When selecting screw conveyor equipment, whether to equip a U‑type shaftless screw conveyor with or without liners is a critical issue that many purchasers and equipment managers tend to overlook.
What may appear to be an “optional accessory” can, in fact, directly determine the equipment’s service life, maintenance frequency, and long-term operating costs. Whether or not to install it is not a matter of personal preference; the key factors are the characteristics of the conveyed material and the severity of the operating conditions.
Today, we’ll delve into the selection process from a professional standpoint, helping you steer clear of common pitfalls in choosing the right solution.
First, understand the core principle: Why should liner plates be given special consideration in shaftless models?
In shafted screw conveyors, the material is conveyed by a central shaft and blades, with a gap between the blades and the bottom of the trough, resulting in relatively controllable friction and wear. In contrast, U‑shaped shaftless screw conveyors lack a central shaft for support; the blades operate in complete suspension, and their outer edges come into direct contact with the bottom plate of the U‑shaped trough, leading to full‑surface, continuous abrasion. When the conveyed material is abrasive, the trough’s steel plate can quickly become thinned or even punctured, directly rendering the entire machine unusable and driving up maintenance and replacement costs. Liners serve to take on the wear that would otherwise be borne by the trough bottom; when damaged, only the liner needs to be replaced, eliminating the need to overhaul the entire unit, thereby significantly reducing operating and maintenance expenses and extending the machine’s service life.

I. Operating Conditions Requiring the Installation of Liners
If any of the following conditions apply, we strongly recommend installing a liner; never skimp on this—doing so could lead to far greater costs down the line.
1. Conveying highly abrasive materials
Sand and gravel, slag, coal powder, furnace slag, construction waste, quartz sand, tailings powder, and similar materials contain a large proportion of hard particles, resulting in extremely severe erosive wear on the trough.
2. Conveying sludge containing impurities and abrasive particles
Municipal sewage sludge, industrial sludge, and grit from grit chambers contain a mixture of sand, gravel, and metallic debris, making their abrasive nature far more severe than that of typical soft materials.
3. High-Intensity Continuous Operation Conditions
24-hour continuous production and heavy-load, long-duration operation double the friction frequency, sharply accelerating wear on the trough.
4. Long-term conveyance of alkaline/corrosive abrasives
Chemical waste residues and metallurgical slags are both abrasive and corrosive; without liner protection, the tank body suffers from dual failure—corrosion combined with wear.

II. Operating Conditions Requiring No Liner Installation
If all of the following conditions are met, a liner need not be installed, thereby controlling equipment costs:
1. Purely soft, non-abrasive material
Food waste, kitchen scraps, rotten fruit and vegetable leaves, pulp, fibrous waste, distiller’s grains, pharmaceutical residues, livestock and poultry manure, and the like.
2. The material contains no hard particulate impurities.
The material is soft in texture and contains no hard particles such as sand, gravel, metal, or broken glass, thus preventing erosive wear on steel plates.
3. Intermittent Light-Load Operation
The equipment does not operate continuously around the clock; its daily operating hours are relatively short, and its load is light.

III. Recommended Selection of Common Lining Plate Materials
1. Wear-resistant nylon liner (industry standard)
It offers the best value for money, with excellent wear resistance, low operating noise, minimal friction, and reduced material adhesion. It is compatible with conventional sludge, food waste, and common abrasives, making it suitable for the broadest range of applications.
2. Polyurethane Liner Board
It boasts exceptional anti‑sticking and anti‑clogging performance, as well as outstanding corrosion resistance, making it ideal for handling high‑moisture, viscous materials, corrosive sludges, and food waste—non‑sticky and easy to clean.
4. Wear-resistant lining plate made of high-manganese steel
Ultra‑high wear resistance, specifically engineered for ore, slag, heavy abrasives, and high‑load, high‑stress operating conditions; maximum durability, but at a relatively higher cost.

IV. Summary: A One-Phrase Guideline for Product Selection
Hard abrasive materials, continuous heavy loads, and sand‑laden sludge all require the installation of liner plates.
For soft materials free of impurities, intermittent light conveying, and non-abrasive materials, liner plates may be omitted.