February 3 2014

A separate divison was formed within the TRA on the recommendation of
Mr D.W.Tull, the Engineering Consultant who was appointed by the Indian
Tea Association in the 1950's. It was headed  by Ian McTear and it continues
to conduct Research. A list of the current personnel and the achievements
to date are listed below"

Tea Processing & Manufacturing Advisory


                                                                  Mr. S. Sanyal

                                                      Email :


  • Mr. R. C. Gogoi
  • Mr. A. K. Hazarika
  • Mr. L. N. Saikia
  • Mr. D. J. Hazarika
  • Ms. Mridusmita Sarmah Goswami
  • Mr. Prafulla Bora
  • Mr. Monuram Dutta
  • Mr. Bendang Ao
  • Mr. Sailesh Sarmah
  • Mr. Sukhdev Nayak


The specific objectives of the department are:

  1. Improvement of Quality through Optimization   of Manufacturing Parameters
  2. Development of New Processing Technique
  3. Development of Tea Machineries
  4. Optimization of Space, Energy & Manpower during Processing
  5. Manufacturing Advisory Service
  6. Tasting of Commercial & R&D Samples
  7. Training of Garden Management Personnel
  8. Manufacturing of R&D samples for other departments


The Engineering R & D department at Tocklai was set up in 1951 on the recommendation
of Mr. D.W. Tull, an Indian Tea Association (ITA) Consultant Engineer. In the initial years,
Mr. I. McTear, the Special Resident Engineer of Tocklai, carried out some trials in
collaboration with Biochemistry department, on some new prototype machines developed
in England. From 1954 onwards the department started developing various machines
and undertook their trials. The Tea Tasting department was started originally as a unit of
the Biochemistry department since 1951 with Mr. J.M. Trinick. By 1959 it became a
separate department and was named as the Manufacturing Advisory and Tea Tasting
(MATT) department. The department was renamed as the Tea Tasting department in
1971. The Engineering R & D and the Tea Tasting departments were then amalgamated
and renamed as the Engineering & Manufacturing Technology Department in 1987.
The department is known as Tea Processing and Manufacturing Advisory (TPMA)
Department since 2001.

Currently, the department consists of the following units:

  • Engineering R & D
  • Tea Tasting
  • Miniature Factory
  • Model Tea Factory.


The department can proudly look back at the various achievements in the field of tea
machinery. To the credit of the department it has more than twenty patents against its
name and a large number of these have been commercially exploited. On two occasions,
national awards were bestowed on this department for the development of Tea machinery.
In 1972 Mr. D. N. Borbora was awarded the NRDC third prize for his machine “Borbora
Leaf Conditioner” and Mr. T. C. Boruah was awarded the NRDC first prize in the year
1980 for “Boruah Continuous Roller (BCR)”. Mr. Boruah also bagged the prestigious
“Vasvik” award in 1981 for the invention.

The list of machines designed and developed by the department and extensively used
by the industry is given below:

      A)   Machines widely used in commercial tea factories
in India and abroad

  1. Rotorvane
  2. Continuous Tray Drier
  3. Rotorvane Attachment
  4. Rotorvane Cone Attachment
  5. Rotorvane Improved
  6. Borbora Continuous Leaf Conditioner
  7. Baruah Continuous Roller
  8. Baruah Continuous Roller Improved
  9. Tea Breaker Cum Stalk Separator
  10. Green leaf Storage System
  11. Electronic Monitoring and Control System for Withering.
  12. Modified Open Trough for Withering
  13. Single Action Modified Rolling Table for Darjeeling

      B)   Machines Commercialised and introduced in the past but not used widely

  1. Tunnel Withering System
  2. Tocklai Continuous Roller
  3. Continuous Tea Fermenting Machine
  4. Cutter Attachment for Continuous Leaf Conditioner
  5. Rotary Type Continuous Tea Roller

      C)   Machines developed in the past but not commercialised

  1. Continuous Withering Machine
  2. Fermenting Cum Drying Machine
  3. Mechanical Harvester
  4. Manual Plucking Machine
  5. Thin Layer Continuous Fermenting Machine
  6. Green Leaf Sprinkler Spreader

      D)   Quality improvement through process modifications

  1. Modified process for CTC manufacturing
  2. Modified Rolling process for Orthodox manufacturing
  3. Application of food grade additive in pre and post harvest treatment
  4. Modified process of withering for enhancement of brightness and briskness



The Tea Processing & Manufacturing Advisory Department is engaged in overall
improvement of tea through application of innovative technologies in processing and
machineries by means of

  • Improvement of Quality through Optimization of Manufacturing Parameters
  • Development of New Processing Technique
  • Development of Tea Machineries
  • Optimization of Space, Energy & Manpower during Processing

The department advises the Tea Industry on factory layout, design specification of
machinery and various aspects of tea processing through

  • Manufacturing Advisory Service and
  • Tasting of Commercial Samples

The department is also involved in training and development of manpower engaged in
the tea processing and allied profession by

  • Training of Garden Management Personnel

The department also extends services to other R&D departments by

  • Tasting of R&D Samples and
  • Manufacturing of R&D samples


Modified Rolling Table for Darjeeling

  1. With fine leaf the Single Action Modified Rolling Table (SAMRT) can produce brighter
    liquor & infusion, improved overall characteristics and higher leaf grades, with a
    shorter rolling time.


  1. With coarse leaf of softer texture, desired twist can be achieved by increasing
    the rolling time, marginally.
  2. With coarse leaf of harder texture (post Puja flush and Back-end crop), application
    of high pressure and increased rolling time produce higher leaf grade percentage.
  3. In both the above cases, the SAMRT produce better liquor, infusion and improved
    overall character, as compared to the conventional Rolling Tables and in all cases
    the rolling time would be less than that required for conventional tables.


The Micronizer could be a viable alternative tea processing machine. It has many
variables in its setting. This is an advantage since this feature allows configuring and
fine tuning the machine to adjust with the type of leaf, processing conditions, desired
quality, etc.

But electrical consumption, output, cleaning and sanitizing and the delivery system
of the Micronizer needs to be attended to. After satisfactory achievement of the above
and regional trials, the Micronizer may be taken up for commercial applications.

Impregnation of Oxygen during Fermentation of CTC Tea

Adoption of Impregnation of Oxygen during Fermentation (technology), especially
with high-yielding slow-fermenting cultivars, increase in productivity can be achieved
due to reduction in fermenting time. Also, the industry can also adopt the technology
to manufacture superior quality of black tea using continuous fermenting machines.

Electronic Monitoring & Control System for Withering

TRA has developed a computerised system for Electronic Monitoring & Control of
Withering process under a joint R&D programme with Central Electronics Engineering
Research Institute (CEERI), Pilani. The system has been commercialised by TRA and
the commercial version is in operation in more than ten factories in the regions of
Upper Assam, North Bank and Terai. The system facilitates total monitoring of the
withering process. It also exercises necessary controls in airflow, heat application,
period of withering, rate of evaporation etc. through computer operated mechanism.

The system provides the following benefits:

  • Can accommodate more fluctuations in the input raw material and adjust to
    changing agro-climatic conditions.
  • Easy to operate due to user friendliness of the software.
  • Easy fault diagnosis as incorporated with self-diagnostic feature for both
    hardware and software.
  • Reduction in total withering time allows handling more leaf for same installed
  • Consistency in withering quality.
  • Saving of electrical energy through judicious operation of fans.


Establishment of Model Tea Factory (MTF)

The Model Tea Factory (MTF) is a complete representative black tea manufacturing
factory equipped with all the facilities and flexibilities of a commercial factory. It houses
the latest generation of tea processing machines coupled with the utmost level of
mechanization. It has been set-up at the Tea Research Association, Tocklai
Experimental Station, Jorhat, under the Tea Automation Project.

Integrated Automation in MTF

While the best industrial tea manufacturing machinery has been commissioned in
the Model Tea Factory, each of such machinery has been augmented with various
sensors and additional control features. Around 90 sensors of various types have
been installed to monitor variety of process parameters. Advanced networking
technology along with PC based distributed data acquisition and measurement
systems have been applied for on-line monitoring and real-time data logging. Logged
operational data permit off-line analysis and model generation to nucleate and
support improved production control rules and strategies.

Brief Outline of Instrumentations Installed in MTF

Processing machinery in the Model Tea Factory have been equipped with various
sensors as detailed below:Withering Trough (Enclosed & Open)

  • Leaf moisture Sensors
  • Leaf temperature Sensors
  • Temperature and RH of air at ambient, above and under the leaf bed


  • Leaf temperature sensor at discharge
  • Current sensor for motor load
  • Interfaced with LCU for CTC.

Triplex CTC Machine

  • Leaf temperature sensors at each cutting unit
  • Current sensor for motor load at each cutting unit
  • Variable speed (AC Drive) for motor speed variation
  • LCU consisting of Industrial PC and signal transmitters.

Continuous Fermenting Machine (CFM)

  • Online display of throughput time
  • Leaf bed temperature sensors
  • RH sensors
  • CO2 sensor
  • O2 sensor
  • Camera
  • LCU consisting of Industrial PC and signal transmitters.

Floor Fermentation (FFM)

  • Leaf bed temperature sensors
  • RH sensors
  • CO2 sensor
  • O2 sensor
  • LCU consisting of Industrial PC and signal transmitters.

Gumla/Fermenting Trough (GFM)

  • Leaf bed temperature sensors
  • RH sensors
  • Interfaced with LCU for Floor fermentation (FFM)

Drier (VFBD)

  • Temperature sensors for T 1, T2, T3 & T4
  • RH sensors at exhaust of wet semi dry and dry zone.
  • 7Airflow sensor (fitted at upstream of the hot air fan)
  • LCU consisting of Industrial PC and signal transmitters.

Continuous belt Weigher (MCW)

  • Continuous and online record of dryer mouth tea
  • Interfaced with LCU for Drier


Name Of Projects Completed Within Last 10 Years With Principal Investigator:

  1. Modification of SEPTU Micronizer for converting green tea leaves into granulated
    black tea.”
    (Project code no.: NTRF 129/08),
    P.I – Mr.S.Sanyal.
  2. Impregnation of oxygen during fermentation of CTC tea” (project code no. NTRF 122/08),
    P.I – Mr.S.Sanyal.
  3. “Application of Single Action Modified Rolling Table (SAMRT) for Commercial
    Production of Tea “.

    Internal project.

Current Project With Name Of The P.I, Period, Any Collaboration, Sanctioned
Amount And Name Of The Sponsored Organization

“Standardization & Optimisation of Processing Conditions for Manufacturing
Tea under North East Indian conditions” Project code: NTRF 137/09. P.I: Mr. S. Sanyal;
Period: 3years; Collaboration with DTR&DC, Darjeeling (under Tea Board India).
Sanctioned Amount: Rs 29,08,800.00

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