Slitter rewinders are essential machines for converting large rolls of plastic films into narrower, usable rolls, primarily through unwinding, slitting, and rewinding processes. They support efficient production in packaging and manufacturing.
Common plastic films for slitting include PE, PP, PET, PVC, BOPP, and BOPET, each with unique properties like elasticity or hardness that influence slitting features and blade demands. Softer films like PVC require anti-stick blades, while harder ones like PET need wear-resistant options.
1. Slitter Rewinders Overview
Slitter rewinders handle the conversion of large "mother rolls" of plastic films into smaller, precise widths. Key components include unwinding mechanisms, slitting systems with adjustable blades, and rewinding shafts that control tension to prevent defects like buckling. They operate via methods such as shear cutting for rigid films, making them vital for high-volume plastic processing.
2. Plastic Films for Slitting
Films, for example, polyethylene (PE) offer flexibility but can stretch during slitting, demanding sharp blades to avoid burrs. Polypropylene (PP) is tougher and heat-sensitive, while polyethylene terephthalate (PET) is hard and wear-intensive on blades. Features include varying thickness and tensile strength, with blade demands focusing on hardness for PET and anti-adhesion for PP. Check Nicely Slitter's article for selection tips.
3. Film Packaging Converting
This process starts with resin extrusion into base films, followed by coating for barriers and lamination for multi-layer strength. Slitting finalizes rolls for end-use in bags or labels, improving efficiency and reducing waste. Sustainable options like bio-based resins are increasingly common. Explore PennPac's breakdown for steps.
4. Knives and Blades for Slitter Rewinders
Types include razor blades for thin films, shear blades for thicker ones, and toothed options for plastics. Requirements emphasize materials like D2 steel for abrasives or carbide for durability, with edge angles tailored to film hardness. Custom designs reduce downtime. Refer to Industrial Blades' guide for best practices.
Plastic films suitable for slitter cutting
Moving to the types of plastic films suitable for slitter cutting, the industry relies on a variety of polymers, each with distinct properties that affect slitting behavior and blade requirements. Common films include polyethylene (PE), known for its flexibility and use in stretch films or recycled PCR variants; polypropylene (PP), including biaxially oriented PP (BOPP) and cast PP (CPP), valued for toughness and tear resistance but sensitive to heat; polyethylene terephthalate (PET) or BOPET, prized for high hardness, strength, and chemical stability; polyvinyl chloride (PVC), which is softer and elastic but prone to deformation and corrosion from chlorine; and others like polyvinylidene chloride (PVDC) for barrier properties. These films are selected based on applications in food packaging, pharmaceuticals, electronics, and household goods, where properties like tensile strength, thickness (typically in microns), elasticity, and barrier capabilities play key roles.
Knives and blades for slitter rewinders
knives and blades for slitter rewinders are critical for achieving clean, precise cuts, with types and requirements tailored to the material and process demands. Common types include razor blades (straight-edged for foils and thin plastics, suspended at angles for economical cuts); shear blades (rotating pairs for thicker films, providing accuracy); crush/score blades (dull against hard surfaces for adhesives); circular or dished knives (top/bottom pairs for rewinders); and toothed blades (for papers and most films). Materials range from D2 tool steel (for abrasive plastics), M2 high-speed steel (heat-resistant for less abrasive cuts), to carbide (for metal foils and high-volume durability) and ceramics (extreme hardness, up to 10x steel)
Requirements focus on hardness, wear resistance, edge angle (sharper for soft films, stronger for hard ones), coatings (Teflon for anti-stick, DLC for durability), and concentricity for balanced rotation. For plastic films, toothed or razor types excel, with custom options reducing kerf waste and downtime—e.g., carbide for PET's toughness. Selection considers tensile strength, speed, and tolerances, with maintenance like regular sharpening essential for longevity. Stock blades suit quick needs, while custom ones optimize for specific machines and substrates.
| Blade Type | Best for Films | Material Options | Key Requirements |
| Razor | Thin, non-rigid (e.g., PE, PVC) | Stainless steel, carbon steel | High sharpness, small angles, anti-friction coatings |
| Shear | Thicker, rigid (e.g., PET, laminates) | High-speed steel (M2), carbide | Wear resistance, medium angles, precise alignment |
| Crush/Score | Adhesives, soft (e.g., PP) | Tool steel, hardened alloys | Durability against pressure, minimal dust generation |
| Toothed/Circular | Most plastics, films | D2 steel, ceramics | Tooth spacing for clean cuts, concentricity for balance |
About Huaxin:Tungsten Carbide Cemented Slitting Knives Manufacturer
CHENGDU HUAXIN CEMENTED CARBIDE CO.,LTD are a professional supplier and manufacturer of tungsten carbide products, such as carbide insert knives for woodworking,carbide circular knives for tobacco&cigarette filter rods slitting,round knives for corugatted cardboard slitting ,three hole razor blades/slotted blades for packaging ,tape,thin film cutting,fiber cutter blades for textile industry etc.
With over 25 years development, our products have been exported to U. S. A, Russia, South America,India,Turkey,Pakistan,Australia,Southeast Asia etc. With excellent quality and competitive prices, Our hard working attitude and responsiveness are approved by our customers. And we would like to establish new business relationships with new customers.
Contact us today and you will enjoy benefits of good quality and services from our products!
The high performance tungsten carbide industrial blades products
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Huaxin Cemented Carbide manufactures custom tungsten carbide blades, altered standard and standard blanks and preforms, starting from powder through finished ground blanks. Our comprehensive selection of grades and our manufacturing process consistently delivers high-performance, reliable near-net shaped tools that address specialized customer application challenges across diverse industries.
Tailored Solutions for Every Industry
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Customer common questions and Huaxin answers
That depends on the quantity, generally 5-14days. As an industrial blades manufacturer, Huaxin Cement Carbide plans the production by orders and customers' requests.
Usually 3-6 weeks, if you request customized machine knives or industrial blades that are not in stock at the time of purchasing. Find Sollex Purchase & Delivery Conditions here.
if you request customized machine knives or industrial blades that are not in stock at the time of purchasing. Find Sollex Purchase & Delivery Conditions here.
Usually T/T, Western Union...deposits firstm, All first orders from new customers are prepaid. Further orders can be paid by invoice...contact us to know more
Yes, contact us, Industrial knives are available in a variety of forms, including top dished, bottom circular knives, serrated / toothed knives, circular perforating knives, straight knives, guillotine knives, pointed tip knives, rectangular razor blades, and trapezoidal blades.
To help you get the best blade, Huaxin Cement Carbide may give you several sample blades to test in production. For cutting and converting flexible materials like plastic film, foil, vinyl, paper, and others, we provide converting blades including slotted slitter blades and razor blades with three slots. Send us a query if you're interested in machine blades, and we'll provide you with an offer. Samples for custom-made knives are not available but you are most welcome to order the minimum order quantity.
There are many ways that will prolong the longevity and shelf life of your industrial knives and blades in stock. contact us to know about how proper packaging of machine knives, storage conditions, humidity and air temperature, and additional coatings will protect your knives and maintain their cutting performance.
Post time: Jan-04-2026
