P17432: Plastic Bottle Rope Machine
/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 Morphological Chart 7 Concept Selection 8 Systems Architecture 9 Designs and Flowcharts 10 Risk Assessment 11 Design Review Materials 12 Plans for next phase 13 Table of Contents

File Locations: Systems Level Design Documents

## Team Vision for System-Level Design Phase

Summarize:
• What did your team actually accomplish during this phase?
• Prototype a cutting system that will be used to cut the plastic bottles into strands of strings.
• Functional decomposition of process specs
• Developed concept ideas for individual processes and systems
• Evaluated Feasibility questions we have for our process/product
• Morph Chart of types of process/products
• Created a few Pugh charts to decide the appropriate process for each product
• System Architecture of processes
• Process Flowchart of our product

## Functional Decomposition

Functional Decomposition

A link to the live document is here.

## Benchmarking

Benchmarking

A link to the live document is here.

## Concept Development

Concept Development

Visual Concept Development Table

String Cutting Concept Sketch

Rope Weaving Concept Sketch

A link to the live document is here.

## Feasibility: Prototyping, Analysis, Simulation

#### Feasibility #1: Diameter

Assume:

• weave of string for rope is so tight that it can be considered as one giant piece of string
• need to meet Engineering requirements of force applied
• use yield stress of material

Research:

• Yield stress for PET = 57 MPa
• Force = Yield Stress * Cross-Sectional Area = Yield Stress * 0.25 * pi * (diameter)^2
• Force = 2,000 N (Min.)
• Force = 3,500 N (Ideal)

Analysis:

• Min. Calculation:
• 2000 N = 0.25*pi*(57 MPa)*(D)^2
• D = 0.00668 m = 6.68 mm
• Ideal Calculation:
• 3500 N = 0.25*pi*(57 MPa)*(D)^2
• D = 0.00884 m = 8.84 mm

#### Feasibility #2: Welding/Joining String Strands Together

Assume:

• the joining of string ends is to be a temporary place holder until the strings are welded together
• should meet the minimum (2000 N) tensile strength from Engineering Requirements

Research:

• use a heat sealer (possibly test heat sealer from Packaging Science)
• hand pull test to see if joining fails
• Minimum strength before yielding = 2000 N (3500 N - Ideal)

Analysis: Test using product equipment similar to a Impulse Heat Sealer.

#### Feasibility #3: Joining ends of Rope Together

Assume:

• Purpose: to prevent unraveling of rope after rope is made
• hand pull test to see if joining fails

Analysis: Test using product equipment similar to a Soldering Iron.

#### Feasibility #4: Blade Cycle Life

Research:

• According to Gillette FAQ page, a razor will last one month of shaving.
• Number of shaves per week = 7
• Average time to shave = 3.5 minutes
• Razor Blades will be used for 8 hours a day
• For the duration of the plastic cutting, the knife is focused on the one section of the bottle

Recommendation: Replace the blade once a week. Beginning of each 8 hour shift, place razor blade at new focal point on the bottle each time.

#### Feasibility #5: Pressure Needed to Reshape the Bottles

Assume:

• Bottles that are crushed are in random orientations (Entropy)
• All bottle heads need to fit
• Pressure needs to be enough to reshape thick and thin plastic bottles but not too powerful that the bottle get shot from the fixture

Research:

• All screw caps are different in sizing and thread (i.e. Powerade and 2 liter Diet Coke are different in sizes and threaded cap)
• There are various thickness of bottles
• There are various sizes of bottles

Perform Research Experiment:

• Crush bottles into different orientations
• Use of different sizes and kinds of plastic bottles

Analysis: Build a Prototype fixture and Test

#### Feasibility #6: Material Input to Product Output

 String Length Equation String Output per Bottle at 85% Material Utilization (2mm Width) String Length per Bottle at 85% Utilization at Varying String Widths
A link to the live document is here.

## Morphological Chart

Morphological Chart

A link to the live document is here.

## Concept Selection

Pugh Chart

A link to the live document is here.

## Systems Architecture

System Architecture

.

## Designs and Flowcharts

Process Flowchart

A link to the live document is here.

## Risk Assessment

Click on photo to zoom in and read the PDF.

Risk Assessment

A link to the live document is here.

## Design Review Materials

• Presentation and/or handouts
• Notes from review
• Action Items

## Plans for next phase

In three weeks, we would like to accomplish:

• Tensile test strings and/or rope
• How to weave string
• BOM
• Prototype each process
• Basic design drawings of equipment
• Feasibility testing of prototypes

The Gantt Chart for next section is here.

Individual Plans:

Koby Kubrin - 3 Week Plan

Colin McGlynn - 3 Week Plan

William Hollomon - 3 Week Plan

Jordan Reynolds - 3 Week Plan

Yi Po (Albert) Lin - 3 Week Plan