How To Choose The Blade Material for A Plastic Shredder?

Plastic Shredder Blade Material Selection Guide

The material of plastic shredder blades directly determines the shredding effect, service life, and equipment operating stability. Different types of plastics (hard and brittle materials / soft and tough materials / fiber-reinforced thick materials) have significantly different requirements for blade hardness, toughness, and shear force. Our factory precisely matches suitable blade materials for three major categories of plastics: ABS/PS/hard PVC, PE/PP/PA/film, and fiber-reinforced/thick/mixed materials. We provide detailed explanations of the core characteristics and applicable scenarios of each material to offer professional guidance.

 Characteristics of Different Types of Plastics and Blade Material Selection

The hardness, toughness, and fiber content of plastics determine the stress points during shredding. Hard and brittle materials are prone to impact, soft materials are prone to blade entanglement and adhesion, and fiber-reinforced materials are prone to wear on the cutting edge. Blade selection should follow the principles of high hardness, wear resistance, and impact resistance for hard materials; high toughness and shear force for soft materials; and high wear resistance and resistance to chipping for fiber-reinforced materials. Precise matching can reduce costs and improve efficiency.

Shredder Blades for Hard Plastics (ABS/PS/Hard PVC)

Plastic Characteristics

Hard plastics are hard and brittle. During the shredding process, the blades are susceptible to instantaneous impact forces, leading to problems such as chipping and rapid dulling of the cutting edge. This requires extremely high hardness, wear resistance, and impact resistance from the blades.

Recommended Material

SKD-11 High-carbon high-chromium alloy steel

Core Material Characteristics

1. Possesses extremely high hardness and superior wear resistance, maintaining a sharp cutting edge for a long time and significantly reducing the frequency of dulling;

2. Excellent impact resistance, able to withstand the instantaneous impact force of hard plastic shredding, preventing chipping and breakage;

3. High cutting edge strength, suitable for high-speed cutting of hard and brittle materials. 1.3 Shredder Blades for Soft/High-Toughness Plastics (PE/PP/PA/Soft PU/Film)

Plastic Characteristics

Soft/high-toughness plastics have strong elasticity and good ductility.  They are difficult to cut during shredding, leading to problems such as blade entanglement, material sticking to the blade edges, and material being discharged in strips. This requires blades with high toughness, shear strength, and smooth cutting edges.

Recommended Material

9CrSi Chromium Silicon Steel (Special alloy tool steel can be used for ultra-thin materials such as films/woven bags)

Core Material Characteristics

1. Excellent toughness, not easy to break, suitable for the high-speed shearing motion of the shredder, effectively cutting highly elastic plastics;

2. High precision grinding of the cutting edge and smooth surface reduce sticking and entanglement of soft plastics, ensuring efficiency;

3. Good processing performance, allowing for fine grinding of the cutting edge.

Shredder Blades for Fiber-Reinforced/Thick/Mixed Materials

Plastic Characteristics

Fiber-reinforced plastics (glass fiber/carbon fiber reinforced plastics) contain hard fibers, which can quickly wear down the blade edges; when shredding thick/mixed materials, the blades are subjected to multiple forces including impact, wear, and shear, making this the scenario with the highest demands on the overall performance of the blades.

Recommended Material

DC-53 High-Strength Tough Alloy Steel

Core Material Characteristics

1. Superior wear resistance compared to SKD-11, with excellent hardness and toughness, addressing the blade wear problem of fiber-reinforced materials and significantly increasing service life;

2. Outstanding resistance to chipping and fracture, suitable for the strong impact force of thick material crushing and the complex stress environment of mixed material crushing;

3. Good high-temperature stability; the cutting edge is not easily deformed during long-term continuous crushing of thick/mixed materials, maintaining a stable shearing effect. 2. Plastic Shredder Blade Selection: Pitfalls to Avoid and Recommendations

Key Pitfalls to Avoid

Don't blindly choose high-end materials: Using SKD-11/DC-53 for small batches of soft plastic waste can lead to wasted costs; 9CrSi is sufficient.

Don't arbitrarily replace sizes: Non-original sizes will lead to uneven assembly gaps, damaging the blade shaft and shredder in the long run.

Don't ignore blade edge precision: Using blades with rough edges for soft plastic shredding will exacerbate blade entanglement and sticking problems, reducing efficiency.

For hard plastics, choose SKD-11; for soft plastics, choose 9CrSi; for fiber-reinforced thick materials, choose DC-53.

Entry-level/general-purpose: Choose 9CrSi, which is inexpensive and suitable for most recycled materials without special requirements.

Professional high-efficiency type: Choose SKD-11, which is currently the mainstream configuration for mid-to-high-end shredders and offers the best overall cost-effectiveness.

Wear-resistant type: If the budget is sufficient and you are processing high-fiber materials and thick materials, choose DC-53.