Drill Diameter Research Articles

Mechanical peck drilling of Inconel 625: Parametric analysis and grey fuzzy logic based multi-response optimization

Nickel-based superalloy Inconel 625 is considered a hard-to-cut material due to characteristics such as high hardness, strain hardening behavior, and affinity with tool materials. It is challenging to machine through micro-holes of less than Ø 500 µm with the desired quality on Inconel 625 using the mechanical micro-drilling (MMD) process under dry conditions. The machining parameters must be selected optimally to enhance hole quality and to avoid frequent drill breakages. In this study, through micro-holes are machined on Inconel 625 by the MMD process using solid carbide micro-drills under dry conditions using a peck drilling strategy. Experiments are carried out by varying machining parameters such as spindle speed (8000 rpm, 11000 rpm, and 14000 rpm), feed (5 µm/rev, 7.5 µm/rev, and 10 µm/rev), and drill diameter (Ø 300 µm, Ø 400 µm, and Ø 500 µm) at three levels based on full factorial design. Thrust force and hole quality features such as exit burr height, radial overcut, and taper angle are measured as output responses. The mean effect plots are used to study the influence of machining parameters on output responses. The drill diameter had a significant effect on thrust force and radial overcut. Whereas feed and spindle speed had a major influence on exit burr height and taper angle, respectively. Finally, multi-response optimization is carried out using the grey fuzzy logic method, and an optimal machining parameter setting for multiple responses is ascertained.

Drilling- and withdrawing-related thermal effects of implant site preparation for ceramic and stainless steel twist drills in standardized bovine bone.

Excessive surgical trauma is believed to be among the most important causes for early implant losses. As thermal injury to the bone is not only dependent on the amount of generated heat but also on the tissue exposure time, and the greatest temperature increase was found within the withdrawing period, the entire osteotomy procedure with the parameters contributing to thermal damage is of particular clinical relevance. The aim of this study was to investigate the thermal performance of metal-based and ceramic implant drills regarding the temperature exposure time during the whole osteotomy process. This investigation consisted of 240 individual preparations in total, comprising two different drilling depths (10 and 16 mm), two irrigation methods (external and without irrigation), two implant drill materials (stainless steel and zirconia), and three consecutive drill diameters per material (2.0/2.2, 2.8, and 3.5 mm) with 10 identical repetitions. Real-time multichannel temperature measurement was conducted during automated drilling procedures in standardized bovine bone specimens. The maximum temperature changes were highly associated with the time period of passive drill withdrawing (p≤ 0.05), irrespective of drill material, drilling depth, or drill diameter. Statistically significant differences in temperature generation between stainless steel and ceramic drills were observed in irrigated testing sites at both drilling depths with smaller drill diameters (2.0/2.2 and 2.8 mm, p≤ 0.05). Results of this in vitro study could demonstrate a strong association between the highest temperature increase and the passive withdrawing time period in both investigated drill materials. Considering these findings and the resulting thermal bone damage due to the whole surgical procedure, high overall temperatures in combination with a prolonged heat exposure time may impact the future osseointegration process.

Study on Mechanical Properties and Delamination Factor Evaluation of Chemically Treated Nettle Fiber Reinforced Polymer Composites

ABSTRACT The exceptional benefits of natural fibers like high weight ratio, biodegradable and low density increased the usage of natural fibers reinforcement in polymers that has increased in recent years. To enhance bonding strength between polymers and natural fibers, this research paper is focused on the possibility of utilizing epoxy resin and nettle fiber to develop a biocomposite. In addition to that surface modification of nettle fibers has been done using different concentration of NaOH, KOH, and NaHCO3. The treated fibers were then reinforced in the epoxy resin to investigate the influence of chemicals on the mechanical properties of developed composites by performing tensile strength, flexural strength, and impact strength. The investigation results revealed that during the experimental investigation, maximum tensile strength (30.13 MPa), flexural strength (22.36 MPa), and impact strength (9.21 J) were discovered for 5% NaOH. Besides the mechanical testing, the fabricated composites were conventionally drilled to investigate the effect of spindle speed (50–800 rev/min), feed rate (0.125–1.2 mm/min), and drill diameter (4–8 mm). The study suggested increase in delamination factor at a higher feed rate and drill diameter. SEM was done on the drilled hole to observe the delamination damage.

Heat generation during implant site preparation and its effects on osseointegration: A review

Dental implants act as a bridge between the oral environment and deep core structures of the jaw. The temperature rise leading to heat generation in the course of operation of the dental implants results in thermal injury of the adjoining bone tissue to the implant site resulting into implant failure. Present review is focused on existing research done in the heat generation and its distribution during dental implant drilling. Various factors such as drill speed, drill design, mode of irrigation, depth of drill, drill diameter, drill material that affect osseointegration due to heat generated while drilling, are compared. The motive of this review is to assess the various factors that are responsible for heat generation and their effects on osseointegration during osteotomy. A systematic study reveals that the rise in the temperature at the implant site mainly depends upon the drill speed, drill diameter, depth of drill as well as irrigation used. The purpose of this review is taking these factors into consideration to find out the best possible parameters during implantation to avoid bone necrosis. The temperature during dental implantation ranges from 35 ℃ to 43 ℃ while in some in-vitro studies the temperature increases up to 50 ℃ was observed which is not admissible due to the thermally induced necrosis.

Study of the burr height at hole exit in bone drilling by twist drills.

The burr at the hole exit is one of the key factors affecting bone drilling performances. In order to reduce burr height at hole exit during cortical bone drilling, the four key parameters in twist drilling of bones are analyzed based on the response surface method (RSM). The prediction model of the burr height is obtained via the analysis of variance. The influence trend and size of each factor on the height of the burr are further analyzed based on the RSM. Experimental results show that smaller point angle and diameter of the twist drill, smaller feed speed, and higher rotational speed can effectively reduce the burr height at hole exit. Then, the geometric variables of the twist drill and process parameters are optimized. When the point angle of the twist drill 2Φ = 95°, the diameter D = 2.5 mm, the rotational speed n = 1500 rpm, and the feed speed vf = 10 mm/min, the height of the burr at hole exit reaches the smallest. At the same time, the burr at the exit of the hole with different diameters of twist drills is studied. It is found to be beneficial to select a twist drill with a smaller diameter for drilling when the requirements of drilling are fulfilled.

Multi-Response Optimization during the High-Speed Drilling of Composite Laminate Using the Grey Entropy Fuzzy Method (GEF)

The machining of glass-fiber-reinforced composites is complex due to their heterogeneous structures. Research has indicated that high-speed machining, at high spindle speeds and feed rates, not only increases productivity but also reduces drilling defects, such as delamination. However, there are several challenges with high-speed machining, such as the heat generated during drilling between the drill tool and chip contact surfaces that can result in hole size errors. Therefore, it is essential to determine the optimum drilling parameters. This paper presents an innovative hybrid optimization approach called Grey Entropy Fuzzy. This approach is a combination of entropy-based weight integrated Grey Relation analysis and fuzzy logic. With the consideration of all responses simultaneously, an optimum machining combination was obtained at a spindle speed of 12,000 rpm and a feed rate of 0.02 mm/rev using a drill bit with a point angle of 118° and a drill diameter of 6 mm.

Delamination studies and effects of machining parameters on delamination of PC-GFRP and aramid-GFRP composites

Delamination is a critical problem in composite machining.. This problem has been studied systematically using the Taguchi L27 array for two composites polycarbonate-GFRP and aramid-GFRP. The Input variables of the spindle speed, feed rate, and drill diameter were varied and the effects of the input variables on delamination was studied. For the aramid GFRP, drill diameter, spindle speed and feed rate affected the delamination in that order, whereas for the GFRP-PC, the order of importance was drill diameter, feed rate and spindle speed. Regression equations were developed for both cases, which can be used to predict delamination for any intermittent combination of the input parameters.

Simplified Method for Reduction of Displaced Condylar Head Fracture Using a Monocortical Screw.

Condylar head fractures is difficult to treat because of medial displacement caused by muscle pull and limited access to visualize the proximal segment and secure them back to anatomic position. A novel technique is proposed to overcome the difficulties and ease the task of a surgeon. The main goal in Open reduction and internal fixation is to achieve anatomical position and establish occlusion, a task possible only after securing the segment back into place. Over decades, many authors have described various techniques to ease the task yet surgeons are forced to treat cases using closed technique which adds limitation to the rehabilitation of stomatognathic system for a prolonged time. Self holding screw driver, 1.5x10mm monocortical screws and drill bit. Using any preauricular access incision, dissection is proceeded anteromedially and the medial segment is identified. A drill hole is made with 1.2 mm diameter drill with counter using periosteal retractor, monocortical screw fixed and segment secured using a self-holding driver and lateralized after increasing the joint space thus achieving the original retromandibular height. The treatment outcomes are better achieved with ease to surgeon and with minimal armamentarium without any special needs per se. The technique proposed is novel and can help achieve desired outcomes even in hands of budding surgeon with minimal time and efforts invested.

Application of grey-fuzzy logic for the optimization of drilling parameters for coir fibre reinforced composite

Coir Fibre Reinforced Composite (CFRC) materials have possible applications in different areas like auto, aviation, structural designing, sports, wind energy and so forth. Yet, CFRC drilling stances numerous issues that decline the nature of openings. The issues which influence the nature of boring are the over measuring, delamination factor, and the harshness of the openings. To acquire the best and ideal machining quality we should think about ideal boundaries of drilling. In this work, Taguchi's L27 symmetrical cluster is utilized to perform drilling of CFRC composite plate. Fuzzy and Grey fuzzy analysis on MATLAB is also conducted to confirms the optimum values for drill diameter, spindle rotary speed and feed rate of drill. The wear rate of the tool, material removal rate from the composite and roughness of the surface are measured and optimized using the MATLAB analysis. Examination of difference (ANOVA) is utilized to observe the rate commitment of the penetrating boundaries and observed that rate of feed is the most powerful variable in boring of CFRC composites. In this investigation, the multi-objective issue is changed over into a solitary objective improvement involving GRA method and further vulnerabilities in the dim result are diminished by fuzzy relational hypothesis.

Study on the Construction Method and Effects of Ipsilateral, Multi-Nozzle, High-Pressure Jet Grouting Cut-Off Wall

High-pressure jet grouting is widely used in the construction of cut-off wall in hydraulic engineering. Compared to the high-pressure jet grouting used for foundation improvement, the high-pressure jet grouting cut-off wall of hydraulic engineering has lower requirements for the advance consolidation and provision of bearing capacity, and more focus on providing an anti-seepage effect and ensuring the continuous integrity of the wall. In the past, the research on high-pressure jet grouting focused more on the application to foundation treatments, and the research on the construction efficiency of cut-off wall is relatively insufficient. Therefore, in this study, a self-developed ipsilateral multi-nozzle jet grouting machine with a large drill diameter and construction method are proposed according to the construction characteristics of the embankment cut-off wall in hydraulic engineering. Based on the dyke protection projects, Jinggangshan navigation hydropower and Xingan navigation hydropower, the large-diameter, multi-nozzle, high-pressure jet cut-off wall test is carried out, and the wall forming effect of the cut-off wall is verified through the combination of indoor and outdoor tests. The results show that the proposed construction method can adapt to the formation conditions in which it is difficult to implement conventional high-pressure jet grouting, and obtains good construction efficiency. A favorable wall quality can be obtained by using more efficient large-diameter and ipsilateral multi-nozzle jet grouting in the construction of high-pressure jet cut-off wall.

Modeling and influence of thrust force torque and delamination during drilling of natural fiber composite

AbstractNatural fiber composites are named sustainable, renewable environmentally friendly materials. Machining the fiber reinforced composite is difficult due to their anisotropic and heterogeneous nature. Computer numerical controlled drilling caused severe delaminating at the entry and exit of the drilled hole. These can be minimized in several ways such as process parameters, fabrication method, and reinforcement arrangements (Orientation/Treatment/Aspect ratio/Fiber volume fraction). Thrust force and torque are caused machining of composites, it can be controlled by spindle speed, feed rate, and cutting velocity. It has been observed that the output responses such as thrust, torque, delamination peel up and push out of composites depend on the diameters of the drill bit (6, 8, 10 mm), cutting speeds (1000, 2000, 3000 rpm), and feeds (10, 20, 30 mm/min). Total 27 numbers of holes were drilled based on Taguchi L‐27 factorial design orthogonal array. Response surface methodology has been employed to compare input drilling parameters and output responses. It is found that a smaller diameter drill bit of 6 mm with a higher speed of 3000 rpm and lesser feed of 10 mm/min produced high‐quality holes.

An analytical and numerical approach to the determination of thermal necrosis in cortical bone drilling.

In the process of repairing fractures in the bone region with orthopedic injuries, the application of supporting and strengthening the bone tissue with screws, wires, rods, and plates is a widely preferred internal fixation method. In this treatment process, it is necessary to drill the bone tissue to fix the screws. Due to the heat generated in the drilling process, mechanical and thermal damage occurs in the bone tissue. In this study, it is focused that the effect of different cutting conditions on the temperature distribution and necrosis zones in the drilling of human cortical bone. In this context, by selecting variable drill geometry (diameter, point angle, and helix angle) and variable cutting parameters (cutting speed and feed rate), temperature distribution and necrosis zones were investigated with finite element analyses and analytical calculations. When the findings were evaluated, it was understood that drill diameter and cutting speed did not have a significant effect on temperatures and necrosis zone at low cutting speeds. At high cutting speeds, it was observed that the feed rate and drill point angle had an indeterminate effect on the temperatures. The lowest temperature values were obtained at cutting speed of 750 rpm and a feed rate of 0.1 mm/rev for low cutting speeds, and cutting speed of 1500 rpm, helix angle of 10° and drill bit diameter of 2 mm for high cutting speeds. The narrowest necrosis zones were obtained at cutting speed of 250 rpm and feed rate of 0.1 mm/rev for both drill diameters. As a result, the effects of different drill geometry and cutting parameters were determined in order to obtain low temperature distribution and narrow necrosis zone in cortical bone drilling.

Accuracy of guide wire placement for femoral neck stabilization using 3D printed drill guides

BackgroundThe goal of stabilization of the femoral neck is to limit morbidity and mortality from fracture. Of three potential methods of fixation, (three percutaneous screws, the Synthes Femoral Neck System, and a dynamic hip screw), each requires guide wire positioning of the implant(s) in the femoral neck and head. Consistent and accurate positioning of these systems is paramount to reduce surgical times, stabilize fractures effectively, and reduce complications. To help expedite surgery and achieve ideal implant positioning in the geriatric population, we have developed and validated a surgical planning methodology using 3D modelling and printing technology.MethodsUsing image processing software, 3D surgical models were generated placing guide wires in a virtual model of an osteoporotic proximal femur sawbone. Three unique drill guides were created to achieve the optimal position for implant placement for each of the three different implant systems, and the guides were 3D printed. Subsequently, a trauma fellowship trained orthopedic surgeon used the 3D printed guides to position 2.8 mm diameter drill bit tipped guide wires into five osteoporotic sawbones for each of the three systems (fifteen sawbones total). Computed Tomography (CT) scans were then taken of each of the sawbones with the implants in place. 3D model renderings of the CT scans were created using image processing techniques and the displacement and angular deviations at guide wire entry to the optimal sawbone model were measured.ResultsAcross all three percutaneous screw guide wires, the average displacement was 3.19 ± 0.12 mm and the average angular deviation was 4.10 ± 0.17o. The Femoral Neck System guide wires had an average displacement of 1.59 ± 0.18 mm and average angular deviation of 2.81 ± 0.64o. The Dynamic Hip Screw had an average displacement of 1.03 ± 0.19 mm and average angular deviation of 2.59 ± 0.39o.ConclusionThe use of custom 3D printed drill guides to assist with the positioning of guide wires proved to be accurate for each of the three types of surgical strategies. Guides which are used to place more than 1 guide wire may have lower positional accuracy, as the guide may shift during multiple wire insertions. We believe that personalized point of care drill guides provide an accurate intraoperative method for positioning implants into the femoral neck.

Optimization of Machining Parameters in Drilling of Glass/Hemp/Bamboo Fibres Based Hybrid Polymer Composites

Significance of composite materials is increasing enormously in the progress of modern science and technology. The composites can be transformed into suitable components with high precision by machining, which can be used for present day applications. Drilling is crucial operation that is often used in the assembly of composite parts to obtain finished product. But the drilling induced damage may affect the performance of the composite. The present work is focused on the impact of various parameters in drilling like feed rate, spindle speed and drill diameter on surface roughness and delamination of glass/hemp/bamboo fibers embedded polymer hybrid composites. The composite is prepared by hand layup method. The drilling on composite is done on a CNC drilling machine and the maximum diameter due to delamination is measured using profile projector. To optimize drilling parameters for the sake of reducing the surface roughness and delamination factor, Taguchi method applied. The measured results are analyzed using commercially available software package Minitab19. The analysis is carried out using ANOVA (Analysis of Variance). In order to obtain best optimal conditions GRA (Grey Relational Analysis) is adopted. The results show that among all important parameters, feed rate and drill diameter are more crucial for surface roughness, whereas delamination is impacted by feed rate and speed of spindle.

Comparative evaluation of the virtual planned position and actual position of implant in mandibular posterior region using a DIOnavi system

Statement of problem: Implant placement in the mandibular posterior regions is often challenging because of limited space and insufficient accessibility. Purpose: The purpose of this clinical study was to investigate the accuracy of computer-guided surgery with a long drill key to place implants in the mandibular posterior regions. Material and methods: Computer-guided implant surgery was performed for 15 participants requiring implants in mandibular posterior region. This procedure involved using 6mm long drill key to guide the 2.0 mm diameter drill. The planned and placed implant position were scanned and superimposed to evaluate the accuracy of the guide. Results: A total of 15 implants were place where the mean linear deviation was 0.4 mm (range, 0.15 to 1.30 mm) for the implant shoulder and 0.45 mm (range, 0 to 1.48 mm) for the implant apex. The mean angular deviation was 1.4 degrees (0.38 to 4.89 degrees). The mean depth deviation was 0.61 mm (0.10 to 1.85 mm). The differences between virtually planned implants and actual positions of the implants were statistically significant for all variables (P<.05).

Undersized Implant Site Preparation to Enhance Primary Stability in Computer-Guided Flapless Surgery: Sequential Drilling Protocol

Achieving primary implant stability in areas with poor bone density is often challenging for the clinician. This modified surgical protocol might be beneficial in such situations in computer-guided surgery. The purpose of the present clinical application is to give the clinician the sequence and steps for undersized implant site preparation in areas with poor bone density. After an evaluation of the bone density with the software on the CT scan, the implant site is prepared with drilling while remaining undersized. The implant is then inserted by setting the torque of the implant motor to 35 N-cm. When the desired torque is achieved, the distance between the implant and the bushing is measured. The rule suggests that if more than 3 mm are missing at the lower limit, it is advisable to remove the implant and prepare again with the next diameter drill, if it is less than 3 mm it is possible to use the method of self-tapping directly with the implant. The surgical drilling protocol allows the clinician to limit the number of drills and to use the implant mounter as a reference point when it stops at a certain distance from the bushing. The results of this clinical application suggest that undersized implant site preparations may help enhance primary implant stability in computer-guided surgery and that there are significant correlations among bone density, maximum insertion torque, implant mounter and drilling kit.

DRILLING MECHANISM BASED ON THE APPLICATION OF DIAMOND DRILLING BITS

In order to express how much the drill selection depends on the rock properties and its effect on the percentage of core and drilling speed, diamond drill selection and drilling mechanisms are taken. In diamond drills, enough pressure should be applied to ensure that each active diamond grain sinks into the rock for the best drilling speed. This stress should be above the surface strength of the rock to be drilled and below the diamond grain strength. The main goal to be achieved in engineering and research and development studies is to ensure that both the designed system and the product to be developed have maximum performance. In order to reveal the conditions in which the best results will be obtained, first the feature that determines the performance is determined and the factors affecting this feature are examined. Then, experiments are carried out to determine the effects of these factors on the feature that determines the performance and to find the most suitable combination (by taking into account the uncontrollable factors). Optimum conditions are determined by evaluating the performance indicator obtained as a result of the experiments. The experiments carried out within the framework of this approach can be perceived as the question asked to the system, and the results of the experiments as the answer given by the system. The critical point is that it is necessary to ask the right question in order to get the right answer. Drilling is a complex event influenced by many factors. Drill type and diameter, rotational speed, pressing force, torque and circulating fluid are controllable parameters. On the other hand, physic mechanical properties of the rock and geological conditions (uncontrollable factors such as discontinuities, bedding conditions, grain size, matrix structure, porosity, cementation degree and abrasive mineral ratio) affect rock drill ability. The drill ability of rocks can be defined by various concepts such as feed rate, drill wear amount, drill life and tooth penetration. Drilling method classification can be made according to several criteria. The most logical classification can be made according to the type of energy required for rock fragmentation. Drilling is done in rocks for many purposes and many methods developed for this purpose have successfully drilled into rocks. Many new methods in rock drilling have been acquired through experience. The most successful practical application is the mechanical shredding process. Although it is mostly applied for cutting soft rocks, this method is done by spraying high pressure water. Keywords: drilling, drilling process, drilling operations, tools, drilling mechanism, drilling diamond.

A comparison of radial increment and wood density from beech provenance trials in Slovenia and Hungary

Provenance trials are a valuable source of information, especially in species such as European beech (Fagus sylvatica L.), which will likely increase its distribution due to global warming. The current study compares radial increment and wood density of beech provenances in the juvenile development stage from contrasting environments in Europe (Belgium, Slovenia, Czech Republic, Italy) planted at a mesic to wet site in Slovenia and a xeric site in Hungary. Existing data (past measurements of diameters and height) were combined with new measurements of tree height, diameter, dendrochronological and resistance drilling density measurements to assess differences in provenance radial growth. The wood density data were evaluated using a Bayesian general linear model. In order to study the differences in radial increment in more detail, two weather-wise contrasting years (2014 and 2017) were selected from the last decade, based on calculations of the 12-month Standardized Precipitation-Evapotranspiration Index. The differences in average tree-ring width among provenances at each sampled site appeared to be relatively small when averaged over a whole decade of data. However, according to year-to-year data, some provenances grew faster than others, especially in favorable weather conditions. In unfavorable conditions, the differences in tree-ring widths among provenances were smaller. For most provenances, variation in tree-ring widths within the same provenance increased in unfavorable conditions. The difference between the provenances with the highest and lowest wood densities at both locations did not exceed 5%. The model results indicate that the Idrija (Slovenia) provenance probably has a higher median wood density than other studied provenances at both sites. Although the current study confirmed some differences in wood density between provenances and trial locations, the differences are negligible in practice due to their low magnitude and the fact that the analyzed trees were still juvenile. As beech has a diffuse-porous wood, negligible differences in wood density would also be expected in adult trees. Beech provenances for planting in relation to changing weather should probably be chosen for their ability to survive more extreme weather events rather than to improve radial increment or wood density, especially as the differences in wood density of juvenile trees are relatively small.

Modeling and Analysis of Surface Roughness Parameters in Drilling of Silk-glass/epoxy Composite

In the recent past, the demand for multifunctional and lightweight materials have increased steadily creating an increase in demand for Hybrid polymer matrix composite which consists multiple fibers in conventional resins. In this study, a hybrid composite comprising of two reinforcements - natural silk fiber and E-Glass fiber - in an Epoxy resin matrix which is a partially eco-friendly composite has been fabricated and the effect of drilling, by using an 8 facet solid carbide drill, on the surface roughness has been studied. Taguchi�s L27 Orthogonal array was used for experimentation by modifying three parameters - feed rate, spindle speed and drill diameter - on three levels (low, medium and high) and thereby studying the effects. From the results of experimentation it has been observed that increase in spindle speed and drill diameter reduces surface roughness however it increases with increase in feed rate. Further, regression analysis and Fuzzy modeling are used in order to determine optimum parameter values to get the desired surface finish. Good agreement between the experimental, regression and fuzzy model is observed with the correlation coefficient of 0.9814 and 0.9677 respectively.

Delamination and surface roughness analysis of jute/polyester composites using response surface methodology: Consequence of sodium bicarbonate treatment

The present research work explores the consequence of eco-friendly sodium bicarbonate treatment on drilling behavior of jute fiber reinforced polyester composites. The fiber surface treatment was done by immersing the jute fibers in sodium bicarbonate solution (10 wt.%) for five days at room temperature. The raw and treated jute fiber composites were produced through compression molding process. The drilling behavior was expressed in terms of delamination factor (at entry and exit) and surface finish. The response surface methodology coupled with three factors—three levels Box–Behnken Design was used to study the interactive effects of process variables (drill diameter, feed, and cutting speed) on delamination factor and surface finish. Furthermore, the significance of the developed model was examined through analysis of variance. The chip morphology of the fabricated composites was examined to assess the quality of the drilled hole. The fractography analysis of the machined surface has also been carried using scanning electron microscopy. The outcomes revealed that the sodium bicarbonate treatment of jute fiber improved the machinability of the composites.