English
Jun 11, 2025
Multilayer films, with their advanced barrier properties and tailored performance, are essential for industries like food packaging, medical applications, and agriculture. The blown film die head, a critical component in the extrusion process, shapes molten plastic into a uniform tube, determining the film’s layer structure and quality. Precision in die head design is vital for achieving consistent layer thickness and optimal film properties. Bojing, a leading CNC machining specialist based in Wenzhou, China, as showcased on wenzhoubojing.com, crafts high-precision die head components that enable superior multilayer film production.
Blown film extrusion transforms plastic resins, such as LDPE, HDPE, PP, or barrier materials like EVOH, into thin films by extruding molten polymer through a circular die to form a tube, which is inflated into a bubble and cooled into a continuous sheet. The die head controls the flow and distribution of molten resin, shaping the film’s thickness, layer structure, and uniformity. For multilayer films, which combine multiple polymer layers to achieve properties like barrier resistance or flexibility, the die head must ensure precise layer alignment and consistent thickness.
Inferior die heads can cause issues like uneven layer distribution, die lines, or thickness variations, compromising film performance and increasing waste. Bojing’s precision-machined die head components, as detailed on their products page, achieve tolerances as tight as ±0.005mm, ensuring high-quality multilayer films.
Multilayer films, often comprising 3 to 11 layers, combine different polymers to achieve specific properties, such as oxygen barriers, moisture resistance, or strength. Precision in die head design is critical for:
Uniform Layer Thickness: Ensures consistent barrier and mechanical properties.
Layer Alignment: Prevents delamination or weak interfaces between layers.
Film Clarity and Strength: Minimizes defects like haze or die lines for optimal performance.
Production Efficiency: Reduces waste and downtime caused by inconsistent output.
Bojing’s expertise in CNC machining enables the production of die heads that meet these demands, supporting advanced multilayer film applications.
Die heads for multilayer films use complex designs, such as co-extrusion dies with spiral or stack configurations, to combine multiple resin streams into a single, uniform tube. Below, we outline the key features of precision die heads and how Bojing’s components enhance their performance.
Feature: Multilayer die heads feature precisely engineered flow channels to ensure even distribution of each resin layer. Spiral mandrels or concentric flow paths merge layers without mixing, maintaining distinct properties.
Bojing’s Contribution: Bojing’s 5-axis CNC milling crafts flow channels with exact geometries, ensuring smooth resin flow and uniform layer thickness. Their components, made from stainless steel for corrosion resistance, prevent resin buildup, reducing defects like die lines that can affect multilayer film quality.
Feature: Consistent layer thickness, often within ±5% tolerances, is critical for multilayer films to achieve balanced barrier and mechanical properties. Precision machining ensures accurate die gaps and layer alignment.
Bojing’s Contribution: Bojing’s CNC machining achieves tolerances as tight as ±0.005mm, as noted on their website, ensuring precise die gaps for uniform layer distribution. This precision supports films with up to 11 layers, ideal for high-barrier packaging applications.
Feature: Multilayer films often combine resins with different melting points, requiring precise temperature control to prevent degradation or uneven flow. Die heads incorporate heating zones to maintain optimal conditions.
Bojing’s Contribution: Bojing manufactures die head components with integrated heating channels, machined to exact specifications for efficient heat transfer. Their use of materials like stainless steel or titanium ensures durability under high-temperature conditions, supporting stable multilayer extrusion.
Feature: Die heads must accommodate various film widths and layer configurations, from 1000mm to 3000mm, to meet industry needs like food packaging or agricultural films.
Bojing’s Contribution: Bojing’s custom fabrication services, as highlighted on their website, produce die heads tailored to specific film widths and layer counts. Their expertise ensures scalability without compromising precision, supporting diverse multilayer film applications.
Bojing’s advanced CNC machining capabilities, as showcased on wenzhoubojing.com, deliver die head components that optimize multilayer film production. Below is a breakdown of key components and their role in achieving precision.
Component | Material | Function | Bojing’s Contribution |
|---|---|---|---|
Spiral Mandrel | Stainless Steel | Distributes resin for uniform layers | 5-axis CNC milling for precise channels |
Die Lip | Stainless Steel, Alloy Steel | Shapes final film thickness | Tolerances of ±0.005mm for accuracy |
Flow Distributor | Stainless Steel | Merges multiple resin streams | Polished surfaces for smooth resin flow |
Heating Elements | Titanium, Stainless Steel | Maintains stable extrusion temperatures | Precision-machined for efficient heat transfer |
Bojing’s spiral mandrels and flow distributors, crafted via 5-axis CNC milling, feature intricate channels that ensure even resin distribution across layers. Polished stainless steel surfaces minimize friction, preventing resin degradation and ensuring clear, uniform multilayer films.
Bojing’s die lips, machined to ±0.005mm tolerances, control the final film thickness with exceptional accuracy. Their corrosion-resistant materials maintain precision over extended runs, reducing maintenance and ensuring consistent layer alignment.
Bojing’s heating elements, made from titanium or stainless steel, are precisely machined to integrate seamlessly into die heads. Their design supports uniform temperature control, critical for processing diverse resins in multilayer films.
Bojing’s ISO 9001-certified quality control, using coordinate measuring machines (CMMs) and laser scanners, ensures every component meets exact specifications, as noted on their website. This reliability guarantees precision for multilayer film production.
Bojing’s die head components deliver significant advantages for multilayer film extrusion:
Consistent Layer Thickness: Precise flow channels ensure uniform layers, enhancing barrier properties.
Improved Film Quality: Tight tolerances reduce defects like die lines, improving clarity and strength.
Increased Efficiency: Stable extrusion minimizes downtime and waste, boosting productivity.
Versatility: Custom components support a wide range of film applications and layer configurations.
These benefits make Bojing’s die heads a critical asset for manufacturers producing multilayer films.
Bojing’s die head components enable high-quality multilayer films for:
Packaging: Barrier films for food preservation, such as vacuum-sealed pouches.
Medical: Sterile films for pharmaceutical packaging with oxygen and moisture barriers.
Agriculture: Multilayer greenhouse films with UV resistance and durability.
Their ability to support film widths from 1000mm to 3000mm ensures compatibility with diverse industry needs.
Based in Wenzhou, Bojing serves clients in North America, Europe, and Asia, offering lead times as short as 7 days for standard orders and 3 days for expedited services, per wenzhoubojing.com. Their customer-centric approach includes design consultation and prototyping, ensuring components meet specific multilayer film requirements. Clients can request quotes directly online, streamlining procurement.
Bojing’s commitment to sustainability aligns with eco-friendly manufacturing. Their machining processes minimize waste, and durable components reduce replacement frequency, lowering environmental impact.
Bojing’s expertise in CNC machining, material versatility, and rigorous quality assurance make them a trusted partner for die head components. Their precision parts ensure uniform layer thickness and high-quality multilayer films, driving production success. With global reach and rapid delivery, Bojing empowers manufacturers to achieve advanced film performance.
Blown film die heads are the cornerstone of precision for multilayer films, ensuring consistent layer thickness and superior properties. Bojing’s CNC-machined components, including spiral mandrels, die lips, and flow distributors, optimize resin distribution and temperature control, delivering high-quality films for packaging, medical, and agricultural applications. As showcased on wenzhoubojing.com, Bojing’s innovation, quality, and customer support make them the ideal choice for manufacturers. Contact Bojing today to explore their die head solutions and elevate your multilayer film production.
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