Plastic Liner Bag Opening via Perforated Plate and Aeration
Solution Overview
Problem
The existing methods for opening and emptying large double-layered Kraft bags with a plastic liner containing food products like milk powder are inefficient and prone to contamination, as they require manual handling and can lead to wastage and hygiene issues due to the physical limitations of human workers and the risk of plastic fragments entering the powder.
Innovation Solution
A method and apparatus involving a plate with perpendicular slots and a bag opener with perpendicular blades, combined with aeration spears that inflate and fluidize the plastic liner bag, allowing for automated or semi-automated opening and emptying without the need for manual tilting, while minimizing the risk of plastic fragments and ensuring hygiene by containing the powder within a housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual opening method is used, then hygiene standards can be maintained, but productivity is reduced due to worker limitations
Solution Approach 1:
The system uses automated mechanisms including conveyor belts for bag transport, pneumatic systems for inflation and fluidization, and automated cutting devices to open and empty bags without human intervention, allowing the system to serve itself while maintaining hygiene and increasing productivity
Solution Approach 2:
Manual mechanical operations by workers are replaced with automated mechanical systems including motorized conveyors, pneumatic actuators for bag manipulation, and automated cutting mechanisms, eliminating human contact with the food product while maintaining operational control
2Productivity
If traditional cutting method is used, then opening speed is improved, but plastic fragments may enter the powder
Solution Approach 1:
A perforated plate is introduced as an intermediary component between the cutting blade and the bag contents. The plate with multiple openings allows the cutting blade to cut the bag while preventing plastic fragments from entering the powder, acting as a protective mediator that separates the cutting action from the food product
Solution Approach 2:
The plate is segmented with multiple openings of different sizes and shapes, creating a filtered pathway that allows air and powder to pass through while blocking plastic fragments. This segmentation of the plate structure enables simultaneous cutting and contamination prevention
3Productivity
If bag is tilted for emptying, then contents can be discharged, but powder may become trapped in corners
Solution Approach 1:
Pneumatic pressure is applied through the perforated plate to fluidize and push the powder contents out of the bag corners and through the plate openings, using gas pressure instead of mechanical tilting to achieve complete emptying without leaving trapped powder in corners
Solution Approach 2:
The physical state of the powder is changed from static to fluidized state by introducing pneumatic pressure, altering the powder's flow characteristics to enable complete discharge from all corners of the bag without mechanical manipulation
4Productivity
If automated equipment is introduced, then productivity increases, but device complexity increases
Solution Approach 1:
The system integrates multiple functions into a single automated platform: the conveyor belt handles bag transport, the same platform supports the perforated plate for cutting and fluidization, and pneumatic systems perform both inflation and emptying operations. This multi-functionality increases productivity while limiting the growth of device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables efficient, automated, and hygienic opening and emptying of plastic liner bags, reducing wastage and contamination risks by inflating and fluidizing the contents for easy discharge and minimizing the risk of plastic fragments entering the powder, thus improving throughput and maintaining a sterile environment.
Implementation Method 1
delivering a gas into the plastic liner bag with the one or more aeration spears
Implementation Method 2
fluidizing its contents with a gas delivered from the one or more aeration spears
Data Source
AI summary
A method and apparatus for opening of a plastic bag containing a food product in the form of powder or similar fine particulate material is disclosed. The bag is positioned atop a plate with a plurality of slots, with at least one slot transverse to the others. Beneath the plate, a bag opener is provided that includes a plurality of blades, with at least one blade transverse to the others. The plastic bag is penetrated with aeration spears and pressurized. The bag opener is moved relative to the plate such that the blades pass through the slots and open the bag. The plate is then allowed to pivot downwards, allowing its contents to be emptied into a hopper beneath the plate.