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Vacuum Forming


Vacuum forming process is a simplified version of thermoforming, where a sheet of plastic is heated to a forming temperature, stretched onto a single-surface mold, and forced against the mold by a vacuum. This process can be used to form plastic into permanent objects such as turnpike signs and protective covers. Normally draft angles are present in the design of the mold (a recommended minimum of 3°) to ease removal of the formed plastic part from the mold.
Relatively deep parts can be formed if the formable sheet is mechanically or pneumatically stretched prior to bringing it into contact with the mold surface and applying vacuum.

Suitable materials for use in vacuum forming are conventionally thermoplastics. The most common and easiest to use thermoplastic is high impact polystyrene. This is molded around a wood, structural foam or cast or machined aluminum mold (expensive ones), and can form to almost any shape. This high impact material is hygienic and capable of retaining heat and its shape when warm water is applied and is commonly used to package taste and odor sensitive products. Vacuum forming is also appropriate for transparent materials such as acrylic, which are widely used in applications for aerospace such as passenger cabin window canopies for military fixed wing aircraft and compartments for rotary wing aircraft. Vacuum forming is often used in low-level technology classes for an easy way to mold.

After forming, we need to finish the part. There is still some work to do. Not so easy Here is the main FINISHING PROCESS

Once a vacuum form has been created out of a sheet of plastic, a finishing operation will be needed in most cases to turn it into a usable product. Common vacuum forming finishing methods include:

A:Guillotining: The product is cut out of the sheet by pressing a blade through the product into a die underneath. This is a clean way of removing vacuum formed parts from the material sheet. It doesn’t require a special cutting tool to be made for an individual product and is therefore suitable for low volumes of parts where straight lines are no problem. Cutting only straight lines and being a fairly slow approach compared to other finishing methods, guillotining can be expensive for projects with larger, more complex quantities.[4]

B:Drilling: If simple round holes are the required finish, manually drilling them is a good solution for small quantities. Drilling guides can be used to ensure holes can be drilled quickly in the right place. As this is a labor-intensive method, it is only suitable for small production quantities.

C: Roller cutting: Process whereby the vacuum formed product is placed on a custom made cutter and pushed through a roller cutter machine. An efficient way of cutting vacuum formed items from the original sheet of vacuum forming material. The cutter can also cut any necessary holes, such as cable or access holes, at the same time. Roller cutting is suitable for fairly large items, where precision alignment is not required. As the vacuum forming and the cutter are rolled sideways through the roller cutter machine, some misalignment can occur. Roller cutting can’t be used for making holes or features in the sides of vacuum forming, as the cutter tool always cuts vertically from the bottom.

D: Press cutting: This is a very precise method of cutting which uses a press and a custom precision made cutting tool. This method is very suitable for items where the roller cutter process wouldn’t achieve the precision required. It’s often used for punching very small finished items out of a plastic sheet, rather than punching features into a product. Press cutting can’t be used to make features in the sides of vacuum forming.

E: Cutting with a CNC machine: Machining is a very precise method of creating holes & features. The real advantage is that it can be used to create features in the sides of vacuum forming, e.g. guide rails for a tray that needs to slide onto shelving. It can also cut sidewalls of a different depth than the pockets – something which cannot be done with roller or press cutting.

AND everything is always working fine, yes? But in manufacturing, specially in plastic, nothing is what it looks like. The thickness, the shape, the color, everything change’s and varies, therefore we need to know what are the most important data in the part. The outside dimension? The inside, a perfect match in the color you tell me

Here are few regular problems that we face during the vacuum process:
1/Absorbed moisture can expand, forming bubbles within the plastic’s inner layers.This significantly weakens the plastic. However, this can be solved by drying the plastic for an extended period at high but sub-melting temperature. Webs can form around the mold, which is due to overheating the plastic and so must be carefully monitored.

2/ Webbing can also occur when a mold is too large or parts of the mold are too close together.

3/ objects that are formed often stick to the mold, which is remedied by using a draft angle of three degrees or more in the mold


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Plastic Fabrication

The acrylic fabrication process is a very clean, detail-oriented way of manufacturing acrylic. There are virtually no defects due to manufacturing.
Fabricating acrylic by hand will eliminate the relief marks and/or blue haze you would get with injection molded pieces. There are four main steps when creating a custom fabricated piece – Cut, Bend, Glue, and Polish.

  1. Cut
    Before anything can be constructed with the acrylic sheets, they must first be cut into necessary sizes.
  2. Linear Bend
    To do so, each piece is set a few inches a top heat strips. Eventually, heat from the strips causes the acrylic piece to soften along the thinner grooved areas, making it malleable and ready for bending. And we bend the part according to the blueprint.
    Some parts require a specific radius. In this case, the heat strip is not working. We need to make a mold and soften the panel in an oven with the correct mold. This process is quite more time consuming .
  3. Glue
    The next step in the acrylic fabrication process is gluing. A very thin strip of acrylic glue is added precisely to where it need adhesion. Then it is held in place by clamps and weights to ensure proper drying. It is very important to glue your acrylic pieces accurately. Failure to do so could result in unfavorable defects.
    The glue seams is a marker of the job quality. For quick cheap jobs, there are bubbles in the seams. For highest quality, there is not.
  4. Polish
    Once all of your pieces of acrylic are cut, bent, and glued it is time to polish the necessary pieces. Some individual pieces must be polished before they are assembled.
    Usually, we polish these pieces by using a very hot flame. By slightly melting the surface of the acrylic, surface tension smoothes out the surface of the acrylic piece. When done properly, flame polishing produces a clear finish. The flame polishing, by changing the tension in the acrylic, makes it subject to creasing (microscopic cracks on the edges) when an alcohol or ammoniac solution (or both like Windex) is used to clean.
    To decrease the risk of creasing and have a better quality, the diamond edge polishing and the sand/buff are two other way with higher quality result. These techniques are more time consuming.
  5. With this process we are able to Build Table Tents Small and large displays as well as wood displays mixed with acrylic also in house Vacuum forming / CNC Machining / Laser Cutting / Engraving. High quality Bubble Free Glue joints

Do you have something in Mind Give us a call 602-340-1236 or

Desert Star Plastics

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Donation Boxes

What Are Honor Boxes?
We wanted to take a moment to cover the topic of “honor boxes” There are many similar names for this, but the basic concept is the same. So what is an honor box and why would you want to get involved with such a thing? Let us explain:
An honor box is basically a box filled with items meant to be bought on the honor system. This is completely different from say, a candy vending machine or a soda vending machine in that no money is REQUIRED for the customer to receive their snack or candy. The customer will walk into an establishment such as a restaurant or bank and see a box on the counter. The box is open with candies in the tray, along with a slot to deposit money.

The honor box can be made of different materials. Some are made in a disposable manner consisting of cardboard while others of a more durable sort will be common Plexiglas. There are various designs and layouts, big and small, but the idea is the same.

Theft from Honor Boxes?
The “honor system” is an interesting idea for some people to grasp. The immediate response is of course: “how can you make any money if anyone could just TAKE your product without paying!?” The answer really is: “You just do.”

Of course that is slightly in jest, the idea is quite so simple. In regard to theft or “shrinkage”, it will happen. It’s guaranteed to happen at any location. The key, as anyone in the business will tell you, is to keep an eye on each snack box location. This doesn’t mean via security camera or hidden spy devices, just a simple tally upon the end of each route-run. You will set an acceptable shrinkage percentage depending on the product in each honor box. If you notice that the level of shrinkage and theft are rising higher than your acceptable threshold, you will simply collect that box on the next route-run and find a new location!
One thing that has been discussed in a various threads on the topic of honor box theft, is that neighborhoods don’t seem to make a large difference. That is to say that a middle-class neighborhood or high-class estates should not see a significant difference in theft from your snack boxes.
A user from the above mentioned thread, AngryChris, posts:
Excellent example of simple economics here. We are in the business of making profits. I have an honor box location that sells only about 7 items per month but PAYS 100%. How much money do I make on this 0% shortage location? About $4/month. It’s not bad when you consider that I am in-and-out in about 5 minutes, but I wouldn’t mind pulling this location if it weren’t a block away from another location.

In contrast, the account that is a block away from that 0% shortage account has about a 35% shortage rate. However… they consume about 80 items/month. So.. even though I may only see $50 out of what should be $80, I probably make about $20/month from this location and it may consume about 30 minutes each month (I go every other week). So the one with 0% shortage makes $4 in 10 minutes, or about $24/hour… while the 35% shortage location makes about $20 in 30 minutes, or about $40/hour. It’s all about the profits! Oh… and I put my short-date items in that location because they buy them all anyway…
I would RATHER have HIGH-VOLUME locations with 30% shortage than low-volume locations with 0% shortage just because it takes a lot less work when you don’t have to check dates on chips… plus… the high-volume locations consume just about everything, including the cheaper-priced items.
You see? It’s not so much about the shrinkage at all. It is more about what products are selling where and how much is being bought as that will often override and make you want to change your allowable shrinkage percentage.

One added note on theft, if you use a charity with their stickers on the honor box, you will have a smaller percentage of theft in most cases. Some have even reported having more money than what they expected (less than 0% shrinkage – profit on top of expected profit). One great charity to contact is the NCCS, link to the NCCS Vending Program Here. If you can find a local charity to sponsor your boxes, it is even better.

Honor Box Locators (not us) We manufacture the boxes

Our main advice is that we recommend you use a locator. They have spent year after year perfecting out locating pitches for honor boxes and vending machines. They understand how time-consuming and stressful it can be. An important excerpt from that article is this part about payment:

You Pay NOTHING Up front to the locator

You pay nothing until the honor box is placed by yourself and accepted by the business. They usually do that to show their commitment to quality locations. The business owner or manager will be expecting you to show up with your brand new honor box or snack box. They confirm and qualify the locations for you. If for any reason there is an issue (rarely), it will be solved. They will resolve any problem you might have quickly because they care and want to be paid.
So remember. If you want to save time, save your money (don’t pay anything until honor box is placed), and keep your business growing steadily.
Call us with any question at 602 340 1236. 

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