复合袋包装袋破袋率如此高的源头
1、热封温度对热封强度的影响为直接。
1. The effect of heat sealing temperature on heat sealing strength is direct.
各种材料的熔融温度的高低,直接决定复合袋的低热封温度。生产过程中,由于热封压力,制袋速度以及复合基材的厚度等多方面影响,实际采用的热封温度往往要高于热封材料的熔融温度。
The melting temperature of various materials directly determines the low heat sealing temperature of composite bags. During the production process, due to various factors such as heat sealing pressure, bag making speed, and the thickness of the composite substrate, the actual heat sealing temperature used is often higher than the melting temperature of the heat sealing material.
热封的压力越小,要求热封温度越高;机速越快,复合膜的面层材料越厚,要求的热封温度也越高。热封温度若低于热封材料的软化点,则无论怎样加大压力或延长热封时间,均不可能使热封层真正封合。
The lower the pressure of the heat seal, the higher the required heat seal temperature; The faster the machine speed, the thicker the surface material of the composite film, and the higher the required heat sealing temperature. If the heat sealing temperature is lower than the softening point of the heat sealing material, no matter how much pressure is increased or the heat sealing time is extended, it is impossible to truly seal the heat sealing layer.
但是若热封温度过高,又易损伤焊边处的热封材料熔融挤出,产生“根切”现象,大大降低封口的热封强度和袋子的耐冲击性能。
However, if the heat sealing temperature is too high, it is easy to damage the heat sealing material at the welding edge by melting and extrusion, resulting in a "root cutting" phenomenon, greatly reducing the heat sealing strength of the seal and the impact resistance of the bag.
2、热封层材料的种类、厚度以及质量对热封强度有决定性的影响。
2. The type, thickness, and quality of the heat sealing layer material have a decisive impact on the heat sealing strength.
一般
济南复合塑料袋常用的热封材料有CPE、CPP、EVA、热熔胶以及其它一些离子型树脂共挤或共混改性薄膜。热封层材料的厚度一般在20~80μm之间,特殊情况下也有达100~200μm的。同一种热封材料,其热封强度随热封厚度的增大而增大。蒸煮袋的热封强度一般要求达40~50牛顿,因此,其热封材料厚度应在60~80μm以上。
Generally, the commonly used heat sealing materials for Jinan composite plastic bags are CPE, CPP, EVA, Hot-melt adhesive and other ion-exchange or blend modified films. The thickness of the heat sealing layer material is generally between 20 and 80 μ Between m, it can also reach 100-200 under special circumstances μ M's. The heat sealing strength of the same heat sealing material increases with the increase of heat sealing thickness. The heat sealing strength of steaming and boiling bags is generally required to reach 40-50 Newton, therefore, the thickness of the heat sealing material should be between 60-80 Newton μ Above m
3、要达到理想的热封强度,一定的压力必不可少。
3. To achieve the ideal heat sealing strength, a certain amount of pressure is essential.
对于轻薄包装袋,热封压力少要达到2kg/cm2,而且随着复合膜总厚度的增加而相应提高。若热封压力不足,两层薄膜之间难以达到真正地熔合,致合局部热封不好,或者难以赶尽夹在焊缝中间的气泡,造成虚焊;当然,热封压力也不是越大越好,应以不损伤焊边为宜,因为在较高的热封温度时,焊边的热封材料已处于半熔融状态,太大的压力易挤走部分热封料,使焊缝边缘形成半切断状态,焊缝发脆,热封强度降低。
For lightweight packaging bags, the heat sealing pressure must reach at least 2kg/cm2, and it will increase correspondingly with the increase of the total thickness of the composite film. If the heat sealing pressure is insufficient, it is difficult to achieve true fusion between the two thin films, resulting in poor local heat sealing or difficulty in removing bubbles trapped in the middle of the weld seam, resulting in false soldering; Of course, the higher the heat sealing pressure, the better. It is advisable not to damage the welding edge, because at higher heat sealing temperatures, the heat sealing material of the welding edge is already in a semi molten state. Excessive pressure can easily squeeze out some of the heat sealing material, causing the weld edge to form a semi cut state, causing the weld to become brittle and the heat sealing strength to decrease.
4、热封后的焊缝若冷却不好,不但会影响焊缝的外观平整度,而且对热封强度有一定的影响。
4. If the cooling of the weld seam after heat sealing is not good, it will not only affect the appearance flatness of the weld seam, but also have a certain impact on the heat sealing strength.
冷却过程就是通过在一定的压力下,用较低的温度对刚刚熔融热封后的焊缝进行定形,应力集中的过程。因此,压力不够,冷却水循环不畅,循环量不够,水温太高,或冷却不及时都会致使冷却不良,热封边起翘,热封强度降低。
The cooling process is the process of shaping the weld seam that has just been melted and heat sealed at a lower temperature under a certain pressure to eliminate stress concentration. Therefore, insufficient pressure, poor circulation of cooling water, insufficient circulation volume, high water temperature, or untimely cooling can lead to poor cooling, warping of hot sealing edges, and reduced strength of hot sealing.
The source of such high bag breakage rate in composite bag packaging can be found from the above four aspects. We hope to provide you with good help. For more information, please come to our website http://www.jingmeisuliao.com Consult!