Hand-blown glass is one of the oldest and most common manufacturing methods in the glass manufacturing process. The basic processes of manual blowing molding are small bubbles, large bubbles, blow molding, shaping, and hot processing in front of the furnace, which includes a notch, mouth expansion, shaping, etc., and the blowing process is different for glass products of different shapes.
Glass products can be divided into burst products and open products according to the operation process.
The excess part of the material cap of the burst product is treated by the cold processing process. after the opening product is molded, another technician needs to take a small amount of liquid glass with another blowpipe to stick to the bottom of the glass product, which is called "top pump".
At the same time, the mold line at the mouth is disconnected and heated repeatedly for pre-furnace hot processing. After annealing in the kiln, the bottom is flattened and polished by the cold working link. Therefore, the most obvious difference between the opening product and the opening product is that there is the impression of the top pump at the bottom of the opening product, while the mouth of the opening product has grinding marks.
Manual blowing process:
1. Pick up the material: the worker dips the glass material in the crucible with the blowpipe, inserts the preheated blowpipe obliquely into the glass liquid and rolls a certain amount of glass liquid into the glass liquid, then turns the blowpipe to the left and front, breaks the material wire in the left front of the taking position, and takes the material round after taking out the material. For the same kind of glass products, the weight of each pick should be the same. After taking the material, the glass blowpipe is placed on the baking machine to rotate.
2. Blowing small bubbles: the glass material taken out cools slightly, which can be judged by the change of color. Blowing air to the glass material becomes a small bubble. If you blow a large glass work of art, you need to use the small bubble for secondary or secondary material extraction.
After taking the material again, the liquid glass is often rolled with a metal rolling plate or a rolling bowl to make it have an asymmetrical shape and a smooth surface.
The vesicles are thin and uniform, and there are no artificial bubbles.
3. Preparation of large bubbles: take the blown bubbles to fetch the material again, insert the bubbles into the glass liquid, rotate, wrap the bubbles neatly, stand steadily when taking the material, push to the left and forward while turning, and break the material wire in front of the material point. After taking the material, the glass liquid should be cooled and reshaped in the rolling bowl, and there should be an appropriate amount of water in the rolling bowl. When operating, the front hand is low, the rear hand is high, and it rotates gently, steadily and quickly, making the material tire thin and uniform. Then the air is given to shake the material tire so that the temperature difference between inside and outside the material tire is reduced, the rotating speed of the blowing pipe and the direction of daily glass manufacturing technology can be controlled, the bubble wall is uniformly symmetrical, the bottom of the bubble is changed vertically, and the blowing pipe is swung vertically down to make the bubble longer. Finally, the shape of the bubble is close to the shape of the mold.
4. Blow molding and shaping in the mold: put the blown bubble into the mold, the blowing product needs to turn the blowing pipe and blow, and the static blowing product can blow directly to make the bubble expand, fill the whole mold cavity and make the desired shape. Start slowly and don't breathe too fast. Metal molds or wood molds need to be cooled with water. Metal molds are lined with a carbon coating, or "soot", and wooden molds are lined with newspapers. After setting, the mold can be released. 
Handblowing is an important craft in making glassware products. It can make the glassware products full of art and beauty. And also it has small quantity requirement compared to the machine-made products.
