The “core equipment” for thin-film production: From particles to finished products, these devices determine the quality of the film.

Preface 

A tea milk drink with an easy-to-peel film. “ Tear open with one pull. ” , one roll of cold-chain film -40℃ Low-temperature resistance ” , a piece of greenhouse film “ High light transmittance and moisture retention — Behind these outstanding performances lies not only the sophistication of the formulation but also the indispensable expertise of those on the production line. “ Unknown and unheralded ” The hardcore equipment. 

Many people think that thin-film production is just... “ Melted material - Tablet pressing ” The seemingly simple process is actually far from it: From plastic pellets to finished rolls, the process involves more than ten steps—including mixing, extrusion, shaping, stretching, slitting, and others—each step requiring its own specialized equipment. “ Gatekeeping ” The precision and stability of the equipment directly determine the uniformity of film thickness, mechanical strength, and functional characteristics. 

This article will take you on a tour of the thin-film production workshop, revealing the core equipment matrix—from raw materials to finished products. Let’s take a look at these... “ Industrial Tool ” How to transform ordinary plastic pellets into functional films suitable for various applications. 

I. Preprocessing Stage: Prepare the raw materials “ adjust ” To reach peak performance, mixing equipment is fundamental. 

The first step in thin-film production is not melting the material, but rather... “ Ingredients ” Different functional films require the blending of multiple raw materials (such as base resins, plasticizers, antioxidants, and functional masterbatches). The core task of mixing equipment is to ensure uniform blending of these raw materials and prevent film defects caused by uneven distribution of components. “ Local performance failure ”。

(1) Core Equipment: High-Speed Mixer 

The high-speed mixer is the first critical step in film production, responsible for blending solid particles, powdered additives, and base resins into a homogeneous premix. It generates centrifugal force through rapidly rotating impellers, enabling rapid and uniform mixing via convective shear of the raw materials. 

• Key parameters Rotational speed 300-1500r/min , mixed 3-10 Minutes, volume 50L-5000L Adaptable to different production scales. 
• Core role Take the example of milk tea easy-peel film—it allows... PE The resin and anti-stick masterbatch are uniformly blended, preventing localized sticking to the milk cap or cracking. 
• Industry Trends The mainstream hot-and-cold dual-cylinder model activates additives via the hot cylinder and prevents caking in the cold cylinder, boosting mixing efficiency by over... 40%。

(2) Auxiliary Equipment: Vacuum Feeder 

The vacuum feeder uses negative pressure suction to automatically convey raw materials to the mixer or extruder. The entire process is fully enclosed and dust-free, enhancing efficiency while maintaining cleanliness. 

Its suction force is adjustable, making it suitable for materials of varying weights and densities, thus preventing material blockages or uneven feeding. 

II. Forming Stage: The Film's “ Moment of Birth ” Extrusion and molding equipment are the core. 

The preprocessed raw materials are melted and plasticized by an extruder and then processed into preliminary blanks by forming equipment. At this stage, the temperature control and pressure stability of the equipment directly determine the film thickness tolerance and surface smoothness. 

(1) “ Melting Master ” Single-screw / Twin-screw extruder 

The extruder is the heart of the production process. After heating and melting the raw materials, it uses a screw to extrude and convey the melt into the mold. Extruders are classified into single-screw and twin-screw models, depending on the type of film being produced. 

• Single-screw extruder Simple structure, low cost, suitable for PE 、 PP Single-resin film production, aspect ratio 20-30:1 The higher the ratio, the more thoroughly the material melts. 
• Twin-screw extruder Strong shear force makes it ideal for producing multi-component functional films, delivering superior mixing performance and ensuring uniform distribution of functional masterbatches. 
• Key technology Segmented temperature control design ( 3-5 One temperature zone, 150℃-230℃ Gradient transition) to prevent overheating and degradation of the raw materials, ensuring stable film performance. 

(2) “ Shaping mold ”： T Mold head 

T The die head shapes the molten plastic into a sheet, with the core being the runner design. By adjusting the gap between the flow restrictor and the lip, the distribution of the melt is controlled, ensuring uniform transverse thickness of the film. 

The precision of the high-quality die lip reaches 0.01mm , the thickness tolerance is controlled within ±5 μm Inside, this is crucial for the cold-chain film and can prevent localized thermal insulation failure. 

(3) “ Cooling and shaping ” Cooling roller and traction machine 

200℃ The high-temperature films on the left and right must be rapidly cooled and shaped by cooling rollers, while the traction machine conveys the films at a stable speed to ensure continuous production. 

The traction and extrusion speeds must be precisely matched; otherwise, the film is likely to overstretch or wrinkle. The intelligent traction machine is equipped with a servo system that achieves speed accuracy of... ±0.1 m/min 。

III. Function Enhancement Phase: Make the film “ More capable ” Stretching and post-processing equipment are crucial. 

The initial embryo film (cast sheet) has single performance characteristics and requires equipment such as stretching and coating to enhance its functionality. —— Greenhouse films rely on biaxial stretching to enhance light transmission, while tea milk drink packaging films achieve non-stick properties through coating. 

(1) “ Strength Booster ” : Biaxial stretching equipment ( BOPP/BOPET Dedicated) 

BOPP 、 BOPET The core reinforcing equipment for high-strength films is the biaxial stretching machine. It works by stretching in the longitudinal direction ( MDO ) and horizontal ( TDO The stretching machines work in synergy to stretch the film in both directions. 3-5 Multiplying [the material] aligns the molecules in a specific direction, enhancing strength, transparency, and barrier properties. 

• Longitudinal stretching The film is stretched in the direction of travel by means of a differential-speed traction roller, enhancing its longitudinal strength. 
• Horizontal stretching The film is stretched in the width direction within the oven by means of a chain. 100-150℃ Temperature control ensures uniformity. 
• Application effect : After stretching BOPP Improved membrane strength 3 More than double, suitable for high-strength food composite films.

(2) “ Function assigner ” Coating equipment 

Coating equipment imparts special properties to thin films by applying functional coatings (such as anti-stick agents and antistatic agents) onto the film surface, which then undergo drying and curing to form a functional layer. 

• Common types : The blade coating offers the highest precision (coating 0.1–5 μm ), suitable for applications requiring easy-peel release liners, anti-stick coatings, and electrostatic-free films; other application methods include roll coating and spray coating. 
• Core requirements Cleanroom operations prevent defects and precisely control temperature to avoid cracking or delamination of coatings. 

(3) “ Surface beautician ” Corona treatment equipment 

PE 、 PP When the surface tension of a thin film is low, direct printing can easily cause ink to flake off. Corona treatment equipment uses high-voltage discharge to create microscopic depressions on the film surface, thereby increasing surface tension and adhesion. 

Its processing width and speed are matched to the production line, without compromising the film’s performance—making it an essential piece of equipment for printing-grade films. 

IV. Finished Product Stage: Precise Cutting and Inspection to Ensure Quality “ The last mile ”

The film master roll, after functional enhancement, must be slit into the required specifications by slitting equipment and then undergo inspection to remove any nonconforming products, thereby ensuring delivery quality. 

(1) “ Precision tailoring ” Slitting machine 

The slitting machine cuts wide-web parent rolls into narrow rolls or fixed-length sheets (such as cup-lid films). The accuracy directly affects dimensional tolerances. Slitting deviations for electronic films and medical films must be carefully controlled. ≤±0.2mm 。

• Key components The round blade determines the smoothness of the cut, while uniform pressure from the pressure rollers prevents the film from shifting off-center. 
• Smart Upgrade : The automatic deviation correction and tension control system adjusts parameters in real time, and the qualified cutting rate has improved from... 95% Rise to 99% The above. 

(2) “ Quality goalkeeper ” : Online detection and offline detection equipment 

Film inspection is divided into online and offline types to ensure that every roll of product meets the standards. 

• Online detection Thickness detector (infrared) / Laser sensing and deviation alarms, along with surface defect detectors (which use high-definition cameras to identify and remove defects), monitor production in real time. 
• Offline detection The performance of finished products, such as tensile testers and oxygen permeability testers, is subject to random inspections. For example, cold-chain films must undergo... -40℃ Low-temperature resistance test. 

V. Industry Perspective: Equipment Upgrades Drive the Thin-Film Industry “ Improve quality and increase efficiency ”

New energy and flexible electronics, among other fields, are driving the diversification of thin-film applications, and equipment upgrades are showing two major trends. 

(1) Intelligence: From “ Manual operation ” To “ Unmanned workshop ”

Traditional production relies on manual parameter tuning, resulting in insufficient precision. The intelligent production line, through... PLC Achieve end-to-end automation with the Internet of Things, automatically match device parameters to recipes, upload data to the cloud, and receive anomaly alerts—boosting efficiency. 30%+ Reduce costs 50%+ 。

(2) Customization: Tailored to meet the production needs of specialty films 

For specialty products such as biodegradable films and ultra-thin electronic films, equipment manufacturers are offering customized solutions: PLA The membrane requires a dedicated low-temperature extruder; 5 μm The following ultrathin films require high-precision die heads and tension systems to prevent breakage. 

Conclusion 

The high-quality performance of thin films stems from the precise control of equipment at every stage. Continuous equipment upgrades are driving the thin-film industry toward... “ Lighter, more functional, and more environmentally friendly ” Development. 

In the future, demand in the new energy and biopharmaceutical sectors will drive equipment upgrades toward higher precision and greater intelligence—these... “ Hardcore gear ” It will provide support for thin-film innovation. 

What film production equipment have you been familiar with? Do you have any questions about specialized membrane equipment? Feel free to share your thoughts in the comments!