Vacuum Forming

Industry Uses
Vacuum forming technology is a low cost and a highly efficient tool used to replicate, scale, or prototype any desired shapes using a range of materials. The HD 2424 Vacuum Former Starter Kit implements a magnetic lock system to secure and pressurize air within the chamber, allowing the thermoplastic sheet material to stretch and form to a mold and create a part. Being an alternative for 3D printing, vacuum forming has an advantage against complex edges and saves time by forming multiple units in a short process.

Many vacuum forming processes include: dental, aerospace, special effects, military, Holster Making, Knife Sheath Forming, Hobbyists, Cosplay, Costume Makers, Orthotics, small prototyping and many other types of thermoforming.

Vacuum Forming Machines Available
The available mechanical engineering vacuum former is located in the Metrology Lab (Room 123) inside the Gauss Johnson Engineering Lab. The sign up process to use these machines is based on a first come first serve basis. For more information on how to use these machines find a graduate student and/or go to the IEW office (GJ 113). {|
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HD 2424 Vacuum Former - Starter Kit
1)   HD Press 2424

2)   High Temp Heavy Duty Membrane

3)   Neodymium Magnets

4)   Heatsink board

5)   Premium Quality Liquid Filled Vacuum Gauge

6)   ON-OFF Valve

7)  Vacuum Release Vent



Thermoplastics for Vacuum Forming Applications
Kydex Thermoform Plastic Sheets are a line of thermoplastic acrylic-polyvinyl chloride materials. For some applications it is used as replacement for leather, where it has the following advantages: waterproof, scratch resistant, holds its shape better, and will not stretch or shrink under normal conditions lower friction.
 * Kydex
 * Applications: Aircraft Bulkhead Partitions, Firearm Holsters, Sheaths, and for Knives.

Boltaron is a proprietary, fire retardant, extruded thermoplastic alloy offering extreme durability, chemical resistance, and a UL 94 V-0 rating while exhibiting exceptional physical properties.
 * Boltaron

Applications: Firearm Holsters, Medical Device Enclosures, Electronic Equipment Housings, Kiosk Housings, Store Fixtures and Displays Kennel Housings

Because ABS Thermoform Plastic Sheets is low cost and has superior physical properties, ABS (Acrylonitrile-Butadine-Styrene) is one of the most popular thermoform plastics used for vacuum forming. ABS produces detailed parts that are tougher and more rigid than other plastics. It is manufactured in both black and white with a “haircell” texture on one side that helps resist and hide scratches, making ABS a popular choice for parts that need to stand up to heavy use.
 * ABS

Applications: Prototypes and Production Parts, Plaster and Concrete Molds, Drone Parts, Theater Props, Cosplay

High Impact Styrene is an inexpensive thermoform plastic that is easy to work with and produces excellent vacuum forming results, making styrene the perfect "beginner plastic" for folks who are new to vacuum forming. High Impact Styrene is capable of reproducing intricate mold details along with complex part geometries. It is smooth on both sides, comes in opaque white, and readily accepts paint.
 * HIPS

Applications: Prototypes, Packaging, Soap and Candle Molds, Scale Models, Theater Props, Cosplay

PETG Thermoform Plastic Sheets (Polyethylene terephthalate) are a transparent thermoform plastic that offers cost-effective vacuum formed parts with deep draws and precise details. PETG is significantly less prone to cracking than acrylic (Plexiglas). It is used for vacuum forming all kinds of clear plastic parts - especially blister and clamshell packaging and point-of-purchase retail displays. PETG is also FDA food safe and is commonly used to make molds and other kitchen products.
 * PETG

Applications: Blister and Clamshell Packaging, Candy and Chocolate Molds, Theater Props, Cosplay

Wonderflex Sheets look like a piece of plastic, but it becomes soft and malleable when heated. It can be shaped by hand or over a mold while hot. Once it cools down it hardens retaining the shape. It can be re-heated and reshaped as many times as necessary, or worked in sections. It glues to itself if enough pressure is applied. It can be cut with scissors and finished with paint, gluing fabric on top, or any other method. It can be heated with a heat gun, a microwave oven, or dipped in hot water.
 * Wonderflex

Applications: Theater Props, Cosplay

Worbla Sheets use hot air, water or steam (min.90 degrees C) to shape the plastic however you want. The material is heat-formable and solvent-free. Scraps can be conditioned and 100% re-blended, so there is almost no waste. These leftovers can be molded just like putty.
 * Worbla

Applications: Theater Props, Cosplay

Polycarbonate (often sold under the trade name "Lexan") is the virtually unbreakable thermoform plastic used to make bulletproof glass. Thin-gauge, transparent Polycarbonate is the material of choice for folks who build ultra light, thin plastic parts that are exposed to a lot of abuse.
 * Polycarbonate / Lexan Thermoform Plastic Sheets

Applications: Prototypes, RC Car Bodies, Slot Car Bodies, Model Airplane Parts, Drone Bodies, Drone Parts


 * Styrene
 * Cork
 * Leather

Design for Vacuum Forming
WEB resources on designing forms

Heat Press

 * Gloves
 * Parchment Paper
 * Heating

Vacuum Former
Before operating the vacuum former, ensure the high temperature membrane is installed correctly for a complete product to work. While placed on the former, the corners of the membrane must be aligned and secured by the magnetic system. Each magnet should sit well within their designated slots to seal the air to create a product.

To operate the vacuum former:

1. Place the product mold in the center of the heat sink board to allow an even surface area between the sealed air and the thermoplastic sheet material.

2. While closing the former, hold down the lid t seal away any excess air and continue to press down until the forming process is complete.

3. To begin vacuum forming a product, open the valve at its horizontal position and power on the pump. The power switch of the pump is located on the back end of the handle, near the power adapter. (The valve should be sealed or aligned vertically before operating the vacuum former).

4. Once the vacuum forming is complete and the thermoplastic material is cooled, close the valve at its initial vertical position and power off the pump.

5. Finally, free the air by pushing and holding down the release found on the right side of the vacuum forming machine. Open the lid and remove the finished product and any left over material at the station.

Troubleshooting
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Clean Membrane
The most common reason for the HD vacuum former to lose vacuum is a dirty membrane. Any dust/debris accumulation on the HD vacuum forming membrane may cause the press to slowly lose vacuum. The membrane itself creates the seal with the unique design of the HD Vacuum Press, so it is important to pay close attention to this.

To clean: Run a damp sponge over the entire membrane surface on the side that will contact the work area. Pay particular attention to the region on the membrane that touches the sealing edge on the vacuum former base. You do not need to remove the membrane from the vacuum press to do this. This only takes a few seconds to do.

Edge Allowance's
Before moving on to further troubleshooting steps, double check that your molds are not too close to the outside edge of the heatsink. Modify your molds to provide enough work area around them for the membrane to engage the sealing edge or upgrade to a larger press size if your molds cannot be modified to fit properly.

Use the Heat-sink
The Heatsink Board is an important part of the HD Vacuum Press. To get the best seal possible in your HD Vacuum Press it is vital that you use the heatsink board as a work platform.

Check Internal Plumbing
To check the plumbing underneath the HD Press:

Remove heatsink and switch your vacuum pump on. Open the control valve and plug the vacuum port(s) in the center of the vacuum grid with a wetted thumb. When you have a good seal with your thumb, allow vacuum to build to its highest point, close the control valve, and check the vacuum gauge. Vacuum gauge should not move until you remove your finger. It should hold full vacuum if there are no leaks in the plumbing and fittings attached to the press.

Obtain Best Seal
In order for the HD Vacuum Press to hold vacuum pressure without leakage, it must first achieve maximum InHG to seal properly.

First, ensure that you are using a fast enough vacuum pump (3CFM or higher - see below) to fully evacuate all air from the vacuum press. With the heatsink in place, allow your vacuum pump to fully remove all air from the press and reach approximately 25 InHg or higher on the vacuum press gauge (relative to your elevation above sea level - see below) before closing the vacuum control valve and shutting off your pump. Your vacuum former should now hold vacuum as expected.

Mold Removal
It is crucial to ensure the pump is fully powered off before releasing the pressurized air. Once the pump is completely off, the valve knob must be aligned vertically to unlock the air. After the mold or created part is complete, release the pressurized air by pushing down on the black button found to the right of the machine. The air pressure gauge should release from -26 inHg to 0 inHg.

Vacuum Forming Policy
The Mechanical Engineering Department maintains the vacuum former for sole use by faculty, staff, and students. The use of the vacuum former shall be consistent with the purpose of the department, which includes facilitating research and learning. In accordance with these purposes, the department has developed policy and procedures for use of the vacuum former:

1.	Administration. All projects (i.e. components) to be formed shall require permission from a faculty member. All projects must originate from U of I classroom, lab, or research. To clarify, personal projects are prohibited.

2.	Certain Uses Prohibited. Regardless of viewpoint, certain uses of the formed are prohibited and violate this Policy:

(a)	Formed any object that is unlawful, threatening, abusive, tortuous, obscene, and racially, ethnically or otherwise objectionable;

(b)	Forming any object that is intended to physically harm, or attempt to harm, an animal or person in any way. This includes any type of weapon (i.e. knives, firearms, etc.) or parts of a weapon (i.e. blades, gun triggers, etc.)

(c)	Forming any object that infringes upon a patent, trademark, trade secret, copyright or other proprietary rights of any party unless consent from the rights-owner has been obtained; The Copyright Law of the United States governs the making of photocopies or other reproductions of copyrighted material. The department reserves the right to deny use of vacuum former's if, in its judgement, use of the former's would violate Copyright Law.

(d)	Vacuum forming any object or any part of an object that is regulated. For example: Undetectable Firearms Act of 1998 which specifically bans plastic firearms.

3.	Usage Subject to Refusal or Revocation. The vacuum former is provided to further the purposes of the department. In accordance with this policy, the department may refuse usage of the vacuum former at any time. Failure to abide by this policy may result in revocation of the user’s forming privileges.