Alkaline pulping processes on different biomasses, used at large scales, have well-known and proven effectiveness. Kraft cooking produces cellulose for paper and dissolving-pulp qualities (case of the PHK process), but its high production unit’s capabilities make it difficult to use them for small biomass quantities, such as biomass wastes. Using such material, our study presents a new mild alkaline pulping process to produce delignified wood fibers and Microfibrillated Cellulose (MFC). The herein developed process has been tested on poplar residues from the wood packaging industry. This pulping process is based on a first cooking step in mild alkaline conditions, followed by a Totally Chlorine Free (TCF) bleaching sequence to complete delignification and increase brightness. Fiber production was compared at laboratory scale with the Kraft process followed by an equivalent TCF bleaching sequence. MFCs from unbleached and bleached pulps were further produced by pulp grinding followed by high pressure homogenization. In order to assess the quality of the resulting bleached and unbleached fibers and MFCs, the various products were evaluated by determining their chemical composition, lignin content, cellulose quality, and fibers and MFCs morphologies. Handsheets and films were also produced to assess their suitability as parts of different new materials. All these properties were compared with those obtained for the reference Kraft pulp.