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Jun 11, 2025
Selecting the appropriate blown film die head is critical for optimizing the performance of your extrusion line, ensuring high-quality films tailored to specific applications like packaging, agriculture, or industrial uses. The die head shapes molten plastic into a uniform tube, directly impacting film thickness, layer structure, and production efficiency. With various die head designs available, choosing the right one requires understanding your production needs and material requirements. Bojing, a Wenzhou-based leader in CNC machining, as showcased on wenzhoubojing.com, crafts precision die head components that enhance blown film extrusion.
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 resin flow, shaping the film’s thickness and layer structure. For single-layer or multilayer films, the die head’s design determines:
Film Uniformity: Consistent thickness for strength and printability.
Layer Precision: Accurate layer distribution in multilayer films for barrier properties.
Production Efficiency: Smooth resin flow to minimize downtime and waste.
An ill-suited die head can cause defects like die lines, uneven thickness, or layer misalignment, increasing costs. Bojing’s precision-machined die head components, as detailed on their products page, achieve tolerances as tight as ±0.005mm, ensuring optimal performance.
Selecting the right die head involves evaluating your production goals, film specifications, and operational constraints. Below, we outline the key factors to consider and how Bojing’s components align with these needs.
Consideration: The number of layers and film properties dictate die head design. Single-layer films, used for basic packaging, require simple dies, while multilayer films (3–11 layers) for barrier packaging need complex co-extrusion dies to combine resins like PE and EVOH.
Bojing’s Solution: Bojing’s 5-axis CNC milling crafts spiral mandrels and flow distributors for multilayer die heads, supporting up to 11 layers, as needed for high-barrier films. Their precision ensures uniform layer thickness, enhancing barrier properties and clarity, ideal for food or medical packaging.
Consideration: Die heads must match the desired film width (1000mm–3000mm) and thickness (10–200 microns). Larger widths or thinner films require dies with precise gaps and flow control to maintain uniformity.
Bojing’s Solution: Bojing’s custom fabrication services produce die lips and mandrels tailored to specific widths and thicknesses. Their ±0.005mm tolerances, as noted on their website, ensure accurate die gaps, delivering consistent film thickness for applications like agricultural films or shrink wraps.
Consideration: Different resins (e.g., LDPE, PP, or nylon) have unique melting points and flow characteristics, requiring die heads with precise temperature control to prevent degradation or uneven flow.
Bojing’s Solution: Bojing manufactures die head components with integrated heating channels, machined from stainless steel or titanium for durability and heat transfer. These components maintain stable temperatures, supporting diverse resins and ensuring smooth multilayer extrusion.
Consideration: High-speed lines demand die heads that minimize pressure buildup and optimize resin flow to reduce downtime and increase throughput, often up to 100 meters per minute.
Bojing’s Solution: Bojing’s polished flow distributors and spiral mandrels reduce friction, enhancing resin flow and minimizing die lines. Their precision components support high-speed production, boosting efficiency and reducing waste.
Understanding die head types helps match your line’s needs. Below is a comparison of common designs and their applications.
Die Head Type | Description | Applications | Bojing’s Contribution |
|---|---|---|---|
Single-Layer Die | Simple design for one resin stream | Basic packaging, bags | Precision-machined die lips for uniform thickness |
Co-Extrusion Die (Spiral) | Spiral channels for multilayer films | Barrier packaging, medical films | 5-axis CNC-milled mandrels for layer consistency |
Co-Extrusion Die (Stack) | Stacked plates for precise layer control | High-barrier films, agricultural films | Custom flow distributors for scalability |
Best for simple films, these dies are cost-effective but limited in functionality. Bojing’s CNC-machined die lips ensure uniform thickness, ideal for basic packaging.
Spiral dies merge multiple resin streams via helical channels, ideal for multilayer films. Bojing’s spiral mandrels, crafted with exact geometries, ensure even layer distribution, supporting high-clarity barrier films.
Stack dies use stacked plates for precise layer control, suitable for complex films. Bojing’s custom components accommodate diverse layer counts, enhancing flexibility for advanced applications.
Bojing’s advanced CNC machining capabilities, as highlighted on wenzhoubojing.com, deliver die head components that optimize multilayer film production. Below is a breakdown of key components.
Component | Material | Function | Bojing’s Contribution |
|---|---|---|---|
Spiral Mandrel | Stainless Steel | Distributes resin for uniform layers | Precision-milled for smooth flow |
Die Lip | Stainless Steel, Alloy Steel | Shapes final film thickness | ±0.005mm tolerances for accuracy |
Flow Distributor | Stainless Steel | Merges resin streams | Polished surfaces to prevent buildup |
Heating Elements | Titanium, Stainless Steel | Maintains stable temperatures | Machined for efficient heat transfer |
Bojing’s spiral mandrels and flow distributors feature intricate channels, crafted via 5-axis CNC milling, to ensure even resin distribution. Polished stainless steel surfaces minimize resin buildup, reducing defects and ensuring clear multilayer films.
Bojing’s die lips, machined to ±0.005mm tolerances, control film thickness with high accuracy. Their durable materials maintain precision, supporting consistent production.
Bojing’s heating elements, made from titanium or stainless steel, ensure 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, delivering reliable performance.
Bojing’s die head components offer significant advantages:
Precision Layer Control: Ensures uniform thickness and barrier properties.
Enhanced Film Quality: Reduces defects like die lines, improving clarity and strength.
Increased Productivity: Optimizes resin flow for high-speed, efficient production.
Customizability: Supports diverse film widths, thicknesses, and layer counts.
These benefits make Bojing’s die heads ideal for manufacturers seeking tailored solutions.
Bojing’s die head components enable high-quality multilayer films for:
Packaging: Barrier films for food preservation, such as vacuum pouches.
Medical: Sterile films with oxygen and moisture barriers.
Agriculture: UV-resistant multilayer greenhouse films.
Their components support film widths from 1000mm to 3000mm, meeting varied 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 their website. Their customer-centric approach includes design consultation and prototyping, ensuring die heads meet specific requirements. Clients can request quotes directly on wenzhoubojing.com, streamlining procurement.
Bojing’s sustainable practices, including waste-minimizing machining and durable components, align with eco-friendly manufacturing trends.
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 optimal multilayer film production, delivering consistent quality and efficiency. With global reach and rapid delivery, Bojing empowers manufacturers to select the right die head for their line.
Choosing the right blown film die head is essential for producing high-quality multilayer films tailored to your line’s needs. Bojing’s CNC-machined components, including spiral mandrels, die lips, and flow distributors, offer precision, durability, and versatility, ensuring uniform layer thickness and superior film properties. As showcased on wenzhoubojing.com, Bojing’s innovation and customer support make them the ideal choice for manufacturers. Contact Bojing today to explore their die head solutions and optimize your blown film extrusion line.
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