The present invention relates to process of synthesizing pine needle granules or
pellets.
The present invention also relates to pine needle granules or pellets prepared by the
process of the present invention. These pine needle granules or pellets can be used to make
various molded articles having antimicrobial properties.
The present invention further relates to molded articles prepared from pine needle
granules or pellets of the present invention.
BACKGROUND
Pine trees are largely found in Himalayan states of India, and is of no direct use for
humans or animals. They are directly implicated in forest fires in the mountain forest which
results in a very destructive disaster which also cause massive pollution. Pine needles are
almost useless and can be easily harvested sustainably without causing any harm to the
environment in any manner. So, reducing pine needles directly traps equivalent carbon and
nitrous emission levels as per the IPCC standard. Pinus roxbughii (pine needle) is known to
have anti-bacterial activity which has been utilized in laboratory experiments chemically for
breaking down the lignin sheath and releasing the required volatile compounds that cause
said anti-bacterial action.
Indian patent Application 201811000279 discloses a method of producing a biomass
fuel product from organic-waste material comprising dry pine needle.
In another Indian patent Application, 201711001977 a process for extraction of textile fibers
from pine needles is disclosed, where the steps included conditioning of pine fibers,
treatment of conditioned pine fibers with Alkali, treatment with metallic salt, decorortication
of metallic salt treated pine fibers, followed by bleaching and drying. Indian Application
7892/DELNP/2015 relates to a process for breaking down (digesting) lignocellulosic5
biomass, in which lignocellulose-containing starting materials are decomposed into
degradation products, the soluble fractions of the degradation products being placed in
aqueous solution and the water-insoluble fractions, which essentially consist of lignin, being
separated out in a precipitated form. Another patent Application 531/DEL/2010 relates to a
process for the manufacture of pine needle composite boards utilizing isocyanate
prepolymer adhesive useful for making panels, partition, door panel inserts, furniture and
other industrial applications. In 638/DEL/2001, a fuel gas was prepared in closed container
3
under pressure by burning pine waste and heating the fuel with the help of compressed air
which produced gas inside the container.
Plastic has become an unavoidable object for humans because of its properties like
antimicrobial, light weight, leakage proof and reliance on packaging and convenience. The
growing involvement of plastic in our daily life and its waste disposal has become a great
crisis for the world. Therefore, there is a growing need for a more environmentally safe and
sustainable plastic substitutes. The present invention addresses the sustainable substitute for
plastics by using pine needles for preparing granules or pellets.
OBJECT OF THE INVENTION
An object of the present invention is to harvest the pine needles from its source to
create granules or pellets which has almost all properties to replace plastics from our life.
It is another object of the present invention to provide an efficient method for
obtaining pine needle granules having antimicrobial properties.
Another object of the present invention is to provide granules from pine needles to
utilize in making molded objects.
Another object of the present invention if to provide molded articles made out of
pine needle granules having properties such as antimicrobial, light weight, leakage proof
etc. Considering these properties, the granules can be very useful to make products for food
packaging, food containers, tableware etc.
Yet another object of the present invention is to utilize the anti-bacterial properties
of pine needles from Pinus roxbhurghii to achieve performance that can actually be utilized
in everyday life.
SUMMARY OF THE INVENTION
The present invention relates to process of synthesizing pine needle granules or
pellets, said process comprising pre-heating of pine needles at a temperature in the range of
150o
C to 180o
C, for 2 minutes to 10 minutes to obtained pre-heated pine needles; and
intermixing of said pre-heated pine needles with 50% to 78% by weight of a polymer and
optionally 2% - 5% by weight of fillers, at a temperature of 150o
C to 180o
C for 7 minutes
to 10 minutes to obtain pine needle granules.
These granules or pellets obtained have favourable antimicrobial properties and
therefore beneficial in manufacturing molded articles such as crockeries having
antimicrobial properties.
4
The present invention also relates to pine needle granules or pellets prepared by the
process of the present invention.
The present invention further relates to molded articles prepared from pine needle
granules or pellets of the present invention.
These and other features, aspects, and advantages of the present subject matter will
become better understood with reference to the following description. This statement is
provided to introduce a selection of concepts in a simplified form. This statement is not
intended to identify key features or essential features of the subject matter, nor is it intended
to be used to limit the scope of the subject matter.
DETAILED DESCRPTION OF THE INVENTION
The present invention provides a process for synthesizing pine needle granules,
comprising: pre-heating of pine needles at a temperature in the range of 150o
C to 180o
C, for
2 minutes to 10 minutes to obtained pre-heated pine needles; and intermixing of said preheated pine needles with 50% to 78% by weight of a polymer and optionally 2% - 5% by
weight of fillers, at a temperature of 150o
C to 180o
C for 7 minutes to 10 minutes to obtain
pine needle granules.
An embodiment of the present invention provides a process for synthesizing pine
needle granules pre-heating of pine needles at a temperature in the range of 150o
C to 180o
C,
for 2 minutes to 10 minutes to obtained pre-heated pine needles; and intermixing of said
pre-heated pine needles, by using a compounding machine at a drive speed of 150rpm to
50rpm, with 50% to 78% by weight of a polymer and optionally 2% - 5% by weight of
fillers, at a temperature of 150o
C to 180o
C for 7 minutes to 10 minutes to obtain pine needle
granules.
In an another embodiment, it provides a process for synthesizing pine needle
granules comprising drying of pine needles by air drying or vacuum drying, followed by
pre-heating of pine needles at a temperature in the range of 150o
C to 180o
C, for 2 minutes
to 10 minutes to obtained pre-heated pine needles; and intermixing of said pre-heated pine
needles, with 50% to 78% by weight of a polymer and optionally 2% - 5% by weight of
fillers, at a temperature of 150o
C to 180o
C for 7 minutes to 10 minutes to obtain pine needle
granules.
Yet in another embodiment of the present invention, the fillers used in the process
of the present invention are selected from sodium hydroxide, activated carbon, titanium
dioxide, or combinations thereof.
5
Still in another embodiment of the present invention, the fillers used in the process
of the present invention is activated carbon.
The polymers in accordance with the process of the present invention is selected
from Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE),
acrylonitrile-butadlene-styrene (ABS), Polyethylene (PE), Polyethylene
terephthalate (PET), Polylactic acid (PLA), Poly(butylene adipate-co-terephthalate)
(PBAT), High density polyethylene (HDPE), Maleic anhydride polypropylene (MAPP), or
combinations thereof.
Still in another embodiment, it provides a process for synthesizing pine needle
granules comprising drying of pine needles by air drying or vacuum drying, followed by
pre-heating of pine needles at a temperature in the range of 150o
C to 180o
C, for 2 minutes
to 10 minutes to obtained pre-heated pine needles; and intermixing of said pre-heated pine
needles, with 50% to 78% by weight of a polymer selected from LLDPE, LDPE, ABS, PE,
PET, PLA, PBAT, HDPE, MAPP, or combinations thereof and optionally 2% - 5% by
weight of fillers, at a temperature of 150o
C to 180o
C for 7 minutes to 10 minutes to obtain
pine needle granules.
Further, another embodiment of the present invention provides a process for
synthesizing pine needle granules, comprising: drying of pine needles in air, or in a vacuum;
pre-heating of dried pine needles at a temperature of 150o
C for 4 minutes to 7 minutes; and
intermixing of said pre-heated -pine needles with 75% by weight of HDPE and 1% by
weight of titanium dioxide, sodium hydroxide or combinations thereof, at 180o
C and drive
speed of 50 rpm to 75 rpm for 10 minutes to obtain pine needle granules.
In another embodiment, the pine needles are obtained from Pinus roxburghii. The
pine needles according to the present invention can also be obtained from any pine species.
In an embodiment of the present invention, pine needle granules is provided which
is prepared by the process of the present invention.
Another embodiment of the present invention provides a molded article prepared by
using pine needle granules obtained by the process of the present invention.
EXAMPLES
The disclosure will now be illustrated with working examples, which is intended to
illustrate the working of the invention and not intended to take restrictively to imply any
limitations on the scope of the present invention. Other embodiments are also possible.
6
Example 1:
Pine needles, dried in a vacuum for 4 hours at 100o
C to achieve optimal dried
conditions, are inserted into a compounding machine where the feed zone for pre-heating is
set at a batch level temperature of 150o
C and at about 50 rpm for 5 mins to 6 minutes. Batch
sizing is dependent on machinery used which can be of any specification. In this example,
100kgs at a time is batched in a ratio of about 40% pine needle and about 58% polymer and
about 2% fillers.
These fillers are added soon after the insertion of pine needles with an interval of 3
minutes during which time the pine needles are cooked for sometime in the chamber itself.
With the addition of fillers such as HDPE and Titanium Dioxide and further NaOH, a stop
time is given and during which the temperature is now increased to 180o
C at which time
maximum cooking of the pine needles has occurred and loss of terpenes from the pine matrix
is determined via olfactory observation. At this time most of the terpenes that have escaped
the pine needles and now are available for matrix stabilization in the chamber at which time
the balance HDPE is added and thereafter this is continuous olfactory observation of loss of
volatiles/terpenes from the cooking chamber when the drive speed is increased from 100rpm
to 125rpm which is an indicator of appropriate mixing taking place and as long as there is
an appropriate action owing to presence of HDPE and TiO2 and NaOH, the result is
sufficient. During this pre-batching time, an expected loss of lignin from the pine needles
can be assessed by weight reduction at end point and this points to the release of three typical
terpenes found in Pinus roxburghii, viz, hydroxyphenyl, guaiacyl and syringyl at which time
the mechanical properties of pine needles have been sufficiently weakened to allow a
uniform melt method granule. The rpm is then lowered in 10 step counts from 150 rpm
down to 100rpm to achieve an optimum use of resource and produce sufficient thermo
mechanical shocks to the batch in order to maximize breakdown of lignin sheath and deliver
stable volatiles throughout the melt matrix and to avoid agglomeration as well. The normal
is to lower in 10 rpm counts from 150 rpm down to 100 rpm in a total of five minutes i.e.
roughly 10 rpm per minute with additional exposure to titanium dioxide thus ensuring
uniform spread and minimum agglomeration.
The most optimal combination to achieve ISO 22196 standards for appreciable
logarithmic reduction of microbes is observed when the dried pine needles are batched for
5-7 minute prior to mixing zone. Table 1 summarizes the effect of pre-heat time on the
antimicrobial effect of the granules obtained. This dry distillation is time specific. If the
7
needles are heated in the feed zone for longer than 10 minutes the gaseous distillates are
vaporized and do not respond to any treatment. While the mechanical properties remain
intact, the anti-microbial properties are lost.
Table 1:
Sl
no.
Pinus
Roxburgii
HDPE Temperature
(
o
C)
Pre
heat
time
NaOH% TiO2% AntiMicrobial
Effect
i. 24% 75% 150 4min 0.5 0.5 0
ii 24% 75% 150 5min 0.5 0.5 Appreciable
Log 4
iii 24% 75% 150 6min 0.5 0.5 Appreciable
Log 4
iv 24% 75% 150 7min 0.5 0.5 Log 3
v 24% 75% 150 8min 0.5 0.5 0
Antimicrobial activities can be expressed by log reduction wherein 1 log reduction
equals 90% reduction, 2 log reduction equals 99% reduction, 3 log reduction equals 99.9%
reduction and 4 log reduction equals 99.99% reduction.
Table 2
Sl
no.
Pinus
Roxburgii
HDPE Temperature
(
o
C)
Pre
heat
time
NaOH% TiO2% AntiMicrobial
Effect
i. 24% 75% 180 4min 0.5 0.5 0
ii 24% 75% 180 5min 0.5 0.5 0
iii 24% 75% 180 6min 0.5 0.5 0
iv 24% 75% 180 7min 0.5 0.5 0
v 24% 75% 180 8min 0.5 0.5 0
Table 2 shows the effect of temperature conditions on the antimicrobial effect of the
granules obtained.
8
Table 3
Sl
no.
Pinus
Roxburgii
HDPE Temperature
(
o
C)
Pre
heat
time
NaOH% TiO2% AntiMicrobial
Effect
i. 30% 69% 150 4min 0 1 0
ii 30% 69% 150 5min 0 1 Log 3
iii 30% 69% 150 6min 0 1 Log 4
iv 30% 69% 150 7min 0 1 negligible
v 30% 69% 150 8min 0 1 0
Table 3 shows whereas the presence of NaOH addition speeds up the process, temperature
and time plays the most significant role in this dry distillation effect.
Example 2
The process as described in example 1 is followed with activated carbon (AC) used as the
filler. Table 4 shows the favourable antimicrobial activity of Log 4 of the pine needle
granules prepared by the process with activated carbon. The AC also helps with larger
barrels where extended exposure i.e., dwell time can have a degrading effect. The quicker
processing ensured that the melt is not vaporized and AC balanced out the heat transfer
equation that takes place.
Table 4:
Sl
no.
P.roxb
urgii
HDPE Temperature
(
o
C)
Pre heat
time
RPM
steps
Activated
carbon
AntiMicrobial
Effect
i. 30% 67% 150 6min 150 3 Log 3
ii 30% 67% 150 5min 125 3 Log 4
iii 30% 67% 150 5min 100 3 Log 4
iv 30% 67% 150 6min 75 3 Log 4
v 30% 67% 150 6min 50 3 Log 4
Example 3
9
The process as described in example 1 is followed with activated carbon as the filler. In
addition to it, the presence of NaOH showed more pronounced effect of antimicrobial
property.
Table 5:
Sl
no.
P.roxb
urgii
HDPE Temp
(
o
C)
Pre heat
time
NaOH RPM
steps
Activated
carbon
AntiMicrobial
Effect
i. 30% 65% 150 4min 2 150 3 Log 3
ii 30% 65% 150 >4min 2 125 3 Log 4
iii 30% 65% 150 5min 2 100 3 Log 4
iv 30% 65% 150 6min 2 75 3 Log 4
v 30% 65% 150 6min 2 50 3 Log 4
Example 4
In this example, the tensile strength of the pine needle granules prepared by the process of
example 1, along with its antimicrobial effect is shown in table 6.
Table 6
Sl
no.
P.roxb
urgii
HDPE Temperature
(
o
C)
TiO2 Tensile
yield
(50mm
/min)
AntiMicrobial
Effect
i. 40% 59.5% 150 0.5% 26 Log 4
ii 40% 59% 150 1% 24 Log 4
iii 40% 58% 150 2% 22 Log 3
iv 40% 57% 150 3% 20 0
v 40% 56% 150 4% 18 0
The primary requirement to add TiO2 is to ensure stabilization of moisture and at
higher percentage loading of Pine Needles, there is a clear requirement to stabilize water
activity else streaking is observed on surface finish of final products. Similarly, the released
10
terpenes are stabilized enough to be able to generate sufficient anti-microbial action.
Therefore, a dessicant like additive has its limitations and cannot be dosed beyond a point
as seen above.
Example 5
The process as in example 1 is carried out at slower drive speed in order to
compensate for cooking time and increase cost savings. However, if the drive is run
continually slower at around 60rpm, shaft breakage can occur from delivering too much
torque at slower speeds.
We therefore chose to lower the rpm in 25 rpm step counts from 150 rpm downwards to see
an optimum use of resource and produce sufficient-thermo mechanical shocks to the batch
in order to assist maximize breakdown of lignin sheath.
Table 7
Sl
no.
P.roxb
urgii
HDPE Temperature
(
o
C)
Pre heat
time
NaOH RPM
steps
AntiMicrobial
Effect
i. 30% 68% 150 6 min 2 150 Log 3
ii 30% 68% 150 6 min 2 125 Log 3
iii 30% 68% 150 6 min 2 100 Log 3
iv 30% 68% 150 6 min 2 75 Log4
v 30% 68% 150 6 min 2 50 Log4
Table 7 shows the favourable antimicrobial effect of the granules or pellets of the present
invention when the drive speed is lowered from 25 rpm step counts from 150 rpm.
Example 6
The granules as prepared by the process of the present invention, are finally drawn
through a water-cooling channel system and cut using a hot air system. The granules thus
produced are used via injection molding technique to make tableware that retains said antimicrobial properties that are then retained for the life of product. This technique ensures
there is no leaching and consequent tests for the material generated against IEC, IS, EU
10/2011 show that there is no contributory and degrading effect by way of food migration.
The molded material prepared by the pine needle granules of the present invention can
11
destabilize RNA cell wall of gram negative and gram positive bacteria with a kill rate of
99.3% as per studies with JIS and ISO method.
Although the subject matter has been described in considerable detail with reference
to certain preferred embodiments thereof, other embodiments are possible. As such, the
spirit and scope of the invention should not be limited to the description of the preferred
embodiment contained therein.
12

We Claim:
1. A process for synthesizing pine needle granules, comprising:
pre-heating of pine needles at a temperature in the range of 150o
C to 180o
C,
for 2 minutes to 10 minutes to obtained pre-heated pine needles; and
intermixing of said pre-heated pine needles with 50% to 78% by weight of a
polymer and optionally 2% - 5% by weight of fillers, at a temperature of
150o
C to 180o
C for 7 minutes to 10 minutes to obtain pine needle granules.
2. The process as claimed in claim 1, wherein said intermixing is done by using a
compounding machine at a drive speed of 150rpm to 50rpm.
3. The process as claimed in claim 1, wherein the fillers are selected from sodium
hydroxide, activated carbon, titanium dioxide, or combinations thereof.
4. The process as claimed in claim 1, wherein the pine needles are dried before said
pre-heating, by a process selected from air drying or vacuum drying.
5. The process as claimed in claim 1, wherein the polymer is selected from a group
consisting of HDPE, MAPP LLDPE, LDPE, ABS, PE, PET, PLA, PBAT, or
combinations thereof.
6. A process for synthesizing pine needle granules, comprising:
drying of pine needles in air, or in a vacuum;
pre-heating of dried pine needles at a temperature of 150o
C for 4 minutes to 7
minutes; and
intermixing of said pre-heated -pine needles with 60% to 75% by weight of
HDPE and 1% by weight of titanium dioxide, sodium hydroxide, activated
carbon or combinations thereof, at 180o
C and drive speed of 50 rpm to 75 rpm
for 10 minutes to obtain pine needle granules.
7. The process as claimed in claim 6, wherein the filler is titanium dioxide or sodium
hydroxide or combinations thereof.
8. The process as claimed in any of the claims 1 to 7, wherein the pine needles are
obtained from Pinus roxburghii.
9. A process for synthesizing pine needle granules, comprising:
drying of pine needles in air, or in a vacuum;
pre-heating of dried pine needles at a temperature of 150o
C for 4 minutes to 7
minutes; and
13
intermixing of said pre-heated -pine needles with 65% by weight of HDPE
and 2% by weight of sodium hydroxide, 3% by weight of activated carbon, at
180o
C and drive speed of 50 rpm to 125 rpm for 10 minutes to obtain pine
needle granules.
10. A pine needle granule prepared by a process as claimed in any of the claims 1 to 9.
11. A molded article prepared by using pine needle granules obtained by a process as
claimed in any of the claims 1 to 9.