The chosen filling material for the designed filling mechanism is the Semperit cookie dough. For the Semperit dough, a non-Newtonian fluid mixture, the liquid phase is made up of an aqueous solution of polymers including gluten, and starch solid particles. The dough mixture at this phase is a suspension of solid particles in a fluid of high viscosity. The particles are flocculated, giving the filling material yield stress that responses differently to different forces applied on it. At small magnitude stresses, dough behaves like a solid because the flocculated particles act like a skeleton.
The Van der Waals forces between flocculated particles are weak as when applied moderate stresses onto the dough mixture, the behavioural flow is like the flow of liquid(Mills, 1985). The Semperit dough mixture are best described as a dilatant non-Newtonian fluid.
Soft doughs such as Semperit dough have rich texture and rheological properties with the associated high viscosity. This type of dough cannot be produced by sheeting, printing, rotary cutting or rotary moulding.
The said properties make shaping and drawing from moulders difficult. Extruding devices were specially designed to address the soft dough’s shape issues. The machine for extruding and depositing is usually designed with grooved roll feeder or plunger feeder.
Design & Prototyping Using SolidWorks
SolidWorks software are the most used 3D design and analysis software being used in education and industry nowadays. SolidWorks software provides various types of features suitable to the necessity of machine or product design. Most SolidWorks software features can be run on a normal laptop fulfil the requirements the software needed. The SolidWorks requirement of different versions are as follows:
Table 3. 5 SolidWorks Software requirements for Windows OS(Dassault Systemes SolidWorks, 2019).
(EDU 2018-2019) SOLIDWORKS
(EDU 2019-2020) SOLIDWORKS
Windows 10, 64-bit
Windows 8.1, 64-bit
Windows 7 SP1, 64-bit
Virtual environments Supported virtual environments (hypervisors)
Processor 3.3 GHz or higher
RAM 16 GB or more
PDM Contributor or Viewer: 8 GB or more
Graphics Card Certified cards and drivers
Drives SSD drives recommended for optimal performance
Microsoft Excel and Word 2010, 2013, 2016 2013, 2016,
2019 (SW2019 SP2) 2013, 2016, 2019
Antivirus Antivirus products
SolidWorks 3D CAD Design
The SolidWorks design software utilises the 3D virtual design approach. The initial of the design within the will be created as a 2D model. From this model, 3D model can be created. SolidWorks are also very good in creating models that are based on multiple components. SolidWorks has features that enable processes of mating different components to make parts or subassemblies that will make up a complete 3D assembly. The finished 3D filling machine can be the same as physical version of the filling machine after fabrication.
Identify the filling mechanism requirements
Conceptualize the filling mechanism based on the identified needs
Develop the filling mechanism based on concepts
Analyse the filling mechanism
Prototype the filling mechanism
Construct the filling mechanism
Edit the filling mechanism for optimisation
Figure 3. 4 Design process steps
SolidWorks Simulation Add-in Tools
SolidWorks are developed to enable any desired analysis to be conducted on a product or system. The software allowed tests to be conducted via simulation without forsaking a physical prototype to achieve research objectives. SolidWorks analysis can be used without worrying about space within the device memory as the software are integrated within the SolidWorks 3D CAD software. SolidWorks can conduct many types of analysis such as static and dynamics stresses analysis, thermal analysis, fatigue studies, and many more. The description of type of analysis can be conducted using the software for this research are as follows(Dassault Systemes SolidWorks, 2015a):
The SolidWorks analysis tool analyse the stresses or deformation of a product or system and compare it to allowable levels in order to predict possible failure modes. The results of analysis will inform whether there is a need to change the design of any core components of the design. This analysis is done using the SolidWorks Simulation tool.
Figure 3. 5 SolidWorks Simulation Interface(Dassault Systemes SolidWorks, 2010b).
The SolidWorks analysis tool allow the virtual testing or simulation of the designed products before the fabrication phase. Any fault in design during concept phase can be easily detected and dynamic interference detection to construct engineering models can be taken. . This analysis is done using the SolidWorks Simulation tool.
The SolidWorks analysis tool are capable of analysing various fluidic systems and help in the system design that consists of nozzles, valving, pump systems and lubrication systems. This analysis is done using the SolidWorks Flow Simulation tool.
Figure 3. 6 SolidWorks Flow Simulation Interface(Dassault Systemes SolidWorks, 2010a).
The SolidWorks tool help the designers that require the analysis run on complex designed machines parts, subassemblies, and full assemblies. The software eases the process of assigning different materials to different parts of the assembly and specify how the components will interact with each other. This analysis is done using the SolidWorks Simulation tool.
The design method utilises the SolidWorks 3D CAD Design to complete the design of the filling mechanism system. The method below focuses on the steps including 2D drawing, 3D extrusion and assembly(Dassault Systemes SolidWorks, 2015b).
Below is the method to apply the 2D drawing tool using SolidWorks 3D CAD Design:
Create new SolidWorks sketch as a .SLDPRT file.
Create sketches of design concepts. Sketch in the form of 2D profile or cross section of a component.
Make use of element such as origin, planes and dimension to determine the correct orientation of the design.
Decide every possible dimension and its magnitude on the design.
Determine where are the part of the design to apply any type of specific relation.
Determine the appropriate features to be used and its order of usage.
Decide the components and its order to mate and types of mate most suitable based on functionality of the design.
Once complete with the sketch, proceed with extruding the 2D model into 3D model.
Below is the method to apply the 3D extrusion tool using SolidWorks 3D CAD Design:
Create 3D model using features such as extrude or revolve for models with curved surface.
The 3D model surface can be further detailed using applied features such as fillets, chamfer, or shells to the existing geometry based on the pre-determined dimensions.
For components that have standards in real world application, the component (screws, nuts and washers) can be imported from sources such as the GrabCAD website.
Once the 3D model of the component is completed, save the work and exit SolidWorks.
Below is the method to apply the assembly tool using SolidWorks 3D CAD Design:
Create new SolidWorks assembly as a .SLDASM file.
Import the required parts for this component assembly that was created earlier.
Mate the components base on how the parts should react with each other in real application.
Use tools such as Move Component or Rotate Component to see how the parts function in the assembly in a 3D context.
Use Collision Detection to find any collision when the parts are supposed to move.
Once all components have successfully assembled to form a complete functioning machine, create drawing blocks of isometric view or the standard 3D view. Import the dimensions from model document to complete the drawing.
Any changes in the finished design can be changed using the SolidWorks Feature Manager design tree and the Property Manager.
Save work and exit SolidWorks.
Simulation and Analysis of the Design
The analysis method utilises the SolidWorks Simulation and SolidWorks Flow Simulation to analyse the fluid flow and the filling machine mechanism. The following steps focuses on the static analysis and fluid flow analysis.
Equations Related to Flow Analysis
Analysis are crucial designing processes as the results of analysis is used to set the specifications of the design. Basic equations can be integrated into SolidWorks Simulation in order to find the needed data. Some basic equations that can be used for filling machine related issues analysis are as follows:
The flow of fluids is highly dependent on the type of the flow: laminar, turbulent or transitional flow. Each type of flows has different ranges of Reynolds number. Flow with Reynolds number smaller than 2300 are considered as laminar flow in a pipe. Flow with Reynolds number bigger than 4000 are considered as turbulent flow in a pipe. The flow with Reynolds number between 2300 and 4000 is deemed as transitional flow(Cengel & Cimbala, 2014).
v_avg = average velocity (m/s),
D = internal diameter (m),
? = dynamic viscosity (Pa*s) and
?/?= kinematic viscosity of fluid (m2/s)
Pressure drop has a direct relation with the power consumption by the pump to maintain the flow. So, it has been a subject of interest for the analysis of fluid flow. The pressure drop in laminar flow can be calculated by the following formula(Cengel & Cimbala, 2014).
?p=(128?Lv ?)/(?D^4 )=(32?Lv_avg)/D^2
Where V ?=v_avg (?D^2)/4
V ? = Volumetric flow rate(m3/s)
? = Dynamic viscosity (Pa*s)
v_avg =Average velocity (m/s)
L = Length (m) and
D = Diameter (m)
A certain amount of energy is required to move a given volume of fluid through a cylindrical body. The energy is required for a liquid to move; the pressure difference provides that. The resistance to flow costs some energizing force during the flow. This resistance to flow is called head loss due to friction. The formula for the calculation of head loss in fully developed circular flow is below called Darcys equation(Cengel & Cimbala, 2014).
h_L = Total head loss (m)
f = Friction factor of pipe internal surface.
L = Length of pipe.
D= Internal diameter of pipe.
V_avg= Average liquid velocity (m/s)
g = Gravitational acceleration (g = 9.81 m/s2)
Volumetric flow rate
It is defined as the Volume of fluid that flows past a given cross-sectional area per second. Its SI unit is m3/s. Volumetric flow rate is a part of mass flow rate since mass has a relation with volume by means of density. It can be calculated as the product of the cross-sectional area (A) of flow and the average flow velocity (V_avg )(Cengel & Cimbala, 2014).
Mass flow rate
Mass flow rate is defined as the measure of the mass of fluid passing through a point. Its unit is kg/s. The mass flow rate is related to the volumetric flow rate as explained above. It can be calculated as the product of density (? ) and volumetric flow (Vavg*A ?)(Cengel & Cimbala, 2014).
Average velocity is defined as the average speed through a cross section of a pipe. For a fully developed laminar pipe flow average velocity is the half of the maximum velocity. The properties of fluid are calculated at an average temperature and treat that as a constant(Cengel & Cimbala, 2014).
Pump efficiency is defined as the ratio of product of volumetric flow rate and pressure
head of the pump to input power. Pump efficiency is the dimensionless quantity and expressed in the form of percentage(Cengel & Cimbala, 2014).
?=((V ??P)/(Input pow?r))^* 100%
V ? = Volumetric flow rate
?P = Pressure head of pump
More equations involved will be discussed in Chapter 4.