Tealeaf harvesting. Mechanisation and the improvement of productivity and efficiency

A case study of an improved harvesting device in the context of Assam, India

Doctoral Thesis / Dissertation , 2017 , 199 Pages

Engineering - Mechanical Engineering

The purpose of this research is to formulate a solution for mechanised harvesting which should be economical and suitable for tea gardens of Assam. To accomplish the stated purpose; a combination of research methods featuring literature survey, questionnaire, direct observation, one to one interview for data collection; statistical analysis of the gathered data, work study technique, virtual human modelling and simulation, prototype development and testing has been used.

After gathering necessary information, it was felt that for tea gardens of Assam, a single operator handheld battery-powered rotary type tea harvesting machine with high productivity in comparison to presently available machines with a similar mode of operation will be the best solution.

The prototype of the proposed machine was developed at Department of Design, IIT Guwahati and field trials were carried out at Dolaguri Tea Estate located in Numoligarh, Assam with a participatory approach. Through these field trials, it was found that the newly designed machine was efficient and had higher productivity compared to hand plucking. The Indian tea industry is one of the major foreign revenue earners for the country. It is one of the major employers of women. Many of the activities, especially the tealeaf plucking activity (constituting 40 percent of the total cost of production of tea leaves) performed by the women workers.

The tea industries of Assam, in are facing revenue losses during recent times. One of the main factors is shortage of workforce engaged in field operations. Studies have shown that acute shortage of workforce takes place in the tea plucking activities during peak season due to various socio-economic reasons. Due to the manpower shortage, a considerable quantity of available tea leaves for tea making remains unplucked. This directly affects the overall production of made tea and hence on the revenue earnings by the tea gardens. In this scenario, the only suitable solution to the problem appears to be the adaptation of mechanised harvesting.

Inhaltsverzeichnis (Table of Contents)

• Chapter 1 Tea Industry in Assam: Present Context
• 1.1 The Indian tea plantations
• 1.2 Origin of tea in Assam
• 1.3 Background of the research
• 1.4 Problem identification
• 1.5 Pilot study to understand requirement of the tea industries regarding tea plucking activities
• 1.5.1 Shear plucking
• 1.5.2 Engine powered mechanised tea harvesting machines
• 1.5.3 Battery powered mechanised tea harvesting machines
• 1.6 Research justification
• 1.7 Research questions (RQ)
• 1.8 State of the art review on mechanical harvesting of tea
• 1.9 Hypothesis
• 1.10 Aim & Objectives of research
• 1.10.1 Aim
• 1.10.2 Objectives
• 1.11 Research paradigm adopted
• 1.11.1 Ontology, epistemology, methodology
• 1.11.2 Ontology
• 1.11.3 Epistemology
• 1.11.4 Methodology
• 1.12 Research approach
• 1.13 The product development lifecycle
• 1.13.1 Analysis
• 1.13.2 Concept generation
• 1.13.3 Design
• 1.13.4 Development
• 1.13.5 Testing
• 1.13.6 Modification / analysis
• 1.13.7 Retesting
• 1.13.8 Final release
• 1.14 The outline of the thesis framework
• Chapter 2 Tea Industry of Assam: Socio-economic and Demographic Situation
• 2.1 Plantations
• 2.2 Characteristics of plantations
• 2.3 Plantations in India
• 2.4 Emergence of the corporate firm
• 2.5 Size of tea estates
• 2.5.1 Small growers
• 2.5.2 Medium and marginal estates
• 2.5.3 Big estates
• 2.6 Economic size
• 2.7 Estate management
• 2.8 Origin and growth
• 2.9 Role of managing agencies
• 2.10 Plantation system and human resource structure in tea plantations of Assam
• 2.11 Classification of tea plantation employees
• 2.11.1 Workers
• 2.11.2 Staff
• 2.11.3 Managers and Assistant Managers
• 2.12 Difference between plantation labour and other agricultural labour
• 2.13 The Plantations Labour Act, 1951
• 2.14 Other legal provisions
• 2.14.1 Maternity benefits
• 2.14.2 Provident fund
• 2.14.3 Gratuity
• 2.14.4 Bonus
• 2.15 Present production scenario of Assam Tea
• 2.16 Background of tea plantation workers of Assam
• 2.17 Migration process
• 2.18 Survival of migrating labourer vs. economía of migration
• 2.19 Governmental intervention
• 2.20 Cultural background
• 2.20.1 Evolution of Ex-Tea tribe
• 2.20.2 Present scenario: Assimilation with native culture and societies
• 2.20.3 Social bonding, merger with main stream
• 2.20.4 Recent turmoil
• Chapter 3 Tea Plantation and Tea Manufacturing Process
• 3.1 Nursery
• 3.1.1 Propagation from seed
• 3.1.2 Propagation from leaf
• 3.2 Pruning
• 3.2.1 Objectives of pruning
• 3.2.2 Procedure of pruning
• 3.2.3 The procedure of checking plant readiness for pruning
• 3.2.4 Types of pruning
• 3.2.5 Pruning time
• 3.2.6 Factors affecting pruning time (Tea Research Institute (TRI), Sri Lanka, 2013)
• 3.2.7 Cycles of tea pruning
• 3.2.8 Procedure of choosing correct pruning cycle
• 3.2.9 Conclusion on pruning
• 3.3 Skiffing
• 3.3.1 Deep skiff (DS)
• 3.3.2 Level off skiff (LOS)
• 3.3.3 Medium skiff (MS)
• 3.3.4 Light skiff (LS)
• 3.4 Tipping
• 3.5 Plucking
• 3.5.1 Tea flushes
• 3.5.2 Method of plucking
• 3.5.3 Standards of plucking
• 3.5.4 Plucking interval
• 3.5.5 The correct time of the year for plucking
• 3.5.6 Time of day and type of weather suitable for plucking
• 3.5.7 Types of leaves suitable for plucking
• 3.5.8 Harvesting guidelines
• 3.5.9 Guidelines for quality plucking
• 3.5.10 Fine leaf percentage
• 3.5.11 Important aspects of plucking
• 3.6 Pest controlling
• 3.6.1 Spraying
• 3.6.2 Types of machines used in spraying
• 3.7 Transportation of green leaf
• 3.8 Processing of tea in factory
• 3.8.1 Various types of tea processing
• 3.8.1.1 Cut, Tear, Curl (CTC) processing
• 3.8.1.2 Orthodox processing
• 3.8.1.3 Green tea processing
• 3.8.2 Withering
• 3.8.3 Rotor Vane
• 3.8.4 Fermentation
• 3.8.4.1 Fermentation process
• 3.8.4.2 Continuous fermenting machine (CFM)
• 3.8.5 Drying
• 3.8.6 Packaging and sorting
• 3.9 Major classification of finished product
• 3.9.1 Black tea
• 3.9.2 Oolong tea
• 3.9.3 White tea
• 3.9.4 Green tea
• 3.9.5 Fermented tea
• 3.9.6 Yellow tea
• Chapter 4 Mechanical Harvesting of Tea
• 4.1 The necessity of mechanised harvesting
• 4.2 Background of mechanical tea harvesting
• 4.3 Introduction to shear plucking and its outcome
• 4.4 Motorised plucking machines
• 4.5 Some common handheld tea harvesting machines
• 4.5.1 Battery operated tea harvester- single operator
• 4.5.2 Single operator, gasoline powered tea harvester
• 4.5.3 Two operator, gasoline powered tea harvester
• 4.5.4 Two- operator gasoline powered selective tea harvester
• 4.6 Status of existing machines
• 4.7 Some common problems associated with motorised tea harvesters
• 4.8 Performance comparison of various mechanised harvesting processes
• 4.9 Conclusion on mechanised harvesting of tea
• Chapter 5 Concept Generation, Design and Prototyping
• 5.1 Working principle of single operator battery powered tea leaf harvesting machine
• 5.2 Expansion of cutting span
• 5.3 Design conceptualisation
• 5.4 Rotors
• 5.5 Drive shaft
• 5.6 Cutting blades
• 5.7 Spacers
• 5.8 Casing
• 5.9 Assembly of different components of the cutting head
• 5.10 Selection of prime mover
• 5.10.1 Mechanical Power (Work done per second)
• 5.10.2 Calculation for equivalent electrical power
• 5.10.3 Calculation for the rated current of the motor
• 5.10.4 Calculation for battery specification
• 5.11 Details of battery and battery pack
• 5.12 Motion transmission
• 5.13 Collection chamber
• 5.14 Integrated motor assembly and motion transmission system
• 5.15 Handling
• 5.15.1 Alternative-1
• 5.15.2 Alternative-2
• 5.16 Design for ease of operation of machine while carrying and operation at field
• 5.16.1 Alternative 1: Single lever mechanism with support from backpack
• 5.16.2 Alternative 2: Carrying mechanism with adjustable hinge
• 5.17 Calculation of optimum revolution of the rotor assembly through functional test
• Chapter 6 Design Validation of the Newly Designed Machine
• 6.1 Materials & methods
• 6.2 The pruning cycles adopted in this section
• 6.3 Experiment design
• 6.4 Experiment details
• 6.5 Findings of experiments
• 6.5.1 Experiment no.1
• 6.5.2 Interpretation of Experiment No 1
• 6.5.3 Experiment no.2
• 6.5.4 Interpretation of Experiment No 2
• 6.5.5 Experiment no.3
• 6.5.6 Interpretation of Experiment No 3
• 6.5.7 Experiment no.4
• 6.5.7.1 Test for left hand
• 6.5.7.2 Test for right hand
• 6.5.8 Interpretation of Experiment No 4
• 6.5.9 Experiment no.5: Body part discomfort study
• 6.5.10 Interpretation of Experiment No 5
• 6.6 Validation of hypothesis
• Chapter 7 Discussions, Conclusion and Recommendations
• 7.1 Brief summery
• 7.2 Precautions to be taken for mechanised harvesting
• 7.3 Guidelines to implement the mechanised harvesting process
• 7.4 Suggestions for successful implementation of mechanized harvesting
• 7.5 Findings of present study
• 7.5.1 Battery charging and replacement system
• 7.5.2 Optimum clearance between rotor assembly and cutting plane
• 7.5.3 Optimum revolution per minute of the rotor shaft
• 7.6 Contribution of present research
• 7.6.1 Benefits for Small tea growers
• 7.6.2 Cost benefits
• 7.6.3 Increase in productivity
• 7.7 Suggestions and recommendations
• 7.8 Limitation of the current research and future scope

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

The primary objective of this research is to develop a solution for mechanised tea harvesting in Assam, India, specifically addressing the labor shortage and increasing productivity and efficiency. The research focuses on designing a single operator, handheld, battery-powered tea harvesting machine that is economical and suitable for the local conditions.

• Labor shortage in the tea industry
• Mechanised tea harvesting
• Product design and development
• Ergonomics and user comfort
• Impact of mechanisation on productivity and efficiency

Zusammenfassung der Kapitel (Chapter Summaries)

Chapter 1 introduces the context of the tea industry in Assam, highlighting the problem of labor shortage and the need for mechanisation. It outlines the research question, hypothesis, and objectives of the thesis. Chapter 2 provides an in-depth analysis of the socio-economic and demographic situation of tea plantations in Assam, focusing on the origin and cultural background of tea workers. Chapter 3 examines the tea plantation and tea manufacturing process in detail, covering various stages of cultivation and processing. Chapter 4 reviews existing mechanical tea harvesting methods and machines, evaluating their advantages and drawbacks. Chapter 5 outlines the concept generation, design, and prototyping of a new battery-powered single operator tea harvesting machine, emphasizing ergonomic considerations. Chapter 6 describes the design validation process through field trials, assessing the performance and efficiency of the newly developed machine. Finally, Chapter 7 summarizes the research findings, discusses the implications of the study, and provides recommendations for future research.

Schlüsselwörter (Keywords)

The thesis focuses on the keywords: product design, tea harvesting, agricultural engineering, tea plucking, battery-powered machine, ergonomic design, human-centered design, and design validation. The primary focus is on addressing the challenges faced by the tea industry in Assam, India, through design interventions that enhance productivity and efficiency while considering the well-being of the workforce. The research draws upon a combination of field study, statistical analysis, and prototype development to develop a practical and effective solution for the mechanisation of tea harvesting.

• Author: Vikramjit Kakati (Author)
• Publication Year: 2017
• Pages: 199
• Catalog Number: V911777
• ISBN (eBook): 9783346264343
• ISBN (Book): 9783346264350
• Language: English
• Tags: tealeaf, mechanisation, assam, india