Flexible packaging composite bag has outstanding barrier, heat sealing, moisture resistance, acid resistance, alkali resistance, wear resistance, so it is widely used in food packaging. With the increasing progress of the quality requirements of flexible packaging composite bags, packaging enterprises pay more and more attention to the quality inspection of flexible packaging composite bags. Today, in this article, we will discuss how to detect whether the flexible packaging composite bag meets the requirements.

1.外觀視覺查看：外觀視覺查看包含對復合袋平整度、透明度的查看等項目。主要用于查看復合袋外表有無顯著的擦傷和針孔，封口處有無污染等

1. Appearance visual inspection: the appearance visual inspection includes the inspection of the flatness and transparency of the composite bag. It is mainly used to check whether there are obvious abrasions and pinholes on the surface of the composite bag, and whether there is pollution at the seal

2.封口密合性的查看

2. Check the sealing tightness

封口處一些纖細的小縫，在視覺查看上稍有忽略就會為日后食物的滲漏埋下危險，因而對復合袋進行封口密合性查看很有必要。常用的辦法為：將一種加有染料的外表活性劑噴于封口內，調查其透過與否，假如染料色澤透過封口處，則闡明密封功能欠好，相反則闡明符合密封質量請求。

Some tiny seams at the sealing place, if neglected in the visual inspection, will lay a danger for the future food leakage, so it is necessary to check the sealing tightness of the composite bag. The common method is: spray a kind of surface active agent with dye into the seal to investigate whether it passes through. If the dye color passes through the seal, it indicates that the sealing function is not good. On the contrary, it indicates that it meets the sealing quality requirements.

在實際工作中，咱們常用一把長20cm、寬5cm、厚0.8mm的光滑、無毛刺的小鐵尺對其封口密合處用力推頂。假如輕輕一頂便有掉落、穿孔等景象，則闡明密封功能差；若封口處仍然堅持應有的封合尺度，則闡明密封功能杰出。

In practical work, we usually use a smooth, burr free small iron ruler with a length of 20cm, a width of 5cm and a thickness of 0.8mm to push the sealing joint. If there are falling, perforation, etc. on one top, it indicates that the sealing function is poor; if the sealing part still adheres to the proper sealing scale, it indicates that the sealing function is excellent.

導致密封功能差的因素有：封刀壓力不行或不均，這種狀況只要調理封刀彈簧壓力即可處理；溫度偏低也會使復合袋封口處密合性變差。咱們注意到，當復合資料總厚度超越80μm時，在制袋加工時易發作密合性變差的疑問，尤其是BOPP/OPP的構造易發作。要想確保商品密合性優良，一定有均勻平穩的密封壓力及合適的溫度。

The reasons for the poor sealing function are: the pressure of the sealing knife is not good or uneven, which can be treated by adjusting the spring pressure of the sealing knife; the low temperature will also make the sealing of the composite bag worse. We notice that when the total thickness of the composite material exceeds 80 μ m, it is easy to have the problem of poor tightness, especially the structure of BOPP / opp. In order to ensure good tightness, there must be uniform and stable sealing pressure and appropriate temperature.