Causes, countermeasures and effects on the quality of BOPP film slitting quality ---
(2) The purpose, method and characteristics of hardness testing
1. OBJECTIVE: The hardness test method provides a quantifiable means for determining the tightness of the film roll and provides a quantifiable basis for the determination.
Some of the product quality characteristics can be quantitative, and some can not be quantified, can only be qualitative. In the past, our judgment on the tightness of the film winding is only based on the hand feeling. The scale of the judgment is difficult to grasp, and the difference between different inspectors Larger. In actual work, when measuring, the non-quantitative characteristics are usually converted into quantifiable substitute quality characteristics, which are used as the basis for evaluation, inspection and assessment. Film roll hardness testing is a means of quantitative control of the main quality characteristics of the slitting under this guiding ideology. However, it is worth emphasizing that not all quality characteristics must be quantified, especially the film as a process material quality characteristic, there are quantitative measurement characteristics, such as thickness, tensile strength, gloss, etc., also have qualitative characteristics, only the process Subjective judgments such as wrinkles, blots, chromatic aberrations, etc.
2. Several characteristics of film roll hardness
1 Different film varieties, the hand tightness is similar but the hardness data is different. This is because the hand roll is used to squeeze the film roll in a certain area of ??the finger, which is a test of one surface, and when the hardness tester is used, it is a The pin point is pressed against the film roll, which is a detection of a point, and there will be differences between the two;
2 different film varieties have different winding hardness requirements, which are based on the characteristics and uses of various films;
3 The tightness and hardness of the film roll are not completely linear. The most sensitive value is between 87 and 95. When the hardness is as low as 85, the rewinding does not affect the hardness. Similarly, when the hardness is high. At 97 o'clock, the effect of rewinding on the film roll hardness is getting smaller and smaller.
4 Winding hardness is a reference index for quantifying the winding tightness. It only reflects a quality characteristic of the film roll surface and does not reflect the fullness of the film roll. Therefore, the key is to effectively control the film roll tightness. The quality of the product used.
Reasons, countermeasures and effects of BOPP film slitting quality ---
thirteen. Foreign matter such as dust and small flying insects in the film roll
In addition, paper-end paper dust contamination, contamination of the film roll by the operator and the packaging staff, uneven size of the paper tube, label identification (length, weight, etc.), bumps, poor packaging, etc. are also easy to cut. For quality problems, we must pay attention to every detail during the operation and packaging process. For example, before the slitting machine starts, the film should be neatly placed and attached to the paper tube. The film should not exceed the end of the paper tube. Pay attention to the hands of the operator. Neat and clean environment of the cutting place, the packaging and handling process should be handled with care. When the film roll is moved down the manual forklift, pay attention to the stability, do not hit the film surface, the sealing box of the packaging process, the sticker cap, the sticker The labeling and labeling should be carried out in strict accordance with the specified requirements, position and size. It is not free to ensure the quality of the film products from every link.
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