Wuhan Handern Cast film
DATE：2020/12/11 10:01:12 / READ： / SOURCE：This station
Wuhan Handern Cast film
Cast film is also called cast film. The casting method is a method in which a plastic solution with a certain viscosity is coated on a continuously rotating carrier by a casting die, a knife coater or a reverse roller, and the solvent is removed by heating to prepare a film.
Compared with other methods of producing plastic films, the casting method has the outstanding advantages of being able to produce films with small thickness (5-10μm), small thickness deviation (±10%), and uniform and pure texture. The product is highly transparent, good gloss, no internal stress, and is mostly used to manufacture plastic films with high optical performance requirements. The disadvantage is that the production speed is slow, a lot of solvents are needed, the cost is high, and the product strength is low. handern.com Spunbond Non-woven Fabric Equipment
The plastics used in the production of cast films are cellulose triacetate, polyvinyl alcohol, vinyl chloride-vinyl acetate copolymer, polytetrafluoroethylene Vinyl fluoride, polycarbonate, etc. The film forming process is shown in Figures 11-9 and 11-10. The prepared plastic solution is cast on a polished annular stainless steel belt or a large-diameter drum, and dried to obtain a cast film.
Casting equipment and operation
(1) The main equipment of the casting method
①Metal drum; ②Annular stainless steel (or large diameter drum); ③Casting head; ④In-and-out system; ⑤Heating and drying system; ⑥Reeling device; ⑦Raw material pretreatment, dissolving, filtering and deaeration device .
(2) Operation precautions The thickness of the cast film can be controlled by changing the carrier running speed or changing the solution casting rate. It is generally achieved by changing the speed of the stainless steel belt and the distance on the slit of the casting nozzle. It is generally achieved by changing the speed of the stainless steel and the distance between the casting nozzle. The main problems that cast films may encounter are the solubility of the resin, the toxicity of the solvent, and the releasability of the carrier. Taking the production of cellulose triacetate film as an example, the solvent recovery is a problem that cannot be ignored in production.
The entire casting device is sealed in a drying room. Blow in 65°C hot air from under the stainless steel belt to make the solution gradually dry. When the coated film is wound from the upper part of the front roller through the upper and lower parts of the rear roller to the lower part of the front roller, the solution has been initially dried to form a film. At this time, it will peel off from the stainless steel strip and send it to further drying. The gas with solvent is discharged from the upper exhaust port and sent to the recovery device to recover the solvent. Solvent recovery often uses two types of devices: freezing recovery and adsorption recovery. handern.com Spunbond Non-woven Fabric Equipment
The film peeled off from the stainless steel belt usually contains 15-20% solvent and needs to be dried. There are two methods for re-drying: drying and ironing, both of which must be carried out in a rectangular drying room. Drying is achieved by dividing the drying room into several parts and adjusting the temperature of each part. Ironing uses a heated roller to directly iron the film to achieve drying. Volatile matter in dried and dried film Should be less than 1%. handern.com Spunbond Non-woven Fabric Equipment
Cast film is also called cast film. The casting method is a method in which a plastic solution with a certain viscosity is coated on a continuously rotating carrier by a casting die, a knife coater or a reverse roller, and the solvent is removed by heating to prepare a film.
Compared with other methods of producing plastic films, the casting method has the outstanding advantages of being able to produce films with small thickness (5-10μm), small thickness deviation (±10%), and uniform and pure texture. The product is highly transparent, good gloss, no internal stress, and is mostly used to manufacture plastic films with high optical performance requirements. The disadvantage is that the production speed is slow, a lot of solvents are needed, the cost is high, and the product strength is low. handern.com Spunbond Non-woven Fabric Equipment
The plastics used in the production of cast films are cellulose triacetate, polyvinyl alcohol, vinyl chloride-vinyl acetate copolymer, polytetrafluoroethylene Vinyl fluoride, polycarbonate, etc. The film forming process is shown in Figures 11-9 and 11-10. The prepared plastic solution is cast on a polished annular stainless steel belt or a large-diameter drum, and dried to obtain a cast film.
Casting equipment and operation
(1) The main equipment of the casting method
①Metal drum; ②Annular stainless steel (or large diameter drum); ③Casting head; ④In-and-out system; ⑤Heating and drying system; ⑥Reeling device; ⑦Raw material pretreatment, dissolving, filtering and deaeration device .
(2) Operation precautions The thickness of the cast film can be controlled by changing the carrier running speed or changing the solution casting rate. It is generally achieved by changing the speed of the stainless steel belt and the distance on the slit of the casting nozzle. It is generally achieved by changing the speed of the stainless steel and the distance between the casting nozzle. The main problems that cast films may encounter are the solubility of the resin, the toxicity of the solvent, and the releasability of the carrier. Taking the production of cellulose triacetate film as an example, the solvent recovery is a problem that cannot be ignored in production.
The entire casting device is sealed in a drying room. Blow in 65°C hot air from under the stainless steel belt to make the solution gradually dry. When the coated film is wound from the upper part of the front roller through the upper and lower parts of the rear roller to the lower part of the front roller, the solution has been initially dried to form a film. At this time, it will peel off from the stainless steel strip and send it to further drying. The gas with solvent is discharged from the upper exhaust port and sent to the recovery device to recover the solvent. Solvent recovery often uses two types of devices: freezing recovery and adsorption recovery. handern.com Spunbond Non-woven Fabric Equipment
The film peeled off from the stainless steel belt usually contains 15-20% solvent and needs to be dried. There are two methods for re-drying: drying and ironing, both of which must be carried out in a rectangular drying room. Drying is achieved by dividing the drying room into several parts and adjusting the temperature of each part. Ironing uses a heated roller to directly iron the film to achieve drying. Volatile matter in dried and dried film Should be less than 1%. handern.com Spunbond Non-woven Fabric Equipment
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