Introduction

When, at the beginning of the semester, we were doing our segment on papermaking, I was intrigued by several samples I had made in the Oriental papermaking fashion. In the experiment we used kozo fiber and formation aid to create a sheet of paper by washing the solution over a bamboo mat rather than letting it drain through the mold. The results were much thinner and more flexible, but much more difficult for me to rip than the paper we had made using cotton or abaca pulp and a regular mold. For this reason I decided to experiment with the Oriental papermaking style. I was mostly interested in creating the thin sheets that result more easily from the Oriental style; the sheets we had made in the traditional Western fashion were thick. In doing some research on the different fibers I found that the kozo fibers, along with the other Oriental fibers, tended to be much longer than other Western fibers. I became curious to see if the shorter fibers in the Western pulps would be able to work in the Oriental style, and to mix Oriental and Western fibers and observe the results.

Background

Purpose:

            The purpose of this lab was to test my hypothesis in discovering which fibers created the strongest and most flexible papers in the Oriental style of papermaking.

Hypothesis:

            My hypothesis is that the kozo pulp will create the strongest and most flexible paper because it has the longest fibers. I think that Spanish flax will be the next strongest, then kozo mixed with the Spanish flax, and finally the kozo and abaca mixed together. I believe that the kozo and Spanish flax will also be the second   most flexible, because Spanish flax also has a fairly long fiber, and then in descending order of flexibility will come Kozo and abaca mixed and then Spanish flax on its own.

Materials:

The materials I used were as follows:

• tub (x2)
• mould
• deckle
• bamboo and mesh mat
• pulps: kozo, abaca, and Spanish flax
• beater
• 3000 ml beaker (x2)
• hot plates
• pH paper
• formation aid
• felts
• pelons
• roller
• board
• ring stand
• weights

Factors:

            There are a fairly large number of factors involved in this project. Included in these are the fibers themselves because qualities such as their length and structure will affect the project. Also, the amount of formation aid used will affect the drainage time of the water and so how the paper is formed. The number of times that the mould is dipped into the solution, the density of the pulp solution, and the method of drying will all have effects on the paper results. The method of preparation of the pulps such as beating times can affect how well the paper forms. The only factors that I want to allow as variables are the different pulps; the rest of the factors will be kept constant.

Procedure

My procedure involved several steps and took several days. The first order of business, besides collecting all of the required materials, was to prepare the pulps. For the abaca it was not a problem; the pulp had already   been beaten by another classmate and I was able to use her pulp. The Spanish flax, however, was still in the form of half-stuff and the kozo was still a bunch of dried out stems.

            The first pulp I prepared was the Spanish flax, since it was the easier of the two.   Because the beater that the laboratory has is a two-pound beater, I had to measure out roughly half a pound to fill the beater sufficiently. I weighed out 208g of Spanish flax half stuff, and then soaked it and tore it into small pieces before I put it into the beater.   I beat the flax at a beater setting of two for thirty-five minutes while taking samples to check drainage time before I decided that it had been beaten long enough. Once that had been beaten I set it aside in a tub and began to prepare the Kozo.

	The kozo as it looks prior to preparation.

            The Kozo preparation took several days to prepare because it was in plant form when I began. First I measured 230g of raw kozo. This had to then be cooked for several hours in a solution of water and washing soda. The washing soda was kept the solution base and helped to break down the lignin that holds the kozo fibers together. This process of cooking took several hours, in which I checked the pH of the solution every ten or fifteen minutes to make sure that it was not becoming too acidic. If the acidity increased I would add a little bit more of the washing soda to maintain the pH. The process of cooking took two hours and fort-five minutes.

	The kozo cooking on the bunsen burners. The water it was cooking in turned brown as a result of the breakdown of the lignin.

        Once it was cooked I drained the solution from the fibers and rinsed it several times until the water draining through the kozo fibers was clear. This was to make sure that the broken down lignin and other bits of bark that would color it were drained off, as well as other impurities that would affect the paper. I then had to cut the long strands up, since they were still in the long form from the branches of the bush. I cut them up into approximately three-inch strips, which was fairly easy since the cooking had broked the fibers down a great deal.

	The kozo after having been cooked for approximately three hours.

            The kozo fibers were now ready to be beaten. The beating time took much less than it had with the Spanish flax; I only beat the kozo for fifteen minutes on a beater setting of three before I decided that the fibers were beaten enough, since the drainage times in the samples I was taking were decreasing. I then stored the kozo in a tub.

	The kozo rotating through the beater.

            Once all of the fibers were prepared the process became a great deal simpler. I decided to begin with the pure kozo sheets, since I had already worked with kozo in the Oriental papermaking style and was more confident that it would work. I placed about 8400ml of the kozo pulp solution in the large tub I had set up, and then about 5600ml of water, since the kozo was fairly concentrated solution and I didn't want too much fiber. I then added about three plastic containers' worth of formation aid (using the plastic container I found in the bucket). I stirred up the solution to make sure it was evenly distributed, and then began to make the paper.

            To do this I had to fasten the bamboo mesh mat between the wooden mould and deckle, being careful to keep the orange-stitched side of the mat facing me. I then would dip the mould and deckle into the solution, allowing the pulp to wash over it three times to coat the mat before I let the solution wash back and forth over the mat. I rocked it back and forth over the mat six times, until I could tell that the pulp was getting thick enough that a sheet would form. I then placed the mould against a stick laid over the tub and let the excess moisture seep out. When it had stopped dripping too much I removed the deckle and liften the mat off the mold. I did not have to hold it horizontally; the fibers would stay on the mat even when help perpendicular to the counter-top. I could then roll the sheets onto the pelons   without having to apply much pressure at all, although sometimes the first edge of the sheet needed to be coaxed to leave the mat. I repeated this proces four times, making four samples of pure kozo sheets.

	The mold and deckle as it is about to be dipped into the pulp solution.

            This process of making the sheets was the same for the kozo and abaca mixture of pulp. I had originally planned on making a set of samples of pure abaca, but the abaca had gone bad by the time I began to use it, and I was only able to use it to mix with the kozo. I made four samples of that mixture, using roughly as much abaca pulp solution as the kozo, though I believe that the abaca solution was more dilute. I did the same for the Spanish flax and the mixture of Spanish flax and kozo, doing my best to make sure that I had roughly the same amounts of pulp solution for all types of fiber.

            Once I had made each of the samples, I rolled it onto a pelon on top of two felts and then laid another pelon and felt on top of the wet paper and rolled it with a soda bottle full of water to squeeze out the excess moisture. I would then take the sheet of paper and press it against a white board to dry.

            When all of the sheets had dried I could then test their tensile strength and their flexibility. For their tensile strength I cut a smaller piece from one sample of each fiber.   I then cut a hole in the top and the bottom of each piece of paper, large enough that I could slide the metal piece sticking out from the ringstand through the hole in the top of each piece of paper. From the bottom of the piece of paper I would then hang the weights, starting with 50g.   I would add weights in 100g and 50g increments until the paper tore all the way through. For this reason I hung the paper fairly close the the counter-top.

	A sample piece of paper being tested with weights: this piece is holding 150g.

Observations and Data

The data and observations for beating Spanish flax:

The observations and data for the preparation of the kozo:

Cooking the Kozo:

Beating the kozo:

Making the sheets of paper:

On April 27, 2004

Kozo:

Kozo and Abaca:

April 29, 2004

Spanish Flax:

Spanish flax and Kozo:

Testing the sheets for tensile strength:

Flexibility test:

Conclusions

When I originally planned this lab, I made my hypothesis based on my observations of the kozo, abaca and by looking at the Spanish flax half-stuff, since I had not originally planned on using Spanish flax and did not have any information on it at the time. Having since done some research on the different fibers, however, I am better able to understand the results that I got.
I was not surprised by the strength of the paper samples made by the kozo fiber; I had observed the strength before, although I did not expect that it would be able to hold 950g of weights before ripping through. However, I was surprised that the Spanish flax had as weak a result as it did, and was not nearly as flexible as I had anticipated. Flax fibers tend to be very long, and I had thought that they would intertwine nicely and form a strong paper like the kozo. The fact that it only held 150g of weight certainly was not what I had anticipated. The results were soft and did not easily bend; the paper ripped when I folded it over a fifth time. From what I understand the cell length of the flax can be very long, anywhere from ten to nearly forty millimeters in length. However, their diameter is thin, which may affect the overall strength of the paper when the fibers are mixed. Also, the way that the fiber is prepared is often by retting, which is a process of basically rotting the fibers to decompose the pectins that bind the fiber to the inner core of the plant stem. This decomposition may have an effect on the fibers themselves and I believe that part of this process may cause the paper to have been as weak as it was.
I was also surprised at the kozo and abaca’s tensile strength and flexibility. The abaca fiber also has a relatively long average length, from 4 mm to 6 mm, which is comparable to the kozo’s average fiber length of around 7 mm. Both abaca and kozo are known for their tensile strength and flexibility, and it would explain their ability to make stronger, more flexible paper. However, given that Spanish flax’s fiber length is much greater there must be other factors that affect the paper’s strength. I think that the abaca would have been even stronger, had it not been beaten for so long and had it not been rotten. Also, I was not able to control several factors that may have had an effect on the fibers. For example, the fact that it began to decompose certainly affected my project in that the pulp was decomposing as I was making the paper. Also, the preparation of the three fibers was different in that the Spanish flax was in half-stuff and I do not know how it was prepared or retted prior to my using it. All of these probably altered my results somewhat, although in what way it is hard to tell.
Another aspect of my project was that it altered significantly from what I had originally planned. First of all, I had initially wanted to use hemp, but decided against it because I did not want to have to order it and risk being rushed at the end, and at Dr. Bordley’s suggestion I ended up using Spanish flax instead. I had also only planned on making three samples with each fiber, but I felt like that was a waste of pulp so I made four, also to give myself more practice in using the mould, since it’s actually a rather difficult process. These changes, fortunately, have not had any great affect on my project.
However, there were some other alterations that had to be made that affected the results somewhat. First of all, I had not anticipated the amount of preparation required for the kozo pulp; I had not realized that the pulp would go bad over time and that I would need to make more. As a resul I prepared the the kozo fibers while the Spanish flax and abaca were prepared by others.
Also, when I decided to change to the Spanish flax as opposed to hemp, I thought that I would make a sample of pure abaca fibers; and I would have liked to have mixed Spanish flax and abaca. However, because I used the pre-beaten abaca it had gone bad by the time I was making the sample sheets of paper and it smelled horrible, so I ended up using the abaca only for a mixture with the kozo. I think that the rotten abaca fibers probably were not as strong as they would have been had they not been rotten and that my results might have changed somewhat; I would at least have had another group of samples to look at.
My conclusion is that my hypothesis was correct for the most part. Kozo was the best fiber in that it was the strongest and most flexible of those that I tested. The Spanish flax, however, was not nearly as strong as I had predicted, probably as a result of the structure and length of the fibers themselves. The abaca was stronger than I had thought, though I think that it might have been stronger had it not been going bad when I was using it. The fact that it had been beaten for sixty minutes may also have had an effect; if it was over-beaten then the fibers may have been broken down so much that their ability to come together in the piece of paper may have been hampered.
I think that my results were accurate as they could have been given the materials that I was working with, but could I do it again I would try to prepare all of the fibers from the beginning so that I could be assured that all of the factors were as much under my control as possible, avoiding too long a beating time and other such misshaps as I encountered this time.
Regarding the results of my experiment, my original idea that the longer fibers would create stronger, more flexible paper clearly did not work out, since the flax tends to have longer fibers than both kozo and abaca. The length may make somewhat of a difference, but I am more inclined to think now that actual physical properties such as the make-up of the fibers themselves and the preparation process required for the fibers in order to make them paper-worthy are more likely to affect the strength and flexibility of the paper.

Links

These are the links I used to find information on the fibers I was using:

www.gametec.com/fiberwars/chp3.html

www.isarogpulp.com/origin.html

www.legionpaper.com/features/japanese.htm

www.noteaccess.com/MATERIALS/Glossary.htm

Acknowledgements

I would like to thank Julie Jones for lending me her equipment for use in this project.