Why does the R-angle often appear on the blister & the solution
Quote from emerson on 2022-04-30, 23:24:25People often ask me why the corners between the mold and the base plate are always not suctioned to the bottom and have R angle🤔
In fact, vacuum forming is a complex process. It is an collaborative work between temperature control and vacuum shaping. The vacuum shaping process can be easily observed, but the temperature change process is very difficult to detect. Therefore, we often mistakenly think that the pump suction is insufficient to cause such a result😕
So we decided to take a video of the molding process at 1:1 speed by thermal imager and marked three temperature detection points so that you can see the temperature change. Please pay special attention to Temperature1, when the mold is placed directly on the stainless steel base plate, the 0.5mm thick PET sheet is pressed down and attached to the base plate, the temperature1 drops from 125 degrees to 78 degrees (hardening temperature) in less than 1 second, in this case, it is difficult for the powerful vacuum pump to be faster than the cooling speed, so the R angle of the blister will be quite obvious!
>>>0.5mm PET attached to stainless base
If we put a wooden board under the mold, temperature1 from 125 degrees to 78 degrees below the time is greatly extended to about 4 seconds, then the pump will have plenty of time to shape, the corner of the R angle will be much improved👍
>>>0.5mm PET attached to wooden board
So if you can understand the process and improve in temperature, for example:
- Using a less heat-absorbing board as the base
- Pre-baking the mold to 50 degrees
- Using a hot air gun during the molding process(Remember to adjust the material thickness to 3.0mm on your FORMART to extend the pumping time before your work)
you can get pretty good results.
Of course, if you insist on using a more powerful pump to solve the problem, it is also possible, but it is like trying to help a Ferrari that accelerates from 0-100 in 3 seconds with a bigger engine to get it into the 2 seconds generally ~ the price may be more huge than you think😆
by Emerson
People often ask me why the corners between the mold and the base plate are always not suctioned to the bottom and have R angle🤔
In fact, vacuum forming is a complex process. It is an collaborative work between temperature control and vacuum shaping. The vacuum shaping process can be easily observed, but the temperature change process is very difficult to detect. Therefore, we often mistakenly think that the pump suction is insufficient to cause such a result😕
So we decided to take a video of the molding process at 1:1 speed by thermal imager and marked three temperature detection points so that you can see the temperature change. Please pay special attention to Temperature1, when the mold is placed directly on the stainless steel base plate, the 0.5mm thick PET sheet is pressed down and attached to the base plate, the temperature1 drops from 125 degrees to 78 degrees (hardening temperature) in less than 1 second, in this case, it is difficult for the powerful vacuum pump to be faster than the cooling speed, so the R angle of the blister will be quite obvious!
>>>0.5mm PET attached to stainless base
If we put a wooden board under the mold, temperature1 from 125 degrees to 78 degrees below the time is greatly extended to about 4 seconds, then the pump will have plenty of time to shape, the corner of the R angle will be much improved👍
>>>0.5mm PET attached to wooden board
So if you can understand the process and improve in temperature, for example:
- Using a less heat-absorbing board as the base
- Pre-baking the mold to 50 degrees
- Using a hot air gun during the molding process(Remember to adjust the material thickness to 3.0mm on your FORMART to extend the pumping time before your work)
you can get pretty good results.
Of course, if you insist on using a more powerful pump to solve the problem, it is also possible, but it is like trying to help a Ferrari that accelerates from 0-100 in 3 seconds with a bigger engine to get it into the 2 seconds generally ~ the price may be more huge than you think😆
by Emerson
