Paper towel dispenser

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Revision as of 22:57, 20 September 2009

Executive Summary

Stakeholders

There are six major stakeholders with regards to the paper towel dispenser: Manufacturer, retailer, customer, user, society. The main needs for the manufacturer are to reduce cost and create a reliable product. For the retailer, it is being able to sell a quality product. For the customer, it is making sure it is an affordable and reliable machine. For the customer, cleanliness and ease of use are paramount. For the maintenance worker, ease of opening and replacing the paper towel are important. Society plays a role with regards to how the use of paper towel affects the ecosystem and earth in general. Listed below are the stakeholders and their respective needs.

Paper Towel Manufacturer

• Material cost
• Manufacturing cost
• Assembly
• Transporting
• Standardize/minimize parts

Retailer

• Cost
• Storage
• Reliability
• Usability
• Transporting

Customer

• Cost
• Mounting
• Ease of use
• Reliability
• Aesthetics
• Safety

User

• Ease of use / ergonomics
• Speed of operation
• Aesthetics
• Cleanliness
• Safety

Maintenance Worker

• Ease of towel replacement
• Safety

Society

• Environment

Usability Study

Assembly Pictures

How it Works

Mechanical Analysis

Parts List

Part No.	Name	Function	QTY	Weight	Material	Manufacturing Process	Image
01	Front Housing	Protects device from exterior	1	935g	Plastic	Injection Molding
02	Front Housing Clip	Holds housings together	1	13g	Steel	Bending, Punching
03	Front Housing Tab	Secures housing clip	1	<1g	Plastic	Injection Molding
04	Rear Housing	Holds mechanical components	1	986g	Plastic	Injection Molding
05	Paper Towel Holding Arm	Holds paper towel roll	2	40g each	Plastic	Injection Molding
06	Phillips Head Screw (1/8 x 1/4 long)	Secures device to rear housing	1	1g	Steel	Machined
07	Wall Mounting Screw (1/8 x 1.25 long)	Secures housing to wall	4	3.5g each	Steel	Machined
08	Screw Anchor	Holds screw in wall	4	~0.25g	Plastic	Injection molding
09	Paper Guide Tube	Guides paper towel to cutting cylinder	1	55g	Plastic	Injection molding	[[Image:| 100x100px]]
10	Spring (uneven hooks)	Holds 09 in place	2	2g each	Metal	Extrusion
11	Spring (even hooks)	Holds lever to spindle housing	2	1.5g each	Metal	Extrusion
12	Screw (3/32 x 5/8 long)	holds turning wheel and lever to spindle housing	2	~1g each	Metal	Extrusion
13	Red Screw Cap	Hides screw in turning wheel	1	<1g	Plastic	Injection molding
14	Locking Spring	Ensures correct wheel spin direction	1	4g	Steel	Extrusion
15	Red Turning Wheel	Turns main spindle	1	30g	Plastic	Injection molding
16	Guide clips for 09	Guides paper on 09	2	2.5g each	Plastic	Injection molding	[[Image:| 100x100px]]
17	Screw (3/32 x 3/8 long)	Holds lever assembly together and spindle housing	2	<1g each	Metal	Machined
18	Lever Arm	Connects spring to spindle	1	1g	Plastic	Injection molding
19	Spring Connector	Connects two springs to lever arm	1	<1g	Plastic	Injection molding
20	Rounded Spring Guide	Angles spring to desired measurement	1	<1g	Plastic	Injection molding
21	Thin Paper Guide	Guides paper out of device	1	24g	Plastic	Injection molding
22	Front Spindle Housing	Final housing before paper leaves device	1	132g	Plastic	Injection molding
23	Spindle Housing Back	Back of spindle housing	1	162g	Plastic	Injection molding
24	Spindle Housing (L)	Left of spindle housing	1	105g	Plastic	Injection molding
25	Spindle Housing (R)	Right of spindle housing	1	105g	Plastic	Injection molding
26	White Spindle Guide	Holds spindle in line	3	2.3g each	Plastic	Injection molding
27	Screw (3/32 x 3/8 long)	Connects spindle halves	2	<1g	Metal	Machined
28	Square nut	For use with 27	2	<1g	Steel	Cast and drilled
29	White Teeth Guide/Arm	Guides cutting teeth in spindle	2	3g each	Plastic	Injection molding
30	Cutting Teeth	Cuts paper towel	1	75g	Steel	Cast, punched and bent
31	Spindle Top Half	Holds cutting tool	1	125g	Plastic	Injection molding
32	Spindle Bottom Half	Holds cutting tool	1	135g	Plastic	Injection molding
33	Metal Key	Helps open housing	1	5g	Steel	Punched

DFMA Analysis

Design For Manufacture

Design For Assembly

FMEA Analysis

Failure mode and effects analysis (FMEA) identifies potential problems of every component in the machinery, lists their effects on the system, and finally provides recommended actions to prevent such failures. The methodology for problem identification depends on ratings of Severity of a failure (S), Occurrence of Failure (O), and Detection of Failure (D). These scales are between 1 and 10 and they are rated in a way that less number of ratings indicates less significant problem and conversely higher rating means more serious failure or effect. The results of a FMEA Analysis (RPN) are calculated by multiplying S, O and D to signify seriousness of the problem.

Conclusion

DFE Analysis

The production of a product has an environmental impact from the creation of the parts that make up the product, to the time when the consumer throws the product in the garbage. In our case, we studied the Economic Input-Output Life Cycle Assessment (EIO-LCA) of a paper towel dispenser using Carnegie Mellon's EIO-LCA site. This tool allows us to quantify the data involved with the environmental impact of manufacturing a paper towel dispenser. Specifically, we focused on conventional air pollutants, greenhouse gases, and toxic releases.

Each of the categories below were calculated using $1 million dollars of activity in the sector of "326199 All Other Plastics Product Manufacturing." Since most of the paper towel dispenser is made from plastic parts, we feel that this sector is appropriate. The data are from the Industry Benchmark US Dept of Commerce EIO model from 1997, a Producer Price Model.

We are concerned impact this product has on the environment; specifically, if Congress were to pass a CO₂ tax, would this have a significant impact on the cost of production of the paper towel dispenser?

Conventional Air Pollutants

Below is a table of the release of conventional air pollutants from the top ten contributors in the supply chain, in units of metric tons (mt).

In this chart of conventional air pollutants, you can see that 52% of air pollutants from the production of the paper towel dispenser comes from the generation and supply of energy. In addition, truck transportation plays a smaller, but still significant role in the production of air pollutants.

Greenhouse Gases

Below is a table of the release of greenhouse gases from the top ten contributors in the supply chain, in units of metric tons of CO₂ equivalent(MTC02E).

In this chart, we focused on the emission of CO₂ since this is what the government would tax. The generation and supply of energy plays a large role again, taking producing 46% of the CO₂ emissions. Truck transportation and plastics material and resin manufacturing play a smaller role, but still impact the emissions to the environment.

Toxic Releases

Below is a table of the release of toxic substances from the top ten contributors in the supply chain, in units of kilograms (kg).

The chart below shows that plastics plumbing fixturs and all other plastics products accounts for 45% of the toxic releases. Another significant part is played by plastics material and resin manufacturing at 18%.

DFE Conclusion

From the results of the EIO-LCA, we can see that there are many factors that contribute to the release of harmful waste and gases into the environmental. For example, the energy supply causes a large number of CO₂ to be released in the air, this may be reduced by the use of renewable resources such as solar or wind. Truck transportation also plays a detrimental role towards the environment. It is difficult to just make trucks more efficient or burn cleaner, but maybe using a strategic network or green-powered locomotives to transport products can reduce the amount of emissions to the environment. We also realize that since most of the paper towel dispenser is made from plastic, it is not biodegradable and would be better if there were a way to recycle the plastic.

Team Member Roles

• Eric Totong: Stakeholders, DFE
• Chang Keun Jung: FMEA
• James Li-Yang Lee: Usability Study, Assembly pictures, How it works
• Nishan Kulatilaka: DFMA, DFA

References

Carnegie Mellon University Green Design Institute. (2009) Economic Input-Output Life Cycle Assessment (EIO-LCA) US 1997 (491) model [Internet], Available from: <http://www.eiolca.net/> [Accessed 20 Sep, 2009]