A knit line is any line, visible or not, where two resin flows meet. Depending on the design of the mold and the material being injected, a knit line may present no problem at all, may be a cosmetic issue, or may cause a serious structural problem.
Good article. In many electromechanical assemblies, Agency requirements can matter also. A polymer may be the perfect match for the strength, finish, etc. needed for the product. However, that particular grade of polymer may not have the flame retardant properties needed to pass 94V-0 at the specified thickness in order to achieve agency certification for the entire product. It is important to also consider agency requirements up front during product development to make sure the entire product can be certified.
In this new Design News feature, "How it Works," we’re starting off by examining the inner workings of the electronic cigarette. While e-cigarettes seemed like a gimmick just two or three years ago, they’re catching fire -- so to speak. Sales topped $1 billion last year and are set to hit $10 billion by 2017. Cigarette companies are fighting back by buying up e-cigarette manufacturers.
Microchip recently released the 3D TouchPad, the first USB PC Peripheral device that couples 2D multi-touch input with 3D air gesture technology. The company seeks the help of developers to further enhance the capabilities of the technology.
To give engineers a better idea of the range of resins and polymers available as alternatives to other materials, this Technology Roundup presents several articles on engineering plastics that can do the job.
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