Bairuijia Standardized Production Process of POF Heat Shrink Film

Equipped with industry-leading 3/5-layer co-extrusion fully automatic production lines adopting the double-bubble method, Bairuijia implements full-process standardized closed-loop control with constant-temperature precision extrusion and synchronous biaxial stretching equipment. With high-end hardware and mature craftsmanship, we manufacture high-stability, high-transparency and eco-friendly POF shrink films. The entire production process consists of six core standardized procedures as follows:

1. Raw Material Selection & Precision Proportioning

We exclusively adopt brand-new food-grade LLDPE and copolymerized polypropylene virgin materials without any recycled materials. All raw materials comply with FDA and EU REACH environmental certification standards. An intelligent proportioning system is applied to precisely adjust the proportion of raw materials for each film layer. The middle PE layer ensures excellent flexibility and tear resistance of the film, while the surface PP layers enhance light transmittance and heat sealing performance. This procedure fundamentally eliminates impurities and stabilizes product quality.

2. Multi-layer Co-extrusion & Molding

Multiple independent constant-temperature extrusion units operate synchronously with precise temperature control, and the primary film tube is integrally molded through a dedicated multi-layer composite die head. The equipment achieves balanced thickness control for each film layer, completely avoiding uneven thickness and interlayer delamination defects commonly found in standard  POF films. The dimensional uniformity of our film products exceeds industrial standards significantly.

3. First Bubble Blowing & Low-temperature Cooling

High-pressure inflation is adopted to complete the primary film bubble forming, followed by a low-temperature rapid cooling process to lock the internal molecular structure of the film. Leveraging advanced low-temperature cooling equipment, our finished films achieve a light transmittance of over 91% and a haze value lower than 4%, delivering superior visual clarity that meets the high display requirements of premium commodity packaging.

4. Secondary Heating & Synchronous Biaxial Stretching

Adopting the mature core double-bubble process, the film tube is secondarily heated via infrared constant-temperature equipment, and synchronous longitudinal and transverse biaxial stretching is completed automatically. The finished film stably achieves a transverse shrinkage rate of ≥60% and a longitudinal shrinkage rate of ≥60%. With uniform and consistent shrinkage performance, our products are suitable for both irregular and regular products, and perfectly compatible with high-speed automatic packaging equipment.

5. Cooling & Shaping

A precision temperature-controlled air cooling system is used for film shaping to prevent subsequent deformation of finished products. The treated films support various customized processing requirements including printing and lamination.

6. Precision Slitting & Full-inspection Dust-free Winding

Our products cover customizable thickness specifications from 10μm to 52μm and width specifications from 15mm to 2000mm. Intelligent slitting equipment ensures extremely minimal dimensional errors. The production line is equipped with a full-process online inspection system to detect shrinkage rate, tensile strength, appearance and other indicators in real time. All defective products are eliminated thoroughly to ensure all delivered products are flawless and dust-free.

Core Advantages of Bairuijia's Production Line & Technology

• Wide heat-sealing window , compatible with nearly all mainstream automatic packaging equipment.
• Full-process automated control ensures consistent batch quality; recyclable material meets global environmental requirements.
• Flexible custom specifications, stable supply, helping clients reduce overall packaging costs.