εταιρικά νέα για How to Choose Granulator Knife Material? Cost-Effectiveness Comparison: Tungsten Carbide vs. High-Speed Steel vs. Cerami

The material of granulator knives is a core factor determining granulation efficiency, tool lifespan, and overall production costs. Currently, the mainstream granulator knife materials on the market include tungsten carbide cemented carbide, high-speed steel (HSS), and ceramics. Different materials vary significantly in hardness, wear resistance, impact resistance, and cost, and are suitable for distinct materials (plastic, rubber, biomass, etc.) and working conditions. Blind selection either leads to frequent tool wear, increased costs from downtime for knife replacement, or waste from overinvesting in high-end materials. This article provides a detailed comparison of the core performance, applicable scenarios, and overall cost-effectiveness of the three materials through plain language and clear tables, helping industry practitioners accurately select materials based on their needs (material type, output, budget) and find the optimal balance between efficiency and cost.

Before comparing cost-effectiveness, let’s briefly understand the core composition and performance characteristics of the three materials to lay the foundation for subsequent selection:

• Core Composition: Composed of tungsten carbide (WC) as the hard phase and cobalt (Co) as the binder phase, sintered via powder metallurgy (common grades: YG6, YG8, YG12);
• Core Performance: Extremely high hardness (HRA≥90, equivalent to HRC68-72), the strongest wear resistance among the three materials, and medium impact resistance (optimizable by adjusting cobalt content);
• Key Features: Suitable for harsh working conditions with high abrasion and impurities, long service life, and reduced frequency of knife replacement, but relatively high cost per knife.

• Core Composition: Alloy tool steel (containing elements such as tungsten, molybdenum, chromium, and vanadium), common models: W18Cr4V, W6Mo5Cr4V2;
• Core Performance: Medium hardness (HRC62-65), good toughness, strong impact resistance, and average wear resistance;
• Key Features: Simple processing technology, low cost per knife, suitable for granulation of ordinary soft materials, but fast wear and frequent knife replacement required.

• Core Composition: Sintered with alumina (Al₂O₃) or silicon nitride (Si₃N₄) as the matrix, supplemented with a small amount of additives;
• Core Performance: Extremely high hardness (HRA≥92, higher than tungsten carbide), strong wear resistance, high-temperature resistance (capable of withstanding temperatures above 800℃), but extremely poor impact resistance (high brittleness);
• Key Features: Suitable for special working conditions with no impurities, high rotation speed, and high temperature, cost per knife between HSS and tungsten carbide, but prone to chipping and requiring high maintenance.

Below is a detailed comparison of key performance, costs, and applicable scenarios of the three materials. "Relative values" are based on HSS (set to 1) for intuitive understanding:

• Comprehensive cost calculation logic: Comprehensive cost = (cost per knife ÷ service life) + downtime loss from knife replacement. Although tungsten carbide has a higher unit cost, its long service life and fewer replacements result in the lowest long-term comprehensive cost;
• "Adjustability" of tungsten carbide: By adjusting cobalt content (low-cobalt YG6 for wear resistance, high-cobalt YG12 for impact resistance), it can adapt to different working conditions, further improving cost-effectiveness;
• "Special Value" of ceramics: It is the only choice for high-temperature (e.g., >500℃) or "metal-free contamination" scenarios (e.g., medical material granulation).

• Applicable Scenarios: Recycled plastic (containing sand grains, metal debris), biomass (straw, rice husk, silicon-containing), waste rubber (containing steel wire, fibers), hard plastic (nylon, ABS hard materials);
• Selection Logic: These materials cause severe tool wear. HSS needs replacement every 1-2 weeks, and downtime losses far exceed the cost of a single knife; ceramics are prone to chipping from impurity impact; tungsten carbide’s high wear resistance and medium impact resistance allow stable use for 1-3 months, resulting in the lowest comprehensive cost.
• Recommended Tungsten Carbide Grades: YG10/YG12 (high cobalt, impact-resistant) for impurity-rich materials; YG6/YG8 (low cobalt, more wear-resistant) for pure hard materials.

• Applicable Scenarios: New soft plastic (PE/PP film, soft PVC), soft rubber (natural rubber new material), low-output granulation (daily output <5 tons);
• Selection Logic: These materials cause minimal wear, and HSS’s wear resistance is sufficient. With a unit cost only 1/5-1/8 that of tungsten carbide, it is suitable for small-scale production with limited budgets and low sensitivity to downtime losses.
• Notes: Prepare multiple spare knives to avoid production delays during replacement; regularly grind the cutting edge to extend single-use time.

• Applicable Scenarios: High-temperature granulation (e.g., engineering plastic granulation, material temperature >300℃), impurity-free precision granulation (e.g., medical silicone, high-purity plastic), impact-free working conditions (e.g., ring-die granulator, low rotation speed);
• Selection Logic: Ceramics’ high-temperature resistance and ultra-high hardness meet special needs, and their metal-free nature is suitable for scenarios requiring high material purity; however, materials must be impurity-free to avoid chipping from impact.
• Usage Suggestions: Use elastic tool holders to buffer impact and avoid tool collision during no-load operation.

1. Blindly Pursuing "Highest Hardness": Assuming ceramics are the best due to their highest hardness, ignoring their poor impact resistance. When used for impurity-containing materials, they may chip in 1-2 days, increasing costs instead;
2. Focusing Only on Unit Cost: Choosing HSS because it is the cheapest, but neglecting downtime losses from frequent replacements (e.g., for recycled plastic granulation with a daily output of 10 tons, each knife replacement causes 2-3 hours of downtime, equivalent to thousands of yuan in losses);
3. Tungsten Carbide "The More Expensive the Better": Blindly selecting high-cobalt, fine-grain high-end tungsten carbide for ordinary soft materials, resulting in performance overcapacity and unnecessary investment;
4. Ignoring Working Condition Adaptability: Selecting ceramics for impact-prone working conditions (e.g., flat-die granulators) or HSS for impurity-containing working conditions, leading to extremely short tool life.

Taking "recycled plastic granulation (daily output 10 tons, containing a small amount of impurities)" as an example, compare the annual usage costs of the three materials (based on 300 working days per year):

Conclusion: In this scenario, the annual comprehensive cost of tungsten carbide is only 22% of HSS and 35% of ceramics, showing significant cost-effectiveness advantages.

There is no "absolutely best" granulator knife material, only the "most suitable":

• High-abrasion, impurity-containing, high-output working conditions → Tungsten carbide cemented carbide (highest comprehensive cost-effectiveness);
• Ordinary soft materials, low output, limited budget → High-speed steel (economical and practical);
• High-temperature, impurity-free, precision granulation → Ceramics (exclusive for special needs).

As a tungsten carbide industry practitioner, we recommend prioritizing tungsten carbide granulator knives for mid-to-high-end, high-output scenarios. Not only can they help customers reduce knife replacement frequency and improve efficiency, but they can also be further adapted to different materials (e.g., high-cobalt for impact resistance, low-cobalt for wear resistance) by adjusting tungsten carbide’s cobalt content and cutting edge structure, maximizing cost-effectiveness.

If you need customized tungsten carbide granulator knife solutions based on specific material types (e.g., biomass, waste rubber), granulator parameters, or output requirements, please contact us for precise selection advice to help balance production efficiency and comprehensive costs!