Film‑Blowing Equipment
Film‑Blowing Equipment
Multiple domestic factories for bidding. Free promotion. Price to be negotiated between winning bidder and buyer.
Please provide below information for posting:
- New or used; 2. Model or functional requirements; 3. Type of raw material; 4. Screw diameter; 5. Screw L/D ratio; 6. Purchase quantity
表格
| Type | Working Principle & Structural Features | Core Advantages | Main Limitations | Typical Applications |
|---|---|---|---|---|
| Single‑Layer Film‑Blowing Machine | One extruder matched with one die head to produce monolayer film. | Simple structure, low investment cost, easy operation & maintenance; suitable for general‑purpose film production. | Limited functions; cannot meet composite performance such as high‑barrier requirements. | Ordinary shopping bags, garbage bags, agricultural mulch films, express packaging bags. |
| Multi‑Layer Co‑Extrusion Film‑Blowing Machine | Multiple extruders feed different materials into one co‑extrusion die head to form multi‑layer composite film. | Customizable performance (high‑barrier, high‑strength); cost‑saving (expensive materials for functional layers, common materials for supporting layers); layers range from 3 to 11. | High equipment investment, sophisticated technology; strict requirements for material compatibility and process control. | Food packaging (vacuum bags, retort pouches), pharmaceutical packaging, high‑barrier industrial films. |
| Dual‑Die‑Head / Special‑Structure Film‑Blowing Machine | Single extruder feeds two independent die heads simultaneously via special flow‑split design. | Small footprint, high output; produces two film rolls of different specifications concurrently and reduces change‑over downtime. | Less independent die‑head performance compared with two separate machines; certain flexibility constraints. | Small plastic bag manufacturers, production scenarios with frequent specification switching, regrind‑material processing. |
Comparison between film‑blowing and cast‑film processes: Besides film‑blowing, plastic films can also be manufactured by cast‑film technology (e.g. CPP, CPE). Film‑blowing features low cost and simple equipment, suitable for wide‑width production. Cast‑film delivers superior thickness uniformity (tolerance ≤±1 %) and higher transparency with better dimensional stability, applied in high‑end fields such as lithium‑ion battery separators and optical films, yet requires larger capital investment.
Core Technical Specifications: Key Indicators for Equipment Selection
Screw Diameter (mm): Core parameter determining extrusion capacity and throughput. Lab‑scale: Φ20‑Φ45 mm; industrial‑scale: Φ45‑Φ120 mm. Larger screw diameter generally yields higher hourly extrusion output.
L/D Ratio (Length‑to‑Diameter): Ratio of effective working length to screw diameter, affecting plasticizing quality and mixing performance. ‑ General‑purpose: 28:1‑33:1 for most PE grades. ‑ High L/D (≥35:1): For hard‑to‑plasticize materials such as HDPE or applications requiring high plasticizing uniformity. ‑ Low L/D (≤25:1): For highly‑filled or recycled materials to prevent polymer degradation caused by excessive shear heat.
Die‑Head Size & Diameter (mm): Determines initial film dimension and blow‑up ratio. ‑ Die‑head diameter ranges Φ40 mm to Φ900 mm. ‑ Blow‑up ratio: 2 × folded‑film width ÷ die‑head diameter; recommended range 1.5:1‑3.0:1, influencing transverse tensile strength and thickness uniformity. ‑ Structural type: Spiral die heads outperform mandrel‑type designs with more even melt distribution and higher film strength, ideal for high‑speed and wide‑width film production.
Product Width / Folded Width (mm): Maximum producible film width, directly defining application scope. ‑ Small‑size unit: 100‑800 mm ‑ Medium‑size unit: 1000‑2000 mm ‑ Large / wide‑width unit: 2500‑4000 mm or broader
Product Thickness Range (mm): Processable film thickness. ‑ Conventional films: 0.008‑0.15 mm ‑ Special applications: ultra‑thin films down to 0.004 mm; heavy‑gauge films above 0.20 mm ‑ Thickness uniformity: premium equipment tolerance ≤±3 %
Maximum Extrusion Capacity / Output (kg/h): Direct indicator of production capacity. ‑ Small‑size unit (Φ45‑55): 30‑50 kg/h ‑ Medium‑size unit (Φ65‑80): 80‑160 kg/h ‑ Large‑size unit (Φ90‑120): 180‑450 kg/h or higher
Take‑off Speed (m/min): Influences productivity and capability for thin‑gauge films. ‑ Conventional models: 30‑80 m/min ‑ High‑speed models: above 300 m/min for mass‑production of thin films.
Applicable Raw Materials: ‑ Main grades: LDPE, LLDPE, HDPE. ‑ Extended grades: PP, EVA, mLLDPE, biodegradable materials such as PLA, PBAT. ‑ Key requirement: Wear‑resistant screw & barrel (nitrided steel or bimetallic alloy), especially for high‑recycled‑content formulations.
Selection Guidelines
Follow clear logic for film‑blowing equipment selection:
Determine machine type by finished‑product requirements ‑ Ordinary packaging bags, garbage bags, mulch films: single‑layer film‑blowing machine suffices. ‑ High‑barrier food packaging, retort pouches, pharmaceutical packaging: select multi‑layer co‑extrusion film‑blowing machine. ‑ Small‑scale multi‑specification production with recycled materials: dual‑die‑head film‑blowing machine is an option.
Define specifications by film width and throughput: Match screw diameter, die‑head dimension and extrusion output according to target film width and expected hourly capacity.
Configure hardware according to raw‑material properties: Select proper screw L/D ratio, compression ratio and die‑head structure for HDPE / LDPE / LLDPE / regrind / biodegradable materials. Pay special attention to screw wear resistance for high‑recycled‑content processing.
Select precision‑control components according to quality requirements ‑ Strict thickness uniformity: equip automatic air‑ring, beta‑ray on‑line thickness gauge and closed‑loop feedback control system. ‑ Superior film flatness & winding quality: adopt rotating take‑off system and automatic web‑guide device. ‑ High‑precision applications (5‑10 μm functional layers): temperature fluctuation ≤±0.5 ℃ and melt pump for metering accuracy.
Consider auxiliary‑machine matching and expandability: Complete production chains require supporting printers and bag‑making machines. Reserve upgrade interfaces for future co‑extrusion layer expansion or on‑line inspection retrofitting to accommodate product‑line extension.
Participation Process
Manufacturers: Contact supplier service for supply registration.
Buyers: Click group‑purchase or contact procurement service to submit requirements. The platform filters suppliers from database or releases bidding based on aggregated demands. Buyers select competitive suppliers and sign sales contracts.
