How to make a good toilet paper that won’t clog the toilet and isn’t easily torn?

You probably use up to 50% of the toilet paper in your lifetime...

so much.

How were they made?

Here is another new series from the Visual Knowledge Institute, How to Make, in which we take you to explore how contemporary life is made and operated.

Why did you choose toilet paper?

because……

Next, we will take you to study this small miracle of human creativity.

Simply put, it only takes four steps to turn a tall and hard tree into the white and soft toilet paper in your hand: making the tree into pulp, further processing the pulp, spraying and drying it into paper, and finally rolling and cutting it into the toilet paper we use.

It sounds simple, but there are some tricks in each step that we are not aware of.

The first step is to create the pulp raw material.

Although there are so many types of toilet paper, the pulp raw material is actually the most important factor that determines the quality and price. The state stipulates that the raw material type must be stated on the packaging of all toilet paper and paper towels. We have specially made a four-quadrant chart to classify the raw materials. With this chart, you can immediately understand the raw material name on the packaging and will not be fooled by the merchants.

The top one is virgin pulp and the bottom one is recycled pulp.

Virgin pulp is made of all new natural plants as raw materials. Pay attention to these three key words: all, new, and natural plants. As for recycled pulp, you can tell from the name that it is produced from recycled materials. What are recycled materials?

We have consulted the national standards and found that recycled pulp can only be made from recycled paper prints and printed white paper edges; it cannot be made from discarded household paper, medical paper, packaging paper, etc.

Recycled pulp toilet paper is generally cheap, but of lower quality. It is easy to lose dust and hair when shaken. You will hardly see this kind of product in supermarkets. Since fluorescent substances and heavy metals are easily mixed in recycled pulp raw materials, this kind of toilet paper is absolutely not recommended for wiping the face or mouth.

In addition to the two concepts of virgin and recycled, toilet paper raw materials are also divided into wood pulp and bamboo pulp. In recent years, there is also pulp made from wheat straw, reeds, sugarcane bagasse and other raw materials, so the horizontal axis can be written as wood pulp and non-wood pulp.

In addition to these clear raw materials, some businesses will use tricky marketing concepts to mislead consumers. For example, "pure wood pulp" sounds high-end, but virgin wood pulp plus recycled pulp can also be said to be pure wood pulp; for example, "pure virgin pulp" may include wood pulp and non-wood pulp.

If you are confused about these concepts, just look for the four words "virgin wood pulp".

After talking about classification, let me tell you something that you may not know: toilet paper is probably the most Nordic product in your home.

The coniferous pulp used to make high-quality toilet paper mainly comes from Nordic countries, as well as Canada, the United States, Chile, Russia and other countries.

my country's environmental protection policy strictly restricts the felling of trees for papermaking. The virgin wood pulp for making high-quality paper needs to be imported in large quantities, with a total volume of 25 to 30 million tons, accounting for almost half of the global trade volume. A giant ship like this one that specializes in transporting pulp is 200 meters long, and it takes more than 700 ships to transport it.

Although the word pulp looks wet and liquid, as a major global trade commodity, it is actually dry and needs to be dried and dehydrated to become fiber blocks like blankets to avoid the shipping industry becoming nature's porter.

The second part is to process the pulp into paper pulp

If the primary processed pulp is made directly into paper, the experience of wiping your butt is similar to that of sandpaper.

In order to make toilet paper soft enough, the pulp must go through a process called pulping. During this process, the fiber shape will be changed, the ratio of long and short fibers will be controlled, and we will feel the softness.

The factory will use pulpers, refiners and other machines to complete this process. Wood pulp is mixed with water to be pulped, and then sand is removed, refined and de-pulped.

After this process, the pulp fibers will be further cut and transformed from thick and straight fibers into broom-like fibers with many fine fiber branches. This process is called "brooming".

Under a microscope, the fibers look like this before pulping, and like this after pulping.

The pulp fibers processed in this way will not only be soft and fluffy, but will also produce a "gel-like substance" on the surface of the fibers when soaked in water, making it easier to combine together to form a piece of paper.

The virgin pulp made from different raw materials has many differences in internal chemical composition and fiber structure, which makes the paper have different properties.

Simply put, the wood pulp fibers of coniferous trees such as pine and fir are long and slender, making the paper stronger and less likely to tear; the fibers of broad-leaved trees such as eucalyptus and birch are short and thick, making the paper soft and more absorbent.

After pulping, manufacturers will mix long and short fibers together according to the product type. Generally speaking, the ratio of long and short fibers is 3:7 or 4:6, so that the final sanitary grade fiber is soft and absorbent, but not easy to be torn during use.

By the way, in order to allow you to flush toilet paper down the toilet, sodium carboxymethyl cellulose (CMC) is added to the paper pulp. It will form a fiber network with plant fibers inside the paper, but it will quickly dissolve when it comes into contact with water, causing the wet toilet paper to disintegrate from the inside and will not clog your home sewer.

The third step is to make semi-finished paper

In this process, the pulp is sprayed evenly onto the mesh through a pressurized nozzle, and then squeezed and dehydrated.

After that, it will enter the drying cylinder for further high-temperature drying. At the same time, high temperature also has a sterilizing effect.

When the dryness is about 93%, a very important process in the toilet paper production process needs to be carried out: wrinkling.

The paper slides against the drying cylinder towards the blade of the scraper, where small wrinkles will be scraped onto the paper, just like the wrinkles left on your face by time.

Wrinkles are essential to toilet paper. The scraper breaks the bonds between the fibers and makes them looser. After wrinkling, the paper can stretch eight times longer, the thickness of the paper increases three times, and the stiffness decreases by 38%, which means that the paper becomes more elastic, thicker, more absorbent, and softer.

This link has a great impact on the final quality of toilet paper. If the scraper is not strong enough, paper will often get stuck; if the paper stays on the scraper for too long, small wrinkles will turn into big wrinkles; generally speaking, the angle between the scraper and the drying cylinder is 18 to 30 degrees.

The cold and hard metal can create fine and even wrinkles on paper through precise angle calculations, and even the slightest change will affect the final user experience.

The paper produced in this process will be rolled into large rolls of paper. Some weigh hundreds of kilograms, and some can weigh several tons. A roll of 200 kilograms of large roll of paper is enough for a family of three to use for 10 years.

Step 4: Finished Product

Single-layer semi-finished paper is too thin and can't give us a sense of security, so the manufacturer will put several large rolls of paper on the machine together and roll them into multi-layer finished toilet paper. Generally speaking, three to four layers of toilet paper can save you paper and prevent your fingers from touching things you don't want to touch.

In order to facilitate tearing when using, dotted lines need to be pressed;

Coreless toilet paper is not a sign of high or low grade, but is suitable for different usage conditions. No matter which one, it needs to be cut into small rolls and then packaged and sold.

After this long journey, a pine tree that had experienced the snowstorms of Scandinavia finally met a fast-growing eucalyptus that had been bathed in the sunshine of South America. In the trials of water and fire, they completely merged into one, becoming white, light, and soft. They embraced each other and walked towards a glorious destination together...

The above is what we have discovered about toilet paper. We will put links to relevant papers and materials at the end. If you are interested, you can do further research.

Finally, there are three points I want to remind you

First, the bacterial colony. The standard for toilet paper is lower than that for paper towels, so the national standard stipulates that toilet paper must be marked with the words "for toilet use" on the packaging. It is really unhygienic to use toilet paper to wipe your mouth.

Second, the amount of powder shed by toilet paper must not exceed 0.5% of its own weight, while paper towels cannot shed powder. Therefore, patients with allergic rhinitis should not use toilet paper to wipe their noses, as the more they wipe, the worse it may become.

Third, paper towels do not contain water-soluble fibers like toilet paper, which can cause them to easily clog the toilet. Therefore, if you temporarily use paper towels instead of toilet paper, it is best to throw it in the trash can.

References:

1.The US Leads the World in Toilet Paper Consumption, Statista

2. "Toilet Paper (including Toilet Paper Base)" GB/T20810-2018, National Standard Information Public Service Platform

3. "Paper Tissue (including wet wipes)" GB/T20808-2011, National Standard Information Public Service Platform

4. Fiber Analysis of Pulp Materials for Daily Use, Chen Chunxia, ​​Chen Runquan, Yu Weimei, Qiu Yugui, Journal of the Chinese Society of Papermaking

5. China Paper Industry 2020 Annual Report, China Paper Association

6. Bamboo pulp papermaking properties and natural color household paper production practice, Fan Leile, Household Paper

7. Optimization of pulping during stock preparation and its effects on paper machine operation and paper properties, Michael J. Kocurek, translated by Fan Jingyang

8. Methods to improve the softness of toilet paper, Yuan Ruihong, Zhao Chuanshan, Heilongjiang Papermaking

9. Research progress on the main factors affecting the softness of tissue paper, Guan Min, Li Chenxi, Liu Hongbin, China Paper

10. Research on the application of sodium carboxymethyl cellulose in water-soluble paper, Hou Yufeng, Tianjin University of Science and Technology

11. Factors affecting wrinkling of toilet paper and their solutions, Li Guangsen, Tissue Paper

12. Optimized wrinkle control technology to improve the production efficiency and softness of toilet paper, Tang Qizheng, Tissue Paper

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