Counter-Rotating Plastic Preprocessor for Clogging Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing plastic recycling devices face challenges in processing sensitive or strip-shaped materials due to premature melting, clogging, and reduced throughput, particularly when materials are heated near their melting point, leading to inefficient processing and maintenance issues.

Innovation Solution

The device modifies the configuration by reversing the rotation direction of the mixing and crushing tools relative to the conveyor, offsetting the central longitudinal axis of the conveyor opposite to the conveying direction, and optimizing the angle of attack and spacing of the mixing tools to reduce feed pressure and prevent overfilling, allowing for better material intake and processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the mixing and crushing tools rotate in the same direction as the conveyor conveying direction, then the material can be actively pushed into the extruder, but the feed pressure becomes too high causing premature melting and clogging

Engineering Contradiction:
ImprovethroughputVSAvoidpremature melting
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies the inversion principle by rotating the mixing and crushing tools in the opposite direction to the conveyor's conveying direction. This creates a counter-rotating effect that reduces the stuffing pressure on the material in the feed area, preventing premature melting while maintaining adequate feed rate to the extruder.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If the extruder intake area is widened to increase material intake, then throughput increases, but the material melts and clogs the system

Engineering Contradiction:
ImprovethroughputVSAvoidclogging
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

By reversing the rotation direction of the mixing tools relative to the conveyor, the patent reduces the compaction pressure in the feed area. This allows the extruder intake to operate at wider opening without causing material to melt and clog, as the counter-rotating tools prevent excessive stuffiness in the feed zone.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If the mixing tools are positioned closer to the extruder to improve material transfer, then feeding efficiency increases, but the material is over-compressed and melts

Engineering Contradiction:
Improvefeeding efficiencyVSAvoidmaterial temperature
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The counter-rotating mixing tools reduce the compression effect on the material even when positioned close to the extruder. This allows efficient material transfer and feeding while preventing excessive temperature rise from over-compression, as the opposite rotation creates a gentler material handling action.

Inventive Principle:
Principle #13The other way round (Inversion)

4Object-affected harmful factors

If the rotation direction of mixing tools is reversed to reduce feed pressure, then premature melting is prevented, but material intake efficiency may decrease

Engineering Contradiction:
Improvepremature meltingVSAvoidmaterial intake
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent applies the inversion principle to rotate mixing tools opposite to the conveyor direction, which reduces feed pressure and prevents premature melting. The counter-rotating tools maintain adequate material intake efficiency by creating a different flow pattern that prevents clogging while ensuring continuous material supply to the extruder.

Inventive Principle:
Principle #13The other way round (Inversion)

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 configuration improves material intake behavior, increases throughput, and enhances the stability and efficiency of the system by preventing premature melting and clogging, allowing for consistent and reliable processing of various plastic materials.

Implementation Method 1

The plastic material fed to the receptacle is comminuted by rotating the comminuting and mixing tools and causing thrombi to circulate and being heated at the same time by the energy introduced

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the screw extruder is arranged approximately at the height of the comminution tools. In this way, the softened plastic particles are actively pushed or stuffed into the extruder by the mixing tools

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2766165B1Apparatus for processing plastic material
Publication Date: 2016.02.10 EREMA ENGINEERING RECYCLING MASCHINEN & ANLAGEN GMBH
  • EP2766165B1 patent drawingFigure 1~2
  • EP2766165B1 patent drawingFigure 3~4
  • EP2766165B1 patent drawing

AI summary

The invention relates to an apparatus for preprocessing and subsequently conveying or plasticizing plastics, comprising a container (1) with a mixing and/or comminuting tool (3) that can rotate about a rotational axis (10), wherein an opening (8) is formed in a lateral wall (9) through which the plastic material can be discharged and a conveyor (5) is provided with a screw (6) rotating in a housing (16). The invention is characterized in that the imaginary extension of the longitudinal axis (15) of the conveyor (5) passes by the rotational axis (10) counter the conveying direction (17), wherein the longitudinal axis (15) is on the outlet side offset by a distance (18) in relation to the radial (11) that is parallel to the longitudinal axis (15). The length/diameter ratio of the screw (6) is >=7 and the angle of attack (gamma) of the radially outermost, nearest-to-ground mixing and/or comminuting tool (3) is defined by the following relationship. gamma = k * d + K, wherein d is the diameter of the screw (6) in mm, K is a factor ranging from 15 to 35, and k is a factor ranging from 0.08 to 0.2.