It is well known that in the structure of electronic products, the protective film is an indispensable part of it. Whether it is a mobile phone, a camera or a tablet computer, a protective film is attached to protect the product screen before leaving the factory.
The transparency, flatness and cleanliness of the protective film affect the consumer's impression of the electronic product. A good quality protective film will also enhance the external image of the electronic product. Therefore, the die-cutting factory has strict control on the production of the protective film. Process control.
Protective film material selection
When producing a protective film, there are several points to be aware of when selecting a material. First of all, we must select materials that are more suitable for printing and die-cutting on the basis of satisfying customer requirements, such as good scratch resistance, good ink adhesion, and not easy to absorb ink.
Protective film production environment control
There are two key points in the quality control of protective film products. Be sure to avoid scratches and dirt. In order to meet these two requirements, we must first have a good production environment, and the die-cutting factory is equipped with an independent dust-free purification workshop for protective film production. The dust-free purification workshop is also called clean room, clean room (clean room), clean room, which refers to the removal of particulates, harmful air, bacteria and other pollutants in the air within a certain space, and the indoor temperature, cleanliness, Pressure, airflow velocity and airflow distribution, noise vibration and illumination, and static control are within a certain range of requirements, giving a specially designed room. No matter how the external air conditions change, it is required that the parameters such as cleanliness, temperature, humidity and pressure that were originally set can be maintained in the clean room. According to the requirements of the production of products, the cleanliness of the dust-free purification workshop has different levels of 100, 1000, 10,000, 100,000 and 300,000.
In the dust-free purification workshop, in the dynamic situation, the largest source of bacteria and dust is the operator. Therefore, before the operator enters the dust-free purification workshop, the clean clothes must be put on and cleaned with clean air for 15 seconds in the air shower to remove the dust particles attached to the surface of the clothes.
Protective film printing process control
Most plastic films (such as polyolefin films) are non-polar polymers with low surface tension, generally 29 to 30 mNm. Theoretically, if the surface tension of an object is less than 33 mNm, currently known inks and bonds None of the agents adhered strongly to the top, so the surface should be corona treated. The protective film is mostly made of polyolefin. Corona treatment is required before printing. Usually, the corona power is 4.0W and the speed is 30mmin. After corona, it is required to print on the machine within 5 minutes. If it is more than 10 minutes, it needs to be re-corona to be on the machine.
During the printing process, since the protective film material comes into contact with the platen roller, the surface of the material may be scratched by friction. Therefore, it is necessary to coat all the embossing rolls that are in contact with the protective film with a soft layer. In the composition of electronic products, the protective film is an indispensable part of it, whether it is a mobile phone, a camera or a tablet computer. A protective film is attached to protect the product screen. The transparency, flatness and cleanliness of the protective film affect the consumer's impression of the electronic product. A good quality protective film will also enhance the external image of the electronic product. Therefore, the die-cutting factory has a protective film product for the production. Strict process control.
Protective film die cutting process
After the protective film is printed, the die-cutting machine should be used for die-cutting. During the die-cutting process, care should be taken to avoid scratching and chipping. The specific performance of the ink-filling is that the ink layer on the edge of the product should be covered and smooth, but the result is There is a local phenomenon of no ink.
The main reason for the ink breakage during the die-cutting process is that the adhesion between the ink and the protective film is not strong enough, and the edge of the product is cut to separate the ink layer from the protective film, thereby producing a jagged edge. Therefore, the printed protective film should be checked for the adhesion fastness of the ink to ensure that the ink adheres well before die cutting. In addition, when the thickness of the ink layer is too thick, ink collapse occurs.
There are many reasons for the scratches easily occurring during the die-cutting process. The most common one is the uneven rotation of the nip rolls, which causes the materials and the nip rolls to rotate relative to each other to cause scratches. Therefore, it is necessary to check the rotation of the nip rolls before die cutting to ensure that the nip rolls in contact with the material are flexible. In addition, foreign matter on the nip roll can also cause scratches on the protective film and scarring. Therefore, use a clean cloth to remove alcohol before the die cutting to wipe the nip roll to ensure that the surface of the nip roll is clean and free of foreign matter. .
The die-cut shape of the protective film is generally designed according to the customer's drawing requirements, mainly according to the screen size of the customer's mobile phone product, usually a rectangle with rounded corners, and a handle in the lower right corner of the rectangle. The handle is printed on the back side, and then covered with a PET film for easy assembly, and it is convenient for consumers to remove the protective film from the screen. The protective film of various shapes is cut with a round knife, but the number of round knives required for the complicated process will increase. For example, if you need a protective film for the handle, you need two round knives and one cutting handle. The other is cut out.
Protective film packaging process control
After the protective film is die-cut, it is usually rolled into a roll. When packaging, it is cut into single pieces, and each piece is packaged in 500 pieces. When packaging, first wrap the protective film with a wrapping film and then put it into the plastic bag. The main concern when packaging is cleanliness, so the operator is required to wear finger cots for manual operation. For example, there is a protective film product that requires a hand-applied handle at a later stage. The operator is required to attach the handle to the exact position of the protective film with the rubber surface (ie, inside), and to ensure that the product is not dirty and cannot have foreign matter. All the above processes are required to be completed in a dust-free purification workshop.
The mobile phone protective film seems to be simple, and the production process is not complicated, but the requirements of each link are strict. In general, always pay attention to cleanliness and avoid bending and scratching the protective film. It is the above-mentioned bit by bit details that determine the grade of the product.