1 Introduction For enterprises equipped with high-speed BOPP and BOPET biaxial stretching production lines, sudden cracking and fracture of corona rolls will lead to unplanned production shutdowns, massive waste of plastic film raw materials and substantial economic losses. This article systematically sorts out three typical fracture positions of corona rolls and their corresponding mechanical inducements, elaborates the core performance advantages and complete technical parameters of high-performance silicone corona rolls, and presents global cooperative application cases, so as to help film manufacturers extend roll service life and realize stable continuous production. 2 Three Typical Fracture Positions and Root Mechanical Causes of Corona rolls 2.1 Central Fracture of roll Core This type of failure mostly occurs on rolls assembled by multiple outer steel tubes connected by welding. If the thermal assembly process is blocked during production and installation, constructors will cut the outer tube and carry out thermal assembly and secondary welding from the opposite side. Multiple welding operations and forced thermal assembly will form persistent hidden structural stress inside the roll core, which will gradually expand and cause complete core fracture after long-term high-speed rotating operation. 2.2 Crack Defects at the Connection of roll Shaft and Disc Excessive interference fit between the shaft and disc is the main inducement of this fault. The corona roll adopts double-shell water circulation cooling design; long-term circulating water will cause tiny seepage to corrode the welding seam, form invisible microcracks, and gradually expand to produce water leakage and structural fracture in the later operation stage. 2.3 Fracture at the 1/3 Axial Position of roll Core Different from the excessive interference fit problem, this fault is triggered by insufficient matching allowance. Loose assembly clearance will make the metal core bear alternating tension during long-time high-speed rotation, resulting in continuous metal fatigue, and finally produce obvious splitting cracks at the one-third position of the roll barrel length. 3 Core Performance Advantages of High-Performance Silicone Corona roll The corona roll is the core functional component of the film corona surface modification system, which undertakes the conveying work of BOPP and BOPET substrates and cooperates with the discharge electrode to generate plasma corona discharge under high voltage. The product is wrapped with imported special silicone rubber that passes strict 200KV high voltage withstand inspection. The high-quality silicone coating can realize uniform transfer of surface energy on the film, significantly improve the adhesion of ink, adhesive and coating on the substrate, and effectively eliminate peeling and bubbling defects of finished film products in subsequent printing, coating and composite processes. 4 Standard Complete Technical Parameters of Corona roll Structural form: Double-shell integrated design, water inlet and outlet ports are arranged on the same end of the rollbody Raw material matching: Inner and outer shells adopt Q345B steel; the journal and outer shell are connected by 42CrMo alloy steel interference assembly process Dynamic balance standard: G2.5 grade, matching the maximum production line speed of 630 m/min Silicone coating index: Coating thickness 4 mm, rubber hardness 75–80 Shore A, surface roughness Ra1.6 μm Precision tolerance: Overall runout ≤0.10 mm, cylindricity ≤0.10 mm Dielectric performance: Stable continuous operation under 200KV high voltage environment 5 Global Production Line Application Cases The enterprise has supplied customized corona roll products to more than 100 BOPP and BOPET complete production lines covering over 10 countries and regions worldwide, and has established long-term cooperative relations with many well-known film manufacturing groups. After replacing the original old rolls with our optimized corona roll products, the comprehensive operating efficiency of the film stretching production line of all cooperative customers has increased by 5% to 10%, and the defective product rate and daily equipment maintenance frequency have been significantly reduced. 6 Customized Technical Service Support The professional engineering team provides one-stop customized matching services for corona rolls, and can formulate targeted product schemes according to the actual production line speed, film processing width and process characteristics of customers. Customers can consult technical drawings, parameter comparison and detailed quotation at any time. Contact Information Email: sale05@huataogroup.com Mobile / WhatsApp: +86 17743789775 Official Website: www.huataorolls.com
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1 Overview of 2026 Global Soft Packaging Industry Development Trend Driven by lightweight transformation, recyclable material policy and high-barrier film market demand, the overall scale of the global flexible packaging industry maintains steady growth momentum. High-precision processing rolls are core supporting components throughout the whole film production flow, which directly affect finished film quality, equipment continuous operation rate and coating uniformity. This article summarizes the main market growth points of the soft packaging industry in 2026, sorts the standard roll configuration of each production section, and introduces a full range of customized roll products that can adapt to mainstream international film stretching equipment. 2 Main Growth Drivers of Soft Packaging Market E-commerce and food catering packaging demand expansion: The market puts forward higher requirements for lightweight and high-strength flexible packaging materials; Popularization of recyclable mono-material films: PP and PE recyclable films become the mainstream development direction of packaging substrates; Rapid expansion of optical and functional film market: BOPET films for display, solar energy and insulation fields gain continuous market increment; Rapid capacity expansion of lithium battery wet-process separator production lines: New energy industry brings stable demand for special film processing equipment; Wide application of shrink film and stretch film in logistics and industrial packaging scenarios. Among various packaging substrate materials, BOPP film still occupies an irreplaceable core position in food, cigarette, textile and food confectionery packaging fields. 3 Complete Matching roll Types for Each Section of Soft Packaging Production Line 3.1 Casting Section Supporting rolls Chill roll is the core equipment of CPP, BOPP, BOPET and optical film casting processes. The matching supporting rolls supplied by the enterprise include chill roll, water tank flow roll, dehydration nip roll and stripping roll, which complete the film forming and preliminary cooling work in the casting link. 3.2 MDO Longitudinal Stretching Section Supporting rolls The MDO section is equipped with preheating roll, nip roll and stretching roll. The first six rolls after preheating belong to high-wear parts. For BOPET optical film production lines, double-layer solid silicone cladding rolls are adopted, with rubber hardness controlled at 70–80 Shore A, stable heat resistance up to 200 Celsius degrees and excellent ozone resistance performance. 3.3 Traction Surface Treatment Section Supporting rolls This section includes PRS cooling roll, corona treatment roll, corona nip roll and flame treatment roll. Corona treatment roll: Made of special silicone rubber, with 200,000V high voltage and ozone resistance, hardness 70–80 Shore A, surface roughness Ra ≤1.6μm, which effectively avoids backside treatment and stabilizes film surface dyne value; PRS cooling roll: Adopts double-shell single and double flow channel structure, the conventional specification is Φ450×8600mm, which eliminates thermal deformation of film before winding; Flame treatment roll: Matched with paper and PE composite production lines, made of special stainless steel alloy with NiCr anti-corrosion coating and internal water cooling structure. 3.4 Winding Section Supporting rolls Carbon fiber contact roll and carbon fiber tension roll, as well as heavy-duty winding cores are the standard configuration of the winding link. The carbon fiber contact roll for BOPP and BOPET lines adopts 14–16mm thick EPDM cladding, with diamond groove design, 1.6mm crown height and G2.5 dynamic balance standard. 3.5 Auxiliary Processing Supporting rolls In addition to the core rolls of film stretching lines, the enterprise also supplies special rolls for slitting machines, film extrusion equipment and metalizing composite machines to meet the full-process supporting demands of post-processing links. 4 Full-Series Industrial roll Product System and Manufacturing Standards 4.1 Compatible Mainstream Film Equipment Brands All roll products can perfectly match complete production lines manufactured by Bruckner, Dornier, Colines, Mitsubishi, Doriner, Reifenhauser and SMT. 4.2 Complete Product Line Coverage Cooling series rolls: Water bath chill roll, double-shell 3OS/2OS cooling drum; MDO processing rolls: Preheating roll, stretching roll, all types of nip rolls with silicone, EPDM and Hypalon coating; Surface treatment equipment: Corona rolland matched electrode accessories; Post-processing rolls: Laminating roll, coating roll, carbon fiber contact roll, slitter special roll. 4.3 Surface Coating Optional Schemes Hard chrome coating (thickness more than 120μm, hardness HV750 and above), ceramic coating, tungsten carbide coating, Teflon coating, silicone rubber, EPDM and Hypalon elastic coating can be selected according to different process environments. 4.4 Unified Manufacturing Quality Standards Product runout controlled within 0.01–0.1mm, all rolls pass G2.5 dynamic balance detection, long-term stable working temperature up to 200 Celsius degrees, and the inner barrel adopts welded spiral double-shell flow channel structure for uniform heat exchange. 5 Core Advantages of Choosing Our Customized roll Solutions Comprehensive cost control advantages: Optimized structural design reduces long-term maintenance and replacement cost for customers; Stable fast delivery cycle: Complete production chain shortens equipment delivery waiting period; One-stop OEM and reverse engineering service: Custom processing can be carried out according to old rolldrawings and on-site equipment parameters; Targeted customized design: Formulate exclusive coating and structural schemes according to specific film materials and production line working conditions, reaching European equipment quality standards with localized flexible pricing system. 6 Customized Consultation Service Whether customers need to upgrade old BOPP and BOPET production lines, solve the problem of short service life of MDO nip rolls, or build new CPP and lithium battery separator film complete lines, the technical team can provide professional coating selection guidance, structural design scheme and full roll manufacturing supporting services. Contact Information Jenny Liu Mobile / WhatsApp: +86 17743789775 Email: sale05@huataogroup.com Official Website: www.huataorolls.com
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