Glass packaging bottles or glass jars are all forming by molds, molds for them are mostly made of cast iron. The main failure modes of forming molds are: oxidation (peeling, peeling, pitting), chamfering and deformation. Scaly peeling is the main form of scrapping of glass bottle forming molds. The key factor affecting the service life of the mold is the heat resistance of the material, that is, the material’s soothing reactivity and anti-growth ability at high temperatures. This depends on the matrix and graphite form in the preparation. Adding copper, chromium, tin and other elements to cast iron can promote the formation of pearlite and increase the hardness of cast iron, thereby improving the mold’s ability to resist chamfering and wear. Adding elements such as silicon and aluminum can form dense Si02 and A1203 Surface oxide film, thereby improving the surface soothing response ability of the mold.
New cast iron materials for glass bottles include low tin cast iron, copper-chromium cast iron, medium silicon rare earth, medium silicon molybdenum rare earth, low tin vermicular iron, low aluminum vermicular iron, etc. Compared with HT200, the mold life of glass bottle mold steel is lower, and the low aluminum Vermicular iron is higher, the difference is about 5 times.
Glass bottle molds will be slightly damaged after long-term use at high temperatures and oxidation of the release agent. During the production process of glass products, high-temperature glass liquid falls from the feeder into the mold. The mold must not be scratched or worn, otherwise any defects will appear on the glass bottles or glass jars produced. This requires the mold to have high high-temperature hardness. That is to say, there cannot be any deformation during the long-term high-temperature production process. If the glass products produced by some factories are not round enough, resulting in poor labeling, it is because the mold material is not good, resulting in uneven mold expansion coefficient and deformation during the heating production process.
Molds must be inspected, cleaned and maintained before being put into storage after production. During the maintenance process, use a high-pressure air pump, fine sand and water to clean, then use a welding gun to repair, and then apply butter for maintenance.
A set of glass bottle molds can produce about 400,000 glass bottles and must be scrapped. The quality of mold use and maintenance has a great impact on the quality of castings and the service life of the mold. The purpose of mold care and maintenance is to improve production efficiency, reduce production costs, reduce failures and quality problems, and extend the service life of the mold. If the production quantity reaches 400,000 pieces, the state of the mold and the matching precision of each component are still within the range, and the service life can be appropriately extended.
Molds need to be continuously polished or filled with toner during the production process. Good mold materials are easy to process and have good welding capabilities, which can shorten the processing time. Each mold should have a certain size and capacity, and it is necessary to strictly follow the plus and minus differences of the dimensions marked on each part of the customer’s confirmation drawing to meet the user’s demand for glass bottles.
For example, the capacity requirements of high-end perfume bottles need to be accurate to 1mL, and some customers also have very strict requirements on the liquid filling level line. These require extremely strict dimensional control of the mold. If the mold cannot meet these key data control requirements, even if the mold can still be used normally or has not been produced to a certain quantity, it will be forced to be scrapped.
The Newray Packaging glass factory has our self-owned mold workshop. We have very strict control and operating standards for the care, maintenance and scrapping of molds to ensure that the glass products produced on our production line meet the factory requirements of our company and customers.
Newray welcomes customers at home and abroad to visit or supervise the mold production and maintenance of our factory!