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The need for stamps in manufacturing sectors is generally met by using punch and die systems. In these systems, the desired slug diameter is processed into the die diameter, the punch diameter is reduced by the amount of the cutting gap size and the punching operations are performed on the molds or apparatus. In this study, the slugs obtained by punching holes in MWCNTs (multi walled carbon nanotubes) doped and undoped GFRP (glass fiber reinforced polymer) materials using Ø8 mm punches with 90°, 15°, 30°, V, C type cutting forms in molds with 0.16 mm cutting gap were examined. As a result of the study, it was determined that the slugs obtained in the punch cutting form took the form of punch cutting, and the diameter of the slugs obtained in the punching of the undoped composites with a 90° flat form punch was % 4.75 and % 0.72 larger than the punch and die diameters, respectively. In addition, MWCNTs additive to GFRP composite materials increased the strength of the materials and ensured that the slugs obtained as a result of cutting the material with a punch were more rigid. For this reason, it was determined that the slug diameter of the doped composites was larger than the punch diameter and smaller than the mold diameter. [ABSTRACT FROM AUTHOR]

Sheet metal molds are preferred for punching identical metal, plastic and composite materials, which are widely used in the automotive and household appliances sectors in the industry. Developing technology, increasing production capacity and competition conditions encourage manufacturers to produce more with less cost and to improve production processes. In this study, the variation in cutting force was investigated by drilling holes with uncoated and TIN coated punches in molds with a cutting clearance of 0.025 mm, 0.10 mm, 0.15 mm on pure and MWCNTs-reinforced GFRP composite materials. As a result of the study, it was determined that the average cutting force needed in punching processes using TIN coated punches decreased by % 10.10 and % 4.50 respectively in doped and pure composites compared to uncoated SBZ punch use. In addition, it was measured that with the reduction of the cutting clearance on the die, the need for cutting force increased. [ABSTRACT FROM AUTHOR]

In the industry, drilling method is used to both assemble materials with bolts, rivets and pin joints and to create holes on them. Burring, delamination and material splintering are observed during the drilling of composite materials. Machining parameters, mechanical properties of the drilled material and drill point angle are the most important factors affecting the hole quality. In this study, the effect of the addition of nano-sized additive to glass fiber reinforced composite plates and the effect of these materials on drillability were investigated. It has been observed that the addition of nanoparticles to the laminated glass fiber composite materials plays an effective role in the strength of the material and affects the quality of the holes. Drilling operations which used by constant spindel revolation, if feed rate increases, burring also increases. It is also clear that drilling point angle increase caused drilling hole diameter increment. It was seen that the epoxy layer was separated from the block-shaped glass fiber layer at the outlet of the holes drilled using 90° and 140° angle drills. [ABSTRACT FROM AUTHOR]