Vacuum Former
⚠️Training Zone Ahead⚠️
To safely use the following equipment, you must receive training by lab64 Staff prior to individual use. To get trained, please attend one of our Office Hours sessions↗. Estimated Length of Training: 25 minutes.
Introduction
Workflow Overview
In order use the vacuum former, one needs to:
Preheat the oven element.
Correctly load buck onto wooden bed.
Secure molding material to former frame.
Connect the hydraulic bed and vacuum.
Heat molding material to desired temperature.
Push buck up into moldable material and pull a vacuum to completely form to buck.
Shutdown vacuum former.
Before using this machine, you need to research the material you are forming to find how long to heat it and to what temperature(s).
1. Starting The Machine
(1) First you need to turn on the main power switch which supplies the entire system with power.
(2) Then turn on the ovens on/off switch and (3) make sure the duty cycle is set to roughly 85%.
The clicking noise you hear is the duty cycle switching the heater on and off again.
You will need to wait at least 15 minutes for the heater to reach a suitable temperature, so make sure you do this step first before your other preparations.
2. Load buck
The buck is your pre-prepared mold that you want to form your material too.
The buck MUST be either metallic or wooden and CANNOT be plastic or 3D printed.
Here is an example of a metallic buck used in EE 285 that was made by pouring aluminum into a sand cast. Note the PRL offers services and classes to teach you sand molding, if you are interested!
For the purposes of this training module we use a piece of 2x4 as the buck.
(1) Place washers around the hole in the bed.
Make sure to NOT DROP the washers into the vacuum hole.
(2) Place your buck on top of the washers.
Use all four washers if necessary; our buck is small, so we can get by using only two.
The washers create an airgap so that the vacuum can be drawn on all sides of the buck.
PLEASE NOTE: If the buck completely covers vacuum hole without leaving an airgap then the vacuum will not be able to form the material perfectly to the buck.
3. Load Material
The loaded material ultimately needs to be sandwiched between the base plate and the top shielding.
(1) Keep a hand on the top shielding to prevent the top shielding to springing up when released.
Please DO NOT let the top shielding spring up; ease it up slowly so it does not crash into the heating element.
Do not lean over the top shielding when undoing the clamps as it can spring up and hit you in your jaw.
Got all that? Now carefully undo both clamps.
(2) Load your material so that it has an edge making contact on all four sides of the base plate.
Material should NOT hang through gap of base plate.
This may cause issues in the forming process.
(3) Close the top shielding and firmly lock the clamps shut.
4. Connect Hydraulic Bed and vacuum
(1) Ensure that the hydraulic bed adjuster knob is in its down position.
If the hydraulic bed adjuster knob is not in its down position, it will raise the bed and slam your buck into your material, potentially damaging it, once the air supply is turned on.
(2) Turn on the air valve behind the vacuum former.
The valve handle should be pointing upwards.
(3) Ensure the cutoff valve for the vacuum is closed.
The valve handle should be vertical.
Then turn the vacuum pump on via the switch on the main control panel.
5. Preheat material
(1) Once the oven is hot, pull the heater ALL the way forward so that it is positioned above your material.
If heater is only partially pulled forward, this will result in unequal heating of your material and ultimately poor forming.
(2) Use the temperature gun to measure the top surface and bottom surface temperature of the material.
While heating, the material may rise and sag which is normal behavior for most plastics.
If material begins to bubble or burning (this usually initiates at the outer edges), begin the forming process immediately--you probably overcooked the acrylic!
IMPORTANT: You need to perform your own research on the material you want to use and determine what temperatures it can be molded at. This depends on thickness, density, and type--all of which you need to take into your own considerations.
6. Mold Material
Once the temperature is to your desired level, push the heater back and turn the heater off using the main control panel.
When the heater is clear, raise the hydraulic bed to its max height using the switch leaver.
Turn on the vacuum and the material should quickly form to your buck.
Once your material is sufficiently cool (80F - 90F), lower the hydraulic bed ever so slightly to let the buck fall out of the mold. Sometimes you have to tap the acrylic to jar the buck free, so you don't want it to fall far--especially if it is a large chunk of metal!
Once the buck has separated from the formed acrylic, lower the bed completely and remove both your material and buck.
Please leave washers and temperature gun near vacuum former.
7. Shutdown
Turn off vacuum on the main control panel and close the shutoff valve on the former so that the handle is in its horizontal position. Make sure the bed height lever remains in the down position.
Ensure the bed is in its lowest position and close the shutoff valve for the air supply at the wall behind the vacuum former.
Ensure the oven is turned off and turn off main power.
building resources
First aid kit: next to the sink in lab64 and near room 166.
Fire extinguisher: in room 130, near the laser cutters and vacuum former.
Eyewash: At the sink in both room 134 and room 129.
EAP (emergency assembly point): EAP #104, meet at the lawn area near Jane Stanford Way.
EMERGENCY CONTACTS
Environmental Health Safety Hotline: Call 650-725-9999 or 9/911
Stanford University Public Safety: Call 9/911 or 650-329-2413/650-723-9633
Facilities Maintenance: Contact the Stanford Dispatch Center at 650-723-2281
In case of injury:
For medical emergencies, call 9/911
For Immediate and Urgent care injuries, visit the Stanford Hospital ER, 650-723-5111
For non-urgent or existing injury, visit the Occupational Health Center or 650-725-5308
Incident reporting, Complete the electronic SU-17 form (https://redcap.stanford.edu/surveys/?s=447TRCAPYP) within 24 hours.