Double-Layer PE Stretch Equipment: An Intelligent Innovation in Food Wrap Production
Publish Time: 2025-09-29
As an essential product for modern households and the catering industry, food wrap continues to see increasing market demand. According to statistics, the global food wrap market is expected to reach US$12 billion in 2023, with PE-based wrap accounting for over 65%. Driven by both consumer upgrades and environmental protection policies, the market is placing higher demands on the functionality (such as high barrier properties and self-adhesion) and production efficiency of cling film. Double-Layer PE Stretch equipment, with its core technologies such as multi-layer co-extrusion and intelligent control, is becoming a key piece of equipment driving the industry's transition towards high efficiency and customization.I. Equipment Technical Architecture: Fusion of Multi-Layer Co-extrusion and Intelligent Control1.1 Double-Layer Co-Extrusion System: Precise Control of Material LaminationThe Double Layer PE Stretch equipment utilizes a dual extruder + dual-layer distributor + dual T-die structure, enabling flexible production of single-layer and dual-layer films:Dual extruder independent feed: The two extruders can each deliver PE raw materials with different formulations (e.g., low-density PE for flexibility, high-density PE for strength). The melts are then compounded in a preset ratio (e.g., 1:1 or 3:2) via the dual-layer distributor to form an AB or BA layered structure.Dual T-die Design: Independent flow channels within the die ensure simultaneous bonding of the two melt layers at the exit, preventing performance degradation caused by interlayer mixing. Experimental data shows that this design achieves an interlayer bond strength of 0.8 N/mm, far exceeding the 0.3 N/mm achieved by traditional coating processes.Customizable Adhesive Layer: By adding an EVA (ethylene-vinyl acetate copolymer) or POE (polyolefin elastomer) adhesive layer to a single or double layer, single-sided adhesive (viscosity 5-15g/25mm) or double-sided adhesive (viscosity 10-30g/25mm) cling film can be produced to meet the needs of various packaging scenarios.1.2 Intelligent Control System: Fully Automated Process ManagementThe equipment is equipped with a PLC + Human-Machine Interface (HMI) control system, implementing five core functions:Automatic Vacuum Loading: PE granules are transported from the storage tank to the extruder hopper via a negative pressure pipe at a loading speed of up to 50kg/min, reducing raw material contamination caused by manual intervention.Online Recycling Device: Scrap is crushed, melted, and filtered before being re-extruded into the main extruder. The recycled material content can reach 30%, reducing raw material costs by 15%.Automatic Counting and Cutting: A laser sensor monitors film roll length in real time with an accuracy of ±1mm. Combined with a servo motor-driven cutter, this enables precise slitting to a fixed length (e.g., 100m/roll).Automatic reel changing system: Utilizing a dual-station rewinding mechanism, a pneumatic device automatically switches to a backup reel when the main reel reaches the set diameter (e.g., Φ300mm). Reel change time is less than 8 seconds, improving production continuity by 40%.Process parameter visualization: The HMI interface displays key parameters such as extrusion temperature (160-220°C), melt pressure (15-25MPa), and draw ratio (3:1-5:1) in real time, supporting historical data traceability and process optimization.II. Process Innovation: Performance Improvement and Efficiency Breakthrough2.1 Dual-Layer Structure Optimizes PerformanceThe dual-layer film design achieves complementary performance through functional zoning of materials:Enhanced Barrier Properties: The outer layer utilizes high-density PE (density 0.941 g/cm³) to improve puncture resistance (up to 3 N/mm²). The inner layer incorporates nano-SiO₂ filler (2%), reducing the oxygen transmission rate from 80 cc/(m²·24h) to 35 cc/(m²·24h), extending the shelf life of fruits and vegetables by 30%.Controllable Self-Adhesion: By adjusting the EVA content (5%-15%), the peel force of the single-sided adhesive film can be adjusted within a range of 5-15 g/25 mm, preventing difficulty in tearing due to excessive adhesion.Optimized Heat Sealing Performance: The heat sealing temperature window of the dual-layer film is expanded from ±5°C (compared to ±8°C) for single-layer film, increasing seal strength by 25% and reducing packaging leakage.2.2 Revolutionary Efficiency Driven by IntelligenceAutomation features increase single-line production capacity from 80kg/h with traditional equipment to 150kg/h, while also reducing operating costs:Reduced Labor Costs: The entire process requires only one operator to monitor, three fewer people than with traditional equipment, saving approximately 120,000 yuan in labor costs annually (calculated at 50,000 yuan per person per year).Scrap Rate Control: The automatic counting and cutting system reduces the scrap rate from 3% to 0.8%. Based on an annual production volume of 500 tons, this reduces waste by 4.1 tons per year.Energy Consumption Optimization: The PLC dynamically adjusts the extruder speed and heating power based on production speed, reducing energy consumption per unit of product from 0.35kWh/kg to 0.28kWh/kg, meeting EU ErP energy efficiency standards.III. Application Scenarios and Market Value3.1 Diversified Food Packaging DemandsDouble-Layer PE Stretch equipment produces cling film for the following applications:Home preservation: Double-sided cling film (viscosity 10-15g/25mm) is suitable for food packaging in the refrigerator to prevent cross-contamination; single-sided cling film (viscosity 5-8g/25mm) is used for covering dishes and bowls for easy reuse.Supermarket Packaging: High-strength double-layer film (tensile strength ≥ 25MPa) is used for pallet wrapping of meat and dairy products, replacing traditional PVC film and reducing the risk of plasticizer migration.Industrial Pre-Packaging: Double-layer film with added antimicrobial agents (such as 0.5% silver ions) can be used in automated packaging lines for prepared foods and salads, extending shelf life to up to 7 days.3.2 Competitive Advantages Under Environmental Protection PoliciesWith the strengthening of China's "plastic restriction" policy, demand for biodegradable PE film has surged. This equipment enables compatible production by replacing raw materials:Bio-based PE blending: 30% PE derived from sugarcane ethanol is co-extruded with petroleum-based PE to produce cling film with a 60% degradation rate within six months, meeting EN 13432 standards.Thin-wall design: The double-layer structure reduces film thickness from 20μm per layer to 15μm, increasing roll length by 25% and reducing packaging material usage.IV. Typical Case Studies4.1 Case 1: Efficiency Improvement at a Large Cling Film ManufacturerAfter introducing the Double Layer PE Stretch equipment, a company achieved the following breakthroughs:Product Diversification: The company now produces single-layer standard film, double-layer adhesive film, and antimicrobial film, expanding its SKU range from 5 to 12.Increased Order Response Speed: The automated roll-changing system reduces changeover time for small-batch orders (<500kg) from 4 hours to 1 hour, resulting in a 30% increase in customer satisfaction.Annual Cost Savings: Through online recycling and energy optimization, the company saves a total of 850,000 yuan in raw materials and electricity costs annually, with a payback period of only 1.8 years.4.2 Case Study 2: Compliance Transformation for an Export-Oriented EnterpriseA foreign trade company developed a biodegradable double-layer film for the EU market. Through equipment adjustments, they achieved the following:Material Replacement: The inner PE layer was replaced with a PBAT/PLA blend (40%), while the outer layer remained PE to maintain strength.Process Optimization: The extrusion temperature was adjusted to 180°C (originally 200°C) to avoid thermal decomposition of the bio-based material, and the product achieved REACH certification.Market Expansion: The company secured orders from major EU retailers, increasing annual exports by 20 million yuan.V. Future Development Trends5.1 Material Innovation: High Performance and SustainabilityNanocomposite Technology: Adding graphene (0.1%) or montmorillonite (2%) to PE improves the film's barrier properties (oxygen transmission rate <10cc/(m²·24h)) and heat resistance (melting point increased by 15°C).Chemical Recycling Breakthrough: Developing alcoholysis-repolymerization technology for waste PE film, achieving closed-loop recycling and reducing raw material costs by 20%.5.2 Intelligent Equipment: Deep Application of AI and the Internet of ThingsPredictive Maintenance: Vibration and temperature sensors monitor extruder bearing status in real time, providing 48-hour early warning of failures and reducing downtime by 60%.Adaptive Control: AI algorithms automatically adjust extrusion parameters (such as screw speed and die gap) based on raw material batches, improving product consistency by 35%.5.3 Customized Production: Small Batch and Fast DeliveryModular Design: The equipment supports rapid die changes (e.g., switching from a two-layer to a three-layer die), accommodating high-variety, small-batch orders.Digital Twin Technology: Virtual commissioning reduces changeover time from the traditional 4 hours to 1.5 hours.The Double Layer PE Stretch machine utilizes multi-layer co-extrusion technology and fully automated control to achieve efficient, functional, and environmentally friendly cling film production. Amidst the transformation and upgrading of the food packaging industry, this equipment not only helps companies reduce operating costs and improve product quality, but also meets the market's urgent demand for safe and sustainable packaging through material and process innovation. In the future, with the integration of technologies such as AI and the Internet of Things, Double Layer PE Stretch equipment will evolve towards greater intelligence and flexibility, continuously driving value upgrades in the food packaging industry.
