From waste to wealth - The story of a humble pineapple leaf fiber

As the saying goes: we are an island that depends on subsistant agriculture and tourism, right? 

Yet, neither of the two have been exploited to the full of their potential. 

To start with, our land and ocean are not seen as potential resources to alleviate poverty and unemployment. Fifty six years ago when the kiwis left Samoa, our agriculture has remained standing still. Poor and unattended farmers are left to their own design without one hint of help from the MAF. 

If so, give us some significant statistical figures to show us examples of said help in the shape of increased yields, less diseases, better varieties, improve farmer’s income, mechanization, marketing. 

Same picture in the animal industry and fish processing. 

S.A.C.E.P., now under a new name not in six years has been able to give us apples, oranges, big tomatoes, carrots, kiwis, etc. healthy fruits all; neither dairy products and meat. Why? M.A.F. does not care or does not know how or both? Apparently the bulk of their budget goes to pay the pen pushers and not the agricultural technicians who could be working shoulder to shoulder with our poor farmers. Theologians do not farm, but they reap from the poor farmers.

S.R.O.S. is now gearing its research and development towards alcoholic beverages (whiskey, gin and the like from taro no less). Who needs alcohol? Beer and cheap alcoholic drinks are killing more people than the opiod epidemic. Enough is enough.

M.A.F. seems to be blind to the enormous possibilities that can be achieved with the creation of cottage industries based on agricultural wastes such as banana pseudo-stem and pineapple leaves among other wastes for now. 

How about some animal feeds and pet feeds, fertilizers (vermicompost) from wastes? Ha! Our merchandisers all they think is buy and sell; pocket the profits and forget about industrializing the country, yet the valuable agricultural “waste” is staring at their faces, pleading: “why don’t you use me, man?! We are free raw material… just like fish. Same thing goes for other government departments. 

Total inefficiency, poor executive performance, money not collected, mismanaged or forfeited (pay us later, if you can), untrained employees, nobody monitors anything, luxury vehicles for big honchos with no place to go, 0.4 % of return of equity (814 m) by the public trading bodies. What a shame.

There is a common denominator to all these disasters: P.S.C. hired the wrong people. I know a better way to hire. Poor Samoa. My previous article dealt with the industrial use of the waste of our banana fields. This one has to do with the use of the pineapple leaves- a waste, that should not be wasted. 

 

IN A NUTSHELL

One pineapple plant has 30-40 leaves, 1m in length, 480 leaves makes 1 m2  of vegan leather or a byproduct of 16 pineapples. Just from one wasted leaf of pineapple an industrious Samoan weaver can obtain 300 m of excellent fiber, better than cotton.

With that fiber, among millions of others, he/she can make beautiful dresses,, carpet making, paper, mats, shoes, bags, wallet, clothes, car upholstery, chair, sofas.

 

INTRODUCTION

In developing countries, there is different approach to deal with organic waste. In fact the word “waste” is often an inappropriate term for organic matter, which is often put to good use. The economies of most developing countries dictates that material and resources must be used to their full potential.

One of the commonly used fruits is PINEAPPLE. From each pineapple fruit, only 52% is used for jam and juice production. Remaining 48%   consists of fruit peel and leaves forming the waste.. These waste are rich in lignin and cellulose and thus   from a very good raw material for allied fibers.

Wood is used as the major material in paper production around the world, and this has resulted in severe deforestation having direct negative impact on our environment. This has made the search for alternative fiber, in non-wood materials imperative, in pulp and paper production.

This has impelled the reasoning of the feasibility of using pineapple leaf fibers for paper production. Wood contributes to about 90% of the conventional raw material for pulp and paper production in the world. Several agricultural food  crops  residues  including  rice  husk, sugar cane bagasse,  corn straw, okra stalks, corn stalk, plantain stalk, pineapple leaf and corn husks  which do not have immediate  beneficial applications in many communities have been proposed to be potential sources of pulp.

Non-wood plants offer several advantages including short growth cycles, moderate irrigation and fertilization requirements and low lignin content to alleviate energy and chemical used during pulping. Since al these plants materials contain cellulose in form of fibers, they stand to be potential sources  for pulp.

 

PRODUCTION OF 

PINEAPPLE FIBER

Since piña (pineapple in Spanish) is from a leaf, the leaf is cut from the plant. Then the fiber is pulled or split away from the leaf or PALF. Most leaf fibers are long and somewhat stiff. Each strand of the piña fiber is hand scraped and is knotted one by one to form a continuous filament   to be hand woven and then made into a Piña cloth. Fiber from pineapple leaves for long has been used  by  Philippine  handicraft  artisans to produce cloth. The fiber is considered to be more delicate in texture than any other vegetal fiber.

Let us see. One hectare of pineapple can produce 21 MT of pineapple fruit, also from that hectare of pineapple you can get 800 kg of fiber from the leaves left on the field.  Now, each pineapple plant bear 42 to 60 leaves and every leaf contains 40 to 60 fibers and those fibers on an average have 1.25 m long, that means that every leaf of the plant can yield about 300 m of long fibers. 

A kilo of leaves may provide up to 15-18 pieces of white-creamy as lustrous as silk fiber about 60 cm long and easily retain dyes.

Considering that this fiber extraction is from an abundant unused raw material, its use by the Samoan weavers could provide them with and extra income that substantially can improve their lives.

 

How to extract the fiber.

Fibers of the leaf are scraped by means of a broken plate or coconut shell and a fast scraper can extract fiber over 600 leaves per day then the fibers are washed and dried in the open air. After which they are waxed to remove the entanglements and then the fibers are knotted and bind into yarns for the next process of weaving it into fabric.

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 The fiber can also be extracted by a decorticating machine. When most of the extractor  or decorticator out there using crashing-like technology to extract PALF. Pineapple leaf is inserted between the two blades. Upon entering the blades,  the leaf will be sort of “grind” and the outer waxy layer  will be removed during this first step. During second step, when the leaf was being pulled off, yet again, the leaf will be grind for the second time   that will  remove  the entire waxy layer, which was left during the first step.

In order to remove the gummy matters in pineapple leaves the extracted fiber are immersed in 3% solution of sodium carbonate for 1 hour at room temperature. After that the fibers were   washed,   rinsed several times with distilled water in order to neutralize  remaining alkali, and the dried directly under the sun. 

A: What is the difference between these 2 methods?

When hand scraped is applied, only one side of the leaves surface will be scraped, while by using the first machine (PALF M1)  both upper and bottom  of leave surfaces  will be scraped at the same time.

By assuming  8 hours of work per day PALF M1 manage to extract  5,760 pieces  of leaves  per day while  with average time taken 5 seconds per pieces while hand scraping  took about 50 seconds to extract  1 piece of leaves. Production rate of PALF M1 is approximately 10 times of hand scrapping.

What about the waste of the pulp waste?

Basically, after scraping process there will be  amount  of green debris  waste accumulated. Those green  debris waste as defined as pulp waste. This kind of waste can be further utilized for several purposes including  vermicomposting and animal pellets.

For every five pieces of scraped leaves, hand scrapped method   produce 11/2 gram   waste. PALF M1  manage to reduce the pulp waste produced after scraping process up to 33%. PALF M1 manage to produce more refined   fiber, creamy white compared to hand scraped brownish by hand scraping. Also extraction by PALF M1 fibers exhibit parallel fiber arrangement, more fine and delicate structured compared to hand scraped showing multi- fibrillary structure and the fibrils were bound together by lignin and hemicellulose.

This kind of agricultural waste for  treatment  has great commercial application  potential which can add value to pineapple cultivation,  facilitate extra income for entrepreneurs  or farmers, and lead to agricultural diversification. MAF to the rescue?

Chemical pulping of wasted pineapple leaves fiber for kraft paper production.

Acetone has been used as a pulping agent  for pineapple leaves. The 3% acetone concentration shows the highest lignin solubility, the best tear properties, better delamination and distribution of technical fibers, hence producing the most acceptable properties of paper.

Why the use of acetone?  And not the classical pulping process such as kraft and sulfite pulping which use sulfur containing reagents? It is because the release of sulfur to the environment can cause serious pollution problem.

This process using acetone is called “organosolv” process thus reducing the sulfur emission by the pulp mills.

The use of acetone was the one with 65% purity.

Dried   pineapple leaves were immersed in a mixture of 3% acetone/water mixture, for 3 days. The pineapple leaf pulp was washed with water and disintegrated in a laboratory blender. The pulp was molded using mold and deckle. The paper was dried in the  oven  at 60 degrees centigrade until the pulp was fully dried. 

 

 

 

Finally, the paper was pressed using the compression molding machine at 100 degrees centigrade and pressure of 10MPa to get even thickness of paper sheet.

The paper produced from pulping with 3% acetone concentration  shows the highest thermal stability, with the least amount of lignin. 28 days of delignification  time at room temperature results in full removal of lignin, the paper had the highest thermal stability.

Producing Paper using Pineapple leaf fiber.

Using pineapple leaf fibers as raw material  in paper production  this to take advantage of its mechanical properties, such as tensile strength, tearing strength and thickness of the paper. In countries where they have the agricultural wastes such as corn straw it can be used to make paper.  It was mixed with recycled newspaper 

• The best mixture was  75% pineapple fiber and 25% of newspapers. The paper thus obtained was found to be more suitable for a a medium for  packaging  such as boxes.

• PALF is very good for carpet   making  because of its chemical processing, dying behavior and aesthetically  pleasing fabric. Other applications include cosmetic, medicine and biopolymers coating for chemicals.

• Pause here. The purpose of this article is to find out thru my research ways to use the pineapple leave fibers in any way or form. Waste is gold!

Here I found a novel extraction method to use the fibers to reinforce plastic (polypropylene) and also   as sound and thermal insulators.  Let me explain.

We know that pineapple leaves  fibers (PALF)  is a source of a high quality fiber but somehow it is left underutilized, as in this case using  a method different to the conventional one.  The conventional method start with scraping, retting and decorticating (using a decorticator) and it starts from long fresh leaf and use mechanical   force to remove soft covering  material  and ended up with long fibers. However, these methods give low yield of coarse fiber bundles and are also difficult to scale up. This novel method explained here   may be called mechanical milling.  It starts from chopped fresh leaf and mechanical force is employed   to crush everything into PASTE. The soft covering material breaks down into fine particles. Fibers due to their strength, can withstand the force and retain their length but the bundles are defibrillated into smaller diameter. Thus, these fibers with smaller diameter can be directly separated by sieving after drying. This method is simple and could be easily scaled up for a large scale production of short PALF.

The short PALF is used successfully to reinforce a high melting polymer such as nylon. Now hear this: One of the most important barriers to the utilization of lignocellulosic materials in polymer matrix composites is their limited temperature resistance.  As a consequence they are  mostly  used  to reinforce low melting temperature polymers such as polyethylene, and polypropylene as well  a  poly styrene, polypropylene to demonstrate its potential application and found superior to PALF obtained with other methods.. Nevertheless, it can be demonstrated that it can be used to reinforce nylon,  a high melting polymer.  Why?   This is because of its very low lignin content 

INDUSTRIAL USE OF THE PINEAPPLE FIBER.

Pineapple leaf fibers can be utilized   as fabrics for textiles materials and in the manufacture of yarns and handicrafts in many countries. The excellent mechanical properties and environmentally sustainable characteristics exhibited by PALF  have triggered the interest  as a potential reinforcement in structural and non-structural applications.

The cellulose content of the pineapple leaf is 65%. Cellulose is the component that makes the fiber inside non-wood materials stronger. The quality of the fiber produced from non-wood material depends on the content of cellulose, hemicellulose and hollocellulose. Higher content of cellulose can provide stronger fibers, thereby increasing the quality of the paper produced. Lignin content is low, 12%, this is one of the advantages inherent in the use of non-wood materials for pulp production as lignin functions as adhesive to bind the cellulose fiber together. Besides it will require small amount of chemicals for pulping.. Also the low ash content of the pineapple leaf indicates that pineapple leaf pulp has the potential to produce good quality paper.

The technology is there, the raw material abundant. 

So, what are we waiting for—leaders?

 

*Orlando Huaman is an agronomist and a freelance writer. Malololelei.

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