• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 14
  • 13
  • 4
  • 2
  • 1
  • 1
  • Tagged with
  • 70
  • 16
  • 14
  • 10
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Case Study: The effect of pallet design on the performance of semi-automatic and fully-automatic warehouses

Mejias Rojas, Alina 05 June 2020 (has links)
Pallets form the base of the unit load, which is the basis for global trade transportation. In order to achieve better performance, improve efficiency, and compete in much more versatile markets, industrial activities and pallet management service firms are becoming more automated than ever; they are adopting advanced manufacturing technologies and flexible manufacturing systems. This study focuses on the investigation of the most common compatibility issues between pallets and material handling systems in semi-automated and fully-automated warehouses. At the same time, it establishes an understanding of the downtime and frequency of problems caused by pallets in these types of facilities. This research was conducted in two phases. The primary phase was a mix mode questionnaire (phone interview and hard copy questionnaire) that was used to survey members of different industries, such as pallet manufacturers, equipment manufacturers, and pallet users. The secondary phase surveyed multiple general warehouses and storage facilities around the U.S., and surveyed warehouse professionals from manufacturing companies in the pharmaceutical, petroleum, dairy, beverage, chemical, and tobacco industries, to name a few. Results showed that 3% of the respondent warehouses are fully automated, and 20-30 % are semi-automated. Additionally, block class wooden pool pallets were identified as the most common pallet class used in semi/fully automated warehouses, followed closely by the use of stringer class recycled wooden pallets. Despite this, stringer class recycled wooden pallets were identified as the main pallet class involved in pallet related downtime in semi/ fully automated warehouses/ DC facilities. Further results present a guideline for improving automated warehouse performance, determine the pallet characteristics needed for this type of application, and expands the knowledge around downtime frequency cause by pallet related issues in these types of systems. / Master of Science / Pallets are the main tool used to transport unit loads throughout the different supply chains worldwide. Currently, industrial activities are becoming more automated than ever; in order to achieve better performance, improve efficiency, and compete in much more versatile markets. This study investigates the most common compatibility issues between pallets and material handling systems, used in semi-automatic and fully-automatic warehouses. Additionally, it presents the downtime and frequency of problems caused by pallets in these types of facilities. This research was conducted in two phases. The first phase identified the most common compatibility issues between pallets and these types of systems; this phase was achieved by surveying members of different industries such as pallet manufacturers, equipment manufacturers, and pallet users. The second phase targeted multiple general warehouses and storage facilities around the U.S.; during this phase, the frequency and downtime of the most common compatibility issues were determined. Results from this investigation present a guideline for improving automatic warehouse performance, determine the pallet characteristics needed for this type of application, and expands the knowledge around downtime frequency cause by pallet related issues in these types of systems.
2

An Investigation of the Plastic Pallet Industry in the United States in 2018

Bugledits, Dorina 10 April 2020 (has links)
Pallets are abundant throughout the supply chain with 2.6 billion pallets in circulation in the United States (Freedonia, 2015). More than 93% of goods are transported in the form of a palletized unit load (White and Hamner, 2005). Plastics are the second most commonly used material to manufacture these shipping platforms (Bond, 2018), yet there is a lack of information to be found about the plastic pallet industry's characteristics. Therefore, the main objective of this research was to investigate the status of the plastic pallet industry in the United States in 2018. To gather information, an online survey was conducted. It was sent out electronically to twenty-six plastic pallet manufacturers with response rate of 54%. The results have shown that almost 16 million plastic pallets were manufactured in the United States by the survey respondents in 2018. Of these, over 80% were multiple use pallets and about 80% were standard size. Most plastic pallets that were manufactured by the respondents were made with high pressure injection molding (63%) using high density polyethylene (HDPE) resin (68%). Close to 50% of the pallets had reinforcement beams and 12% had fiberglass reinforcement. Although most plastic pallets were manufactured using virgin resin, 34% were manufactured from recycled resin which reduces the cost and increases the sustainability of the plastic pallet. In addition, this study has shown that most of the plastic pallets manufactured in 2018 had no flame-retardant additives since only 20% from the respondents indicated that their pallets were Underwriter Laboratories (UL) or Factory Mutual (FM) certified. Based on these results, a new survey format and framework is designed with a recommendation to conduct it in every five years in order to further explore the state and market trends of the plastic pallet industry. / Master of Science / Pallets are abundant throughout the supply chain with 2.6 billion pallets in circulation in the United States (Freedonia, 2015). In 2005 it is estimated that more than 93% of goods are transported in the form of a palletized unit load (White and Hamner, 2005). Plastics are the second most commonly used material to manufacture these shipping platforms (Bond, 2018), yet there is a lack of information to be found about the plastic pallet industry's characteristics. Therefore, the main objective of this research was to investigate the status of the plastic pallet industry in the United States in 2018. To gather information, an online survey was conducted. It was sent out electronically to twenty-six plastic pallet manufacturers with response rate of 54%. The results have shown that almost 16 million plastic pallets were manufactured in the United States by respondents in 2018. Of these, over 80% were multiple use pallets and about 80% were standard size (48 in. x 40 in., 45 in. x48 in.). Most plastic pallets manufactured by the respondents were made with high pressure injection molding (63%) using high density polyethylene (HDPE) resin (68%). Close to 50% of the pallets had reinforcement beams and 12% had fiberglass reinforcement. Although most plastic pallets were manufactured using virgin resin, 34% were manufactured from recycled resin which reduces the cost and increases the sustainability of the plastic pallet. In addition, this study has shown that most of the plastic pallets manufactured in 2018 had no flame-retardant additives since only 20% from the respondents indicated that their pallets were Underwriter Laboratories (UL) or Factory Mutual (FM) certified. Based on these results, a new survey format and framework is designed with a recommendation to conduct it in every five years in order to further explore the state and market trends of the plastic pallet industry.
3

Investigation of New and Recovered Wood Shipping Platforms

Gerber, Nathan Samuel 28 June 2018 (has links)
This study was performed in order to acquire key market information and information on raw material usage for the wood pallet and container industry in 2016. Historical trends in the wood pallet market were also analyzed between 1991-2016 using the results of previous Virginia Tech and U.S. Forest Service pallet surveys. Paper mail questionnaires and online questionnaires were sent to 2,520 companies that manufactured or wholesaled wood pallets and crates in the United States to obtain these data. The wooden pallet and container industry produced an estimated 508 million new wood pallets in 2016, which is a 22% increase since 2011. Approximately 35% of this was 48” x 40” pallets, which continues to be the dominant standardized pallet size. Approximately 39% of new wood pallets were custom sizes which is a significant decrease from the 60% share found in 2011. Stringer class pallets remained the dominant pallet class with 76% share while block pallets and skids only accounted for 21% and 3% of the market, respectively. Approximately, 38% of these new wood pallets were heat treated. Furthermore, an estimated 341 million pallets were recovered and sold as recycled/repaired or remanufactured pallets in 2016. The most common size of the recycled or remanufactured pallets was 48” x 40”, accounting for 69% of the recycled market. Ninety-one percent of recycled or remanufactured pallets were stringer class pallets while block class pallets made up the remaining 9%. Wood byproduct usage has changed since 2011. The conversion of broken pallets and wood waste to landscape mulch (37.5%) and animal bedding (4.2%) have declined with a proportional increase in other uses (28.3%). Biofuel conversion has remained steady since 2006 at 30%. / Master of Science / This study was performed in order to acquire key market information and information on raw material usage for the wood pallet and container industry in 2016. Historical trends in the wood pallet market were also analyzed between 1991-2016 using the results of previous Virginia Tech and U.S. Forest Service pallet surveys. Paper mail questionnaires and online questionnaires were sent to 2,520 companies that manufactured or wholesaled wood pallets and crates in the United States to obtain this data. As a whole, the wooden pallet and container industry has shown growth. The industry produced an estimated 508 million new wood pallets in 2016, which is a 22% increase since 2011. Furthermore, an estimated 341 million pallets were recovered and sold as recycled/repaired or remanufactured pallets in 2016. This is a small increase in the recycled/repaired or remanufactured pallet market. Wood byproduct usage has changed since 2011. The conversion of broken pallets and wood waste to landscape mulch (37.5%) and animal bedding (4.2%) have declined with a proportional increase in other uses (28.3%). Biofuel conversion has remained steady at 30%.
4

Stohovač palet / Pallet destacker

Kubíček, Lukáš January 2014 (has links)
This thesis focuses on the design pallet stacker for 15 pallets in accordance to economy and simplicity of design. Thesis involves critical research of stackers several producers, design of construction, fundamental calculations of construction, construction design of components, FEM analyses of components and drawing documentation.
5

Pall-logistik: Aspekter och påföljder vid införande av plastpall för Volkswagen Parts Logistics / Pallet Logistics: Aspects and impacts of implementing plastic pallets at Volkswagen Parts Logistics

Nordh, Henrik, Klasson, Robin January 2017 (has links)
Författare Henrik Nordh och Robin Klasson. Forskningsfrågor Fråga 1: Vilka aspekter för införande av plastpall som lastbärare mellan Volkswagen Parts Logistics och dess återförsäljare behövs tas hänsyn till vid lagring, distribution och retur av deras reservdelar? Fråga 2: Vilka blir de ekonomiska påföljderna vid lagring, distribution och retur av att införa plastpall som lastbärare för reservdelar hos Volkswagen Parts Logistics? Syfte Syftet med studie är att utveckla ett ramverk för införande av plastpall som lastbärare för reservdelar till eftermarknaden i bilindustrin. Metod Utförd studie genomfördes som en fallstudie, den empiri som samlades in för att användas i studie utfördes genom att respondenter valdes utifrån bekvämlighetsurval och snöbollsurval. Respondenter deltog i semi- och ostrukturerade intervjuer och författare genomförde även observationer som deltagare. Slutsats Det finns ett antal aspekter och påföljder som Volkswagen Parts Logistics behöver ta hänsyn till vid plastpalls införande: (1) Retursystem (2) Tredjepartsleverantör (3) Avtal (4) Materialrelaterade (5) Prestationsmått (6) Transaktions- och Säkerhetslager (7) Miljö och Hållbarhet (8) Kalkylering. De ekonomiska påföljderna av att införa plastpall är till stor del beroende av vilken grad som RFID-teknik implementeras. Med nuvarande situation hos VPL, det vill säga sämsta möjliga förutsättningar och endast träpall byts ut mot plastpall utan RFID, uppnås en kostnadsbesparing på i snitt 620 000 kronor per år vid normalt utfall av känslighetsanalys och kräver en grundinvestering på 3 000 000 kronor med break-even tid 6–7 år. Motsvarande vid beräkningar av realistiska förutsättningar uppnås en snittbesparing på 1 200 000 kronor per år utan RFID med break-even tid på 3–4 år med normalt utfall i känslighetsanalys och en grundinvestering på 2 250 000 kronor. Samma förutsättningar med RFID ger 575 000 kronor i snittbesparing per år med normalt utfall i känslighetsanalys, uppskattat till break-even tid över 8 år med en grundinvestering på 7 250 000 kronor. / Authors Henrik Nordh and Robin Klasson. Research Questions Question 1: Which aspects are to be considered with implementation of plastic pallets as load carriers between Volkswagen Parts Logistics and its resellers regarding stocking, distribution and return of their spare parts? Question 2: What are the economic impacts regarding stocking, distribution and return of implementing plastic pallets as load carriers for spare parts at Volkswagen Parts Logistics? Purpose The purpose of the study is to develop a framework for implementing plastic pallets as load carriers for spare parts in the aftermarket of the automotive industry. Method The study was performed as a case study, the information to be used in the conducted study was gathered through a number of respondents who were chosen from a comfort- and snowball selection. The respondents participated in semi- and unstructured interviews and the authors also conducted observations as participants. Conclusion There are a number of aspects and impacts for Volkswagen Parts Logistics to consider with implementing plastic pallets. (1) Return system (2) Third party logistics provider (3) Agreement (4) Material related (5) Performance measure (6) Transaction- and Safety stock (7) Environment and sustainability (8) Calculation. The economic impacts of implementing plastic pallets are in great extent depending of what degree of RFID- technology is to be used. If current situation at VPL exists, with the worst situation possible and only wooden pallets are to be substituted without RFID- technology, savings can be made up to 620 000 kronor on average per year at normal results in the sensitivity analysis, demanding an investment of 3 000 000 kronor and 6– 7-year breakeven time. Corresponding calculations of realistic result, savings can be made on average 1 200 000 kronor a year without RFID and break-even time of 3–4 years with normal sensitivity analysis and an investment of 2 250 000 kronor. The same conditions with RFID results in average 575 000 kronor in savings a year with the normal sensitivity analysis, break-even time over 8 years and an investment of 7 250 000 kronor.
6

Re-Load lastpall : En jämförelse mellan Re-Load och alternativ lastpall

Engström, Per January 2011 (has links)
Syftet med denna undersökning har varit att underlätta för företaget Re-Load att presentera sin lastpall som produkt för potentiella kunder. Syftet har också varit att stötta Re-Load till att bli licenserad EUR-pall samt att successivt ersätta befintliga lastpallar och långsiktigt exekvera företagets affärsplan. Målet har varit att undersöka produkten avseende lönsamhet, miljöinverkan och hur den påverkade arbetsmiljön. Under-sökningen har genomförts med ett befintligt flöde där produkten använts och utifrån detta kunde en flödesstudie samt en komparativ produktstudie utföras med en alternativ lastpall. Med data hämtat ur detta flöde utfördes en investeringskalkylering, miljöberäkningar, subjektiva intervjuer samt dokumentation. Kalkyleringar och beräk-ningar har redovisats grafiskt för att erhålla ett presentabelt och över-skådligt resultat. Undersökningen visar att Re-Load lastpall har en dyrare grundinvestering men är mer lönsam i längden. Efter 15 måna-der har Re-Load lastpall och den alternativa lastpallen uppnår samma kostnad. Vidare visar undersökningen att pallen släpper ut mindre koldioxid än den alternativa lastpallen i det givna fallet. Resultatet visar också att pallen är mer hållbar än alternativa lastpallar, framförallt gällande tyngre transporter. Slutsatsen är att Re-Load lastpall är en lönsam investering i längden för detta specifika fall, men att resultaten inte bör generaliseras. Slutsatsen visar vidare att pallen har en positiv inverkan på miljön i jämförelse med denna alternativa pall. Detta är knutet till att Re-Load lastpall har en lägre vikt än den alternativa. Jämförelse av pallarna i arbetsmiljön är problematiskt och analyserna visar att Re-Load lastpall saknar utbredning för att kunna göra en betydande inverkan på arbetsmiljön. / The purpose with the investigation has been to support the company Re-Load represent their pallet as a product to potential clients. The purpose has also been to support Re-Load in getting their pallet licensed as a EUR-pallet, gradually replacing existing pallets and over time execute their business plan. The goal has been to study the product regarding profitability, environmental effects and impact on the work environment. The research has been carried out with an existing flow where to product has been used thus allowing a comparative product study with an alternative pallet. Investment calculation, environmental calculating, subjective interviews and documentation were performed with data from the flow. Calculations have been shown graphically to receive a presentable and foreseeable result. The research shows that the Re-Load pallet has a higher investment cost but is more profitable in the long run. After 15 months the Re-Load pallet and the alternative pallet reaches the same cost. Further on the research shows that the pallet discharges less carbon dioxide than the alternative pallet in the specific case. The result also shows that the pallet is more durable than alterna-tive pallets, specifically regarding heavy transports. The conclusion is that the Re-Load pallet is an profitable investment in the long run for this specific case, but the results should not be generalized. The conclu-sion further show that the pallet has a positive impact on the environ-ment in comparison to this alternative pallet. This is related to the Re-Load pallet being lighter than the alternative. Comparison of the pallets in the work environment is problematic and the analysis shows that the Re-Load pallet lacks expansion to make a significant impact on the work environment.
7

The influence of semi-rigid connections on the behaviour of slender structures

Feng, Xiu January 1994 (has links)
No description available.
8

Wood-based material use in the United States pallet and container industry /

Christoforo, John Carmen, January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 87-88). Also available via the Internet.
9

Carton Clamp Methodologies and the Effects on Load Containment and Retention

Blumer, Tyler D 01 December 2013 (has links)
ABSTRACT Carton Clamp Test Methodologies and the Effects on Load Containment and Retention Tyler Don Blumer A carton clamp is an alternative device for moving packages and material. Instead of using iron tines like that of a conventional forklift, a carton clamp uses two large aluminum platens to slightly compress and secure the load for handling. This is advantageous as it allows operators to move layers of a unitized load individually, and eliminates the need for a pallet when handling full unitized loads. When using a carton clamp attachment, it is often difficult for operators to accurately gauge the amount of force being applied to the load. The required clamping force changes depending on the size, shape, and weight of the load. This creates the potential for under-clamping (slippage) and over-clamping (compressive damage). Seeing a market need for a reliable means of testing, two organizations set out to develop a testing protocol. A rift formed between schools of thought regarding the correct testing procedure. ISTA provides a sterile, calculated, and stationary simulation of carton clamp handling in its ISTA 6-SAMS test protocol. ASTM offers a more holistic, dynamic, observational approach in its mobile ASTM 6055 standard protocol. One school of thought is suggested to imply that a package should be developed to be handled by the carton clamp (ASTM). The other school of thought is that the carton clamp attachment should be properly adjusted to the package specimen (ISTA). Previous studies have been performed citing the ISTA standard and using a specialized carton clamping device vibration device that is calibrated for laboratory research. Arguably, this method, though repeatable in nature, does not accurately simulate carton clamp handling found in industry. Likewise, the equipment investment is cost prohibitive for those in industry wishing to duplicate such a study. ASTM uses a carton clamp truck as used in industry, but does not specify any specific parameters making repeatability between laboratories and practitioners ambiguous. This study examined whether or not a common ground can be reached; implementing a carton clamp lift truck as found in industry allowing for mobile (hazard course) testing. A modified version of ISTA 3B will be paired off against ASTM 6055 for evaluating both column and cross stack pallet patterns with a variety of treatments. This study attempted to determine if carton clamps as found in industry are capable and repeatable enough to provide consistent data. Similarly, this study examined the test methodologies effect on load containment via stretch film force, load retention via unitized load slippage, and the effects of ride height and driver interaction. The study sought to understand if these effects are uniform across the unitized load, or if particular layers of the load more affected than others.
10

Preliminary Examination of Factors Affecting Manufacture of Value Added Products From Recycled Pallet Parts

Hosterman, Nathan Scott 26 June 2002 (has links)
Pallets are the single largest consumer of hardwood lumber in the United States. While the pallet industry has effectively adopted widespread pallet recycling, many pallets still go into landfills with little or no value gained from their material. Recovered pallet lumber has been proposed as a potential source of material for value added wood products. This study sought preliminary data on issues pertinent to the development of pallet parts as a source of raw material for value added products, with a focus on oak strip flooring. Issues examined included pallet disassembly efficiency, characteristics of recovered boards, and yield of blanks compatible with commercial flooring production. Disassembly of pallets was affected by pallet design. Overall 81% of the deckboards from all pallet designs were recovered, along with 70% of stringers. Oak boards useable in strip flooring represented 21% of the recovered boards studied. Proper board stacking was found to maintain a uniform (MC) which would reduce drying defects and complications. The manufactured blank dimensions would allow production of some of the thinner strip flooring commercially available. National Oak Flooring Manufacturers Association Pre-finished Oak Strip Flooring Grading Rules found almost 80% of the blanks made Prime and Standard Grades. Wide spread adoption of flooring production from recovered pallet would increase the value of recovered pallets, presumably justifying an increased rate and expanded scope of pallet recovery. Economics favoring such valued added recovery would create recovery-related jobs, decrease pallets going into landfills, and ease the demand on timber resources. / Master of Science

Page generated in 0.0428 seconds