What are the production process and technical difficulties of BOPP synthetic label paper?

The production process and technical difficulties of BOPP (biaxially oriented polypropylene) synthetic label paper mainly involve multiple links such as raw material preparation, extrusion plasticization, casting and stretching, surface treatment, coating and printing, as well as winding and slitting. The following is a detailed analysis of these links and their technical difficulties:

1、 Production process

Raw material preparation

The main raw material is polypropylene (PP) resin, especially isotactic polypropylene, whose content needs to reach a high standard (such as 95%~97%) to ensure the tensile strength and physical properties of the film.

Add functional fillers (such as pigments, dyes, etc.) as needed to give the paper specific colors and functional characteristics, as well as additives such as antioxidants, lubricants, fluorescent whitening agents, titanium dioxide, etc. to improve the processing performance of the paper and the performance of the final product.

Extrusion plasticization

Mix polypropylene resin, functional fillers, and various additives in a certain proportion and send them to an extruder for plasticization.

The processing temperature of the extruder is generally around 250 ℃, and the specific temperature is adjusted according to the temperature resistance of the raw materials and the performance of the extruder.

The raw materials are melted into a uniform melt through high temperature and high pressure in the extruder.

Casting and stretching

The melted polypropylene melt is extruded into thick sheets through a die and rapidly cooled into regular thick sheets. The cooling process usually uses a chill roller and a water tank, and the temperature is controlled at 30-45 ℃.

Perform longitudinal and transverse stretching treatment on the cast pieces, with stretching ratios between 4.55.5 and 910, respectively. During the stretching process, it is necessary to control the temperature and stretching speed of the preheating zone, stretching zone, and shaping zone to ensure the uniformity and tensile strength of the film.

surface treatment

Perform corona treatment or other surface treatments on the stretched film as needed to improve the surface tension of the film and enhance the adhesion of the coating layer.

Coating and Printing

Coating thermosensitive coatings, base coatings, and protective layers on the surface of thin films requires strict control of the composition, concentration, and coating amount of the coating liquid during the coating process.

The printing process requires the use of high-quality ink and printing equipment to ensure the clarity and durability of the printing effect.

Roll up and slitting

Roll the coated film into a uniform large roll, and control the tension of the contact roller and pressure roller during the winding process to maintain the flatness and tightness of the large roll.

Cut the large film roll into appropriate sizes according to customer requirements, and strictly control the cutting accuracy and edge quality during the cutting process.

2、 Technical difficulties

Thermal sensitive layer stability

The thermal sensitive layer of BOPP color thermal sensitive synthetic paper needs to remain stable under different temperature and humidity conditions to ensure the durability and clarity of the printing effect. However, thermal sensitive materials are susceptible to external environmental factors such as light exposure, oxidation, etc., which can cause color fading or blurred images.

Physical performance optimization

The physical properties of BOPP film, such as tensile strength, tear strength, wear resistance, etc., are crucial for the effectiveness of the final product. Continuous optimization of material formulations and processing techniques is needed to improve the durability and reliability of products.

Color consistency

BOPP color thermal sensitive synthetic paper needs to achieve a high degree of color consistency to meet the needs of different customers for color reproduction. This requires strict control over the quality of raw materials, the accuracy of printing equipment, and the stability of color management systems during the production process.

Environmental Protection and Sustainability

With the increasing awareness of environmental protection, there is a growing demand in the market for environmentally friendly BOPP color thermal synthetic paper. This requires companies to use environmentally friendly raw materials, reduce pollution emissions during the production process, and develop biodegradable or easily recyclable products.

Energy Efficiency and Cost Control

Improving energy efficiency in the production process, reducing energy consumption and carbon emissions, are also important technical challenges facing the BOPP color thermal synthetic paper industry. Meanwhile, factors such as fluctuations in raw material prices and rising energy costs may have an impact on production costs, requiring enterprises to reduce production costs through technological innovation and management optimization.

In summary, the production process of BOPP synthetic label paper involves multiple complex links and there are multiple technical difficulties that need to be overcome. By continuously optimizing production processes and technological innovation, the quality and performance of products can be improved to meet the diverse needs of the market.