Release paper coating machine for the base paper requirements and processes
Release paper on the base of the original paper that is the paper base has high requirements, not only requires it to have high strength and in the heat resistance of the thickness of the pine moisture and other aspects also have strict requirements. According to the coated online understanding, in the raw paper quantitative aspects of the general selection of 125g/m2 above the paper, its production technology is difficult, the thickness of the raw paper and heat resistance control. In the pine thickness of general selection of coniferous wood pulp and broadleaf wood pulp ratio copying way to control the heat resistance needs, add heat-resistant agent in the pulp to enhance the heat-resistant properties of the paper. So the general release paper will use the film paper production release paper, because of its good flatness, good toughness, in line with the basic requirements of the production of release paper.
Release coating layer can be divided into two categories, namely, silicone-based release coating layer and non-silicone-based release coating layer. Silicone-based release materials, including silicone resin and modified silicone resin with alkyd resin acrylic resin.
Non-silicone release materials include chromium complex methacrylic acid type or fatty acid type polypropylene resin, polymethylpentene resin and other special resins amino alkyd resins, epoxy resins and so on. Different types of release coatings have different characteristics, such as silicone resin-type coatings with excellent peel performance and heat resistance, chrome complex-type coatings with poor solvent resistance, polypropylene-type coatings with high gloss but poor heat resistance. Different types of release coatings and their technical processes are different, silicone-based release coatings are generally used roller or doctor blade coating method, and requires the raw paper used to be a layer of primer coating. Coating Online believes that the main purpose of the primer is to improve the smoothness and resistance to penetration of silicone-based coatings. Polypropylene resin and polymethylpentene resin type coating mainly through the extrusion coating method, it used in the raw paper can not be primed, the coating of other added components through the extrusion coating machine feed slot feeding, these release coating technology process involves the control of the peel strength of the coating, which is also where the technical difficulties lie. Because this in turn involves the choice of peel strength control agent and its impact on the other properties of the release coating.
The production process of release paper is divided into four categories:
The first process: release paper with printing, lamination paper, silicone oil paper must be printed first, in order to do the latter process: lamination and silicone coating.
The second process: PE lamination (plastic coating), PE lamination machine, also known as plastic coating machine, will be hot melt PE plastic film evenly coated on the surface of the paper to form lamination paper, also known as plastic coated paper or plastic paper. It is also the first process to produce plastic release paper.
The third process: silicone coating, silicone oil has the physical properties of non-affinity, silicone coating is the use of coating machine will be coated with silicone on the surface of other materials in rolls, forming a layer of silicone oil layer, called silicone oil paper (film), so as to achieve the role of non-stick, oil, is the production of grease-proof paper, anti-adhesive paper, the main material of the release film.
The fourth process: slitting, because many companies have large silicone coated production lines, and customer demand is generally narrower or single sheet of finished products, so the last process is to slit the large rolls of release paper (film) into the finished product required by the customer. After slitting, the rolls of silicone coated paper, release film or lamination paper are then slit into rectangular sheets by a sheet-fed machine to meet the customer's needs for flat sheet products.