire contents of a Big Bag of crushed material.
This model is suitable for high-capacity plastic recycling lines and facilities where crushed material is continuously sent to an extruder or other processing unit.
Advantages of Crushing Material Systems
* 60° conical hopper supporting flow
* 600-2,000 liter capacity options
* Aluminum or stainless steel hopper
* Vacuum or pressurized material transfer
* Side suction or rotary valve outlet
* Use with granular and free-flowing crushed material
* Various suction point options
* Level and filter connections
* Robust steel support construction
# Big Bag Discharge for Powdered Raw Materials
During the discharge of powdered materials from Big Bags, problems such as dust emission, material bridging, and uncontrolled flow can occur. ACHBERG 350-liter dust removal systems are designed to create a closed and as dust-free as possible connection between the Big Bag outlet and the intermediate hopper.
The Big Bag outlet is connected to the station with a special clamping system. For materials with low fluidity, different flow aids can be used to ensure the regular emptying of raw materials from the Big Bag and the hopper.
Available flow aids:
* Big Bag shaking system
* Vibration system
* Fluidization
* Hopper vibrator
* Application-specific mechanical discharge equipment
Features of dust removal systems:
* 350-liter intermediate hopper
* Dust-free clamping system
* Iris cuff closing mechanism
* Electric chain hoist
* Maximum lifting capacity of 2,000 kg
* Dust collection system connection
* Level sensor connections
* Discharge aid for slow-flowing materials
* Optional safety fence and light curtain
* PLC control
* Connection to advanced plant automation
These systems; Adaptable to plastic compound applications using mineral fillers, additives, calcium carbonate, talc, pigments, and similar powdered raw materials.
Big Bag Discharge System for PET Flakes
PET flakes can create flow problems in standard granule discharge systems due to their irregular particle geometry and tendency to clump together.
The 450-liter PET flake discharge system is specifically designed for the safe dissolution, transfer to the hopper, and discharge of plastic flakes.
Oscillation applied to the Big Bag
These movements help loosen the PET flake particles. The rotary discharger on the flat bottom of the hopper moves the material, directing it in a controlled manner to the outlet.
Features of the PET flake system:
* 450 liter intermediate hopper
* Electric chain hoist
* Maximum lifting capacity of 2,000 kg
* Big Bag shaking and loosening system
* Flat bottom hopper
* Rotary bottom discharger
* DN200 or DN250 outlet
* Controlled material dosing
* Level sensor connection
* Optional safety fence and light curtain
* PLC control system
* Connection to central plant automation
This solution can be used in flake feeding applications such as PET bottle recycling, rPET production, PET sheet extrusion, and similar processes.
Big Bag Filling Systems
Big Bag filling systems are designed for filling Big Bags with granular or crushed material, primarily used in plastic recycling and compound production.
Filling stations can be fed by vacuum or pneumatic pressure conveying systems. It can be integrated into the existing production system thanks to cyclone separator or vacuum loader connections.
In applications where multiple filling stations need to be automatically fed, piping systems with a filling direction change valve can be used.
BB.FILL.10 Manual Big Bag Filling System
The BB.FILL.10 model is designed for manually controlled filling applications.
The Big Bag inlet is fixed to the filling pipe with a quick-connect clamping system. Big Bag rings are suspended from four carrying hooks. A DN200 manual butterfly valve is used to open, close, or restrict the material flow.
Main Features
* Vacuum or pressure conveying
* Quick-connect Big Bag mouth clamp
* Four Big Bag carrying hooks
* Manual DN200 butterfly valve
* Maximum level sensor
* Overfill warning light
* Construction adjustable to different Big Bag heights
* Optional cyclone separator
* Application-specific control system
BB.FILL.20 Weighing and Dosing Filling System
BB.FILL.20 is designed for applications where Big Bags need to be filled in a controlled manner up to a specified weight.
The pneumatic dosing flap has three operating positions: coarse filling, precise filling, and closed. The filling weight is measured by a U-shaped platform scale with calibratable load cells.
Main Features
* Pneumatic pressure conveying for feeding
* DN200 dosing flap capable of coarse and fine filling
* Flap position monitoring sensors
* Air inflation system shaping the Big Bag
* Maximum filling sensor
* Platform scale with four load cells
* Maximum weighing capacity of 2,000 kg
* Approximately ±1 kg dosing accuracy
* Application-specific control and automation
BB.FILL.30 Intermediate Storage Filling System
The BB.FILL.30 system is equipped with a 2,500-liter intermediate storage hopper for applications requiring high filling capacity.
Material from the production line is first stored in the intermediate hopper. When a Big Bag is changed, the material from production continues to be held in the intermediate hopper. This prevents the Big Bag change from stopping the production line.
Main Features
* 2,500 liter aluminum buffer hopper
* Feeding via vacuum or pressure conveyor
* Coarse and fine filling dosing flap
* Platform scale with four load cells
* Maximum weighing capacity of 2,000 kg
* Approximately ±1 kg dosing accuracy
* Big Bag inflation system
* Maximum level control in hopper and filling tube
* Inspection opening and sight glass
* High filling capacity
* Integration into automatic control system
# Safe and Dust-Free Operation
Operator safety and maintaining a clean working environment are of paramount importance at Big Bag stations.
Depending on the application, the system can be equipped with the following safety equipment:
* Safety fence surrounding moving parts
* Light curtain in the entry area
* Electromechanical safety locks
* Safe lifting traverse for Big Bag conveyor rings
* Maximum level and overfill control
* Warning lights
* Dust extraction connection
* Dust-free clamping between Big Bag and hopper
* Flow shut-off system with iris cuff
* Operator platform and access steps
High-Capacity Big Bag Unloading and Homogenization
When a total of approximately 25 tons of raw material is delivered in Big Bags in a shipment, the Big Bags need to be unloaded quickly to reduce vehicle waiting time at the facility and logistics costs.
In their systems, the material in the Big Bags can be transferred to a large intermediate hopper or to two separate unloading stations in a single operation. Depending on the application, a conveying capacity of approximately 10-18 tons/hour can be achieved.
If there are differences in properties between raw materials from different Big Bags, the material can be transferred to a homogenization silo after unloading. Even a single-pass homogenization process can help improve the distribution between different batches.
Control and Automation
Big bag unloading and filling systems can be offered at different control levels, from manual operation to fully automated operation.
PLC control
The following functions can be managed via the system:
* Big Bag filling and emptying sequence
* Rotary valve control
* Vacuum or pressure conveying
* Level sensors
* Vibration and shaking systems
* Rotary base unloader
* Coarse and precise dosing
* Weighing system
* Filling directional valves
* Overfill alarm
* Safety fence and light curtain
* Communication with central plant automation
The control system can be designed to communicate with high-level production management or a central raw material handling system.
# Advantages of Big Bag Systems
* Specialized solutions for granules, crushed material, powder, and PET flakes
* Modular and application-adaptable system structure
* Operation with forklift or electric chain hoist
* Maximum 2,000 kg Big Bag carrying capacity
* Vacuum or pneumatic pressure conveying
* Aluminum and stainless steel hopper options
* 60-2,000 liter discharge hopper options
* Dust-free connection and closing systems
* Flow supports for difficult-to-flow materials
* Feeding from a single station to multiple production lines
* Manual, dosing, and weighing filling options
* High-capacity buffer hopper solutions
* PLC control and integration into plant automation
* Comprehensive safety equipment
* Suitable for recycling and compounding lines
Application Areas
Big Bag systems can be used in the following facilities:
* Plastic compound production
* Masterbatch production
* Plastic recycling plants
* PET bottle recycling
* rPET granule and flake processing
* Plastic injection molding plants
* Film and sheet extrusion
* Pipe and profile extrusion
* Technical plastics production
* Mineral-filled compound production
* Crushed material collection and reuse systems
* Granule and regranule packaging lines
* Centralized raw material handling systems
Determining the Right Big Bag System for Your Project
To select the correct Big Bag filling or emptying system, not only the name of the material but also its flow characteristics and process requirements should be evaluated.
The following information is required for project planning:
* Raw material type
* Material particle or grain size
* Bulk density
* Fluidity and bridging tendency
* Big Bag dimensions
* Big Bag weight
* Hourly unloading or filling capacity
* Vacuum or pressure conveying preference
* Target conveying distance
* Required intermediate hopper volume
* Material in contact with raw material
* Weighing and dosing requirements
* Dust collection requirements
* Plant automation connection
* Dimensions and height of the installation area
Polmak Plastik provides technical support in determining the appropriate ACHBERG Big Bag filling and unloading system for your material properties and production process, selecting accessories, and integrating the system into your existing raw material handling infrastructure.
