This project shall be completed in a time span of two ...



Improvements to Juice Work Cell

February 2004

Midterm Report

Technical Data Package

Project Sponsor: Kraft Foods, Avon, New York

Team Members:

Jessica Vastola - ISE

James Hildick - ME

Molly Kearns - ISE

Michael Leiston - ME

Laura Pleten - ME

Michael Russell - ME

Nicole Verley - ME

Table of Contents

Chapter 1: Project Overview 3

1.1 Introduction 3

1.2 Background 3

1.3 Ergonomic Risk Factor Assessment – Juice Supply 4

1.4 Ergonomic Risk Factor Assessment – Juice Placing 5

Chapter 2: Needs Assessment 6

2.1 Project Mission Statement 6

2.2 Product Description 6

2.3 Scope Limitations 6

2.4 Stakeholders 7

2.5 Key Business Goals 7

2.6 Financial Parameters 7

2.7 Critical Performance Parameters (Order Qualifiers, Minimum Required Performance) 7

2.8 Critical Performance Parameters (Order Winners, Desired Performance) 8

2.9 Describe the Need 9

2.10 Constraints 9

2.11 Project Management 9

Chapter 3: Concept Development 9

3.1 Brainstorming Technique 9

3.2 Group Drawing Method 10

3.3 Empathy Method 10

3.4 Concept Alternatives 11

3.5 Handheld Device 12

3.6 Concept Selection 13

3.6.1 Pugh’s Method 13

3.6.2 Weighted Comparison 13

3.6.3 Radar Chart 14

3.6.4 Qualitative Evaluation 15

3.6.5 Decision 16

Chapter 4: Feasibility Assessment 17

4.1 Feasibility Introduction 17

4.2 Design Feasibility 17

4.3 Materials Feasibility 17

4.4 Fabrication Feasibility 19

4.5 Cost Feasibility 20

4.6 PERT and DSM 21

Chapter 5: Design Objectives and Performance Specifications 21

5.1 House of Quality 22

5.2 Design Objectives 23

5.3 Performance Specifications 24

Chapter 6: Analysis of Problems and Synthesis of the Design 25

6.1 Analysis Introduction 25

6.2 Compressed Air Cylinder 25

6.3 The Main Frame and Mounting the Cylinder 26

6.4 Toggle bolt mounting plate 27

6.5 Guide Plate and Box Guide Plates and Rods 28

6.6 Toggle Rods 29

6.7 Mounting the Directional Valve and Throttle 30

6.8 Formulae, Calculations and Free Body Diagrams 31

6.9 Purchased Items 33

6.10 Failure Modes and Effects Analysis -Design FMEA 34

Chapter 7: Preliminary Design Documents 36

References 44

Appendix A (Org Chart) 47

Appendix B (WBS) 48

Appendix C (Timeline & Gantt) 49

Appendix D (PERT) 50

Appendix E (DSM) 51

Appendix F (FAST) 52

Appendix G (FFBD) 53

Appendix H 54

Appendix I 56

Appendix J 58

Appendix K 60

Appendix L 61

Chapter 1: Project Overview

1.1 Introduction

Currently, a technique and tool are used to accomplish the task of opening pre-packaged juice cases. Both result in excessive workload and physical strain on the workers. The juice pouches are then fed to several placing stations by way of conveyor. The scope of this project will be to design and create a prototype device to improve the box-opening process. In addition the team will conduct a feasibility assessment to automate the entire juice placing method. Furthermore, suggestions will be offered to address ergonomic concerns of the current workstation. Since the introduction of the current tool, the juice supply process has not been further addressed by Kraft Foods.

1.2 Background

Kraft Foods, Avon, NY receives corrugated cases of juice pouches in two bulk quantities of 10-packs and 60-packs. These cases must be opened manually at a rapid pace. The 10-pack cases are of highest concern.

Up to four pallets of juice are staged to the supply area at a time. The 10-pack cases are shrink-wrapped in bundles of four. The shrink-wrap must first be scored and removed by hand. Then a tool is used to aid in breaking the glue sealed flaps. Following the initial pass with the tool, a worker must break the opposite flap to fully open each case. The cases of juice pouches are then manually lifted and dumped onto an auxiliary conveyor that transports them to the juice-placing position at the main conveyor. Once the cases are dumped, the empty cases are then placed in tipper carts. The pace of this operation can create a good deal of congestion in the area due to full tipper carts and the exchanging with empty ones. Additionally, the U-shaped design of the line allows only one entry and exit point for all materials.

1.3 Ergonomic Risk Factor Assessment – Juice Supply

An Ergonomic Risk Factor (ERF) Assessment of the juice supply process was performed by Kraft personnel prior to involvement by the Rochester Institute of Technology Senior Design Team. The study resulted in a score of 29 out of 82 on the Kraft scale, the highest of all processes evaluated at the Kraft site. According to the rating scale, a total score of 0-2 is classified as Green, “within established criteria”; 3-11 is Yellow indicating “opportunity for continuous improvement”; greater than 11 is Red, noting “high priority action item requiring intervention.”

Based on the ERF evaluation sheet, the Juice Supply process scored a three, for “occurs more than one time per cycle” in the following areas:

• F1: Two handed lift greater than 20lbs

• F8: Trunk rotation with a weight greater than 10lbs

• F9: Wrist rotation while manipulating greater than 6lbs

• F10: One hand horizontal palmer push greater than 15lbs

• P1: Trunk forward flexion greater than 45°

• P4: Neck flexion

• P8: Elbow flexion greater than 135°

• P9: Wrist flexion or extension greater than 65°

• P11: Forced pronation or supination of hand and wrist

The following “Other Risk Factor” scored a “Yes” which is equivalent to 2 points:

• O5: Squat or kneel for greater than 50% of the cycle

The number of passes and the speed, at which the opening must occur, creates extensive ergonomic strain on the worker. Four passes are required over each box: shrink-wrap removal, open first flap with tool, open second flap by hand, and empty the box. This process requires bending, rapid hand movement, twisting, kneeling, squatting, and lifting. The tool aids in the process, but causes additional strain to the hand due to the shape of the handle, as well as the second pass without the tool.

1.4 Ergonomic Risk Factor Assessment – Juice Placing

The juice-placing position is where the juice pouches are manually placed in a slot provided on the pin-line. Employees rapidly place these pouches by hand at a rate in the range of 130-240 per minute. The high level of hand activity poses ergonomics concern. This is a standing position and the juice pouches must be correctly oriented to ensure visibility in the product packaging. The study resulted in a score of 7 out of 82 on the Kraft scale.

Based on the ERF evaluation sheet, the Juice Placing process scored a three, for “occurs more than one time per cycle” in the following areas:

• P10: Wrist ulnar or radial deviation greater than 25°

• P11: Forced pronation or supination of hand and wrist

The following scored a one, for “Occasional, not every cycle”

• P4: Trunk or neck side-bent plus twisted

Chapter 2: Needs Assessment

2.1 Project Mission Statement

The mission of this design project team is to design a process and/or device to replace or improve the existing box opening and unloading process currently in place at Kraft Foods. The final design should address ergonomic and manpower concerns.

2.2 Product Description

Currently, a technique and tool are used to accomplish the task of opening pre-packaged juice cases before placing them into Lunchables trays. Both the technique and the tool in use result in excessive workload and physical strain on the workers.

2.3 Scope Limitations

A team comprised of mechanical and industrial engineers shall design the new process and/or device, with any electrical engineering concerns alleviated by consultation.

This project shall be completed in a time span of two academic quarters ending in late February and late May, respectively. Formal proposals and drawings for the team’s designs must be presented by the end of the first quarter. A working prototype shall be the final deliverable for the second academic quarter.

With respect to the team’s time constraints, the scope of this project will be to design and create a prototype device to improve the box-opening process. In addition, the team will conduct a feasibility assessment to automate the entire juice placing method. Furthermore, suggestions will be offered to address ergonomic concerns of the current workstation.

2.4 Stakeholders

Primary Stakeholders:

• Fifth year Mechanical and Industrial engineering students

• Kraft Foods, Avon, New York and their employees

Secondary Stakeholders:

• Rochester Institute of Technology

• Additional Kraft Food plants and their employees

2.5 Key Business Goals

• Produce a prototype, which will facilitate process efficiency and reduce ergonomic risk.

• Improve cost effectiveness by eliminating non-value adding steps

• Create a safer working environment

2.6 Financial Parameters

In absence of an actual budget, the team must produce a low-cost tool and other process improvements using Kraft site funds. Any spending must be justified and approved by Kraft, based on return on investment.

2.7 Critical Performance Parameters (Order Qualifiers, Minimum Required Performance)

• The process shall reduce ergonomic risk factor of 29 out of 30

• The improved tool shall be able to open the pallet of boxes in the amount of time necessary to keep up with the packaging line, running at 130 to 240 pouches per minute (six bundles of four 10-packs per minute)

• The tool shall consist of an ergonomic style handle

• The tool shall reduce the passes necessary to open the box flaps

• The design shall meet all Kraft required regulations and standards for plant machinery

• The design concept shall meet Kraft safety requirements

• The tool shall be able to be used by all workers

• The tool shall be an acceptable weight (TBD)

• The tool shall not be larger than TBD square inches to allow for convenient use and storage

2.8 Critical Performance Parameters (Order Winners, Desired Performance)

• The tool should open four 10-packs at one time

• The tool should be easily cleaned and sanitized

• The tool should be constructed with primarily over-the-counter or easily-made parts, allowing for easier replacement parts

• The tool should not destroy any juice pouches when opening the boxes

• The tool should require only one employee to perform the job without assistance of another worker

• The tool should improve ease of box opening by using pneumatic cylinders to assist with the force needed to open the boxes

• An improvement should be made to the current conveyor speed

• The height of the unloading table should be made adjustable with respect to the conveyor

• An ergonomic assessment should be performed, resulting in suggestions for further workstation improvements

2.9 Describe the Need

The objective of this project is to design a process and/or device to replace or improve the existing box opening and unloading process currently in place at Kraft Foods. The final design should address ergonomic and manpower concerns.

2.10 Constraints

• Limited Time (6 months)

• Limited Funds (Use only Avon site funds)

2.11 Project Management

The team is comprised of a team leader, a lead engineer, one staff Industrial and Systems Engineer and four Mechanical Engineers. One faculty member serves as a mentor and advisor. The Industrial and Systems Engineering Department Head serves as the Project Coordinator. An organizational chart illustrates these relationships, located in Appendix A. Appendix B is a high level Work Breakdown Structure to show resource allocation. The timeline and Gantt chart in Appendix C has been created to keep track of tasks and assignments.

Chapter 3: Concept Development

Techniques for concept development were used to determine the best tool design to build. Outlined below is the process and criteria used to choose between the three different concepts.

3.1 Brainstorming Technique

The first approach used was a brainstorming technique to generate numerous ideas. All ideas, no matter how unrealistic, were accepted for this part of the process. In this step of the concept development process there is no specific criteria to be followed. The ideas were listed on the form provided in the EDGE. After a significant list had been generated each team member was allowed to cast five votes which included multiple votes for one item if the individual felt it was necessary. Due to the changing scope of the project, the team used this technique two separate times. This first attempt at this method was to solve the problems with the entire juice placing process. It was then used a second time to brainstorm ideas for a tool to open the boxes. After all votes had been cast, they were counted and the three concepts with the highest number of votes were pursued in more depth.

3.2 Group Drawing Method

The three concepts: a wedge tool, a stationary tool, and a handheld tool were developed in greater detail using the group drawing method. Each team member was assigned a concept to draw. Since the team members are from different engineering disciplines the perspectives from each member was unique. During this process, the design of the box and the orientation of the pallet were taken into account. After thirty seconds of drawing the designs were passed to the person on the right for further detail to be added. This was repeated until each team member had worked on every drawing.

3.3 Empathy Method

In order to identify system interactions and coupling between subsystems, the team conducted an empathy method exercise to help get inside the problem. Each team member represented a component involved in the system, and after ten minutes of role-playing, a greater insight was revealed concerning what is involved in the situation and also what other elements may be needed to address the problem.

3.4 Concept Alternatives

At this point three possible design ideas still remained: the wedge tool, a handheld tool using toggles, and a stationary tool to be mounted to the tabletop also utilizing toggles. The team discussed the feasibility of each concept.

The wedge tool involves a wedge shaped device to open the boxes by introducing the wedge’s tip where the major flaps meet on the ends of the Kool-aid boxes. The operator would drive the wedge down the flaps opening an eight-high column of four 10-packs at once. This operation could be done by hand but the team looked into a pulley system to divert some of the force needed to open the boxes.

The stationary tool would have the same performance operations as the handheld tool, but instead it would be mounted on a table that is currently located at the top of the feeding line. The operators’ only function with the device would be to introduce the four 10-packs into the tool. A foot pedal or switch would be used to open the boxes and then the operator would empty the boxes onto the feeding line.

The third and final concept is hand-held and capable of opening one shrink-wrapped bundle of four 10-packs at a time.

3.5 Handheld Device

This device consists of spring-loaded toggles that are pushed into the box through the slit between the major flaps. The toggles’ default position is spread open so that the toggles are approximately three inches wide. When they are pushed into the box, the toggles are pushed down to a closed position. Once inside, the toggles spring open again and are pulled back out. The spread toggles grab the flaps and rip them open as they are pulled back.

Initial brainstorms envisioned a device that was purely manual, where the operator would push and pull the device by arm power alone. This idea was quickly dismissed after measurements were made as to the force necessary to rip the box flaps open using a spread toggle. Using a push/pull measurement scale, it was found that a force in excess of sixty pounds was needed in order to recover the toggle. This force is far greater than what would be considered acceptable for repetitive work on the part of the operators. Furthermore, this is only the force needed to open one box. A device that opens one 10-pack box at a time will not be able to keep up with production standards of 130 to 240 pouches per minute.

These initial thoughts led the team to decide that the only way to make the handheld device practical is to make it powered in some way. The cheapest, safest and most accessible form of power available to the plant floor is compressed air. Compressed air lines containing 110 psi are present throughout the plant, thus pneumatics was the natural choice for power on the handheld device. A compressed air cylinder of appropriate size was chosen to handle the load necessary to open four 10-pack boxes at once. Through a system that includes a throttle, a control valve and the cylinder, the operator will be able to place the device against the boxes and simply push a button while the toggles are pushed into the boxes and then retracted as the boxes are opened. The specifics of the design process, as well as drawings and finite element analysis results, will be presented and discussed in chapters six and seven.

3.6 Concept Selection

In order to proceed with a single design, it is important to objectively evaluate design concepts. By applying Pugh’s Method of Direct Comparison of Alternatives, a Weighted Comparison Method, and a Radar Chart, an evaluation of the chance that the project will be successful is accomplished. By comparing alternatives against a baseline concept, the concept among the alternatives that best meets the feasibility criteria can be chosen. In this case, the baseline concept refers to the current tool used at Kraft.

3.6.1 Pugh’s Method

In Pugh’s Method, each attribute used to evaluate the feasibility is scored against the baseline with either -, 0, or +. The minus represents that the concept is inferior to the baseline, the zero suggests the attributes match up evenly, and the plus suggests the alternative concept is superior to the baseline.

3.6.2 Weighted Comparison

The Weighted Comparison Method, like Pugh’s Method, compares alternatives against a baseline concept. However, this technique yields comparisons having greater resolution than Pugh’s Method. This weighted approach takes into consideration the magnitude of the differences of the levels of attainment of each concept. Each attribute is scored in a range of 1 to 5 where: 1 = much worse than the baseline, 2 = worse than the baseline, 3 = same as the baseline, 4 = better than the baseline, 5 = much better than the baseline.

3.6.3 Radar Chart

The purpose of a radar chart is to display the level of achievement among alternatives, to evaluate concepts and concept feasibility. The alternative that covers the most area on the diagram is the best alternative. Each Concept is evaluated based on the baseline of the currently used hand tool. Attributes are Resource Feasibility, Economic Feasibility, Schedule Feasibility, and Technological Feasibility.

|Resource Feasibility |

|R1: |Sufficient Skills |

|R2: |Sufficient Equipment |

|R3: |Sufficient Number of People |

|R4: |Sufficient Space |

|R5: |Safety |

|Economic Feasibility |

|E1: |% of Total Required Funds |

|Schedule Feasibility |

|S1: |Chances of meeting the intermediate mileposts |

|S2: |Chances of meeting the PDR Requirements |

|S3: |Chances of meeting the CDR Requirements |

|Technologically Feasible |

|T1: |Feasibility Level (L0, L1, L2, L3, L4) |

|T2: |Keep up with Packaging Line (130-240 pouches/min) |

Table 1: Feasibility Attributes

[pic]

Figure 1: Radar Chart

In the juice supply case, Concept 2, the Handheld device covers the most area. Concept 1, the Wedge, covered the least area, proving to be a worse option than the baseline tool. The Stationary device, Concept 3, likewise was little better than the baseline and in some cases worse.

After completing these evaluation processes, it was concluded that the handheld device rated best compared to the baseline and to the other concept alternatives. Other factors were considered in addition to the Pugh’s and weighted methods for concept selection.

3.6.4 Qualitative Evaluation

The Wedge concept was rejected because this type of opening device would require too much space in order to attach a pulley system. Also without the pulley system, the force needed to drive the wedges down a column of juice boxes would be unreasonable for the operators, hence increasing the ergonomic risk factor.

The stationary device was rejected due to space limitations, reduced productivity and an increase in ergonomic risk. The tabletop is currently used as a staging area for 10-pack boxes that will be emptied onto the conveyor. If this design were to be pursued, the operator would have to put the boxes in the opener, wait for them to be opened, and then dump them onto the conveyor. This process would be entirely too slow, and may compromise the ability to achieve high productivity. The motions associated with this method also require the workers to lift and put down boxes with greater frequency, which results in an increase in ergonomic risk.

3.6.5 Decision

In respect to the quantitative methods and qualitative evaluation, the concept of a handheld device to open four bundled 10-packs at once was the best alternative.

Figure 2: Design Concept

Chapter 4: Feasibility Assessment

4.1 Feasibility Introduction

The question to be answered by the evaluation of the feasibility of this project is whether the team’s goals and design requirements can be met within the allotted amount of time and with the given budget constraints. These feasibility constraints were responsible for the team’s decisions as far as setting the scope of the project. The early stages of the brainstorming process saw the team trying to solve a problem that would have been far too time consuming and expensive to complete in twenty weeks and on a reasonable budget. The requirements for the project dictated just how extensive the project could be and the final design goal is one that was feasible given time and budget constraints.

4.2 Design Feasibility

The design of the handheld device will have to be completed within the given time and budget constraints, as mentioned above, as well as within the limits of the team’s design and fabrication capabilities. To achieve this, the design was kept relatively simple, without unnecessary components or other gadgetry that would increase the complexity, cost and weight of the design. As stated, the device will work on compressed air and does not include any electrical or robotic components. The design is purely mechanical in nature and was designed to be as robust as possible without adding excess weight.

4.3 Materials Feasibility

All materials that will be used in the fabrication of this design are standard materials that can be purchased from any number of distributors. The design is a compromise between an effort to reduce weight, provide adequate strength and to make the design compatible with the working environment.

There are four main load-bearing components in the design that will bear the brunt of the 250 pounds of force needed to open four boxes of juice at once. These components were made of stainless steel. The steel was used in the design to provide adequate strength in a robust design. Finite element analysis of the part helped the team to strengthen specific areas of high stress and then cut off unnecessary material from low stress areas to cut down on overall weight of the design. The final design will incorporate the stainless steel in order for the device to be compatible with the food-grade working environment at Kraft. (Reference Appendix I)

All tools are periodically cleaned to maintain a sanitary working environment and must be able to cope with both acidic and basic cleaning solvents. The stainless steel will not corrode and will be easily cleaned in the sanitary conditions. Other components on the design may be comprised of materials other than steel. None of the components will be made of any type of metal other than stainless steel because of corrosion characteristics and the ability to be welded. Aluminum, for instance, would be nice because of its lightweight. Aluminum, however, will corrode in the acidic and basic cleaning solutions and is very difficult to weld effectively. Polymers may be used for some components in an effort to reduce weight. The polymers would have to be able to withstand sanitation measures and must not be too expensive to purchase.

4.4 Fabrication Feasibility

This device was designed with fabrication in mind. Every component that was added on to the device was added amid questions of “how will it be assembled and attached?” The skills and resources available to the team members were established during the beginning stages of the design of this concept and were kept in mind throughout the design process.

The major mode of fabrication to be used is the welding of the steel components. Welding is a simple operation that offers a very strong bond, requires fewer parts and is relatively cheap. The device consists of a main steel tubing frame that will have the other necessary components of the device welded onto it. Mounting brackets needed for the pneumatic cylinder, the control valve and the throttle will all be welded onto this main frame. The other components such as the guide plate and the toggle bolt mounting plate will also be welded onto this main frame. Further descriptions of these parts will be provided in proceeding chapters.

Apart from welding, fabrication will also include fastening devices such as typical nuts, bolts and washers. Any part of the device that is considered a permanent component will be welded to the main frame, while other objects that may need to be replaced periodically will be attached to these permanent components via fasteners. For example, mounting brackets for the pneumatics will be welded to the main frame, while the pneumatic components themselves will be attached to these brackets using nuts, bolts and washers. Aside from the pneumatic components, the rods and the toggles will also be attached with fasteners.

Laser cutting is a method that will be used during the fabrication process, and will be used mainly to help in the reduction of unnecessary material in order to reduce the weight of the device. Finite element analysis was used to determine how much material was needed in order to achieve the proper strength for the device to be reliable. A satisfactory factor of safety was achieved while using the smallest amount of material possible. Where possible, holes were cut in steel parts to reduce weight. Laser cutting of steel is available to a member of the team and this resource will be utilized to achieve optimum performance of the final device. (Reference Appendix J)

4.5 Cost Feasibility

As was the case with fabrication, this device was designed with cost in mind. Where possible, the team used off the shelf components to keep the price as low as possible. There are components on this design that require parts to be custom made, but those parts are made from raw materials that are easily accessible and not very expensive. For example, the steel tube main frame needs to be custom made, but the steel tubing needed for the component uses standard sizes and is easily purchased. All of the smaller components, such as the nuts and bolts, are used in standard sizes and are also easily purchased from any distributor. (Reference Figure 17)

There is one area in which the team opted for higher price in order to achieve higher performance. The need for stainless steel in the sanitary food-processing environment led the team to make the decision to make or purchase all of the steel components with stainless steel. Other than the need for stainless steel, the team was able to design the device with economy in mind.

4.6 PERT and DSM

“Complex projects require a series of activities, some of which must be performed sequentially and others than can be performed in parallel with other activities. This collection of series and parallel tasks can be modeled as a network. The Program Evaluation and Review Technique (PERT) as illustrated in Appendix D is a network model that allows for randomness in activity completion times.” (Netmba) The PERT chart illustrates the tasks necessary to build the concept design.

Stemming from the PERT charts is a Design Structure Matrix (DSM), in Appendix E. The purpose of this technique is to decide the order of tasks by sequencing the specification of design parameters. The DSM iterates a list of tasks to make dependent tasks sequential.

Chapter 5: Design Objectives and Performance Specifications

The purpose of this facet is to clearly define the project’s design objectives and performance specifications. The design objectives are based on the customer’s requirements for the project. The team based on the project definition, determined design objectives. These are discussed in detail in the following sections.

5.1 House of Quality

Figure 3: House of Quality

The House of Quality, figure 7, combines the design objectives and customer requirements to ensure all requirements are met. It is a means of quantifying the Voice of the Customer. The objective is “the overall goal of the project.” (Stiebitz, Eng Des) The Engineering Characteristics include “measurable quantities that relate to customer requirements and desired direction of improvement.” (Stiebitz, Eng Des) The customer requirements section lists “what is important to the customer.” (Stiebitz, Eng Des) This section includes items such as “cost, availability, packaging, performance, ease of use, assurances, life cycle costs, and social standards.” (Stiebitz, Eng Des) The Customer Important ratings scale the Customer Requirements from 1-10 on a scale of importance in producing the product or process. The Target Values section specifies the “nominal specification for the new product or process. It utilized benchmarking data and results from value analysis.” (Stiebitz, Eng Des) The “roof” or correlation matrix shows interaction between engineering characteristics. The interactions are denoted by “+” for a strong relationship, “-“ for a negative relationship, and circles for very strong or very negative. A strong relationship indicates that the two characteristics aid in achieving the respective target values. The relationship matrix creates a link between engineering characteristics and customer requirements. The scale is 1 to 9, with 9 being the strongest relationship.

To analyze, thus calculating absolute and relative importance, for each engineering characteristic, the rating is multiplied by the relationship for each customer requirement, then summed. The total becomes absolute importance. Relative Importance is calculated by dividing absolute importance by the sum of all absolute importances.

According to the House, the most heavily weighted factors are addressing 10-packs (0.25) and Using available resources (0.23). As indicated by the House, Decreasing the number of passes (0.19), Reducing Ergonomic Risk (0.16) and Line Speed (0.10) are the next highest group of importances. Least important is utilizing the number of workers assigned at 0.08.

5.2 Design Objectives

Kraft approached Rochester Institute of Technology’s Occupational Safety and Ergonomic Excellence Department for assistance in addressing ergonomic concerns with their provisional box-opening tool. The scope of the initial opportunity was expanded to include overall ergonomic issues of the juice supply process. The main objective is to design, build, and demonstrate the functionality of a single tool to replace or improve the existing box opening and unloading process currently in place at Kraft Foods.

5.3 Performance Specifications

The entire tool should be as small as possible while still maintaining overall effectiveness and should weigh no more than x.

In terms of performance, the improvement should reduce the ergonomic risk factor from 29/82 on the Kraft scale, should reduce the number of passes per box. The improvement should open the pallet of boxes in the amount of time necessary to keep up with the packaging line, running at 130 to 240 pouches per minute (six bundles of four 10-packs per minute).

Environmental Requirements focus on safety and regulations required at Kraft. All materials used shall be resistant to acid and base wash down. The Federal Food and Drug Administration (FDA) shall approve all materials

Functional Specifications include, the tool shall consist of an ergonomic style handle, and all workers shall be able to operate the tool.

The team shall complete a final design package, which includes a concept design report, a technical paper, and a working prototype. Each team member shall submit a personal logbook which details design progress.

Chapter 6: Analysis of Problems and Synthesis of the Design

6.1 Analysis Introduction

The initial analysis that was performed was done so with the performance specifications of the device in mind. Toggle testing with a push/pull scale was done to establish the amount of force needed to tear open a box of juice pouches. A force of approximately 60 lbs. was needed to accomplish this task. The team planned to be able to open four boxes at once, as the boxes are shrink-wrapped together into bundles of four; therefore, a total force of approximately 240 lb. would be necessary to open all four boxes at once. In the interest of creating a robust design, the team proceeded with analysis with a force of 300 lb. in mind, which results in a factor of safety of 1.25.

With the experimentation that yielded the necessary amount of force to open the boxes, the decision had been made to use some form of power to open the boxes. Applying a force of 60 lb. repetitively at a rapid pace would have been far too strenuous on even the strongest workers. Furthermore, the team insisted that opening one box at a time was not enough. The device needed to be able to open several at once.

6.2 Compressed Air Cylinder

The form of power that would be used to operate the device was compressed air, and a compressed air cylinder would be the simplest and most economical way of applying the necessary force to the boxes. The type of cylinder to be used is known as a double acting compressed air cylinder. The term ‘double acting’ means that there are two air inlets in the cylinder; this means that compressed air can be introduced to either side of the piston inside the cylinder. By alternating the side on which the force is applied, the piston can be pushed back and forth with the full force of the compressed air. This will allow the box opening device to have enough force available to both get the toggles into the boxes and to pull them out.

In order to calculate the size of the cylinder that would be needed in order to achieve the necessary 300 lbs. of force, the team worked backwards from the known knowledge to arrive at the size of the bore that would be needed in the cylinder. The given facts are that 300 lbs. of force is needed and that there is 110 psi available in the plant’s airlines. Force divided by air pressure will yield the amount of surface area needed for the application of the air pressure. Once this surface area is known, the equation for the area of a circle is used to calculate the necessary diameter of a circular bore inside of a cylinder (see section 6.8). The final diameter was calculated at 1.95 in. The compressed air cylinder to be purchased will have a bore size of two inches.

6.3 The Main Frame and Mounting the Cylinder

The design of the device began with a basic rectangular frame made from steel tubing. Everything on the device would be based on and attached to this frame. As time went on and the specifics of the design became more clearly defined, the exact dimensions of the frame and the size of the tubing would be modified to achieve optimal performance.

The cylinder was to be mounted directly in the center of the rectangle that was formed by the frame. If this cylinder was to be opening several boxes at once, it should be placed in the center so that the force application is equally divided and no unnecessary moments were created. In order to mount this cylinder to the frame, a plate was placed across the frame, with each end of the plate being welded to the tubing. In the center a hole was cut where the cylinder would be placed. There are threads built in to the cylinder so that a washer and nut can be used on the bottom side of this plate to hold the cylinder in place (reference Figures 1-16). Finite element analysis was performed on this plate to ensure that it could handle the necessary loads. Each end was fixed with a load of 300 lb. applied at the hole. The 12-gage sheet steel that was originally to be used ended up failing, so the material was increased to a thickness of 0.179 in., or 7-gage sheet steel. In an attempt to compromise between added strength and added weight, material was removed from low stress areas on the plate, and the present shape resulted. (Reference Appendices I and J)

6.4 Toggle bolt mounting plate

The toggle bolt mounting plate is the plate that attaches the piston shaft from the cylinder to the toggle rods that will be used to open the boxes. One cylinder is used to operate eight toggles, while two toggles are assigned to opening each box. A rectangular plate similar in size to the frame was designed so that the cylinder shaft could be mounted to the center and the eight rods could be mounted to the opposite side in the same manner. The rods would be attached to the plate in such an orientation as to allow two toggles to open each box. (Reference Figure 6)

Finite element analysis was carried out on this plate, as it would be bearing the force necessary to open the boxes. The center mount was held in a fixed position, while the load of 300 lb. was evenly distributed among the eight rod mounting locations. Upon examination of the results and in order to optimize the design, holes were cut in the center to eliminate extra weight, while the outer edges on the long side of the rectangle were bent down to act as an I-beam in order to increase the stiffness of the plate. The result of this optimization is the present form of the part. (Reference Appendices I and J)

6.5 Guide Plate and Box Guide Plates and Rods

The guide plate is a device that was needed to fulfill two separate roles. First, something that was fixed and had guide holes in it for the toggle rods was needed to ensure that the rods traveled straight and did not bend or twist. As was stated previously, the cylinder was placed in the center of the frame to avoid any undesirable moments or uneven application of power. The guide plate would serve the same purpose, causing the rods to travel in a straight line. This plate is to be welded to the main frame to provide a stable platform for guiding the rods. The box guide plates and rods will be attached to this fixed platform and will serve to push against the boxes as they are opened. Some fixture was needed to provide a reaction force against the boxes as the cylinder pulled at the flaps with 300 lb. of force. If this reaction force was not provided, the flaps on the boxes might hold and simply pull the boxes off the pallet. These box guide plates are situated between the boxes where they will not interfere with the opening of the flaps. A rod will be welded to the bottom of each of these guide plates to act as a buffer so that the plate will not cut into the cardboard of the boxes. (Reference Figures 7, 8 and 9)

As was the case with the toggle bolt mounting plate, FEA was performed on the guide plate. There are five box guide plates attached to the large guide plate and the 300 lb. of force will be transferred through them to the guide plate. The guide plate will be fixed on its edges where it will be welded to the frame. The FEA produced results that told the team that the 12-gage steel that was originally planned for use would be sufficient. Some of the material was able to be removed in order to save on unneeded weight. So too with the box guide plates, which are subjected to simply compressive forces. Much of the material in the middle of these plates was able to be cut out in order to save weight; the ability of these parts to perform under the applied loads was not compromised. (Reference Appendices I and J)

6.6 Toggle Rods

The design of these rods was relatively simple, in that the only loads they would need to endure are simply tensile and compressive loads, applied longitudinally. Both ends of the rods were threaded for fastening purposes. One end will be attached to the toggle bolt mounting plate, and will be fastened with a washer and a nut on each side of the plate. The other end will have the toggle threaded onto it and an acorn nut holding the toggle in place. The purpose of the acorn nut is to provide a smooth rounded tip to the rod so as to cause minimal damage to anything the rod may touch once inside the flaps. 7mm diameter rod was used in order to have something large enough to be easily handled and formed, and small enough to be lightweight. The strength of these rods was never a problem, as the steel can easily handle the applied loads in tension and compression.

6.7 Mounting the Directional Valve and Throttle

The directional control valve and the throttle both needed to be mounted to the main frame so that the air could be easily supplied to the cylinder and controlled by the operator. The control valve needed to be mounted next to the handle, so that the worker can easily reach the finger-operated lever that is used to operate the device. This need dictated the orientation in which the control valve needed to be placed. With this in mind, a simple bracket was designed to be welded to the main frame; this bracket also included holes that line up with the mounting holes on the particular valve that has been chosen for this application. The bracket was made from 14-gage steel, which is slightly thinner than the 12 or 7 gage sheet steel that has been used elsewhere on the design. The reason for this is that the bracket really does not have to handle any significant load, other than the weight of the valve (approximately 0.14 lb.), and so a lighter form of sheet steel was used to keep weight to a minimum.

The mounting bracket for the Throttle was designed in a similar manner. The throttle weighs approximately 0.25 lb. The bracket that holds this throttle in place will not have to experience any load other than the weight of the throttle, and so was also made to be as small and light as possible. As was the case with the mounting bracket for the control valve, the mounting bracket for the throttle will also be welded to the main frame to provide a stable platform for the throttle.

6.8 Formulae, Calculations and Free Body Diagrams

Variables

Asw = Effective area of ¼ inch stainless steel washer

Alw’ = Effective area of ½ inch stainless steel washer with 2 inch outer

diameter

Alw = Effective area of ½ inch stainless steel washer with 0.6250 inch

outer diameter

Agp = Effective area of guide plate

Acyl = Area required for cylinder

Dcyl = Diameter required for cylinder

Fgp = Force due to box guide plates reaction force

Fc = Force due to cylinder push/pull force

Fmf = Force on main frame due to cylinder mount reaction force

FR = Force applied through each rod from juice boxes

Pgp = Pressure due to box guide plates reaction force

Pc = Pressure due to cylinder push/pull force

Pmf = Pressure on main frame due to cylinder mount reaction force

PR = Pressure force applied through each rod from juice boxes

Area

Circle: [pic]

Rectangle: [pic]

Force [pic]

Pressure [pic]

CYLINDER CALCULATIONS

Area [pic] (where 110psi is plant pressure)

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Diameter [pic]

FREE BODY DIAGRAM CALCULATIONS

Area

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Force

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Pressure

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6.9 Purchased Items

Any items that were to be purchased off the shelf and not manufactured by the team were chosen with the same thoughts in mind that dictated the design of the other parts. First to be considered was performance. Could the part do its job? Once options were found, the products that were the lightest were preferred. It is the goal of this team to create a product that any employee can use in a repetitive and rapid manner, and so creating a device of minimal weight was a top priority. Such items included the cylinder, control valve, throttle, toggles and all nuts, bolts and washers.

The cylinder is the most important single item on the design. It was no problem finding a cylinder that could produce the 300 lb. of force needed to get the job done. Furthermore, cylinders are relatively cheap and so economy was not a problem. Weight, however, was an important issue. The first cylinder considered weighed 8 lbs. This ended up being a very significant portion of the final weight of the entire device, and so a lighter model was sought. A model was found that uses polymers as well as steel, rather than making the entire cylinder out of steel. This resulted in a cylinder that weighs approximately 1.5 lbs. and was still able to deliver the necessary force.

The purpose of the control valve is to control when the cylinder’s shaft is retracted and extended. The type of control valve that was needed for this application is a 5 port, 2-position valve. The compressed air comes in one end and the valve sends it in one of two possible directions. One output direction corresponds with extending the shaft, the other with retracting the shaft. The default position is for the cylinder shaft to be retracted. When the operator pushes on the lever, it changes the direction of the airflow and causes the cylinder shaft to extend. The valve is spring loaded, so that when the operator lets go of the switch, the valve returns to its default position.

The purpose of the throttle is to have a device capable of monitoring the airflow into the cylinder. It would be undesirable to have all 110 psi immediately flow into the cylinder, causing the shaft to slam to one end or the other. This would significantly decrease the life of the piston inside the cylinder, as well as cause danger to the operator. The throttle will slow down the application of power, so that all the necessary force is applied, but in a gradual manner. The throttle is set via a nut on top, rather than a hand knob. This way, the level of airflow can be set at a safe level and then will not be manipulated by employees.

6.10 Failure Modes and Effects Analysis -Design FMEA

FMEA - Failure Mode and Effects Analysis is a pro-active, structured engineering quality method that helps to identify and counter weak points in the early conception phase of products and processes. (fmeainfocentre) FMEA is used to identify potential failures in a system, product, or process operation. Causes are then identified either as design or process; Recommended Actions are then identified to eliminate potential failures or reduce their rate of occurrence. FMEA also identifies design or process characteristics that require special controls to prevent or detect failure modes. (go-psi) The Food and Drug Administration (FDA) has recognized FMEA as a design verification method for Drugs and Medical Devices. (quality-one)

To perform an FMEA, all functions of the device are listed. Next potential failures are listed for each function. The effect of each failure is determined and noted, followed by a rating of severity. The effect is what a user would experience from the failure. The severity rating is “the seriousness of the potential failure on a scale of 1 to 10.” (Stiebitz, Eng Des) Potential causes of failure are determined, as well as an Occurrence estimate. The Potential cause is the mechanical means of failure or “a list of conceivable causes of the failure.” (Stiebitz) The Occurrence estimate is “a scaled estimate of the likelihood that a specific cause will occur during the design life of the product.” (Stiebitz) Current design controls are noted for each failure. These are activities or devices already in place to prevent a failure, such as a guide. Failure detection and Risk Priority are noted next. Recommended actions as well as Responsibility for actions are noted for each mode of failure. The final section is a record of correction, what actions were taken, and a resulting estimate of corrective actions.

The FMEA in Table X is the analysis of the handheld tool concept. Four failure modes are noted, with five potential failure effects for the function of Opening Boxes. Three failures have controls already built in the design and place the burden of correcting on the operator, should the tool fail in these manners. However, an uncomfortable tool would require a design change by the design team. This form of failure would be noted during prototype testing.

Chapter 7: Preliminary Design Documents

The following design documents are representations of the scaled drawings. Actual documents, scaled to the title block notations, can be located in the EDGE.

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Figure 4: Main Frame Tube

[pic]

Figure 5: Handle Mount Tube

[pic]

Figure 6: Toggle Bolt Mounting Plate

[pic]

Figure 7: ¼-20 x 4” Rod

[pic]

Figure 8: Guide Plate

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Figure 9: Box Guide Plate

[pic]

Figure 10: Box Guide Rod

[pic]

Figure 11: Pneumatic Cylinder Mount

[pic]

Figure 12: Threaded Handle Mount

[pic]

Figure 13: Removable Handle

[pic]

Figure 14: Control Valve Mount

[pic]

Figure 15: Control Valve Mount Gusset

[pic]

Figure 16: 10-Pack Box Opener

Figure 17: Bill of Materials

References

All Fill. All Fill Incorporated. 2004. Jan 2004. .

Back Design Guide: Health Benefits of Saddle Sitting. Back Designs, Inc. and Eileen Vollowitz. 2003. Dec 2003 .

Banner Engineering: Photoelectric Sensors. Ohio Belting and Transmission. 2004. Jan 2004.

Banner Engineering: Vision Sensors. Ohio Belting and Transmission. 2004. Jan 2004.

Banner Engineering: Parts Sensing Light Screens Sensors. Ohio Belting and Transmission. 2004. Jan 2004.

Chase Logemen. Chase Logeman Corporation. 2003. Jan 2004. .

Ergonomic Risk Factor Assessment. Kraft Foods, Inc.: 2003. 1 Feb 2004.

Ergosource. . 2003. Dec 2003.

Ergosource Ergonomic Solutions for Today. 2003. Dec 2003. .

Dura Tread Light Duty: ½” Light Duty Ringmat. Direct Mat.2002. Dec 2003. .

Fanuc Robotics: M-420iA/M-421iA. 2004. Jan 2004. .

FMEA Infocenter. FIC - FMEA Information Centre. 2003. Feb 2004. .

FMEA Failure Modes and Effects Analysis. 2003. Feb 2004. .

Functional Analysis Systems Technique – The Basics. Save International 2003. Feb 2004. .

Functional Flow Block Diagram. Relationships between Graphical Representations. Vitech Corporation 2002.

General Conveyor Ltd.: Series 20 Robo-matic Palletizer/depalletizer. 2003. Jan 2004. .

Hoppmann: Pouch Feeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Orient/Accumulator. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Centrifugal Accumulator. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Flexlink Conveyors. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Centrifugal Feeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Food-Grade Centrifugal Feeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Prefeeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Overhead Prefeeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Elevating Prefeeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Hoppmann: Elevated Prefeeder. Hoppmann Corporation. Jun 2003. Dec 2003. .

Infinity Packaging. Infinity Packaging. 2004. Jan 2004. .

Kenneth Crow. Value Analysis and Functional Analysis System Technique. DRM Associates, 2002. Feb 2004. .

Langen: rpa_rolco. Langen Packaging Inc. Nov 2002. Dec 2003. .

Langen: Case Studies. Langen Packaging Inc. Nov 2002. Dec 2003. .

Langen: System Integration. Langen Packaging Inc. Nov 2002. Dec 2003. .

Langen: Applications List. Langen Packaging Inc. Nov 2002. Dec 2003. .

Manufacturing Innovative Machinery Inc.. 2004. Jan 2004. .

McMaster-Carr McMaster-Carr Supply Company. 2004. Jan 2004. .

Nercon. Nercon Engineering and Manufacturing Inc. 2004. Jan 2004.

NetMBA. 2004. Feb 2004. .

Packaging World Buyers Guide: Robotic Palletizer/depalletizer. Summit Publishing, Inc. 2004. Jan 2004. .

Packaging World Buyers Guide: Pack Expo Video: Pick and Place System. Summit Publishing, Inc. 2004. Jan 2004. .

Packaging World Buyers Guide: Robotic Palletizer. Summit Publishing, Inc. 2004. Jan 2004. .

Packaging Today. Polygon Media Ltd. 2004. Jan 2004. .

Packexpo. 2004. Jan 2004.

Quality Associates International Inc. Quality Associates International Inc. 2004. Jan 2004. .

Reliance Electric Variable Speed AC Motors: Rockwell Automation. 2004. Jan 2004. .

Stiebitz, Paul H. Engineering Design Lectures. Building 78, Rochester Institute of Technology. Spring 2003.

Torque Systems: BMR 400 Series. 2004. Jan 2004. .

Appendix A (Org Chart)

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Appendix B (WBS)

Appendix C (Timeline & Gantt)

Appendix D (PERT)

Appendix E (DSM)

Appendix F (FAST)

Appendix G (FFBD)

Appendix H

| |Kraft Foods, Inc. | |

| |Ergonomic Risk Factor Assessment | |

| | | |

|Job Name: |Juice Supply | |

| | | |

|FORCE: | | |

|# |Risk Factor |RV |

|F1 |Two handed lift greater than 20lbs |3 |

|F2 |Vertical travel distance of lift, greater than 60" |0 |

|F3 |Horizontal lifting reach greater than 20" from the body |0 |

|F4 |Two handed carry greater than 30 lbs |0 |

|F5 |Horizontal carry distance of greater than 20 ft |0 |

|F6 |Two handed horizontal push / pull greater 40 lbs |0 |

|F7 |Two handed vertical push / pull greater than 25 lbs |0 |

|F8 |Trunk rotation with a weight greater than 10 lbs |3 |

|F9 |Wrist rotation while manipulating greater than 6 lbs |3 |

|F10 |One hand horizontal palmer push greater than 15 lbs |3 |

|F11 |Use of hand tool greater than 7 lbs |0 |

| |FORCE RF TOTAL= |12 |

| | | |

|POSTURE: | |

|# |Risk Factor |RV |

|P1 |Trunk forward flexion greater than 45o |3 |

|P2 |Trunk extension greater than 20o |0 |

|P3 |Neck flexion or extension greater than 45o |0 |

|P4 |Trunk or next side-bent plus twisted |3 |

|P5 |Shoulder abduction greater than 90o |0 |

|P6 |Working with hands or arms behind the body |0 |

|P7 |Full elbow extension with shoulder elevation |0 |

|P8 |Elbow flexion greater then 135o |3 |

|P9 |Wrist flexion or extension greater than 65o |3 |

|P10 |Wrist ulnar or radial deviation greater than 25o |0 |

|P11 |Forced pronation or supination of hand & wrist |3 |

| |POSTURE RF TOTAL= |15 |

| | | |

|OTHER RISK FACTORS: |(Note: Each "Y"=RV Value of 2) |

|# |Risk Factor |YES |

|O1 |Unusually high tool or floor vibration |N |

|O2 |Frequent ladder or stair climbing |N |

|O3 |High exposure to direct pressure or mechanical stress |Y |

|O4 |Work with hands over shoulder level for greater than 50% of cycle |N |

|O5 |Squat or kneel for greater than 50% of cycle |Y |

|O6 |Stand on one leg for greater than 50% of cycle |N |

|O7 |Awkward / immobile body position for greater than 50% of cycle |N |

|O8 |Greater than 6 thumb and or finger exertions with one hand |N |

| |OTHER RF TOTAL= |4 |

| |ERF Total= |31 |

| |Kraft Foods, Inc. | |

| |Ergonomic Risk Factor Assessment | |

| | | |

|Job Name: |Juice Placing | |

| | | |

|FORCE: | | |

|# |Risk Factor |RV |

|F1 |Two handed lift greater than 20lbs |0 |

|F2 |Vertical travel distance of lift, greater than 60" |0 |

|F3 |Horizontal lifting reach greater than 20" from the body |0 |

|F4 |Two handed carry greater than 30 lbs |0 |

|F5 |Horizontal carry distance of greater than 20 ft |0 |

|F6 |Two handed horizontal push / pull greater 40 lbs |0 |

|F7 |Two handed vertical push / pull greater than 25 lbs |0 |

|F8 |Trunk rotation with a weight greater than 10 lbs |0 |

|F9 |Wrist rotation while manipulating greater than 6 lbs |0 |

|F10 |One hand horizontal palmer push greater than 15 lbs |0 |

|F11 |Use of hand tool greater than 7 lbs |0 |

| |FORCE RF TOTAL= |0 |

| | | |

|POSTURE: | |

|# |Risk Factor |RV |

|P1 |Trunk forward flexion greater than 45o |0 |

|P2 |Trunk extension greater than 20o |0 |

|P3 |Neck flexion or extension greater than 45o |0 |

|P4 |Trunk or next side-bent plus twisted |1 |

|P5 |Shoulder abduction greater than 90o |0 |

|P6 |Working with hands or arms behind the body |0 |

|P7 |Full elbow extension with shoulder elevation |0 |

|P8 |Elbow flexion greater then 135o |0 |

|P9 |Wrist flexion or extension greater than 65o |0 |

|P10 |Wrist ulnar or radial deviation greater than 25o |3 |

|P11 |Forced pronation or supination of hand & wrist |3 |

| |POSTURE RF TOTAL= |7 |

| | | |

|OTHER RISK FACTORS: |(Note: Each "Y"=RV Value of 2) |

|# |Risk Factor |YES |

|O1 |Unusually high tool or floor vibration |N |

|O2 |Frequent ladder or stair climbing |N |

|O3 |High exposure to direct pressure or mechanical stress |N |

|O4 |Work with hands over shoulder level for greater than 50% of cycle |N |

|O5 |Squat or kneel for greater than 50% of cycle |N |

|O6 |Stand on one leg for greater than 50% of cycle |N |

|O7 |Awkward / immobile body position for greater than 50% of cycle |N |

|O8 |Greater than 6 thumb and or finger exertions with one hand |N |

| |OTHER RF TOTAL= |0 |

| |ERF Total= |7 |

Appendix I

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Appendix J

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Appendix K

Appendix L

| |Kraft Foods, Inc. | |

| |Ergonomic Risk Factor Assessment | |

| | | |

|Job Name: |Anticipated Juice Supply Procedure | |

| | | |

|FORCE: | | |

|# |Risk Factor |RV |

|F1 |Two handed lift greater than 20lbs |2 |

|F2 |Vertical travel distance of lift, greater than 60" |0 |

|F3 |Horizontal lifting reach greater than 20" from the body |0 |

|F4 |Two handed carry greater than 30 lbs |0 |

|F5 |Horizontal carry distance of greater than 20 ft |0 |

|F6 |Two handed horizontal push / pull greater 40 lbs |0 |

|F7 |Two handed vertical push / pull greater than 25 lbs |1 |

|F8 |Trunk rotation with a weight greater than 10 lbs |2 |

|F9 |Wrist rotation while manipulating greater than 6 lbs |0 |

|F10 |One hand horizontal palmer push greater than 15 lbs |0 |

|F11 |Use of hand tool greater than 7 lbs |2 |

| |FORCE RF TOTAL= |7 |

| | | |

|POSTURE: | |

|# |Risk Factor |RV |

|P1 |Trunk forward flexion greater than 45o |0 |

|P2 |Trunk extension greater than 20o |0 |

|P3 |Neck flexion or extension greater than 45o |0 |

|P4 |Trunk or next side-bent plus twisted |0 |

|P5 |Shoulder abduction greater than 90o |0 |

|P6 |Working with hands or arms behind the body |0 |

|P7 |Full elbow extension with shoulder elevation |0 |

|P8 |Elbow flexion greater then 135o |0 |

|P9 |Wrist flexion or extension greater than 65o |0 |

|P10 |Wrist ulnar or radial deviation greater than 25o |0 |

|P11 |Forced pronation or supination of hand & wrist |0 |

| |POSTURE RF TOTAL= |0 |

| | | |

|OTHER RISK FACTORS: |(Note: Each "Y"=RV Value of 2) |

|# |Risk Factor |YES |

|O1 |Unusually high tool or floor vibration |N |

|O2 |Frequent ladder or stair climbing |N |

|O3 |High exposure to direct pressure or mechanical stress |N |

|O4 |Work with hands over shoulder level for greater than 50% of cycle |N |

|O5 |Squat or kneel for greater than 50% of cycle |N |

|O6 |Stand on one leg for greater than 50% of cycle |N |

|O7 |Awkward / immobile body position for greater than 50% of cycle |N |

|O8 |Greater than 6 thumb and or finger exertions with one hand |N |

| |OTHER RF TOTAL= |0 |

| |ERF Total= |7 |

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