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How does the thermal conductivity of glass bottles affect shaping?

Update:30 Aug 2018
Summary:

We have seen a variety of glass bottles in our lives, b […]

We have seen a variety of glass bottles in our lives, because glass bottles have a wide range of applications in our lives, glass bottles are a healthy packaging, and the shape of glass bottles can be set into various shapes, in fact, the thermal conductivity of glass bottles and molding there is a great relationship between today's glass The manufacturer of glass bottles will tell you what influences the thermal conductivity of glass bottles will have on molding.

The thermal conductivity of glass has great influence on the cooling rate during glass forming. The greater the thermal conductivity of glass, the faster the cooling of glass, and the faster the formation speed. In practice, the thermal conductivity of open glass is greater than that of dark glass. Therefore, for artistic glass products manufactured by hand, the thermal conductivity of glass is required to be slow, and for mechanical glass products, the thermal conductivity is required to be fast. In artificial shaping, the blowing technicians should properly control the shaping operation speed according to this principle, especially the complicated shape glass products and dark color glass products.

The glass expands or contracts when forming, and is characterized by the thermal expansion coefficient of the glass. It is related to the stress generation in glass and the tolerance of glass products. After the glass is formed into the die, the contact between the glass and the die wall shrinks due to cooling. At the coldest point, the shrinkage of the glass surface layer is the largest, and the shrinkage to the thickness is gradually reduced. In this way, there is Zhang Yingli on the surface of glass. When the glass is still in liquid state, the stress is quickly eliminated due to particle flow, but when the glass partially reaches elastic solid state and the model is heated to expand, the shrinkage of the glass product and the expansion of the cast iron model are about 1% - 2% difference, so the residual stress is produced on the formed glass product, which is easy to cause. Surface cracks are produced. Therefore, in the process of forming, we should consider the speed of stress elimination without defects. This point is often found in the actual production of the mold when the glass products burst, sometimes in the mold sent to the annealing furnace before the burst.