P19433: Plastic Bottle Chip Melter
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Detailed Design

Table of Contents

Team Vision for Detailed Design Phase

During this phase our team set out to finalize all aspects of our design. By the end of this phase the team would like to have completed the 3D model, the 2D drawings of parts that need to be machined as well as assembled, a completed BOM with all the materials that are in the assembly as well as those that need to be purchased, and a thorough test plan.

What the Team Actually Accomplished During this Phase

During this phase we received the electrical components ordered so they could be tested by the electrical engineers. The team also had a phone interview with Paul Kayser and Joe Kelley to go over some more questions the team had about melting plastic, notes can be found below in the Subject Matter Experts (SME's). After these phone calls the team decided to reevaluate the feasibility of compression melting PET in configuration chosen. The decisions made during this phase can be found in the Roadblocks & Major Decisions section of this page.

Progress Report

The teams progress report can be found here

Report Highlights

Prototyping, Engineering Analysis, Simulation

After preliminary testing, the team decide that adding insulation around the heaters and mold would reduce the amount of heat loss. Mineral wool insulation with an approximate R value of 8 K. m²/W was installed around the heaters and a new thermocouple was also installed. The results from the testing are shown below and unfortunately, the insulation did not drastically improve the heating time. The temperature was recorded from the PID every 10 minutes for a total of 80 minutes. A trendline was created using the collected data to predict the time it would take to reach the desired temperature range of 200-260° C, the melting temperature of PET. The team plans to fill open spaces between the insulation and the melter to reduce all heat loss and secure the insulation with washers and screws.

Melter with Mineral Wool Insulation View 1

Melter with Mineral Wool Insulation View 1

Melter with Mineral Wool Insulation View 2

Melter with Mineral Wool Insulation View 2

 Data collected during insulation testing

Data collected during insulation testing

 Plot of insulation testing data

Plot of insulation testing data

Electrical Updates

melting process)

Model

During this phase the model was put on hold as the team decided between continuing with this design, or moving in a different direction. It was discussed weather or not the jack would be welded to the frame, or if a screw would be used to attach the jack to the mold while enclosing only the mold instead of the jack with the insulation. Other changes considered were where how to attach the insulation to the melter and the depth of the mold.
Current model of the new melter

Current model of the new melter

 Model of Mold Layout

Model of Mold Layout

 Front view of mold

Front view of mold

Roadblocks & Major Decisions

Location to Test Melter: Update

Last phase, the team was unable to find a location with a 208V 3 phase outlet with a ventilated area to safely test the melter. During this phase, EHS inspected the proposed area with a fan in the MSD design floor and concluded the team should design and build an enclosure. With this addition, fumes would be able to flow through the enclosure directly to the fan and outside, eliminating the need to build a large enclosure around the cubicle. EHS will supervise the first test after the enclosure is installed to ensure it is functioning properly.

Subject Matter Experts (SME's)

The team had the opportunity to connect with Paul Kayser, an RIT Alum, and the current CEO and President of Pretium Packaging. After explaining the team's proposed concept and process, Paul expressed his doubt that PET will melt properly and will be extremely difficult to shape. PET is typically re-shaped using extrusion and blow molding methods, both are method the team as benchmarked in previous phases and have concluded they are too expensive to recreate. Paul suggested switching to a material such as HDPE since it has a lower melting temperature and may work better with the current design.

After the call with Paul another call with Joe Kelley, the VP of Supply Chain of Pretium Packaging, was scheduled. Joe has a great deal of experience with plastics and was able to provide the team with additional information concerning melting PET and other plastics. PET is the hardest plastic to recycle, and is usually melted and reoriented by rolling with very high pressure. Typically, PET is re-chipped and produced into bottles using extrusion or blow molding or used in textiles such as carpets where the fibers are extruded. They suggested to brainstorm additional ways the team can reuse plastic bottles since the current shape would be more effective.

Current Options

After meeting with Sarah Brownell and discussing the team concern's after speaking with the SME's, a few options to move forward with:

PET in Current Electrical Design

The team will continue to work with melting PET in a similar configuration to the current melter design.

HDPE with Current Electrical Design

After researching HDPE properties and speaking with SME's, the team has decided to obtain HDPE chips to test in the current system. The properties of HDPE make it easier to melt at lower temperatures than PET and it is still obtainable in El Sauce, but in smaller quantities.

PET and Propane

After talking with Sarah Brownell the option of heating the plastic with a propane system came up. One of the other MSD teams are working on a vacuum former that uses propane to heat the system instead of electricity. Propane is accessible in El Sauce and could provide faster and cheaper heating.

Other Project Ideas

A final option that the team has considered but will most likely not pursue due to time and resources is changing the scope of the project to reuse the plastic bottle waste in ways other than melting and remolding/shaping.

Explanation/Recommendations

If the other options are not successful, the team will develop a document explaining the team's efforts and progress during the year. The document will include the team's conclusions and will provide recommendations for potential teams in the future. The team will only resort to this option if the previous methods are not successful.

Notes from the meeting with Sarah can be found here

Bill of Material (BOM)

During this phase the team compiled a list of items (the Bill of Materials) that need to be purchased in order to build the melter device. Currently, the BOM is combined with the Budget and is up to date, but may need to be further changed as the design is finalized. The BOM and the Budget will be two separate documents when finalized.

 BOM and Budget

BOM and Budget

The working copy of the BOM can be found here

Test Plans

The team developed test procedures specifying the type of data to be collected, instrumentation, procedures and personnel who will conduct the tests. This process is crucial to verify that the melter is meeting all ERs developed during Phase 1.

Testing Categories:

The Test Procedures that will be performed to verify the melter meets the ER's.

A Test Plan Template was created to use during testing.

All Test Procedures correlate to an ER and can be found here

The Test Procedures and Test Plan Template were adapted from P18433.

Risk Assessment

The team continued to run into roadblocks during this phase which led to re-evaluating the risks from the Preliminary Detailed Design Phase. The team's high risks this phase relate to the budget and the ability to melt PET.
 Phase 4 Risk Assessment

Phase 4 Risk Assessment

The working Risk Assessment can be found here

Design Review Materials

Include links to:

Plans Moving Forward

Finishing Phase 4

Tasks left for Phase 4

Due to roadblocks, we didn't complete as much as we had intended. We will be working to finish the remaining tasks within the next few weeks.

 Gantt Chart

Gantt Chart

Prep for MSD II

Before MSD II, the team needs to work with our customers to determine if the original goal of melting and reshaping PET is still attainable. After speaking with SME's, the team has considered other options to move forward with the project. Determining the final goal of the project will result with the final budget and BOM with the possibility of requesting additional funds, depending on the selected end goal. The team also needs to make adjustments to the newly installed insulation by ensuring all gaps are filled with insulation to eliminate all heat losses. The team will also determine a method to safely secure the insulation around the heating strips. The location of the new jack and the method of attachment to the current frame will also be decided to allow testing during MSD II. Lastly, an enclosure from the fan to the melter will be designed to provide a safe testing environment in the Design Center.

Three week plans for team members at the end of Phase 4:


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