For the flexible packaging industry, the direct performance of “packaging reduction” is thin film thinning. At present, thin film thinning has become a hot topic in the research of flexible packaging manufacturers and enterprises. Some matters that should be paid attention to during the film making and use of ultra-thin BOPA film can better promote the process of “packaging reduction” in the flexible packaging industry.

Matters needing attention during film making

The most common problem in the ultra-thin BOPA film in the film making process is the phenomenon of film rupture, which not only affects the quality of the film product, but also affects the yield and yield. The operator's production habit is one of the main causes of membrane rupture. From the production operation habit of 15μm BOPA film to the production operation habit of 12μm BOPA film, there must be an adaptation process. Once the operator adapts, he can operate freely.

In particular, it is necessary to point out the problem of moisture control of raw materials. Once the moisture content of raw materials exceeds the standard, it may cause membrane breakage during the film making process. Therefore, raw materials should be tested before feeding, and the testing items include water content, ash, melt index, viscosity and so on.

Secondly, since the ultra-thin BOPA film is thin, it should be paid attention to when controlling the stretching and traction during the film forming process. The size is suitable and balanced, and the heat setting temperature can be appropriately lowered, which is beneficial to the smooth progress of production. . In addition, the control of the die bolts is also important because the BOPA film produced is too thin and any fluctuations in the discharge bolts may affect the flatness of the final film product.

Matters needing attention during use

(1) The BOPA film itself is a highly moisture-absorbing material, and the ultra-thin BOPA film has a stronger moisture absorption property. Once the moisture is absorbed, the ultra-thin BOPA film will become soft, and sometimes the "raw edge" phenomenon will occur due to the inconsistent moisture absorption, which will cause quality problems such as printing registration difficulties and composite wrinkles. Therefore, in the daily production and storage process, special attention should be paid to the moisture resistance of the ultra-thin BOPA film.

(2) Since the tensile strength of the ultra-thin BOPA film is also reduced, the tension of the ultra-thin BOPA film is appropriately adjusted during the printing and compounding process to make it smaller, so as to prevent the tension from being excessive. Deformation wrinkles, especially when compounding with aluminum foil, pay more attention to the adjustment of tension.

(3) Since the ultra-thin BOPA film has a large moisture absorption property, it is necessary to minimize the use of solvents and inks containing water and alcohol.

(4) Requirements for printing plates and composite coating rolls. When printing ultra-thin BOPA film, it is required that the mesh of the printing plate used should be appropriately lightened to prevent the ink layer from being too thick and not dry thoroughly during printing to cause solvent residue.

The development of packaging film in the direction of lightweight and ultra-thin is an inevitable trend. Enterprises can make full use of material modification technology to obtain new packaging materials, fundamentally improve the barrier properties of materials, improve their mechanical properties, and achieve ultra-soft packaging materials. Thinning, "lightweight", "high performance" and "multi-functionality".

　　 The above content is selected from the third issue of 2011, Printing and Printing , Packaging and Decoration, and more journal content. Please pay attention to the journal channel.