"Paper" PPT

Description

"Paper" PPT

Part One: Learning Objectives

(1) What is the tensile strength of paper in different directions? How to study? (experiment)

(2) After looking at the edge of the torn paper, what did you find?

(3) What is the water absorbency of paper related to? how to prove?

(4) How to conduct transparency experiment? What to pay attention to?

Part 2 content: Classification of paper

Mosquito-proof paper: The UK has developed an easy-to-carry, economical and practical mosquito-proof paper. This small piece of paper is soaked in mosquito repellent and wrapped in tin foil. A small amount can be applied all over the body's limbs, face and neck, and is effective for 5 to 6 hours.

Cold paper: This paper has three layers, with the middle layer containing a mixture of citric and malic acids and sodium lauryl sulfate. Tests have shown that this paper, which is about 6cm2 in size, can kill thousands of cold-causing viruses in less than 1 minute.

Edible paper: A dietary fiber newspaper is made in the United States. This kind of newspaper uses edible ink to print text, which is sterilized and sold to readers. When the reader has finished reading the newspaper, he or she can fold it and enjoy a full meal.

Luminous paper: It emits light in the dark night. Using this kind of paper, the words or pictures on the paper can be clearly seen even without light.

Heat collecting paper: The United States has successfully developed a solar thermal insulation paper that can convert light energy into heat energy. If you use it to wrap food and place it in a place exposed to light, it will continue to heat, and the food can be heated and kept warm. The heat will not dissipate until you open the paper.

Durable paper: Paper generally used for printing will turn into powder after 50 years. If it is a precious document, it must be printed on special paper. A kind of paper has been invented abroad that is not afraid of water, fire, acid, alkali, insect infestation and fermentation mold. It has a variety of lifespans: 100 years for the first grade, 200 years for the second grade, 300 years for the third grade, and some can be stored for 500 to 600 years. Not a bad year.

Part Three: Classroom Extension

Nowadays, almost all major paper-making countries in the world use wood to make paper, and large quantities of trees are cut down all over the world.

Relevant data shows that to make 1 ton of paper, 17 large trees need to be cut down. In addition, a large amount of wastewater is discharged during the papermaking process, polluting rivers and causing serious damage to the environment.

So what do you plan to do in our study life in the future?

Think boldly: What will paper look like in the future? What materials are they made of?

Keywords: Free download of Qingdao version of fourth grade science PPT courseware, first volume, paper PPT download, .PPT format;

For more information about the "Paper" PPT courseware, please click on the "Paper PPT" tab.

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Update Time: 2024-11-02

This template belongs to science courseware Qingdao Edition Fourth Grade Science Volume 1 industry PPT template

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