The present invention relates to a pineapple leaf fibre decorticator assembly. More particularly, the invention relates to a decorticator for efficient extraction of fibres from pineapple leaves by retting of decorticated pineapple leaves.
Prior Art
Pineapple leaf fibre (PALF) is a multicellular lignocellulosic fibre and is extracted manually as well as by decorticating with a decorticator prior to retting in water. Retting is defined as the separation of the fibre bundles from the cortex or wood effecting partial digestion of the cementing material between the fibres in the bundles. Retting of PALF is analogues to general retting process in which water is imbibed, swelling occurs and the soluble substances, like pectinuous gum, are removed and the fibre from pineapple leaf is extracted. The process of extracting PALF is of great importance since the quality as well as quantity of extracted fibre is strongly influenced by the method of extraction employed. The common method, in practice, is a combination of scrapping the pineapple leaf and water retting. In conventional method of extraction, retting of pineapple leaves steeped in water for 18-20 days yield good spin able fibres. To overcome the prolonged retting period of 18-20 days, a number of devices for decorticating pineapple leaves prior to retting have been developed by different workers to extract fibre from the pineapple leaf so that retting can be done more efficiently resulting in lesser retting period and better quality of fibre.
In case of manual extraction, the pineapple leaves are scraped with a broken China plate (antique porcelain is the best) and/or coconut shell prior to retting in water. The bundle of retted fibres are washed in a stream of water and scraped again gently with a broken China plate and/or a sea-shell to remove all traces of green matter and again washed in water to get finer linwal fibres. This process requires a lot of patience, skill and time which act as a limitation to stagnate and deprive the PALF industry of the prospect of an income generating product from the country's vast pineapple plantations.
In another case of extraction, a decorticator has been developed consisting of a scraper roller with blades. Beneath the roller, there is a depth plate to set the depth of scutching (i.e. scrapping). In this arrangement, a pair of serrated rollers is coupled

with the scrapper roller. The pineapple leaves are first dragged through the gap between the depth plate and scrapper roller and finally in between the serrated rollers for removing the epidermis layer or waxy material on the leaf surface. Trial with the said machine reveals that the leaves are not perfectly gripped by the scraper roller due to which the epidermis layer is not sufficiently removed. Moreover, human drudgery hinders continuous and uniform running of the decorticator and manual operation does not facilitate uniform quality of extracted fibres.
A number of improvised devices and machines have been developed by which pineapple leaf can be decorticated for extraction of fibre. A small sized portable raspador capable of scrapping 5.6 kg of pineapple leaves in about 8 hours was developed in which the yield of fibre is 1.5 to 2% and fibre obtained is very short.
Moderate efforts were made at Khadi and Village Industries Commission (KVIC) towards development of suitable decorticating machine consisting of a rotating drum mounted on a shaft. On the circumference of the drum a number of blades are mounted to create a beating action during rotation. Leaf is pulled in between the drum and a backing plate. Owing to the crushing, beating and pulling action, the pulpy material (paraffin/waxy coating on the leaf) is removed. This machine is capable of handling about 5 tonnes of pineapple leaves per day. Extraction trials carried out at South Indian Textile Research Association (SITRA), Coimbatore (TN) using KVIC developed decorticator machine achieved a production of about 5.0 kg fibre in 8 hours and fibres obtained are short.
SITRA, Coimbatore (TN) has developed a semi-automatic high production decorticating machine, which essentially consists of multiple rows of beaters and multiple rows of plain horizontal toothed blades, mounted in alternate rows, on a drum for effecting beating followed by scratching action. The said decorticator machine is capable of decorticating 70-80 kg of fibres per 8 hours shift.
Object of the Invention
It has been established that extraction of pineapple leaf fibre by soaking of decorticated pineapple leaves in water, yields fibres of improved quality with relative

advantages over traditional system of retting (soaking) the whole leaves which takes a long duration and human drudgery. In view of this, a Pineapple Leaf Fibre (PALF) decorticator assembly has been developed to make the extraction process efficient and viable by decreasing the retting time of the pineapple leaf.
Summary of the invention
The PALF decorticator assembly is developed to decorticate 4 to 6 leaves at a time depending on the width of the leaves. It comprises of feed zone, working zone and delivery zone. In the feed zone, a pair of feed rollers collects the green pineapple leaves from the belt conveyor assembly and delivers to the scrapper roller of the working zone. The scrapper roller scraps the surface paraffin/waxy coating of the green pineapple leaves and the scrapped leaves are subjected to scratching on both sides by passing through a pair of serrated rollers.
Advantages
The Pineapple leaf fibre decorticator assembly has been developed to achieve efficient decortication, vis-a-vis good quality fibre by a portable decorticator suitable for operating in small land holdings. Presently, there is no suitable machine available in the market and manual extraction is mostly followed which does not facilitate uniform quality of extracted fibres. A few prototypes were developed but they could not sustain because of their incompatibility for use by small and marginal farmers. The invented model is very compact and handy and consumes less power. Human drudgery does not come in the way of continuous and uniform running of the machine.
Brief Description of the invention
The decorticator is developed to extract fibre from pineapple leaf with a feed rate of 150 kg/h of leaves. The unit comprises of a belt conveyor assembly comprising conveyor belt mounted on a pair of conveyor rollers fixed on a base frame. The width of the conveyor belt is sufficient to feed at least 4 to 6 leaves at a time to the machine. The pineapple leaves on the moving conveyor belt are made to pass in between a pair of rotating feed rollers and are subjected to surface scrapping by a scraper roller. The scrapper roller consists of six blades on its periphery

screwed with their respective holders so that when the cutting edges of the blades get blunt they may be unscrewed from the holders for sharpening and refitting. The scrapped pineapple leaves are then passed in between two rotating serrated rollers which serrate both sides of the pineapple leaves surfaces and expose the fibres for easy removal by retting and finally by washing.
The conveyor rollers, feed rollers, scrapper roller and serrated rollers are mounted on a base frame supported on 6 main legs and 4 intermediate legs by means of shafts and bearing housing arrangements. An inclined plate has been provided at the delivery side for discharge of scrapped and serrated pineapple leaves.
Power has been transmitted from an A.C. motor to the top feed roller through a combination of motor pinion, intermediate sprocket, intermediate pinion and feed roller sprocket, which are engaged by chains. The lower feed roller is rotated with the help of a spur gear pair fixed with the shafts of each of the feed rollers. The rotating bottom feed roller rotates the conveyor rollers, which in turn rotates the conveyor belt by means of the sprockets, attached to each of the lower feed roller shaft and conveyor roller shaft adjacent to the lower feed roller, which are engaged by a chain. The A.C. motor also transmits drive to the scrapper roller through a combination of motor pinion, scrapper roller sprocket and chain engaged around them. Subsequently, the scrapper roller imparts drive to the upper serrated roller through a combination of chain and a pair of sprockets. A spur gear pair fixed with the shafts of each of the serrated rollers mesh with each other such that the rotating upper serrated roller rotates the lower serrated roller.
According to the present invention there is provided:
A pineapple leaf fibre decorticator assembly comprises: a belt conveyor assembly a pair of feed rollers
a scraper roller consisting of blades on its periphery screwed with their respective holders,
a pair of serrated rollers,
a power drive mechanism comprising of an A.C. motor, an intermediate sprocket and an intermediate pinion;
an inclined plate and a base frame.
Detail description of the Invention
The invention is now described in details with reference to the accompanying drawings.
Fig. 1 is a pineapple leaf fibre decorticator.
Fig. 2 shows the base frame of the decorticator assembly.
Fig. 3 shows conveyor belt assembly.
Fig. 4 shows feed roller assembly.
Fig. 5 shows scraper roller assembly.
Fig. 6 shows sectional view of blade arrangement on scraper roller.
Fig. 7 shows serrated roller assembly.
Fig. 8 shows serrations on the serrated rollers.
Fig. 9 shows power transmission mechanism for driving the decorticator.
A pineapple leaf fibre decorticator assembly is developed to decorticate pineapple leaf, for efficient retting of pineapple leaf, necessary for extraction of fibre, with a feed rate of 150 kg/h of pineapple leaves. The decorticator assembly comprises of a belt conveyor assembly (45), a pair of feed rollers (4), a scraper roller (16), a pair of serrated rollers (6), a power drive mechanism which includes an A.C. motor (2), an intermediate sprocket (10) having an intermediate pinion (11) and a base frame (1). The belt conveyor assembly (45) comprises of conveyer belt (18) mounted on a pair of conveyor rollers (3), which includes conveyor roller shafts (20) and conveyor roller housing bearings (15) and are fixed to the base frame (1) by means of nuts and bolts (19). The width of the conveyor belt (18) is sufficient to feed at least 4 to 6 leaves at a time to the machine. A conveyor roller sprocket (43) is also fixed to the shaft (20) of the conveyor roller that is adjacent to the feed rollers. The pineapple leaves on the conveyor belt are fed to a pair of feed rollers (4). Here, the leaves are allowed to pass in between the rotating feed rollers (4) and are subsequently subjected to surface scrapping by a rotating scraper roller (16). The feed rollers (4), comprising feed roller shafts (21) and feed roller housing bearings
(22), are fixed to the base frame (1) by means of nuts and bolts (23). An upper feed roller sprocket (12) and a lower feed roller sprocket (14) is fixed to each of the shaft (21) of the upper feed roller and lower feed roller. A pair of spur gear (39, 40) is fixed to the feed roller shafts (21) such that they are meshing with each other. The scraper roller (16), comprising scraper roller shafts (25) and scraper roller housing bearings (24), is fixed to the base frame by means of nuts and bolts (17). The scrapper roller (16) also consists of six blades (26) on its periphery screwed with their respective holders (5) so that after use for a certain period once the cutting edges of the blades (26) become blunt, the blades can be removed from the holders and refitted after sharpening the edges. Two scraper roller sprockets (13, 29) are fixed to the scraper roller shaft (25). The scrapped leaves from the scraper roller are then made to pass in between a pair of rotating serrated rollers (6) which serrate either side of the pineapple leaves surface and expose the fibres for easy removal by retting and finally by washing. The serrated rollers (6), comprising serrated roller shafts (37) and serrated roller housing bearings (28), are fitted to the base frame (1) by means of nuts and bolts (27). An upper serrated roller sprocket (42) is fixed to the shaft (37) of the upper serrated roller and a pair of spur gears (8, 41) is fitted to the shafts (37) of both the serrated rollers such that they are meshing with other.
The conveyor rollers (3), feed rollers (4), scrapper roller (16) and serrated rollers (6) are mounted on a base frame (1) supported on 6 main legs (35) welded at the bottom with foundation plates (34) and 4 intermediate legs (33). An inclined plate (36) has been provided after the serrated rollers (6) for collection of discharged scrapped and serrated pineapple leaves.
The power drive mechanism comprising an A.C. motor (2) which drives the feed rollers (4) and scrapper roller (16) and each of these in turn provides driving force to the conveyor rollers (3) and serrated rollers (6) respectively. An intermediate sprocket (10) including an intermediate pinion (11) is fixed to the intermediate support frames (33) and positioned above the A.C. motor. The A.C. motor is provided with a pinion (9) having two sprockets. The pinion (9) of the A.C. motor provides drive to the sprocket (10) and consequently the intermediate pinion (11), coupled with the sprocket (10), by a chain (7) engaged around the sprocket (10) and one of the sprocket of the pinion (9) of the A.C. motor. The intermediate pinion (11)
subsequently drives the upper feed roller (4) by the chain (38) engaged around the intermediate pinion (11) and the upper feed roller sprocket (12) fixed to the upper feed roller shaft (21). The spur gears (39) and (40), fixed to each of the shafts (21) of the upper feed roller and the lower feed rollers respectively, are meshing with each other such that the rotating upper feed roller also rotates the lower feed roller. The other end of the lower feed roller shaft (21) is also provided with a sprocket (14) which is engaged by a chain (32) to the conveyor roller sprocket (43) fixed to the shaft (20) of the conveyor roller (3) that is adjacent to the feed roller (4) and thereby the rotating lower feed roller initiates rotation to the belt conveyer assembly.
The second sprocket of the pinion (9) of the A.C. motor imparts drive to the scrapper roller (16) by means of the chain (30) engaged around the second sprocket of the pinion (9) and the scraper roller sprocket (13) fixed to the scrapper roller shaft (25). The scraper roller shaft (25) is also provided with a second scraper roller sprocket (29) which is engaged with the upper serrated roller sprocket (42) fixed to the upper serrated roller shaft (37) by means of the chain (31) such that when the A.C. motor drives the scraper roller, it also imparts drive to the upper serrated roller and makes it to rotate. With each of the shaft (37) of the upper and lower serrated roller, a spur gear (8) and a second spur gear (41), respectively, is fixed such that both the spur gears (8 & 41) are meshing with each other thereby enabling the rotating upper serrated roller to rotate the lower serrated roller.
Mode of Operation
The A.C. motor is switched on and the decorticator assembly is activated. Subsequently the pineapple leaves, numbering 4 to 6, are fed to the moving conveyor belt manually along its length. These pineapple leaves are then gripped by the pair of rotating feed rollers and subjected to scraping by the rotating scraper roller. The rotating feed rollers pair enables the feeding of the pineapple leaves in forward direction so that the leaves are scrapped under fully stretched condition by the scrapper roller. The scrapper roller consisting of 6 blades on its periphery during the course of its rotation remove the paraffin or waxy layer on the leaves surfaces to allow easy penetration of water during retting. The scrapped leaves then pass in between a pair of rotating serrated rollers to expose the fibre matrix in order to
economise on the retting duration. The decorticated leaves are collected in a container through a discharge spout for easy removal and subsequent retting.
As will be apparent to those skilled in the art, in view of the foregoing disclosure, many modifications and alterations are possible in the practice of this invention without departing from the spirit or scope of the invention.

We Claim:
1. A pineapple leaf fibre decorticator assembly comprises:
a belt conveyor assembly (45),
a pair of feed rollers (4),
a scraper roller (16) consisting of blades (26) on its periphery screwed with their respective holders (5),
a pair of serrated rollers (6),
a power drive mechanism comprising of an A.C. motor (2), an intermediate sprocket (10) and an intermediate pinion (11);
an inclined plate (36) and a base frame (1).
2. A pineapple leaf fibre decorticator assembly as claimed in claim 1,
wherein the belt conveyor assembly (45) comprises:
a pair of conveyor rollers (3);
conveyor belt (18) mounted around the conveyor rollers (3);
conveyor roller shafts (20);
conveyor roller sprocket (43) fixed to the shaft of the conveyor roller adjacent to the feed roller; and
conveyor roller housing bearings (15) by means of which conveyor rollers are fixed to the base frame (1) by means of nuts and bolts (19).
3. A pineapple leaf fibre decorticator assembly as claimed in claim 1,
wherein the feed rollers (4) comprises:
feed roller shafts (21) and feed roller housing bearings (22) and are fixed to the base frame (1) by means of nuts and bolts (23);
upper feed roller sprocket (12) and lower feed roller sprocket (14);
a pair of spur gears (39, 40) fixed to each of the feed roller shafts (21) such that they are meshing with each other.
4. A pineapple leaf fibre decorticator assembly as claimed in claim 1,
wherein the scraper roller (16), comprises:
scraper roller shaft (25) and scraper roller housing bearings (24) and is fixed to the base frame by means of nuts and bolts (17); and
scraper roller sprockets (13, 29) fixed to the scraper roller shaft (25).
5. A pineapple leaf fibre decorticator assembly as claimed in claim 1,
wherein serrated rollers (6) comprises:
serrated roller shafts (37) and serrated roller housing bearings (28) and are fixed to the base frame by means of nuts and bolts (27);
upper serrated roller sprocket (42) fixed to the shaft (37) of the upper serrated roller;
a pair of spur gear (8, 41) fitted to the shafts (37) of each of the serrated rollers such that they are meshing with each other.
6. A pineapple leaf fibre decorticator assembly as claimed in claim 1,
wherein the power drive mechanism comprises:
an A.C. motor (2) having a pinion (9) with two sprockets;
one of the sprocket of the pinion (9) is engaged with the intermediate sprocket (10) by a chain (7) and the other sprocket of the pinion (9) is engaged with the scraper roller sprocket (13) by means of chain (30);
the intermediate pinion (11), of the intermediate sprocket (10), is engaged with the upper feed roller sprocket (12) by means of a chain (38);
the lower feed roller sprocket (14) is engaged by means of a chain (32) with the conveyor roller sprocket (43);
a second scraper roller sprocket (29) is engaged with the upper serrated roller sprocket (42) by means of a chain (31).
7. A pineapple leaf fibre decorticator assembly substantially as herein
before described with reference to the accompanying drawings.