Vacuum Brazing of Insulation Cup

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What tailless vacuum technology?
The traditional insulating cup is made of two layers inside and outside, and vacuum is pumped in the middle to insulate heat transfer. So there is an exhaust tail at the bottom of the cup gallbladder. This exhaust tail is very easy to be damaged. Therefore, tailless vacuum technology was born. The tailless vacuum technology is to weld the bottom of the cup with special technology, so there is no exhaust tail, which avoids the damage of the cup gallbladder due to the damage of the exhaust tail.

At present, stainless steel vacuum utensils sold on the market are generally divided into tail vacuum and tail-free vacuum due to the different technical means of vacuum extraction.
“Tailed vacuum” (tubular vacuum) is a traditional process technology, which uses “sealing technology”. The pity is that this technical measure can not completely guarantee the sealing in micro.
“No tail vacuum” is one of the most advanced technology at home and abroad, that is, under the condition of vacuum environment, the process of exhausting, sealing and cooling is completed by computer control. It uses the “melting sealing technology” to ensure long-term non-ventilation and non-leakage.

The equipment of “tailless vacuum” is a large-scale equipment with high automation, high quality and high cost. Moreover, the technology of management and use is complex and difficult to master. The power consumption of single product is several times higher than that of “tailed vacuum”. However, due to the characteristics of high technology level, it must become the development direction of stainless steel vacuum vessel production technology and the technical conditions for consumption to pursue products.

Characteristics of tailless vacuum technology:
1. High vacuum and long holding time
Because vacuum is pumped and sealed at nearly 1000 C, the vacuum degree is the same as that of tailed vacuum. When the product returns to normal temperature, the vacuum degree is much higher than that of tailed vacuum.
2. Large effective capacity
Because there is no such defect as “tail vacuum”, the effective space is large. Compared with the products with the same appearance volume of “tail vacuum”, the effective space of “tail-less vacuum” products is much larger.
3. Long service life
The “tailed vacuum” adopts the “pressure sealing technology”, which can not completely guarantee the sealing in micro. The “tailless vacuum” uses the “melting sealing technology”, which makes the solder melt at high temperature and seal the gas extraction hole, so it can ensure long-term non-venting and non-leakage.

Welding is used for the inlay of inner tank and outer shell. Brazing is a kind of welding method which uses filler material with lower melting point than base metal as filler metal, heating the filler metal and the filler metal to a temperature higher than and lower than the melting point of base metal, filling the gap between base metal by melting filler metal and connecting with base metal by diffusion.

There are many kinds of vacuum brazing process for insulating cup, which can be divided into soldering iron, wave soldering, flame soldering, dipping soldering, induction soldering, furnace soldering and vacuum soldering according to heat source.

The brazing of the insulating cup is flame brazing. Combustible gas and oxygen or compressed air mixed combustion flame are used as heat source for welding. Flame brazing equipment is simple and easy to operate. According to the shape of the workpiece, it can be heated by multiple flames at the same time. At the same time, the brazing of insulating cup belongs to hard brazing.

Application characteristics:
The joints have smooth surface, good air tightness, stable shape and size, little change in the structure and properties of the weldments, solder melting and non-melting weldments, which can connect the same or different metals and some non-metals.

Brazing Material for Vacuum Brazing of Insulation Cup
Nickel-based solders can be used in 304,316
Titanium-based solder or active solder can be used in titanium insulating cup

Learn more: Vacuum Brazing furnace of Insulation Cup