I have 3D printed and tested the parts using ABS and HIPS, because the plastic being used to create the mold will be hot I would not recommend using PLA.
Illustrated Parts Breakdown of the Vacuum Forming Box
You only need to 3D print one vacuum attachment. Most vacuums will fit the Generic Vacuum Attachment. If you have a Dyson DC35 3D print the Vacuum Attachment – DC35 part.
3D print the Frame Template, Vacuum Box Lid, Vacuum Box Body, and the applicable Vacuum Attachment. If you are using the Dyson DC35 Vacuum Attachment, position the locating key at the 12 o'clock position (position marked with red arrow in the image below).
Gently press the Vacuum Attachment piece into the Vacuum Box Body; the snap lock clips will hold the two parts together.
Insert the Vacuum Box Lid into the Vacuum Box Body.
I found it easiest to insert the snap lock clips of the vacuum attachment one at a time.
Attach the vacuum to the Vacuum Attachment piece.
Place the part/s you want to vacuum mold on the top of the Vacuum Box Lid.
It is best to choose a part to mold that can be easily removed and is lofted outwards towards the base. If you are experiencing webbing at the base, try elevating the mold piece.
Wood and MDF dust particles can be hazardous. When cutting MDF/wood wear the applicable protective equipment e.g. glasses and particle/dust respirator.
Trace the Upper/Lower Frame Template onto the two pieces of MDF/Wood. Using cutting tools, remove the inner body; the finished MDF/wood piece will look the same as the Frame Template.
This was the MDF backing from a photo frame, easy to obtain and cut to size. If you use a MDF or wood that is thicker than 5mm you will have issues obtaining a good vacuum seal.
The edges of frame don't have to be perfectly straight, they just need to easily clear the Vacuum Form box lid.
Cut up the HDPE sheet to the outside dimensions of the Upper/Lower Frame Template, 100mm x 155mm (L x W).
Remove any glue and/or labels from the HDPE sheet.
Mount the HDPE sheet between the Upper and Lower Frames. Secure the three parts together using a binder clip on each side.
For best results use the flatest part of HDPE container. The thicker the HDPE sheet the more heat and suction you will require to make a mold.
Heat the HDPE sheet on a heat resistant surface. Use heat resistant gloves to handle the Upper/Lower Frame Assembly
Evenly heat the HDPE sheet using the oven or heat gun until the sheet droops and its transparency changes from its original slightly white colour to transparent.
Turn off the heat gun/oven.
This piece has been not been evenly heated. Note the transparent patch in the middle, you want to achieve that level of transparency for the whole piece of HDPE. Other plastics do not act the same as HDPE e.g. if you use PETG, it is already clear.
For best results ensure that the object that is to be molded is warm.
Quickly place the Upper/Lower Frame Assembly over the top of the Vacuum Box Assembly and lower the frame down over the object to be molded.
Turn on the vacuum and operate it until the HDPE plastic is tightly molded onto the object, typically only a few seconds.
Turn off the vacuum.
Remove the molded object from the HDPE plastic.
The length and width of the vacuum forming box was chosen because I wanted to reuse the High-Density Polyethylene (HDPE) from 2 litre milk bottles. The height was chosen because I originally designed it to work with my Dyson C35 vacuum; I have included a generic vacuum attachment fitting in the files.
The vacuum attachment features 2 snap lock clips which have chamfers on the side to increase their strength. I investigated using screws and glue to mount the vacuum piece to the box, I preferred the user having to use a few non 3D printed parts as possible.
All overhang areas are equal or greater than 45° to allow support free printing.
Vacuum form box lids are typically made up of round holes; square holes seemed more efficient to 3D print. I have included both designs for 3D printing.
The HDPE holding frame stop piece is positioned 5mm below the top of the lid, this was to allow the MDF I recycled from a picture frame to sit below the seal line for the HDPE, ensuring a good vacuum seal.
Vacuum Forming Process: Learn more about other plastic manufacturing processes.
Overview & Background
Students will learn about the vacuum forming process and how 3D printing can be a complimentary manufacture process for creating molds and equipment for vacuum forming.
- Identify equipment and processes used for vacuum forming
- Identify how 3D printing can be utilised to create molds and equipment for vacuum forming
- Identify how to design molds in CAD to meet the physical limitations of vacuum forming and 3D printing
- Recognise hazards and follow appropriate hazard control/minimisation methods.
- Make adjustments to remedy faults that occur during the vacuum forming process
Science, Technology, Manual Arts
Skills Learned (Standards):
- the impact of chemical reactions/mechanical processes on the condition of materials
- products, materials and material characteristics
- quality requirements at each production stage
- function and operating principles of vacuum forming equipment, machine components and ancillary equipment
- vacuum forming cycle and the importance of machine set up and warm up for effective processing of materials
- safety procedures and the use of PPE in relation to handling materials, equipment operation and cleanup
- the hierarchy of control, including engineering controls
- impact of variations in raw materials and equipment operation in relation to final product
changes to materials at various stages of production
- waste management and importance of non-conforming materials
- polymer properties and their interactions with process conditions
- relationships between polymer properties and process conditions
- changes to polymer properties to better suit process requirements
- product problems related to polymer properties
- product problems related to process conditions
- adjustments to process conditions to meet polymer and product requirements
- plan own work, including predicting consequences and identifying improvements
- interpret from production requests the correct selection and use of equipment, materials, processes and procedures
- identify and describe own role and role of others involved directly in the vacuum forming process
- identify factors which may affect product quality or production output and appropriate remedies
- identify when the operator is able to rectify faults and when assistance is required.
- 3D print the required components
- Discuss the vacuum forming process with the students
- The steps of the vacuum forming process
- Show examples of vacuum formed parts
- Typical applications
- Types of plastics used
- Discuss the pros/cons of vacuum forming compared to 3D printing
- Required knowledge and tooling
- Manufacturing limitations
- Guide the students through the assembly of the vacuum former
- Demonstrate the operation of the vacuum former
- Cover the troubleshooting guide examples listed in the Assets Section of this page
- Guide students through selecting/creating a suitable component to model, either work in teams or individually
- Students 3D print their selected components to be molded
- Supervise and assess students performing vacuum forming
- Print the 3D components – Various Timings
- Assemble the vacuum former – 30mins Practical Lesson
- Describe the vacuum forming process – 40mins Theory Lesson
- Perform Vacuum Forming Demonstration – 20mins Practical Lesson
- Students create a component in CAD or find a model on Thingiverse to vacuum form – 30-120mins
- Students 3D print component – Various Timings
- Student vacuum form component – 20mins Practical Lesson
- 3D filament 120 grams (0.26lb)
- 3D Printer
- Computer with access to Thingiverse
- 4 x small binder clips
- Wood or MDF sheets to create two frames that are 100mm x 155mm x < 5mm (L x W x H)
- HPDE plastic sheet from a milk/juice container 100mm x 155mm (L x W). One sheet of HDPE per mold is required.
- Wood/MDF cutting tools
- Vacuum cleaner
- Oven or heat gun
- Heat resistant gloves
- Safety glasses
- Particle/dust respirator
- Basic writing and numeracy is required
- The ability to read and interpret typical product specifications, job sheets and material labels as provided to operators.
Rubric & Assessment:
By the end of the project the student will have a vacuum formed mold of a 3D printed object.
- Did the student choose a 3D model that was able to be successfully molded
- Was the object able to be removed from the mold
- Was the appropriate level of detail transferred from the 3D part to the mold
- Did the student operate the vacuum former safely and with the correct PPE
- Did the student perform the vacuum former process correctly
Handouts & Assets: