Parallel Filling of Plastic Granulate for Injection Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for dosing plastic granulates in injection molding machines are inefficient, leading to interruptions due to bridging and inaccurate dosing, especially for disproportionately high amounts like virgin material and material to be ground, resulting in increased processing time and potential overdosing.
Innovation Solution
The method involves parallel or multiple parallel filling from at least two material hoppers into a weighing container, with continuous weighing and precise dosing control, avoiding bridging and overdosing by stopping filling short of the target and adjusting based on measured amounts, and using a device with a platform load cell and ball mixer for exact formula adherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If single material hopper filling is used, then device complexity is reduced, but productivity decreases due to bridging interruptions
Solution Approach 1:
The system divides the material supply function into multiple independent material hoppers (at least two), each capable of supplying plastic granulate separately. This segmentation allows parallel filling operations to occur simultaneously, eliminating bridging interruptions and increasing overall throughput while maintaining manageable device complexity through modular architecture
Solution Approach 2:
Multiple material hoppers are merged into a coordinated parallel filling system that operates under unified control. The control unit synchronizes the discharge of multiple hoppers into a common weighing container, enabling simultaneous material input from multiple sources to achieve continuous filling without interruptions while maintaining system integration
2Manufacturing precision
If continuous filling is used, then processing time is reduced, but dosing precision deteriorates due to bridging and overdosing
Solution Approach 1:
The system implements continuous weight measurement during the parallel filling process, with the control unit monitoring the actual weight in real-time and comparing it against the target weight. This feedback mechanism allows the system to stop filling at the precise moment when the target weight is reached, eliminating both underdosing and overdosing while maintaining rapid processing speed
Solution Approach 2:
The control unit intentionally stops the parallel filling process slightly before the target weight is reached, leaving a small margin. This partial action approach prevents overdosing by accounting for potential material flow variations and bridging effects, ensuring that the final dosing remains within acceptable precision limits while minimizing processing time
3Productivity
If parallel filling from multiple hoppers is used, then productivity increases, but measurement precision becomes more difficult due to simultaneous material flow
Solution Approach 1:
A common weighing container serves as an intermediary receptacle that collects material from multiple parallel hoppers simultaneously. The weighing container is positioned on a platform load cell that measures the total weight of all incoming materials together, simplifying the measurement task to a single aggregate measurement rather than requiring simultaneous measurement of multiple separate streams, thereby maintaining high productivity while ensuring accurate dosing
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 approach significantly increases throughput, reduces processing time, ensures accurate dosing, and maintains product quality by preventing overdosing and bridging, while minimizing device footprint and operation interruptions.
Implementation Method 1
the amount of plastic granulate is continuously weighed during the filling
Data Source
AI summary
The invention relates to a method and a device for dosing bulk material, in particular plastic granulate, for machines processing plastic granulate, in particular for injection molding machines. Different amounts of different plastic granulates are filled in batches according to freely adjustable formulas and each individual type of a plastic granulate, such as for example virgin material, masterbatch, additives and/or material to be ground, is successively released into a weighing container from a material hopper (2) via a material valve. Weighing occurs in the weighing container (4) and the formula amount is subsequently blended into a mixer. The amount of plastic granulate, preferably the virgin material and/or material to be ground, disproportionately high for the formula is filled into the weighing container (4) from at least two material hoppers (2) by means of a parallel filling or multiple parallel filling.