Due to the imperfection of the glass melting process, the physical and chemical internals of the glass are uniformly damaged, which causes various defects in the glass products. The most common defects are stones, stripes and bubbles. Let's take a brief look at these three shortcomings.
The stone is a non-vitreous inclusion in the glass that not only destroys the appearance and optical uniformity of the glass article, but also creates additional forces. Reducing the mechanical strength and thermal stability of the glass article makes it difficult to retract the head, and no stone is allowed in the product.
There are many reasons for the formation of stones. Some of them are caused by poor reaction and melting of the components in the batch. Some of them are caused by erosion of molten glass at high temperature or by flying of soda ash in the batch. The block falls into the glass solution, and some of the glass liquid itself has too much oxide content and is caused by crystallization.
[Stripes are also called streamlines]
Stripes are glassy inclusions in glass that destroy the uniformity of the glass, affect the appearance, and reduce mechanical strength, thermal stability, and chemical uniformity.
There are many reasons for the formation of stripes. Some are caused by insufficient melting of the batch material and insufficient homogenization of the glass. Some of them are caused by the refractory material entering the glass liquid after being eroded by the glass liquid at a high temperature. Some of the stones are initially dissolved in the glass liquid, but the diffusion is not diffused. It is also possible that during the melting process, a large amount of some components of the surface of the molten glass volatilize to cause "volatile stripes".
It is a gas inclusion in the glass liquid, which affects the appearance quality and also affects the mechanical strength of the glass.
The reason for the bubble generation is that the glass is not well clarified during the melting, the air is introduced into the powder, and a large amount of gas is liberated from the carbonate, sulfate, etc., which is not completely excluded, and remains in the glass. Some are secondary bubbles formed by the glass during cooling, and some are formed by the interaction of the glass with the refractory; others are caused during the molding operation.
When the glass has defects, it is necessary to carefully analyze the causes of these defects and take effective measures to eliminate the defects.
I hope that the above simple sharing will help everyone!