P17676: Vacuum Former
/public/

# Systems Design

 Table of Contents 1 Team Vision for System-Level Design Phase 2 Functional Decomposition 3 Benchmarking 4 Concept Development 5 Feasibility: Prototyping, Analysis, Simulation 6 Concept Selection 7 Bill Of Materials With Associated Cost 8 Plans for next phase

## Team Vision for System-Level Design Phase

During this phase:
• We visited both the industrial design and the packaging science vacuum former's to get a better understanding of the ones available on campus. During these visits we gathered information like the pros and cons of each machine to help us decide how we wanted our vacuum former to function and assist in the benchmarking process.
• We visited Faro, a local vacuum forming company to further understand the process. From this we now have a contact for sample plastic to test.
• We used the benchmarking parameters we established to determine our optimal design.
• We designed a 3-D model of our vacuum former concept that will be updated as we make further decisions on components we will use in our prototype.
• We have two designs for our vacuum former for evaluation by the customer.
• We have evaluated each subsystem and its components to determine the pros and cons of each potential purchase.
• We created a bill of materials based on our component selection to get an initial idea of the cost of our project.
• We looked at feasibility of different subsystems for the vacuum former.
• We have looked through the approved list of vendors to find the best components for our project with the lowest possible cost. This allows us to further refine our design based on specific features the components have.
• We started to discuss how we think each component should be produced to make sure we are not designing something that cannot be made.

## Concept Development

#### Single Heater Model

A single heater model still shows a significant temperature difference through the thickness of the plastic after 236 seconds.

After 235.6 seconds:

• Top of plastic: 149 deg C
• 1/4 - way through plastic: 116 deg C
• 1/2 - way through plastic: 83.5 deg C
• 3/4 - way through plastic: 51.6 deg C

#### Double Heater Model

The double heater model shows a symmetric heat distribution after 236 seconds, the plastic is nearly the same temperature throughout.

After 235.6 seconds:

• Top of plastic: 149 deg C
• 1/4 - way through plastic: 148 deg C
• 1/2 - way through plastic: 147 deg C
• 3/4 - way through plastic: 148 deg C

## Feasibility: Prototyping, Analysis, Simulation

### Tank Volume Analysis

"Vacuum Pumps Explained." Vacuum Pumps Explained. Pierson Workholding, n.d. Web. 04 Oct. 2016. <http://www.vacuumchuck.com/vacuum-pumps-explained/>.

## Concept Selection

#### Purpose

Two system designs have been created, a single and a double heater model. In addition to the two designs, subsystem components can be swapped in or out. Considering all possible subsystems for our two designs, there are 18 possible combinations to chose from. Based on price, safety, quality, and other important factors, we've picked what we believe to be the best combination and design.

#### Our Top Pick

The design we would like to move forward with is a combination of:
• Double heater
• Calrod heaters
• Venturi vacuum

As shown in our heat analysis of 1/4" plastic sheet, a double heater model produces a much more symmetric and uniform heat distribution through the plastic. The more uniformly the plastic is heated, the easier it will be to produce quality parts.

Although ceramic heaters are the highest quality of all our choices, the amount of quality they add is not equal to the financial expense they would add. The calrod heaters have more than enough quality for the purpose we hope to use them for.

In order to utilize the pre-exiting shop air, we have decided to use venturi air for our vacuum. A venturi will require little to no maintenance, as opposed to the electric pump, or shop vac options. Venturi is also the only choice that does not require power. This reduces use cost in the long term, as well as environmental impact.

## Bill Of Materials With Associated Cost

Note: Any price listed without a dollar sign (\$) next to it is an approximation, and has not yet been sourced to a vendor.

## Plans for next phase

### Moving forward

• Acquire a larger budget (based on design choice)
• Acquire scrap plastic
• Purchase heating elements
• Build mock-up wooden vacuum box
• Test vacuum forming manually using heaters, electric vacuum pump, and box