Processing of Lac and Gums

1. Dr. Sakharam Kale
Scientist (AS&PE)
Mechanization and Process Engineering Division
ICAR-National Institute of Secondary
Agriculture
Namkum, Ranchi-834010
Processing of Natural Resins
and Gums

2. • India is a rich habitant of plant bio-
diversity
• Over 45,000 plant species including
about 120 gum and resin yielding plants
• Indonesia, India and China are the largest
producers of resins and gums
• A multi-billion dollar global industry
• India is the largest producer of lac, guar
gum and karaya gum.
Natural Resins and Gums:
Introduction

3. Natural Resins:
Solid or semi-solid materials, usually a
complex mixture of organic compounds
(called terpenes) which are in-soluble in
water but soluble in certain organic
solvents
Examples :
• Lac (source – Insects)
• Rosin, Copal, Dammer etc.
(source - Plants )
What are Resins?

4. Gums :
Polymeric material that can be dissolved
or dispersed in water to give a thickening
and gelling effect
Examples:
Guar gum, Karaya gum, Gum Arabic,
Xanthan gums etc.
(Source – Tree exudates,
plant seeds, microbs)
What are gums?

5. Gum-resins:
Natural mixtures of gums and resins in
variable proportions, therefore possess
properties of both the groups. They
contain traces of essential oils, and are
partly soluble in water. They have a
penetrating and characteristic odour and
taste.
Examples :
Asafoetida, Myrrh, Guggul, Olibanum etc.
(Source – Plants)
What are Gum-resins?

6.  Natural gum and resin exports is the source of
earning foreign exchange for the country
 Supports 50 to 60 million population inhabiting
forests and sub-forests
 70% of about 2.3 M man-days employment in
forest areas are from gums, resins & other
MFPs.
Role of Natural Resins andGums in
National Economy & Livelihood Support

7. Commodity Applications
Resins Paints, varnishes, lacquers, cosmetics,
adhesives, medicines and food industries
Gums Food (thickening agents, gelling agents,
stabilizers and emulsifiers), textile,
pharmaceutical and cosmetics industries
Gum-resins Perfumery, cosmetics, medicine, spices and
incense
Applications of Natural Resins, Gums and
Gum-resins

8. Some Important Resins of India

9. Lac is produced by a specialized group of insects
called lac insects (Coccoidea: Tachardiidae)
Commercially exploited lac insects - Kerria lacca & K. chinensis
Freshly settled lac insects Fully mature lac insects
Lac Resin

10.  Rosin or Greek pitch is the solid form of resin obtained from
pines and some other plants, mostly conifers.
 It is semi-transparent and varies in color from yellow to
black.
 At room temperature rosin is brittle, but it melts at stove-top
temperatures.
Rosin

11.  Dammar belongs to a group of resins harvested from Indian or East-Asian
trees of Dipterocarpaceae and Burserraceae families.
 The name is a Malay word meaning "resin" or "torch made from resin".
 There are three types of dammar, known as sal, black and white dammar.
It is popular as “sal dhuna” in India.
Damma
r

12. Lac processing
 Primary processing
crushing, washing, drying, cleaning and grading, and
the end product is seedlac (semi-refined)
 Secondary processing
refining of seedlac to produce refined lac in the form of
button lac, shellac, bleached lac, DDL etc.
Lac
Dye Wax
Crude lac
(Sticklac)
Resin

13. Sticklac
(scrapped lac)
Raw form
Seedlac)
(Semi-refined)
Button lac
(Refined)

14. Sticklac (100 kg) Seedlac (75 kg) Shellac (65 kg)
Primary
processing
Secondary
processing
(refining)
Primary
processing
Secondary
processing

15. Primary Processing of Lac
Crushing
Washing
Drying
Winnowing
Grading
Seedlac Impurity –stick,
stone, sand,
insect body etc.
Byproduct: Lac
dye
Sticklac
Primary
Processing

16. Process Flow Chart of Primary Processing of
Sticklac
Crushing up to
8-10 mesh
Sieving by 8-10
mesh sieve
Washing
Grading
Drying
Winnowing
Centrifuging Seedlac
Oversiz
e
Dye, insect
body, stick
etc.

17. Lac Crushing
 The idea behind crushing is to expose more surface of lac
cell to washing.
 However care is taken to prevent the breaking of the cells
too much, since in subsequent processing, fine dust is not
favored.
 The Roller Crusher operated either by hand or power are
used for crushing.

18. Lac Washing
 After crushing and sieving, the lac is subjected to a
washing process, to free it from water soluble dye, sugars,
insect bodies, woody matter and uncrushed lac cells.
 Washing is done manually or mechanically.

19.  Golden Washing
– Soda is used @ 4.25 g/ kg sticklac
– Impurity should be less than 2 %
 3 % Washing
– Soda is used @ 2.5 g/ kg sticklac
– Impurity should be less than 3 %
 5 % Washing
– Soda is used @ 1.0 g/ kg sticklac
– Impurity should be less than 5 %
Types of washing carried out in lac
processing units

20. Manual washing is done either in stone vat or
cement vat.
Vat size Diameter – 75 cm
Depth - 75 cm
Washing Capacity per person per day – 140 kg
Water requirement: 7-10 lt/kg of lac
Manual Washing

21. Mechanical Washing
In mechanical washing, lac is washed in barrel
washing machine.
Barrel size Diameter – 1.2 m
Length - 2.4 m
Capacity per batch – (410-750) kg
Speed of rotation of barrel axle – (80-90) rpm
Time of operation per batch – (1.5 to 3) hours
Water supply rate – (15-20) lt/min
Power source – Diesel engine/ Electric motor

22. Lac Drying
After washing, grain
lac commercially
known as seedlac, is
dried by spreading it
on a cemented
courtyard, preferably
in the shade.
The wet seedlac is
spread in very thin
layer and turned from
time to time with a
wooden rake and hoe.

23. Lac Winnowing & Grading
After drying the seedlac is
winnowed to separate the
particle of sand, wood
etc. which could not be
removed during washing
and also to grade it
according to the grain
size.
A woman labourer using
a soop can winnow upto
150 kg of seedlac in a day.

24. Machines/Equipments used in different
unit operation of making seedlac in Lac
Processing Units
S.
No.
Unit Operation Machine/Equipment/Method
used
1 Crushing Crusher
2 Washing Stone or cement Vat
Barrel Washing Machine
3 Drying Centrifuge
Sun Drying
Shade Drying
4 Winnowing Hand Operated Winnower,
Manual using soop (bamboo
tray)
5 Grading Manually using Sieve
6 Others Sand separating machine

25. Yield of Seedlac
(Mukhopadhyay & Muthana, 1962)
Type of
Host
Crop Average
Yield, %
Kusum Aghani
Jethwi
68
69
Ber Baisakhi
Katki
59
52
Palas Baisakhi
Katki
57
56

26. Small Scale Lac
Processing Unit (Capacity 100
kg/day)
Developed by IINRG, Ranchi

27. Lac Crusher
Handle
Motor
Feeding
Hopper
Drive
mechanism

28. Lac Washing Machine
Moto
r
Feeding Hopper
Pedalling
System
Wash
water
outlet

29. Hand Operated Lac Grader
Positive Feeding
Mechanism
Outlet ( 10 > Grain >
30 mesh )
Outlet (Grain >
10 mesh)
Handl
e
Hoppe
r
Sieve (10
mesh)

30. Lac Winnower
Feed hopper
Positive
feeding
mechanism
Discharge
hopper
Handle
Motor
Drive
mechanism

31. Estimated Project Cost
Unit capacity : 100 kg/day
Building : Rs. 5 lakhs
Equipment, machine etc. : Rs. 1 lakh
Working capital (3 months) : Rs. 8 lakhs
Net Profit per month : Rs. 0.25 lakh
Employment generation
(in manual unit) : 750 man-
days/year
(in power operated unit) : 450 man-
days/year
Daily needs
Workers (in manual unit) : 5
(in power operated unit) : 3
Sticklac : 100 kg
Soda : 0.5 kg
Water : 2500 lt
Electricity (in manual unit) : Nil
(in power operated unit) : 7.5 KWH
Lac Processing Unit

32. • Refining of Seedlac : two methods
 Hot filtration method
 Solvent method
• In India, hot filtration method is predominantly used for
refining of seedlac: Two processes
 Hand-made process (bhatta process)
 Machine-made process
Hand-made process Machine-made process
Secondary Processing
of Lac

33. I. Hand-made process
• Traditional, manual, adopted at cottage level
• Small-scale (capacity: per bhatta per day of 8 h is 40 kg of
seedlac)
• Heat source is a furnace made of clay (bhatta)
• Filter is a woven cloth bag filled with seedlac
• Refined product is obtained either in the form of button lac or
hand-stretched shellac
button lac hand-stretched shel

34. Limitations of Hand-made process
• Although, hand-made process is low-investment business, it is
disadvantageous in terms of
 Operator drudgery
 Un-even product quality
 Low capacity
 Higher manpower requirement
o Refining every ton of sticklac involves on an average 92 man-
days

35. II. Machine-made process
• Mechanical process, adopted by industry
• Involves steam heating, hydraulic press and roller
• Seedlac is melted by the heat of steam
• Molten lac is passed through filter cloth by means of hydraulic press
• Filtered molten lac is drawn into long and continuous sheets with the
help of roller
• Sheet is broken into pieces called shellac
Melting and filtration
Heating the filtrate in steam-
heated intermediate tanks Drawing in to sheets

36. Limitations of machine-made process
• High initial investment
• Requires large capacity boiler to provide an un-interrupted supply of
steam
• Requires large space (horizontal and vertical) to accommodate the
filtration units, intermediate hot tanks and roller
• Hydraulic press /filter press is run by electricity, generator is required
• Operator drudgery
• Manpower requirement

37. Some Important Gums of India

38.  Extracted from the seeds of the guar plant
(Cyamopsis tetragonoloba)
 Guar is grown mainly in India, Pakistan,
Sudan and parts of USA. India grows over
8,50,000 tons or 80% of the total guar
produced all over the world
 Widely used as an emulsifier, thickener,
and stabilizer in food and cosmetics
Guar
gum

39. Dried exudates obtained from
the stems and branches of
Acacia senegal or closely
related species.
It has wide applications in
various industries including
food, pharmaceutical, textile
and chemical industries.
Gum Arabic

40.  Dried exudates obtained from trees of Sterculia
species.
 Most of the gum is of Indian origin
 India produces approximately 1500 tons of karaya
gum per annum.
 In Europe it has been assigned the food
additive number E416 and its usage is
overwhelmingly in pharmaceutical, dental
or other medical applications,
 In foods, karaya is used in small amounts as
a texturizer and stabilizer.
Gum Karaya

41. It is the exudation from two
species of the giant fennel
(Ferula asafoetida) mainly
cultivated in North India.
It is used as a flavouring
agent and forms a
constituent of many spice
mixtures.
Asafoetida is widely used in
alternative medicines like
Unani
Asafoetida

42. Processing of Guar Gum

43. GUAR GUM
• Guar is a legume crop, which
grows best in sandy soils and
needs moderate, intermittent
rainfall with lots of sunshine.
• Guar Gum is derived from
endosperm of the guar plant
(Cyamopsis tetragonolobus).

44. STRUCTURE OF GUAR SEED
20-25%
28-30%

45. Guar Seed
Guar Split
Guar Powder

46. Guar Gum: Stage wise Process
Guar Seed
• First, the pods are dried in sunlight and then threshed and
winnowed to get guar seeds.
• The seeds are supplied to the industry for processing.
• Guar by-products, churi and korma are used for Cattle feed.
feed.
Undehusked Guar Splits
• The gum is commercially extracted from the seeds
essentially by a mechanical process of roasting, differential
differential attrition, sieving and polishing.
• The seeds are broken and the germ is separated from the
endosperm.
• Two halves of the endosperm are obtained from each seed
and are known as Undehusked Guar Splits.
Refined Guar Splits
• Refined Guar Splits are obtained when the fine layer of
fibrous material, which forms the husk, is removed and
separated from the endosperm halves by polishing.
Guar Powder
• The refined Guar Splits are then treated and finished into
powders by a variety of routes and processing techniques

48. IN SIDE GUAR SPLIT MAKING
PLANT

49. There are two types of Guar Gum Powder
1)Food grade Guar Gum Powder: for used in industries like food,
pharmaceutical, cosmetic etc
There are various applications of food grade guar gum powder
Particle Size Viscosity Range (Cps)
200 MESH 2000-7500
90-95% MIN.
300 MESH 3500-5000
-200 99% MIN.
2) Industrial grade Guar Gum Powder: For used in industries like
paper, mining, explosive, Oil-drilling etc
There are various of applications of industrial grade guar gum
powder
Particle Size Viscosity Range (Cps)
300 to 60 MESH 3000-6000
Types of Guar Gum Powder

50. Applications
• Guar gum extracted from the pods of
of the guar plant is widely used as an
emulsifier, thickener, and stabilizer in
in food and cosmetics.
• The largest market for guar gum is in
in the food industry, where it is used
as a thickener and binder of free
water.
• Guar gum also finds extensive use in
many industrial applications.

51. Industry Uses
Bakery · Improves texture
· Increases dough yield
· Increases shelf life
· Improves crumb structure
Processed Cheese · Improves texture and flavour
· Stabiliser
Soups · Thickener
· Stabiliser
Pastry Ices · Absorbs free water
· Prevents excessive stickiness
Noodles · Improves texture and form
· Improves moisture retention.
Meat · Binder in sausages
· Absorbs free water
· Improves flow rate
· Prevents separation and migration
Dressings and
Sauces
· Thickener
· Emulsion stabiliser
· Improves flow properties
Beverages · Controls viscosity
· Improves body and mouth feel
· Improves shelf life
Food Applications

52. Industrial Applications
Industry Uses
Textiles · For sizing and finishing
Oil well drilling · Fluid-loss controlling agent
· Additives in fracturing fluids
Mining · Concentration of ores
· Flocculation and better recovery
Construction · Waterproofing agent
Explosives · Water binding agent for aqueous
slurry explosives
Cosmetics and
Pharmaceuticals
· Conditioner and viscosifier
· Thickener in toothpastes and
shampoos
· Binder in tablets
· To disintegrate compressed tablets
tablets
· Mild laxative and soluble dietary
fiber
Paper · For improved sheet formation
· Increased bursting strength
· Increased fold strength
· Denser surface for printing
· To get better finish