Product design is removable at the design stage， so that parts of the Products has a good performance of the demolition. Conducive to the re-use of components or recycled materials to save not only protect the environment and Materials . The demolition of the design requirements， Product First， connect the various parts and components， as far as possible the use of detachable connection， such as threaded connections， unified type fasteners， reducing the number of fasteners， try not to use welding， riveting， bonding and other non-removable the connection； Second， in the selection and processing of raw materials， the demolition of the connection； to use and reuse of recyclable materials， the types of materials， such as less as possible.

  Recyclable design refers to product design， to take full account of the various materials Product components the possibility of recycling， recovery treatment， recycling and product recovery of costs related to a series of questions， thus saving materials and reducing waste， minimum of environmental pollution for the purpose of a design method. Long-life design is the design of products based on life in the economic indicators to ensure that products， value and environmental requirements at the same time try to make our products to extend the life to achieve the slow resource consumption of a design method. Specifically include the following： First， improving product reliability and durability； Second， products are easy to repair and maintenance； Third，using standard， modular product structure.

3.4 The impact of design material

  ”3r” principle in guidance and norms， product design， material selection should be taken into consideration： First of all， minimize the use of materials. Try using high quality materials to enhance the service life of products； the prohibition of the use of contaminated material against big， look for the corresponding sound material substitution； reuse as much as possible the use of recyclable materials. Secondly， the preferred sound of the ecological environment of the material， after the preferred decomposition of waste and the natural world to absorb the material， preferred low power， low cost， low-polluting materials， preferred easy processing， and processing of non-polluting or less polluting materials， preferred materials recycling. Finally， to reduce the use of the types of materials in order to reduce the cost of Recycling Materials； maintain original material， as far as possible the use of simple materials， the use of alloy materials， to avoid material harm to the environment of the surface treatment； marked parts Products material composition for the materials to facilitate recyclingand so on.

4 From “3r” to 4R

  In the recycling economy mode， the product life cycle from the previous end-of-life for the end product， after the extension to the end-of-life recycling. It should be noted that starting from the waste products for the consideration of a second use for them， so that the product design is no longer a product before， but the other products. Therefore， the design process we will call it "re-engineering (Redesign)"

4.1 The concept of re-engineering

  The so-called re-engineering， that is， through the product components as well as their overall utilization of the re-design method to save resources. Given the United Kingdom Environmental Design Alliance is defined as： "Materials by Product， the structure of a meaningful way to re-use， in order to save resources for the purpose of the premise， to extend the product life cycle， and tap the potential ecological value of the design method." In short， the product re-engineering refers to the product life cycle after the re-use design.

  Whether they are re-engineering the design of a new trend， or the design of a self-activity changes， which are related to the sustainable development strategy in line belong to the scope of green design. If it is said that green design is usually considered the entire product life-cycle environmental impact， and re-design considerations are at the end of product life-weeks to reduce the environmental impact of problem， it is the “3r” principle in the extension of the field of industrial design. Therefore， the re-engineering in conjunction with the “3r” principle， as a mode of circular economy 4R principles of industrial design. “3r”原则对工业设计的影响英文文献和中文翻译(4):http://www.751com.cn/fanyi/lunwen_54641.html