Sumino Seiko Cast Film Production Line
Compared with extruded blown film, extruded cast film has the advantages of good film transparency and thickness uniformity. Cast film resins are mainly polypropylene, polyethylene, and polyamide.

In order to manufacture extrusion cast film, in the extruder, the plastic melt flows through the head of the opening shape of the mold is a slit, known as the slit head, the melt through the slit to form a rectangular cross-section of the continuum, and its cross-section of the width is much larger than the thickness. Extruder through the head of the molten film downstream to the cooling roller surface, cooling and shaping, after haul-off, cutting and winding, the production of single-layer cast film. The thickness of the film is 0.05~0.1mm.

The film and sheet are made by extruding the melt onto a chrome-plated roll that is quenched. The melt leaves the slit and flows downward or at an angle to the cooling rolls, where it contacts the rolls in a tangential direction. The surface of the rolls is very smooth, which results in a very low surface roughness of the resulting film. Usually before the film is cooled to be cut and wound, the film has to pass through a set of S-shaped distribution of rollers, and at least two quenching rollers, the first cooling rollers work at a temperature of at least 40 ° C, with the air nozzle cooling, this method of production of film has a better transparency and high toughness, and high production volume, the size of the film is mainly dependent on the extrusion rate and the haul-off speed.

In this process, the film shrinks as it cools, so that the size of the resulting film or sheet is smaller than the size of the die, and the edges are thickened, and the thickened portion must be cut off. Similarly, in the film winding, due to the unevenness of the thin thickness, resulting in further thickness variation is increased, resulting in violent tendons, film thickness of the normal deviation of ± 3%, in the roll of the film produced violent tendons to the back of the operation caused by the difficulties, there are two ways to reduce the violent tendons, the general traditional method is to swing the film in the process of rolling so that it produces a random change in the thickness of the biggest drawback of this method is that it reduces the film's The biggest disadvantage of this method is that it reduces the width of the film and increases the amount of scrap, but this scrap can be reused as recycled material. A more advanced method utilizes sensors to detect the film thickness in real time and automatically adjusts the required die gap through computer control.

The film can be "oriented" or stretched under certain conditions, so that some molecules are rearranged in the direction of stretching, when the external force is removed, this arrangement will remain, the orientation can increase the crystallinity, improve the barrier properties, strengthen the strength in the direction of stretching, weakened in the direction of the strength of the unstretched.



Nanjing Suminoe Precision Machinery Co., Ltd. is a collection of scientific research, production, sales in one of the high-tech enterprises, has always adhered to the integrity, equality, customer interests first business philosophy, in order to better improve the quality of equipment, into a more professional standardized production track. We set up a plastic sheet, sheet, casting, bi-oriented, non-woven nonwoven meltblown cloth, film composite, renewable pelletizing environmental protection and recycling system and coating machine manufacturing system and other seven categories of equipment, independent research and development of technology centers and production departments, to provide a full set of professional technical solutions to meet the special needs of each customer use. Among them, the bi-directional stretch film manufacturing system has: BOPP bi-directional stretch film manufacturing system, PVC bi-directional stretch shrink film production line, PET bi-directional synchronized stretch film production line, BOPA bi-directional stretch film production line, BOPLA bi-directional stretch film production line and so on.

Translated with DeepL.com (free version)