The primary function of the packaging is to protect the product, the reason why the jelly cup packaging seal is easy to break and the detection method.
The jelly cup is composed of a cover film and a plastic cup. During the storage and transportation of the product, the internal pressure of the jelly cup is easily increased due to the stacking and stacking of the product, and the jelly cup sealing film is easily damaged. This damage occurs mostly in the heat seal area of the sealing film. The heat sealing process means that the sealing portion of the plastic film is changed into a molten viscous flow state by external heating conditions, and is pressurized by the head and held for a certain period of time to bond the upper and lower layers, and has a certain strength after cooling. There are many influencing factors in this process, in which the heat sealing temperature, pressure and time have great influence, so it can be solved by adjusting the heat sealing parameters or changing materials. In the case of jelly cup packaging, the heat sealing temperature is generally between the melting temperature and the decomposition temperature of the sealing film. If the temperature is too high, the film of the sealing portion is easily melted and extruded under the action of pressure, thereby reducing the heat sealing portion. Thickness and heat seal strength. If the temperature is too low, the sealing film will not reach the molten state and cannot be sealed. After the film is melted, a certain pressure is applied to the viscous flow surface to make the film and the cup mouth contact each other, penetrate and fuse, and the pressure also greatly affects the sealing product of the molten material. It should be noted that the size of the heat sealing pressure is directly related to the properties, thickness, width and the like of the sealing film. For example, the pattern sealing form is required to appropriately increase the heat sealing pressure due to the reduced contact area. Heat sealing time refers to the time the head stays on the film. In the case of constant temperature and pressure, the longer the time, the stronger the sealing, but too long will cause deformation or even degradation of the sealing film. Therefore, the root cause of seal damage in the jelly cup is mainly due to the imbalance of the above three indicators. How to obtain reasonable process parameters is a problem that needs to be paid attention to.
Heat seal performance test The heat seal tester can be used to simulate the heat sealing process of the production line, and then the heat seal process is judged by the heat seal strength test at the seal to obtain the heat seal parameters. The HST-H3 heat sealing test developed by Labthink uses hot-press sealing method to determine the heat sealing temperature, time and pressure of plastic film or composite film material. The equipment adopts advanced digital PID temperature control system, which can quickly heat up, infinitely close to the preset temperature, and the temperature control accuracy can be as high as ±0.2°C; the upper and lower independent temperature control settings, the aluminum can seal equal temperature heating tube device, and the lower double cylinder The design of the synchronous circuit makes the instrument more accurate and easier to operate.
The heat seal strength test for the jelly cup seal film can be tested with the Labthink XLW series of intelligent electronic tensile testing machines. After analyzing the storage and transportation status of the jelly cup, it was found that another reason for the breakage of the seal was that the seal film was subjected to extrusion and the internal pressure of the cup was increased, so the expansion heat seal strength test must be performed. This test uses the leak and seal strength tester to pressurize the jelly cup, record the time of the jelly cup seal blasting and the large bursting force through the change of pressure, thereby further adjusting the heat sealing process parameters and improving the sealing effect.
