Base belt

Recently, the engineering service team from QBF rubber was dispatched to a tunnel project site and successfully completed on-site installation guidance for the sidewall conveyor belt. Supported by one-stop full-process technical services, the project’s conveying equipment achieved stable commissioning and high-efficiency operation. Tunnel construction presents tough site conditions, featuring steep conveying angles and considerable risks of material back-sliding and spillage. Breaking away from the traditional product-only supply model, QBF rubber provides a full-chain custom service package for this project. The service scope includes preliminary site survey, working-condition analysis, custom belt selection and design, bespoke belt manufacturing, on-site hot-splicing joint execution and full-cycle installation technical guidance. This complete set of services fully meets the operational demands of steep-angle material handling for tunnel construction. Shield tunnel jobs have tight working spaces, limited on-site manoeuvring, high muck volumes and wet excavated spoil. These conditions commonly cause spoil and fines to stick and pile up on conveyor belts. For this project, QBF rubber Anti-stick Sidewall Conveyor Belt was selected to tackle such field-proven issues. The belt’s special surface treatment resists sticking and enables good self-cleaning capability. It keeps damp tunnel muck and fine sand from clinging to the belt surface, helping avoid common problems triggered by material build-up: belt mis-tracking, slippage, faster-than-normal wear and reduced conveying capacity. Built with heavy-duty sidewalls and cleats, the belt is robust in structure, offers high tensile properties and holds up well against abrasion. It runs reliably for both vertical and steep inclined conveying work, cutting down significantly on material fallback, spillage and leakage. This brings tangible savings in on-site cleaning work and lowers the frequency of equipment maintenance. Having expanded from standalone product supply to end-to-end technical services, QBF rubber keeps addressing practical tunnel conveying challenges through professional, custom-built solutions. Moving ahead, QBF rubber will keep focusing on shield-tunnel muck transport and steep-angle material handling applications. Continuous upgrades to product performance and service frameworks will deliver reliable support for the efficient, eco-friendly and safe running of more engineering projects.

According to industry statistics, up to 80% of sidewall conveyor belt failures occur due to rigidity loss–induced sagging during operation. QBF rubberaddresses this root cause with an innovative “free zone ” base belt design, significantly extending the service life of sidewall conveyor belts. What Is Belt Sagging and Why Does It Shorten Belt Life? Under heavy load, especially on the return run, the base belt often sags due to insufficient transverse rigidity. This sagging triggers a chain of serious issues: Stress concentration – Sagging causes abnormal flexing at the sidewall root as it passes over the drum, concentrating stress in a localized area. Fatigue cracking – Repeated flexing leads to fatigue cracks at the sidewall root, which can develop into through-wall damage. Baffle detachment – Vibration and deformation from sagging transfer to the baffle connection, accelerating adhesive aging and causing baffle loosening or separation. Once sidewall tearing or baffle detachment occurs, the entire sidewall conveyor belt often fails prematurely. Therefore, solving the sagging problem is the key to extending belt service life. Root Cause of Belt Sagging The core cause of sagging lies in structural deficiencies of traditional base belt designs: Insufficient transverse rigidity – Traditional base belts cannot maintain a flat profile under heavy loads or long-span conditions. Unbuffered stress transfer – The sidewall-to-base belt connection lacks a flexible transition, so abnormal sagging stress directly impacts the sidewall root. Accelerated fatigue accumulation – Repeated flexing at stress concentration points causes cracks to grow from micro to macro levels. Understanding these causes makes it clear: simply increasing sidewall thickness or changing the rubber compound is a temporary fix. The solution must start with the base belt structure. Solution: QBF rubber Free Zone Base Belt Design QBF rubber introduces a “free zone ” base belt design to directly target the root cause of sagging. How the free zone  Works Blocks stress transfer – The free zone  acts as a stress buffer, absorbing and isolating abnormal sagging stress before it reaches the sidewall root. Dissipates flexing energy – The flexible edge allows the base belt to adaptively deform as it passes over the drum, spreading concentrated flexing over a larger area. Protects sidewall and baffles – By mitigating the extra load caused by sagging, the risk of fatigue tearing at the sidewall root is greatly reduced, and the baffle adhesive layer no longer suffers excessive vibration stress. Key Advantages of the free zone  Design Advantage Result sidewall tear resistance Eliminates stress concentration points; fatigue life extended by 2–3 times Baffle detachment risk Smoother operation; significantly slower adhesive aging Overall belt service life Comprehensive service life increased by 30% or more   QBF rubber’s Free Zone Base Belt design achieves a leap from “reacting to sagging consequences” to “eliminating the root cause of sagging.” Summary: Eliminate Sagging at the Source for Longer Sidewall Belt Life The sagging problem in heavy-duty sidewall conveyor belts originates in the base belt structure. QBF rubber’s free zone  design solves this industry pain point by blocking stress transfer, dissipating flexing energy, and protecting both sidewall and baffles. If you are experiencing frequent sagging, sidewall tearing, or baffle detachment with your sidewall conveyor belt, contact QBF rubber for professional technical support and customized solutions.