bedrijfsnieuws over Why Are Cemented Carbide Slitting Circular Blades the First Choice for Tape Slitting?

Tape slitting is a critical process in tape production and processing, requiring adaptation to the characteristics of different tape types—such as BOPP transparent tape, double-sided tape, foam tape, and masking tape. Some are as thin as 20μm (e.g., ultra-thin tape for the electronics industry), some are adhesive and prone to sticking, and others have tough substrates (e.g., cloth-based tape). This places core demands on slitting blades: "smooth, burr-free cuts, wear-resistant edges with fewer blade changes, anti-adhesion to avoid gumming, and compatibility with high-speed slitting." Cemented carbide slitting circular blades (with tungsten carbide as the core, combined with cobalt/nickel binders) perfectly meet these requirements due to their high hardness, excellent wear resistance, and strong edge stability. They not only improve the precision and efficiency of tape slitting but also reduce long-term maintenance costs, making them the mainstream choice for slitting processes in the current tape industry. This article starts from the needs of tape slitting, breaks down the adaptive advantages of cemented carbide slitting circular blades, and compares the shortcomings of other material blades, helping you clearly understand why they hold the "first choice" position.

1. First, Clarify: 3 Core Requirements for Tape Slitting

To understand why cemented carbide blades are the preferred choice, it is first necessary to clarify the key problems that blades must solve in tape slitting scenarios—these needs directly determine the direction of blade material selection:

1.1 Cut Quality: Burr-Free and No Stretching Deformation

Tape slitting requires "neat edges," especially in fields with high precision requirements such as electronics and packaging (e.g., slitting of mobile phone screen protectors):

• If the cut has burrs (> 0.02mm), it will cause uneven adhesion during tape use and even affect product appearance;
• If the blade edge is not sharp, the tape substrate (e.g., BOPP film) will stretch during slitting, leading to dimensional deviation (> 0.1mm) that cannot meet the consistency requirements of mass production.

1.2 Durability: Fewer Blade Changes and Adaptability to Long-Term Production

Tape production is mostly a continuous operation (some production lines run 24 hours a day). If the blade has poor wear resistance, the edge will quickly become dull (e.g., high-speed steel blades slitting ordinary transparent tape may need sharpening every 1-2 days), resulting in:

• Frequent shutdowns for blade changes, affecting production efficiency (each blade change requires debugging, taking 30-60 minutes);
• Repeated sharpening shortens blade life and increases tool procurement and maintenance costs.

1.3 Anti-Adhesion and High-Temperature Resistance: Adaptation to Adhesive Tapes and High-Speed Slitting

When slitting adhesive tapes (e.g., double-sided tape, hot-melt adhesive tape), the adhesive layer is prone to sticking to the blade edge, causing "gumming" and rough cuts. At the same time, high-speed slitting (production line speeds are mostly 100-300m/min) generates heat due to friction between the blade and the tape (temperatures can reach 300-500°C). If the blade has poor high-temperature resistance, the edge is prone to softening and deformation. Therefore, blades must have the characteristics of "anti-adhesion to avoid gumming and high-temperature resistance without deformation."

2. 4 Core Advantages of Cemented Carbide Slitting Circular Blades for Tape Slitting

The characteristics of cemented carbide slitting circular blades are highly compatible with the needs of tape slitting, directly solving key pain points in tape slitting from four dimensions: "cut quality, durability, anti-adhesion and high-temperature resistance, and adaptability."

2.1 High Hardness + Excellent Wear Resistance: Long-Lasting Sharp Edge with Fewer Changes

Tungsten carbide, the core component of cemented carbide, has a room-temperature HRA hardness of 88-93—2-3 times that of high-speed steel and 4-5 times that of ordinary carbon steel:

• When slitting ordinary BOPP tape, the sharpness of the cemented carbide blade edge can be maintained for 3-6 months (continuous production), while high-speed steel blades only last 1-2 weeks, reducing the blade change frequency by more than 80%;
• For tough substrates (e.g., cloth-based tape, PET film tape), cemented carbide blades will not experience edge chipping or dulling due to substrate friction, avoiding "waste tape" caused by tool issues (the proportion of unqualified slit tape can be reduced from 5% with high-speed steel blades to less than 1%).

2.2 Strong Edge Stability: Smooth, Burr-Free Cuts with Precise Accuracy

After precision grinding, the edge roughness of cemented carbide slitting circular blades can be controlled at Ra ≤ 0.02μm, and the edge straightness is ≤ 0.005mm:

• When slitting ultra-thin tape (e.g., 20μm electronic-grade tape), it can achieve "no stretching or burrs at the cut," meeting the tape dimensional accuracy requirements (±0.05mm) for electronic component packaging;
• Compared with ceramic blades (which have high hardness but are prone to edge chipping), cemented carbide blades have better edge toughness (enhanced by cobalt binders). Even when slitting tapes with tiny impurities (e.g., some masking tapes containing fillers), edge notches are unlikely to occur, ensuring cut consistency.

2.3 Anti-Adhesion and High-Temperature Resistance: Adaptation to Adhesive Tapes and High-Speed Slitting

Through surface treatments (e.g., Diamond-Like Carbon (DLC) coating, Titanium Nitride (TiN) coating), cemented carbide slitting circular blades can further improve anti-adhesion and high-temperature resistance:

• Anti-Adhesion: The surface friction coefficient of DLC coating is ≤ 0.1. When slitting double-sided tape or hot-melt adhesive tape, the adhesive layer is not easy to stick to the edge, avoiding shutdowns for cleaning caused by gumming (cleaning frequency is reduced from 2-3 times a day to once a week);
• High-Temperature Resistance: Cemented carbide can retain more than 80% of its hardness below 500°C. Even when frictional heat is generated during high-speed slitting (300m/min), the edge will not soften or deform, adapting to the continuous high-speed operation needs of tape production lines.

2.4 Wide Adaptability: Efficient Slitting of Different Tape Types

There are various types of tapes with significant differences in substrate and adhesive layer characteristics. Cemented carbide slitting circular blades can adapt to different scenarios by adjusting "tungsten carbide grain size" and "surface treatment":

• Slitting thin tape (e.g., BOPP transparent tape): Fine-grain cemented carbide (1-3μm) is used for a sharper edge and smoother cut;
• Slitting thick/tough tape (e.g., cloth-based tape, foam tape): Medium-coarse grain cemented carbide (3-5μm) is used to improve edge toughness and avoid chipping;
• Slitting highly adhesive tape (e.g., hot-melt adhesive tape): DLC anti-adhesion coating is used to reduce adhesive layer sticking.

3. Intuitive Comparison with Other Material Slitting Blades: Cemented Carbide Has Obvious Advantages

To clearly demonstrate the "first choice" status, we compare cemented carbide slitting circular blades with common "high-speed steel blades, carbon steel blades, and ceramic blades" in tape slitting based on core indicators, showing their overall performance:

As shown in the table: Cemented carbide blades outperform other materials in "wear resistance, applicable speed, continuous service life, and maintenance cost," and their cut quality is comparable to ceramic blades (but with better chipping resistance), making them the most comprehensive performance choice.

4. Practical Application Cases: Adaptation Effects in Common Tape Slitting Scenarios

Theoretical advantages need to be verified with practical scenarios. Below are the application effects of cemented carbide slitting circular blades in common tape slitting scenarios, further illustrating their adaptability:

4.1 BOPP Transparent Tape Slitting (Most Common Scenario)

• Requirements: High-speed slitting (200-300m/min), neat cuts, and fewer blade changes;
• Cemented Carbide Blade Performance: Fine-grain (2μm) cemented carbide is used, with an edge roughness of Ra ≤ 0.01μm. After continuously slitting 1 million rolls (20m per roll), the edge shows no obvious wear, and the cut is burr-free. The blade change frequency is reduced from "once a week" with high-speed steel blades to "once every 3 months," increasing production efficiency by 15%.

4.2 Double-Sided Tape Slitting (High Adhesion Scenario)

• Requirements: Anti-adhesion to avoid gumming and no adhesive layer sticking after slitting;
• Cemented Carbide Blade Performance: Equipped with DLC anti-adhesion coating, the adhesive layer does not stick to the edge during slitting, eliminating the need for frequent shutdowns for cleaning (previously required every 2 hours with high-speed steel blades, now only once a day). The adhesive layer at the cut has no stretching, and the slitting dimensional deviation is controlled within ±0.03mm.

4.3 Foam Tape Slitting (Thick Substrate Scenario)

• Requirements: Strong edge toughness (foam substrates are elastic and prone to stress during slitting) and no edge collapse at the cut;
• Cemented Carbide Blade Performance: Medium-grain (4μm) cemented carbide with 10% cobalt content is used to improve edge toughness. When slitting 20mm thick foam tape, there is no edge chipping, the cut is smooth without collapse, and the service life is 1.5 times that of ceramic blades (which are prone to chipping due to foam elastic impact).

5. Comprehensive Cost Advantage: More Cost-Effective in Long-Term Use

Some users may be concerned about the "initial procurement cost" of cemented carbide blades (about 3-5 times that of high-speed steel blades), but in long-term use, their comprehensive cost is lower:

Taking a production line with a daily output of 100,000 rolls of ordinary transparent tape as an example, compare the annual costs of cemented carbide blades and high-speed steel blades:

• Cemented Carbide Blade: 1 blade costs $120, 2 blade changes per year (total $240), 2 sharpenings per year (each $15, total $30), annual total cost $270;
• High-Speed Steel Blade: 1 blade costs $30, 24 blade changes per year (total $720), 48 sharpenings per year (each $12, total $576), annual total cost $1,296;

It is evident that the annual comprehensive cost of cemented carbide blades is only 21% of that of high-speed steel blades, significantly reducing production costs in long-term use.

Conclusion: Cemented Carbide Slitting Circular Blades—Guarantee of Efficiency and Precision for Tape Slitting

The demands of tape slitting for "precision, durability, anti-adhesion, and high-temperature resistance" exactly correspond to the core advantages of cemented carbide slitting circular blades: high hardness ensures a long-lasting sharp edge with fewer changes; strong edge stability guarantees smooth cuts; anti-adhesion coatings adapt to adhesive tapes; and wide adaptability covers different tape types. At the same time, their lower long-term comprehensive cost meets both technical needs and enterprises' goals of cost reduction and efficiency improvement.

As a professional in the tungsten carbide industry, when recommending cemented carbide slitting circular blades, you can suggest corresponding grain sizes and surface treatment solutions based on the customer's tape type (thin/thick, adhesive/non-adhesive) to further improve adaptability.

If you need to customize cemented carbide slitting circular blades for specific tapes (e.g., electronic-grade ultra-thin tape, high-temperature resistant tape) or want to learn about specific parameters of different specifications of blades, feel free to contact us—we can provide sample testing and targeted solution design to help you optimize the slitting process.