Reading Guide
1. Overview
Dual-Shaft Shredder Blades Selection Guide
This guide from Tyrone Environmental Protection Company is specifically designed for Twin shredder users. It focuses on two core principles: “matching material characteristics + optimal cost-effectiveness,” systematically outlining blades material selection solutions for different types of shredded materials.
The content covers common shredded material classifications, key parameters of suitable materials, cost-effectiveness comparisons, and application recommendations. All solutions are based on the low-speed, high-torque working characteristics of dual-shaft shredders and extensive practical engineering case studies. The aim is to help users quickly identify the most suitable material, balancing shredding efficiency, blades lifespan, and operating costs.
2. Classification of Core Materials and Corresponding Tool Material Selection
The following are the cost-effective material selections for various types of materials:
Dual-shaft shredders are suitable for a wide range of materials, which can be divided into six main categories based on core characteristics such as hardness, wear resistance, and impurity content.
I. Lightweight, Soft Materials (without impurities)
Representative materials: Waste PE/PP films, woven bags, foam plastics, paper packaging, soft PVC films, non-reinforced plastic scraps (thin-walled injection molded parts)
Cost-effective material recommendation (prioritizing cost control): 65Mn spring steel
Core requirements: Moderate blade sharpness, basic impact resistance, no need for extremely high wear resistance
– Material parameters: Excellent toughness, strong impact resistance
– Cost-effectiveness advantages: Low processing cost, unit price is only 1/3-1/4 of alloy tool steel, service life can reach 80-120 tons of material when processing lightweight materials, simple maintenance, can be sharpened independently, lowest overall operating and maintenance costs
– Alternative material: If higher sharpness and longer sharpening cycles are required, SK5 carbon tool steel can be selected, which is slightly more expensive than 65Mn, suitable for fine shredding of film-like materials.
(II) General-Purpose Hard Plastics (No impurities/small amount of soft impurities)
Representative materials: ABS/PS/HIPS casings (appliance casings, daily necessities casings), ordinary PC/PMMA sheets, PP/PE thick-walled pipes (diameter ≤ 200mm), plastic pallets (non-reinforced), sprue waste (general-purpose plastics)
Recommended high-cost-performance material: SKD-11 cold work tool steel
Core requirements: Wear resistance superior to materials suitable for light materials, with good toughness, capable of withstanding medium impact loads
– Material parameters: High hardness + balanced toughness, good hardenability, wear resistance is 2-3 times that of 65Mn
– Cost-performance advantages: Mainstream general-purpose material, moderate unit price, service life can reach 150-250 tons of crushed material, suitable for a variety of general-purpose hard plastics, no need for frequent tool changes, balancing efficiency and cost; can handle a small amount of soft impurities (such as paper scraps and fabrics adhering to the material surface), wide range of applications
– Alternative materials: For limited budgets, 9CrSi alloy tool steel can be selected, costing 0.7 times that of SKD-11; M6V alloy tool steel, costing about 0.8 times that of SKD-11, with wear resistance between 9CrSi and SKD-11, suitable for small and medium-sized users with a daily crushing volume of ≤ 8 tons; for sufficient budgets and increased lifespan requirements, Cr12MoV can be selected, costing 1.3 times that of SKD-11, with a service life increased to 200-300 tons
(III) Reinforced/Filled Plastics (including glass fiber/mineral fillers)
Representative materials: PA6/PA66 + glass fiber reinforced materials (glass fiber content ≤ 30%), PP/PC reinforced materials (glass fiber content ≤ 20%), modified plastics containing mineral fillers, automotive interior reinforced parts
Recommended cost-effective material: W6Mo5Cr4V2 general-purpose high-speed steel
Core requirements: High wear resistance, capable of withstanding the cutting and abrasive wear of glass fiber/mineral particles, and possessing sufficient toughness to prevent chipping.
– Material parameters: Excellent red hardness (high temperature resistance ≤ 600℃), wear resistance is 1.5-2 times that of SKD-11, and strong fatigue resistance.
– Cost-effectiveness advantages: Optimal suitability for medium-to-low glass fiber content fillers, unit price is 1/3-1/4 of cemented carbide, service life can reach 300-500 tons of crushed material, no need for complex cooling systems, and lower maintenance costs than cemented carbide; if the glass fiber content is ≤ 10%, SKD-11 can also be used (requires shorter sharpening cycles) to further control initial procurement costs.
– Alternative materials: When the glass fiber content is ≥ 25%, M2 high-performance high-speed steel can be selected, at a cost 1.2 times that of W6Mo5Cr4V2, with a 20% improvement in wear resistance and a service life of 400-600 tons.
(IV) Materials Containing Impurities (including sand/metal impurities/hard particles)
Representative materials: PET bottle bales (containing sand and dust impurities), waste household appliance casings (containing trace metal impurities), plastic pipes (containing concrete impurities), industrial waste plastics (containing metal fragments)
High-cost-performance material recommendation: Tungsten carbide (WC-Co) (insertable cutting head)
Core requirements: Extreme wear resistance, moderate impact resistance, able to withstand the impact and abrasion of impurities, reducing the risk of chipping.
– Material parameters: Wear resistance is 5-8 times that of high-speed steel, and hardness is close to diamond.
– Cost-effectiveness advantages: Adopting a “tool body + insertable carbide cutting head” structure, the cost is reduced by more than 50% compared to integral carbide tools. The service life can reach 800-1200 tons of material containing impurities, avoiding frequent tool changes due to impurities, resulting in the best long-term overall cost. The cutting head can be replaced individually after wear, without replacing the entire tool, further reducing maintenance costs.
– Alternative material: If the budget is limited, TiAlN coated SKD-11 can be selected. The cost is 1/2 of the insertable carbide, and the wear resistance is increased by 30%-50%. It is suitable for materials containing a small amount of minor impurities, with a service life of approximately 200-300 tons.
(V)Special Corrosive/High-Temperature Materials
Material Examples: Plastics containing halogenated flame retardants, rigid PVC products (containing chlorine), PEEK/PTFE modified materials, high-temperature cured plastic waste
Cost-Effective Material Recommendation: TiAlN coated SKD-11 (base material)
Core Requirements: Excellent corrosion resistance, high temperature resistance, and certain wear resistance
– Material Parameters: Surface hardness after coating HRC 70-72 degrees, excellent corrosion resistance and anti-sticking properties, high temperature resistance ≤800℃
– Cost-Effectiveness Advantages: Compared to overall corrosion-resistant alloys, the cost is reduced by more than 60%. The coating effectively isolates corrosive materials from the blade body, and the service life can reach 180-250 tons of corrosive material; the coating can be recoated after wear, and the blade base material can be reused, further improving cost-effectiveness.
– Alternative Materials: For limited budgets, TiAlN coated SKD-11 can be selected, costing 1/2 of cemented carbide inserts, with a 30%-50% increase in wear resistance, suitable for materials containing a small amount of slight impurities, with a service life of approximately 200-300 tons; for mixed plastics with slight impurities or low-hardness rubber and plastic composite materials, Hardox550 wear-resistant steel can be used, costing 1/2 of cemented carbide inserts, with a service life of 350-450 tons, and strong versatility; for industrial plastic waste with moderate impurities or high-hardness plastic alloys, Hardox600 wear-resistant steel is recommended, costing 70% of cemented carbide inserts, with a service life of 600-800 tons, suitable for high-load mixed crushing scenarios.
(VI)Large, Heavy Materials (High Impact Load)
Large, Heavy Materials (High Impact Load)
Representative Materials: Large plastic pallets, thick-walled PE/PP pipes (diameter ≥300mm), giant injection molded sprues, plastic fuel tanks (heavy-duty)
Cost-Effective Material Recommendation: Cr12MoV Cold Work Tool Steel
Core Requirements: High toughness + high wear resistance, capable of withstanding the impact load of large materials, preventing blade breakage
– Material Parameters: Extremely high wear resistance, outstanding deformation resistance, and superior toughness compared to ordinary high-speed steel
– Cost-Effectiveness Advantages: Suitable for high-impact load scenarios, with a service life of 200-300 tons of heavy material shredded; the unit price is 0.8 times that of high-speed steel, resulting in lower overall costs compared to using high-speed steel; can withstand repeated impacts from large materials, reducing the risk of blade breakage and the high cost of replacing the entire blade.
– Alternative Material: For large-scale production scenarios with a daily shredding volume of ≥30 tons, M2 high-performance high-speed steel can be selected. The cost is 1.5 times that of Cr12MoV, and the service life is increased to 400-600 tons, suitable for high-frequency, high-intensity shredding needs.
3.Core Principles for Cost-Effective Blades Selection
Select cutting blades based on cost-effectiveness
1. Priority of Matching Principle:
Avoid “overkill” or “underkill” – for lightweight, soft materials, 65Mn is sufficient; there’s no need to blindly pursue high-speed steel/carbide. For materials containing glass fiber/impurities, using ordinary tool steel will lead to frequent tool changes and soaring overall costs; it’s better to directly choose high-speed steel/carbide.
2. Scale Adaptation Principle:
For small and medium-sized users with a daily crushing volume of ≤5 tons, prioritize low-cost materials such as 65Mn and 9CrSi; for users with a daily crushing volume of 5-20 tons, prioritize SKD-11 (general scenarios) and W6Mo5Cr4V2 (enhanced material scenarios); for large-scale users with a daily crushing volume of ≥20 tons, prioritize long-life materials such as Cr12MoV and inlaid carbide to improve overall efficiency by reducing downtime for tool changes.
3. Maintenance Cost Trade-off Principle:
Ultra-hard materials such as carbide have high initial purchase costs, but low maintenance frequency and long lifespan; ordinary tool steel has low initial costs, but requires frequent sharpening and has a short lifespan. Small and medium-sized users can prioritize materials that are easy to maintain, while large users can choose long-life materials to reduce downtime losses.
4. Structural Optimization Principle:
For materials containing impurities, prioritize “inlaid carbide tool heads” rather than integral carbide tools, which can significantly reduce initial purchase costs; for coated materials, prioritize types where the “base material can be repeatedly coated,” improving the reusability of the tool body.
4.Comparison Table of Common Materials and Their Cost-Effectiveness
Choosing the Right Knife Material
| Material Type | Applicable Material Range | Service Life (tons/blade) | Adaptation |
|---|---|---|---|
| 65Mn Spring Steel | Lightweight, flexible materials (films, woven bags, etc.) | 80-120 | In applicable scenarios |
| M6V Alloy Steel | High-fiber reinforced materials with a glass fiber content of 25%-40% | 120-200 | Ideal for various application scenarios |
| SKD-11 Cold Work Tool Steel | Rigid plastics (appliance casings, thick-walled pipes, etc.) | 150-250 | Preferred for general scenarios |
| W6Mo5Cr4V2 High-Speed Steel | Reinforced/filled plastics (glass fiber content ≤ 30%) | 300-500 | Preferred for reinforced materials |
| Inlaid WC-Co Cemented Carbide | Materials containing impurities/highly abrasive materials | 800-1200 | Ideal for impure materials |
| TiAlN Coated SKD-11 | Corrosive/Sticky materials | 180-250 | Ideal for corrosive environments |
| Cr12MoV Cold Work Tool Steel | Large and heavy materials | 200-300 | Ideal for heavy materials |
| H13 Alloy Steel | Metal-containing plastics | 300-500 | Ideal for metal-containing plastics |
5.Additional Suggestions
Basic Knowledge of Cutting Blades
1. If the types of materials to be shredded are complex (e.g., shredding general plastics and a small amount of reinforced materials simultaneously), it is recommended to prioritize SKD-11 material, considering both adaptability and cost; if there are large quantities of both materials, consider customizing a dual-set of cutting tools, each adapted to different materials.
2. New users can first verify material compatibility through small-batch testing to avoid incompatibility issues after direct bulk purchase.
3. The service life of cutting tools is closely related to operating procedures (such as feed particle size, speed adjustment, lubrication, and cooling). Standardized operation can increase tool life by 10%-30%, further improving cost-effectiveness.
