Polyurethane Polycarbonate Composite Scraper Blade
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing scraper blades for conveyor belts suffer from insufficient abrasion resistance and shape maintenance, leading to reduced useful life and scraping efficiency, with previous solutions causing unnecessary wear or contamination.
Innovation Solution
A scraper blade composed of polyurethane (PU) with a longitudinal reinforcement of polycarbonate (PC), allowing for a larger contact surface and improved durability, while the PC material serves as both reinforcement and scraper, preventing lip formation and maintaining flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a homogeneous elastomeric or plastic material is used for the scraper blade, then the scraping effect is effective, but the abrasion resistance is insufficient
Solution Approach 1:
The scraper blade is constructed as a composite material consisting of a polyurethane layer bonded to a polycarbonate layer. The polyurethane provides effective scraping properties while the polycarbonate provides high abrasion resistance and structural support, resolving the contradiction between scraping effectiveness and abrasion resistance.
Solution Approach 2:
Different regions of the scraper blade are made of different materials with different properties. The polyurethane layer contacts the conveyor belt surface to provide effective scraping, while the polycarbonate layer provides structural support and abrasion resistance in the support region, allowing each material to perform its optimal function.
2Strength
If a hard metal insert is used in the scraper tip, then the abrasion resistance is increased, but unnecessary wear on the conveyor belt surface occurs and contamination of the conveyed material may happen
Solution Approach 1:
The invention uses a composite of polyurethane and polycarbonate materials that provide high abrasion resistance without the harmful effects of metal. This composite material achieves the required durability while maintaining compatibility with the conveyor belt surface and conveyed material, avoiding wear and contamination issues associated with metal inserts.
Solution Approach 2:
The invention changes the material parameters from metal to polymer composite, specifically using polyurethane bonded to polycarbonate. This parameter change maintains or improves abrasion resistance while eliminating the harmful effects of metal contact with the conveyor belt and material.
3Productivity
If the scraper blade is oriented obliquely to scrape off wet material from a curved surface, then the scraping coverage is improved, but the soft material layer forms a thin lip that does not come loose and impairs scraping result
Solution Approach 1:
The composite structure of polyurethane bonded to polycarbonate prevents lip formation by ensuring the materials remain in a plane together. The strong bond between layers and the rigidity of the polycarbonate support prevent the soft polyurethane layer from deforming and forming lips when the scraper is oriented obliquely, maintaining effective scraping even at improved angles.
Solution Approach 2:
The invention allows the scraper blade to be oriented obliquely to curved surfaces by preventing lip formation through its composite construction. The polycarbonate layer provides sufficient rigidity to maintain the blade's orientation and prevent the soft layer from deforming, enabling effective scraping on curved surfaces at optimized angles.
4Reliability
If a two-layer laminate with softer grade elastomeric material is used, then effective scraping is provided, but the softer layer forms a thin lip when oriented obliquely
Solution Approach 1:
The invention uses a specific composite material combination of polyurethane and polycarbonate where the bond strength and material properties prevent lip formation. Unlike previous two-layer laminates that used incompatible materials, this composite ensures the layers remain planar even when oriented obliquely, maintaining both effective scraping and proper shape.
Solution Approach 2:
The invention changes the material parameters by selecting polyurethane and polycarbonate with compatible bonding characteristics and appropriate hardness differences. This parameter selection ensures the softer polyurethane layer does not deform and form lips while still providing effective scraping contact with the conveyor belt.
5Duration of action of moving object
If fracture lines are provided on the scraper to maintain a constant tip, then the scraper life is extended, but the fracture lines cause weakening of the scraper and the new tip will be blunt
Solution Approach 1:
The composite structure of polyurethane bonded to polycarbonate provides inherent strength and durability that extends scraper life without requiring weakening fracture lines. The polycarbonate layer provides structural support that prevents premature failure, while the polyurethane layer maintains scraping effectiveness, eliminating the need for fracture line design.
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
The combination of PU and PC enhances scraping efficiency and extends the blade's life by maintaining a flexible scraper lip, reducing wear on the conveyor belt, and ensuring reliable adhesion and cost-effective production.
Implementation Method 1
supplying polyurethane to said casting mould, the polyurethane binding to the polycarbonate plastic reinforcement, to provide a coherent structure
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A scraper blade adapted to scrape off material from a conveyor bel surface (24) has a scraper tip (15) at one end and a mounting bas (16) at its other end and is tapered towards the tip at least in th outer end of the scraper blade, its scraper blade portion whic extends from the tip (15) and to a point adjacent to or in th mounting base (16) being made with at least two layers (40, 41) , which extend longitudinally along said scraper blade portion, and i characterised in that at least one first layer (40) is made o polyurethane with a lower hardness and a higher abrasion resistanc than at least one second layer (41) which is mainly made o polycarbonate plastic, said at least one second polycarbonat plastic layer (41) being adapted to reinforce and stiffen said a least one first layer, which constitutes a main contact surface (42) against said surface (24) . A method of manufacturing scraper blade for scraping webs of material is also included.