Materials Included In Kit

Additional Materials Required

Prelab Preparation

Organize paper-making workstations in your classroom. Place the tubs close to the sink areas, if possible. Collect a good quantity of old newspapers for use in this activity. Spread newspapers on top of all work areas to help preserve tabletops and speed up the eventual cleanup.

Safety Precautions

This activity is considered safe. Use cautions when using a blender. Follow blender directions carefully. Follow all other normal laboratory safety rules. Wash hands thoroughly before leaving the laboratory. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron.

Disposal

Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. Do not pour paper pulp down drains! Pulp will clog drains. Allow pulp vats to settle and pour the water off the top of each vat. If a fine strainer is available, the pulp can be more quickly separated from the liquid. Dispose of pulp according to Flinn Suggested Disposal Method #26a.

Teacher Tips

• Enough materials are provided in the kit for all students to make their own paper. Major items, such as the tubs, screens, grids and frames, must be shared by teams of four students. Since these items are used only briefly, this should pose no problem. Batches of pulp may be stored temporarily in other large containers if different student groups want to experiment with different recipes and paper types.

• After the initial paper-making activity, many variations and experiments can be conducted utilizing the basic procedures outlined in the activity. Scents, colors, edging materials, papier-mâché, glue, starch, linen, fibers can all be added to the basic recipe to produce many different types of papers.
• Paper pulp can also be used for art projects and other creative projects. Coordinate with the art department to make the paper-making activity a part of an interdisciplinary project.

Introduction

Glass, plastics, metal cans—we live in an era of recycling. What about recycled paper? More paper is recovered in the U.S. for recycling than all other materials combined. How is recycled paper used in the paper-making process? Learn the principles of paper-making as you make your own recycled paper.

Concepts

• Recycling

• Paper-making
• Sizing

Background

According to historical records paper-making and its use originated in China about 104 AD. Up until then, all writing was done on silk scrolls, which was an extremely expensive and time-consuming process. The empress at the time sought to have a cheaper and easier way to record the printed word. Eventually, a paper was developed using hemp, tree bark, silk and old fishing nets, all ground up into a mushy pulp. The pulp was rolled flat and dried to produce a reasonable paper. Paper-making remained a Chinese art until around 700 AD when, during a war with China, the Arab nations captured paper makers and started making paper in the Middle East. The craft was learned several hundred years later by Western Europeans during the Crusades.

In the 17th century, Europeans were making paper from cotton and linen rags. When paper is made wholly or in part from cotton or linen fibers, it is called “rag bond.” Rag-bond paper is extremely durable and long lasting. In the 18th century, a rag shortage resulted in exploration for alternative paper fiber sources. The industry turned to use trees as a fiber source because of the long cellulose fibers in wood. This started the widespread use of wood fiber for paper-making.

Paper, in its simplest terms, is a very thin layer of bonded fibers. Paper has been made from many different fibers throughout history, but today most paper fiber is cotton, linen, wood or some combination of these. Paper pulp is basically made in one or two ways: (1) raw materials are placed into a giant “blender” and beat to a “pulp” or (2) raw materials are chipped and then reduced into a pulp by cooking them with various chemicals. Expensive papers are usually prepared by the beating method and cheaper papers by the chemical method. Once pulp is made, the rest of the procedure in paper-making usually involves some or all of the following steps: (1) The pulp is rinsed and impurities are removed. (2) The pulp may be bleached white. (3) The liquidy pulp is run over a wire cloth in a large paper-making machine. (4) The sheet is pressed to remove water and then run through a series of rollers. (5) The sheet is dried (often with steam). (6) The sheet is coated or “sized” so it can accept ink. (7) The finished paper is rolled or cut to size.

Paper that is “100% recycled” is made from fibers that have been used before—for example, from small scraps left over from the manufacture of cotton garments. Other papers use cotton pulp often referred to as linters in their mixture. Linters are fibers left on the cotton seed which are too short to be spun into cloth but are excellent for paper. Other recycled paper or paper products of lesser quality are made from cotton fibers and various amounts of wastepaper that has been recycled.

In order for paper to effectively take ink, a special coating called “sizing” must first be applied to the paper. Without sizing, ink simply runs into the fibers and causes blurry print. From medieval times, up to fairly recently, albumin—egg white—was used for sizing paper. As the demand for paper exploded in recent times, much effort was expended to find alternative sizing materials. Modern sizing materials, such as aluminum potassium phosphate and other chemicals, are “acidic” and work well for short-term paper use. However, these acidic chemicals slowly react with the cellulose fibers in the paper. As the fibers deteriorate, they tend to discolor and make the paper brittle. This is not a problem for paper that is used and discarded in a short time. It can be a problem for documents that are to be kept for long periods of time, such as books in libraries. The search for more “neutral” and less “acidic” sizing materials continues in paper research laboratories.

Materials

Safety Precautions

This activity is considered safe. Use caution when using a blender and follow all other normal laboratory safety rules. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron.

Procedure

1. Recycling Materials: Your recycled paper will be a mixture of cotton fibers and recycled paper. The final paper will somewhat be a reflection of the recycled materials used. If recycled brown paper bags are used, your paper will likely be brown and coarse fibered. If notebook paper is used, the resulting paper will likely be more like notebook paper, etc. Collect various types of paper(s) to use in your recycled paper.
2. Making Pulp: Rip the recycled paper into small pieces (size of a penny) and place them into a blender. The loose paper should fill the blender about half full. Fill the blender about half full with hot tap water. Add about 10 g of linters to the mixture. Run the blender slowly at first and then increase the speed until the pulp looks smooth and well blended (30–60 seconds). Blend until no actual pieces of paper still exist.
3. Lifting a Sheet of Pulp: Spread newspapers over the entire work area since the next steps can be messy. Fill the tub about half full with hot tap water. Add the blended pulp to the hot tap water in the tub. The amount of pulp added will determine the thickness of the final paper. If the contents of the tub look like thick cream, the paper will be thick. If the contents look like thin milk, the paper might be very thin. Experiment to find out what consistency is needed for a good thickness of paper.

Place a piece of plastic screening material on top of the rigid plastic grid. Place the wooden frame on top of the plastic screening. With the blended pulp evenly mixed in the tub, lift a uniform sheet of pulp out of the tub on top of the plastic screen. Do this by sliding the entire frame into the tub of pulp and then slowly and evenly raise it back out of the pulp. The goal is to collect an even layer of pulp across the entire screen surface. If not satisfied with a particular sheet, it is easy to return it to the tub and re-suspend the pulp into the tub by stirring. After lifting a sheet of wet pulp out of the tub, it is a good idea to let it drain over the tub before moving it. Tilt the screen slightly out of horizontal for draining. As the wet pulp begins to drain, tilt the frame more steeply until it is almost vertical and let as much liquid drain as possible.

4. Couching the Formed Sheet: Make a couching bed by placing a section of moistened newspaper on a flat, protected work area. (Protect the surface of the desk or countertop with a sheet of plastic or other waterproof material under the wet newspaper.) Pulp will migrate and stick to a damp surface.

Slowly lift and wiggle the wooden frame off, leaving the pulp and screen on top of the plastic grating. Place a piece of couching felt on top of the pulp. Holding the felt, flip the entire set up over onto the newspaper so that the felt is on top of the newspaper. Remove the plastic grid. Carefully peel the plastic screen from the pulp. This might take practice and patience. Once removed, place a second couching felt on top of the wet pulp.

Use a rolling pin or heavy, flat object to press down and squeeze out the excess water. This will bind the pulp fibers together. Remove the felt “sandwich” from the wet paper, place it on top of dry, flat newspaper, and press further with a rolling pin or other flat, heavy object. Continue to press until no more moisture can be pressed out of the felt sandwich.

5. Drying the Paper: Lay the felt sandwich on a flat surface and remove the top felt. The paper sheet should now be exposed. Carefully take up two corners of the paper by curling them back. Hold a corner of the remaining felt and slowly peel the sheet of paper off of the remaining felt.

Dry your paper overnight or speed up the process by ironing it dry. Lay the paper flat on a hard surface to dry overnight. If irons are available, the paper can be ironed flat and dried completely. Do this with the iron set on a very low setting.

Drying time will vary with the temperature and humidity. It is best to dry the paper overnight on a very flat, hard surface under a heavy weight such as a book.

6. Sizing, Experimenting and Using the Paper: Draw two pencil lines on your sheet of paper to divide the paper into three equal sections.

Do not treat section 2 in the middle. Use one end of a cotton swab to smear a thin coating of albumin solution over section 1 of your paper. Use the other end of the cotton swab to smear a thin coating of aluminum potassium sulfate solution over the surface of section 3 of your paper. Allow the paper to dry completely. Use a pen to write your initials on each of the three sections of your paper. How does the ink react to the various sections of the paper? Which section is the best? Which is the worst?

7. Disposal: Do not put paper pulp solution down the drain! Consult your instructor for appropriate disposal procedures.