Lesson Two Materials of Packaging1. petrochemical a 石油化工的2. synthetic rubber n 合成橡胶3. adhesive n 粘接剂4. solvent n 溶剂5. paragraph n 段，章节，v 分段6. limestone n 石灰石7. jar n 广口瓶8. tumbler n 平底杯9. jug n 带受柄壶罐10. carboy n 大型圆形瓶11. vial n 小药水瓶12. (be) spotted in 出现于13. item n 条款，工程，物品14. carbonated beverage n 碳酸饮料15. spice n 香料16. granular a. 成颗粒状的17. instant coffee n. 速溶咖啡18. mayonnaise n. 蛋黄酱19. pickle n. 泡菜20. fruit preserve n果脯21. screw n.螺旋，螺丝； vt. 拧紧，用螺旋紧固22. drug n. 药物23. drum n. 桶，钢桶24. secure vt. 使平安，使紧闭25. coated with tin 镀锡的26. lined with sealant 以密封胶添衬27. dent n. 使凹陷28. susceptible (to) a. 易于 ，对什么敏感的29. folding carton n 折叠式纸盒30. collapsibility n 可压扁性，可折叠性31. supportive a 支持的，拥护的32. rival vt. 同竞争； n. 对手，竞争者33. durability n 耐久性，耐用性34. pasted open mouth 粘制开口袋35. sewn open mouth 缝制开口袋36. stitch vt. 缝合； n. 缝纫37. reusable a. 可重复使用的38. palletize vt. 把装在托盘上，托盘化Materials of PackagingTwo major aspects in designing the package are careful consideration and evaluation of all available materials that could be used. Of particular importance are the static electricity, humidity, temperature, and barrier qualities; the material should keep out water and moisture, greases, oils, gases, and odors while holding in the product. The most common types of packaging materials are glass, steel, aluminum, paper, cardboard, wood, and petrochemical products such as synthetic rubber and plastics. Various chemicals, adhesives, inks, and solvents are also used in developing the final package. We discuss a few of these materials in the following paragraphs.u Glass One of the oldest packaging materials is glass. It is formed by melting the sand with limestone and soda ash. Glass has the advantage of being strong so as to securely hold the product, but it is relatively heavy for handling and is fragile, breaking easily upon dropping or bumping. Packages formed from glass include bottles, jars, tumblers, jugs, carboys, and vials.The bottle is the most popular form of glass container. It is generally characterized by its narrow neck and mouth. The bottle is used primarily for holding liquids, and the small mouth minimizes the overall size of the closure. Numerous bottles can be spotted in the average home, storing such items as medicines, carbonated beverages, juices, and spices. A bottle with a wide mouth is classified as a jar, which is commonly used for food in a viscous, semisolid, or granular state.Common kitchen items stored in jars include instant coffee, jelly, mayonnaise, peanut butter, and pickles. The tumbler and jug are two more glass containers that are variations of the bottle. A tumbler is an inexpensive drinking glass that is frequently used for packaging jams, jellies, and fruit preserves. The top is pressed on instead of being screwed on as in the case of a jar. When the original contents are consumed, the tumbler may become a drinking glass. A large bottle with a handle and a screw-on cap is called a jug and is frequently used to store liquid chemicals and foods. Carboys and vials are so named because of the relative thickness of the glass. A carboy is a bottle made of very heavy glass used to hold liquid industrial chemicals, whereas a vial is a small, thin, tubular glass container used for expensive and sensitive drugs.u MetalSteel and aluminum are the most commonly used metals because they are readily formed into cans and drums. Cans are constructed in two or three pieces. In two-piece construction, the metal is formed into the shape of a cup, and the top is added to seal the can. For three-piece construction, the metal is formed into a tube, the top and bottom are produced separately and are then secured to the cylinder to make the can. The inside of the can is frequently coated with tin or lined with a plastic sealant. The light weight of these cans and their resistance to chemical reaction with the product make them attractive, but they dent easily; and if made of steel, they are susceptible to rusting.u Paper ProductsCartons and bags are two major paper products used in packaging. They are very common because of their availability and ease of manufacturing, storing , and labeling.u Cartons:The folding carton is the most popular form of cardboard packaging because it is economical in terms of both the cost of the material and the cost to produce the finished carton. Their collapsibility makes them easy to ship, since they can be folded flat and may be stacked. Cardboard cartons are versatile, allowing for different styles and numerous printing and labeling methods. Lightweight cartons are relatively flimsy, not giving much much protection to the contents; but heavy corrugated cardboard boxes rival those made of wood.u Bags:Bags are a form of packaging that can be made resistant to moisture, is easy to