Views:1 Author:Site Editor Publish Time: 2020-03-10 Origin:Site
Aerosol products have four major components, aerosol cans, valves, feed liquids, and propellant gases. Due to the differences in product formulations, we often need to consider the corrosion and pressure resistance between the filling material and the container when selecting packaging materials. We know that there is a water-based aerosol product that is highly corrosive to tanks. Therefore, the key problem of filling water-based aerosol products is the corrosion of the tank, and the quality of the aerosol tank directly affects the corrosion resistance. There are many factors that affect the quality of aerosol cans, from raw materials, canning equipment and processes to quality inspection, etc. The following is a brief introduction:
1. The quality of tinplate itself:
The tinplate substrate used for manufacturing cans requires high purity. For example, the content of impurities is too high, which affects the processability and corrosion resistance of ductility, brittleness, and hardness. At present, most of our tinplate substrates are imported from abroad. In order to reduce costs, some manufacturers use low-quality thin tinplate cans. The tinplate itself has tiny pits, which can cause leaks. Special attention should be paid to the selection.
2. Can body welding and repair quality:
For tinplate cans, one of the weaker links is the weld. In addition to strict mechanical properties, the weld is easily corroded due to the damaged tin layer. Therefore, recoating is a key technology for three-piece cans. Many water-based product leaks are caused by incompatibilities between the topcoat and the contents. In addition, the current is unstable or the quality of the copper wire is unstable, etc., which are prone to false soldering of the product and form leakage points.
3. Type and density of inner coating:
Internal coating is one of the effective anti-corrosion methods for water-based products (except for DME as a propellant), but the quality of the internal coating material itself and the coating process will affect the corrosion resistance of the product. For example, some coatings are difficult to find with the naked eye. The electrochemical reactions that occur in these places are particularly strong. As time goes by, they are prone to corrosion and rusting, which can cause penetration of the can, especially where the top and bottom cover contact the weld of the can body. It is easy to cause damage during canning and coating. The compactness is even more important. Many leaks of water-based products appear here. There are several kinds of epoxy-phenol-formaldehyde, imide-epoxy, and PVC used in the inner coating at present. Most of them are epoxy-phenol-formaldehyde, but the quality of different manufacturers is different, and compatibility tests should be done when selecting.
4. Sealing quality:
Good sealing equipment and technology is an effective guarantee for the aerosol tank sealing performance. The amount of hooking of the roll seal is an important indicator of detection. If the control is not good (including production process and testing), it is easy to appear in the seal at the seal. leak.
5. Leak detection:
Most aerosol products are flammable and explosive. Each aerosol canister that leaves the factory must be tested by an on-line pressure leak detector. At the same time, random inspection of deformation pressure and burst pressure must be performed in accordance with regulations to ensure product production, storage, Safety during transportation and use. In order to reduce costs, some manufacturers do not perform leak detection in accordance with regulations. These tanks are likely to have quality or safety risks.
The sealant can be used to achieve the sealing requirements between the aerosol can body and the lid. The selection of a good sealant and glue application process is critical to the quality of the can. In addition to the strict control of the quality of the sealant itself, the sealant The swelling and dissolution performance of various solvents, especially strong solvents, DME, etc., must be tested strictly and for a long time, otherwise the sealant will be damaged and leakage will occur, which has occurred in some can-making factories. Problems such as broken glue or uneven distribution, foaming, insufficient glue application, etc. during gumming are easy to occur. As the contents of aerosols vary widely, and the sealing performance cannot be judged in a short time, the quality of the sealant must be ensured by the long-term production experience and strict quality control of can manufacturers.