Causes, countermeasures and effects on the quality of BOPP film slitting quality ---
(2) The purpose, method and characteristics of hardness testing
3. Method for detecting film roll hardness
1 selection of testing equipment
There are various instruments for detecting the hardness of an object, but so far there has not been a hardness tester that professionally detects the hardness of a film roll. Due to the large difference in surface hardness between various objects and the variety of hardness testers, it is important to select a hardness tester that can effectively reflect the tightness of the film roll. After screening and comparison, our company has determined the "A-type rubber hardness tester" for detecting the surface hardness of rubber products as an auxiliary instrument for detecting the tightness of the film roll.
2 detection instrument correction
Since the "A type rubber hardness tester" is not a special test instrument for the film roll, in order to improve the detection accuracy of the instrument, we have modified the structure of the hardness tester according to the characteristics of the film, and increased the presser area by 5 times.
3 detection methods a.
Before the test, the pointer of the hardness tester should be in the free state and point to the zero position. When pressing the hardness tester on the glass plate, the pointer should be 100 degrees (the end face of the press pin and the bottom of the foot are in close contact with the glass). If the zero position and the 100 degree are not indicated, the needle can be pressed slightly several times, if not When referring to zero and 100 degrees, it cannot be used. The hardness tester to be confirmed can be used again if it meets the requirements for use. b.
When testing the hardness, put the hardness tester on the side of the film product, take the left, middle and right positions, at least 40mm from the edge of the film roll, and firmly press the end of the hardness tester with both hands, so that the pressure pin is pressed vertically. The sample is read within 1 s until the pressure is fully contacted with the sample, and the average is taken and recorded.
Reasons, countermeasures and effects of BOPP film slitting quality ---
thirteen. Foreign matter such as dust and small flying insects in the film roll
In the slitting process of the film, the mother roll film needs to be unwrapped and then slit and wound, which creates conditions for the entry of foreign matter. Since many film products themselves need to be in direct contact with foods, medicines, etc., the hygiene requirements are very strict, and the film is not allowed to be attached with foreign objects such as mosquitoes. Once found, it causes major quality complaints and claims, directly causing the company's economic loss and product brand. Damaged and negatively affected, therefore, the environmental cleaning and purification work in the production workshop plays a very important role in ensuring the quality of the film.
Slitting machine parts ---
1. Type of inspection system for the tension and speed of the slitting machine:
1 Tension sensor detection: The tension sensor is installed under the bearing of the tension detecting roller, converts the detected aluminum foil tension into an electrical signal, sends it to the tension adjuster, compares it with the original set tension signal, performs PID calculation, and then inputs The winding motor controller achieves the purpose of controlling the tension and rotation speed of the winding roller.
2Floating roller indirect tension detecting system: a set of floating roller is installed in front of the aluminum foil tracking roller. The position of the floating roller is detected by a potentiometer. The tension control method is to keep the tension constant by keeping the position of the floating roller as constant as possible. .
3 The magnetic powder clutch is used to control the rotational torque of the input winding roller to achieve tension control: the magnetic powder clutch is composed of an active part and a driven part, and is connected to the winding roller through a transmission mechanism such as a universal joint, and the fine ferromagnetic powder is filled in the middle. As a torque transmission medium. A magnetic field is formed by applying a constant current to the exciting coil, and the magnetic powder is magnetized. The magnetized magnetic powder attracts each other to form a chain arrangement. When the active part rotates at a constant speed, the coupling force between the magnetic powders is broken to form a circumferential tangential force, and the product of the tangential force and the radius of the magnetic ring is the driving driven part. The winding torque of the winding realizes the coupling of the output torque from the active part to the driven part in continuous rotation, thereby achieving the purpose of controlling the tension.
4 slitting Unwinding capacity and speed detection system: The magnetic powder tension brake is mainly used to control the unwinding force and speed. The working principle is: the coupling is installed in the magnetic powder brake, and the input parts and output with magnetic coils are installed. component. Below the magnetic coil is an annular groove, the underside of which is an annular rotor or output member. The annular groove is located at the center of the output member and is filled with magnetic powder. When there is excitation current in the magnetic coil, the coil generates magnetic flux to align the magnetic powder in the direction of the magnetic field, thus generating damping between the input member and the output member, and transmitting the torque. If the tension and speed applied to the aluminum foil are increased or decreased, the magnitude of the exciting current can be changed, or the magnitude of the current applied to the coupling coil by the varying amplifier can be effectively controlled.
Zhengzhou EAST IMPORT AND EXPORT co., ltd . ( a goulian group of company) a manufacturer and exporter for all kind of packaging machinery , like bopp tape coating machines, bopp tape slitting machines. Bopp tape core cutter, bopp tape core loader etc