Views: 0 Author: Site Editor Publish Time: 2023-05-20 Origin: Site
1. Basement membrane
In industrialized large-scale production, the base films used for coated PVDC films are mainly BOPP, BOPET, BOPA, CPP, etc. In addition, films such as PE, PVC, and cellophane can also be used. The base films used must be surface-treated before coating. Treatment to achieve a good enough surface state to ensure a continuous, pinhole-free PVDC coating and good bonding fastness between the PVDC coating and the base film, so as to obtain a PVDC coating film with good barrier properties.
The commonly used methods for surface treatment of the base film are corona treatment and primer coating. Corona treatment can cause a chemical reaction on the surface of the base film to generate polar groups, increase the lonely surface tension, and help PVDC emulsion Wetting on the surface of the base film improves the coating effect; during corona treatment, it also produces a certain roughening effect on the surface of the base film, thereby improving the bonding strength between the coating and the base film. The primer coating is to combine the base film and the PVDC coating through a specific coating. If the primer coating is selected and applied properly, the PVDC coating effect can be significantly improved. Therefore, high-quality PVDC coatings Cloth packaging materials are generally suitable for primer coating without exception, and the most widely used primer is polyurethane glue. www.susumino.com Nanjing Susumo Seiko specializes in R&D and manufacturing of coating machines
2. PVDC emulsion for coating
PVDC coating can use PVDC solution or PVDC emulsion. Based on the needs of environmental protection and cost reduction, PVDC emulsion is generally used in the production of industrialized PVDC coated packaging materials.
The PVDC emulsion for coating is a copolymer of vinylidene chloride and Shaoling comonomer (mainly acrylic monomer). The introduction of comonomer reduces the melting temperature of PVDC resin, thereby widening the gap between melting temperature and decomposition temperature. The distance is conducive to film formation to improve the coating process performance of PVDC emulsion. The content of comonomer is usually controlled at a low level (only about 10%), so that PVDC resin has excellent oxygen barrier and moisture resistance.
Coating PVDC resins must not only have good barrier properties, but also have good coating processability, anti-blocking properties, and good emulsion storage stability and other coating process properties. www.susumino.com Nanjing Susumo Seiko specializes in R&D and manufacturing of coating machines
3. PVDC coating process
crafting process
Base film---surface corona treatment---primer coating---infrared drying---hot air drying---PVDC (surface glue)---infrared drying---hot air drying---coiling-- -curing---product
Note: Fast drying by far infrared can prevent skinning on the surface of the coating and help the coating dry.
The function of curing is to make the PVDC coating crystallize uniformly and improve the barrier property of the PVDC coating. At the same time, curing at a set temperature can prevent the coating from cracking due to uneven crystallization, so as to obtain high barrier properties. product.
When the film needs to be coated on both sides, repeat the above coating construction. www.susumino.com Nanjing Susumo Seiko specializes in R&D and manufacturing of coating machines
Nanjing Sumino Precision Machinery Co., Ltd. specializes in the production of release paper coating machines. The company is committed to creating a coating machine production line with uniform coating, high smoothness, and high cleanliness. The company mainly operates coating machine production lines including release paper coating machine, optical film coating machine, automotive heat insulation film coating machine, water treatment film coating machine, aluminum foil coating machine, dimming glass coating machine, thin film coating machine Fabric machine, PDLC dimming film coating machine, lithium battery extrusion coating machine, laboratory lithium battery coating machine, etc.
