2 results about "Cast films" patented technology

The invention discloses a defoaming method in the synthesizing process of polyamide resin. The method comprises the following steps: heating and slowly stirring polyamide resin solution in a kettle at first at the temperature of 35 to 100 DEG C at normal pressure for 0.5 to 1.5h, wherein the stirring speed is less than or equal to 50r/min; then, quickly stirring the polyamide resin solution at a stirring speed of 60 to 100r/min at the same temperature for 2 to 4h; and casting film when the defoaming is completed, wherein CO2, nitrogen or other inert gas can be fed during the casting of the film to prevent the resin from discoloring and deteriorating at a gas flow of 0.1 to 0.8 m<3>/min, and a relative pressure of 0.3 to 0.5MPa is kept in the kettle. According to the method, the foaming is thorough, the surface quality of the film obtained later is improved, the defoaming time is short and the defoaming process is convenient in operation.

The invention discloses a preparation method of biodegradable cast film paper, which comprises the steps of weighing the following raw materials in parts by weight: 60 to 70 parts of poly (butylene terephthalate)-adipate, 30 to 40 parts of polylactic acid, 10 to 15 parts of polyethylene glycol, 2 to 4 parts of citrate, 5 to 8 parts of nanofibers, 2 to 4 parts of silicon dioxide and 2 to 4 parts of a silicone slipping agent, wherein the molecular weight of the silicone slipping agent is 0.9-1.1 million. The manufacturing method comprises the steps of mixing the raw materials, carrying out mixing extrusion through a twin-screw extruder, and granulating the extruded material to prepare plastic particles; preparing the plastic particles into a film by adopting a tape casting method; and performing uniaxial stretching on the film, and performing stretching and shaping to obtain a finished product. By adopting the manufacturing method of the biodegradable cast film paper, the problem that a cast film cannot be degraded is solved, meanwhile, the water vapor permeability is relatively good, the cost is reduced, and the preparation method is simple.