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The term "gel" is usually used to describe any small defect that distorts a film product.It is a common phenomenon in film made of polymers including LDPE, LLDPE, PP and PA etc.The presence of gels is undesirable due to its negative impact on aesthetic and mechanical properties.Eliminating gel defects from extruded polymeric film products is difficult, time consuming and expensive because of the complexity in the formation of the gel.The gels might be unmelted or cross-linked polymer or inorganic contamination which could be characterized by different techniques.In industrial analytical labs, the optical microscope (OM) with hot stage and scanning electron microscope (SEM) are mostly used to observe the shape and size of the gel, in addition,the energy dispersive X-ray spectrometry (EDX) and Fourier transformed infrared microscope (micro-FTIR) can indicate the chemical information of the gel.However, EDX and micro-FTIR analysis are destructive to the film and take extra efforts to prepare samples from the film.In this paper, it is the first time to introduce a direct non-destructive chemical micro-analysis method with confocal Raman microscope (Micro-Raman), which does not need any pre-melt process.