Consumers who drink beverages from polystyrene cups four times a day for three years will have ingested about one foam cup worth of styrene along with the beverages themselves. Although this is an extreme scenario, it paints a vivid picture as to how quickly this toxic substance could bioaccumulate. Some short-term symptoms of exposure to styrene can include irritation of the skin, eyes, and upper respiratory tract, as well as a number of gastrointestinal diseases or distress.
The more severe cases of exposure have been observed in individuals who reside near a polystyrene factory. These individuals can develop more extreme side effects from coming into contact with the substance.
Some hallmark acute symptoms include headache, fatigue, lack of general coordination, and an inability to think clearly. Some hallmark acute symptoms include headache, fatigue, lack of general coordination and an inability to think clearly. As the harmful effects of polystyrene contamination continue to become more well recognized, many coffee cup manufacturers are switching to mainly producing paper cups. Most of these cups are composed of cellulose paper with a PLA lining bioplastic derived from renewable biomass 7.
These paper cups are ideal for holding hot and cold drinks that do not contain ice. The PLA coating provides a protective barrier around the paper to prevent it from becoming oversaturated and saggy. This plastic coating also acts as a glue that keeps the seams of the cup secured together.
Paper cups are normally produced with either a single layer of paper or a double layer. Single-layer paper coffee cups perform extremely poorly when holding really hot liquid due to the dramatic temperature difference between the inside and the outside of the cup that allows condensation to form.
This condensation will soak the paper, causing it to lose its rigidity, and the entire cup could potentially collapse. Double-walled paper cup stack. This additional insulative barrier is present in double-layer paper coffee cups, which are essentially a disposable thermos with an air gap between the two layers of paper. This air gap further reduces the thermal conductivity allowing the coffee to stay hotter for longer and provides an additional protective barrier between the consumer and the hot beverage.
The corrugated ripple cup is another popular choice in the disposable coffee cup industry. This design has the lowest thermal conductivity and lowest thermal effusivity compared to both single- or double-layer paper cups. A corrugated ripple cup consists of three layers of cellulose paper and a top layer formed into a uniquely shaped relief structure.
This design facilitates more effective heat dispersion and eliminates the need for a coffee cup sleeve, an additional source of waste that is frequently associated with serving coffee 7. This is popular among many restaurants and business because it provides them with an additional opportunity to advertise their brand on the plastic wrap. Ideal for Espresso — easy to print — low stacking height. For example, a thin paper label can be applied to an EPS-cup in order to realize a wide variety of prints.
In addition to the perfect de-stacking feature, the CALYX also requires significantly less paper than comparable insulated cups. Naturally, this has a significant effect on the cost of production. We also offer you the possibility to work together with us on the development of new products; from brainstorming to drawings and from sample production through to realization. Contact us! Benefit from the flexibility of our solutions and go new ways.
Our strength lies in the joy of innovation. Insulate with air. Insulate with structure. It is for this reason that electrical wires are coated to make them more safe to handle.
Metals, on the other hand, usually make good conductors. In fact, copper is used in most electrical wires and circuit boards for this reason. Pre-Activity Prediction : Have students feel and examine the test insulating materials Styrofoam, aluminum foil, cotton, air , and have groups make predictions about which they think will work best. Their predictions give some indication of their understanding of heat transfer and insulation concepts. Embedded Assessment : Observe students during the experimental process.
Evaluate their comprehension of the subject matter and activity engagement using the criteria provided in the Rubric for Performance Assessment , which considers their understanding of insulating materials and teamwork.
Homework : Ask students to write paragraph-long answers to the two following questions, to turn in the next day or share in a class discussion. Review their answers to gauge their comprehension of the activity content. Use data obtained from the Data Chart for the bar graph. So students can experience first hand that foil is not a good insulator, extend the activity with this quick hands-on demonstration:.
Kessler, James H. Boston, MA: Delmar Publishers, ISBN: The contents of this digital library curriculum were developed under a National Science Foundation GK grant.
However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government. Why Teach Engineering in K? Find more at TeachEngineering. Quick Look Grade Level: 4 Time Required: 5 hours 15 minutes minute set-up, minutes to freeze, 90 minutes to melt, minute assessment. Quick Look. Print this activity. Suggest an edit. Discuss this activity.
TE Newsletter. Subscribe to TE Newsletter. Summary That heat flows from hot to cold is an unavoidable truth of life. People have put a lot of effort into stopping this natural physical behavior, however all they have been able to do is slow the process.
Student teams investigate the properties of insulators in their attempts to keep cups of water from freezing, and once frozen, to keep them from melting. Grade 4 Do you agree with this alignment? Energy can be moved from place to place by moving objects or through sound, light, or electric currents.
Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced.
Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light.
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