What to Do If Aluminum Foil Bags Always Have Bubbles?

Aluminum foil bags are widely used in many fields such as food, medicine, and electronics due to their excellent barrier properties and sealing performance. However, during the use of aluminum foil bags, bubbles often appear, which not only affects the appearance of the product but also may reduce its barrier performance and sealing effect, thereby affecting the quality and shelf life of the product. So, what should we do if aluminum foil bags always have bubbles?​

1. Composite Process Issues: In the composite process of aluminum foil bags, the composite temperature, pressure, and the coating of glue will have an important impact on its quality. If the composite temperature is too high, it will make the glue dry too quickly and cannot fully wet the substrate, resulting in bubbles; if the temperature is too low, the fluidity of the glue is poor, and it cannot fill the gaps of the substrate well, and bubbles will also appear. The same is true for improper pressure. If the pressure is too small, the substrates cannot be tightly combined, and air is likely to remain to form bubbles; if the pressure is too large, the glue may be squeezed out, leading to local lack of glue and bubbles. In addition, if the glue is coated unevenly, with some places coated too much and some too little, bubbles are likely to appear in the places with less glue.​

2. Substrate Problems: If the surface of the selected substrate is uneven, has impurities or oil stains, it will affect the combination of glue and the substrate, making it impossible for the substrates to bond well, thus resulting in bubbles. Moreover, different substrates have different thermal shrinkage rates. When compounded and treated at high temperatures, bubbles may also be generated due to inconsistent shrinkage.​

1. Improper Storage Environment: If the storage environment of aluminum foil bags is too high in temperature, it will cause the air inside the bags to expand when heated, thereby generating bubbles; if the humidity is too high, it will cause the surface of the aluminum foil bags to get damp, affecting their sealing performance, and thus may introduce air to generate bubbles.​

2. Transportation Problems: If aluminum foil bags are subjected to severe extrusion and collision during transportation, it may damage the structure of the bags, leading to air entering and generating bubbles. In addition, drastic changes in the environmental temperature during transportation may also cause the air inside the bags to expand or contract, thereby generating bubbles.​

When using aluminum foil bags to pack items, if the temperature of the packed items is too high and they are directly put into the bags, the air inside the bags will expand when heated, and the high temperature may affect the performance of the glue, leading to the generation of bubbles. In addition, if the air in the bag is not fully exhausted during packaging, air will remain in the bag to form bubbles.​

1. Optimize the Composite Process: Strictly control the temperature and pressure during compounding, and set appropriate parameters according to different substrates and glue types. At the same time, ensure that the glue is coated evenly. This can be achieved by regularly checking the gluing equipment and adjusting the pressure and speed of the gluing roller.​

2. Select High-Quality Substrates: When purchasing substrates, strictly inspect them to ensure that the surface of the substrates is flat, free of impurities and oil stains, and select substrates with similar thermal shrinkage rates for compounding.​

1. Store Reasonably: Store aluminum foil bags in an environment with a suitable temperature (generally 15-30℃), dry and ventilated, avoiding direct sunlight and being close to heat sources. At the same time, the aluminum foil bags should be stacked neatly to avoid extrusion deformation due to excessive stacking.​

2. Standardize Transportation: Handle with care during transportation to avoid severe collision and extrusion. Special packaging materials can be used to protect the aluminum foil bags to prevent them from being damaged. In addition, pay attention to the temperature changes in the transportation environment and try to avoid transportation under extreme temperatures.​

When using aluminum foil bags to pack items, ensure that the temperature of the items drops to room temperature before putting them into the bags. During packaging, try to exhaust the air in the bag as much as possible, and a vacuum pumping method can be used to reduce the possibility of bubbles.​

In a well-lit environment, carefully observe the surface of the aluminum foil bag to see if there are raised small dots, which are usually bubbles. Fully inspect all parts of the bag, including the corners and the sealing area.​

Gently squeeze the aluminum foil bag and observe whether the bubbles move or disappear. If the bubbles move, it indicates that the bubbles are caused by residual air; if the bubbles do not move, they may be bubbles generated during the production process.

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Bubbles in aluminum foil bags will bring many adverse effects to products, so we must pay attention to the bubble problem. By understanding the causes of bubbles, taking targeted solutions, and strengthening the detection of aluminum foil bags, we can effectively reduce the generation of bubbles, ensure the quality of aluminum foil bags, and thus better protect the packaged products. In all links such as production, storage, transportation, and use, we must strictly operate in accordance with the specifications to prevent the appearance of bubbles and improve the market competitiveness of products.