How to improve the wear resistance of BOPP film?
To improve the wear resistance of biaxially oriented polypropylene membrane (BOPP membrane), a novel polypropylene surface modification coating with good transparency and wear resistance was prepared by sol-gel method, using silane coupling agent (KH550), aluminum sec butanol (ASB) and ethyl orthosilicate (TEOS) as precursors, solid acid (p-toluene sulfonic acid) as catalyst, and water in the air as the source of hydrolysis; In order to improve the binding property between the surface modification coating and biaxial oriented polypropylene film, potassium permanganate (KMnO4)/sulfuric acid (H2SO4) solution was used as oxidant and oxalic acid as cleaning agent to pretreat the surface of biaxial oriented polypropylene film; On this basis, the BOPP film pretreated by potassium permanganate and the developed surface modification coating were compounded to prepare the biaxially oriented polypropylene film with high wear resistance by dipping and pulling method.
First of all, by optimizing the preparation process, the surface modification coating with uniform particle size and average particle size of about 30 nm was prepared in situ. Infrared spectrum analysis showed that Si-O-Al covalent bond was formed in the prepared modified coating; The transmittance analysis found that the aluminum sol can effectively inhibit the whitening phenomenon caused by the massive cross-linking and agglomeration of the silica sol, which shows that the surface modification coating can make the modified film maintain the excellent optical properties of the original BOPP film.
Secondly, through the surface pretreatment of BOPP film, polar groups such as COOH and - OH were successfully introduced on the surface of BOPP film, which significantly increased the surface free energy by 28.1%, which provided a good basis for improving the interfacial bonding ability between BOPP film and the coating formed by surface modification coating.
That is, the common point of blistering and film stripping of the film-coated products processed by the gluing wet composite process is that the film breaks away from the substrate of paper and printing, and damages the compactness and smoothness of the paper/plastic composite.
To improve the wear resistance of biaxially oriented polypropylene membrane (BOPP membrane), a novel polypropylene surface modification coating with good transparency and wear resistance was prepared by sol-gel method, using silane coupling agent (KH550), aluminum sec butanol (ASB) and ethyl orthosilicate (TEOS) as precursors, solid acid (p-toluene sulfonic acid) as catalyst
The printing and film are combined by professional laminating equipment to form a paper-plastic product. This technology is called lamination. The surface of the printed matter coated with film is brighter and smoother, the pattern is more bright, and the performance of wear resistance, folding resistance, tensile resistance, moisture resistance, chemical corrosion resistance and other properties are also enhanced. Even some apparent defects in the printing process can be largely compensated. Therefore, not only the service life is extended, but also the beauty of the product is greatly improved. Since the film coating technology was born in the 1950s, the film coating technology has experienced three important development stages:solvent-based coating technology, water-soluble coating technology, and precoating technology.
Precoating film refers to the process of laminating plastic film with paper print after pre-gluing and rewinding. The precoating film structure is composed of substrate and adhesive layer. According to different substrates, the precoating film can be divided into BOPP precoating film, BOPET precoating film and BOPA precoating film. The adhesive layer is mainly EVA hot melt adhesive and LDPE hot melt adhesive. Downstream mainly applies to the packaging of books, food, medicine, daily necessities and other products in the field of industrial printing, digital printing, card certification, anti-counterfeiting, commercial advertising and construction materials in the special products market in the field of commercial printing.