Academic literature on the topic 'Cncu'

Pressure sensitive adhesives (PSAs) are polymeric materials with versatile applications in industrial and consumer products such as protective films, product labels, masking tape, and sticky notes, to name a few applications. World demand for emulsion–based products is on the rise due to worldwide legislation on solvent emissions. In order to completely replace emulsion-based PSAs with their solvent-based counterpart, the property modification of emulsion-based PSAs is required. The use of nanomaterials to modify polymer properties is well established. The aim of this thesis was to use cellulose nanocrystals (CNCs) as property modifiers for emulsion-based PSAs. CNCs are recognized as a highly efficient reinforcement nanofiller. Owing to their environmentally friendly characteristics, low density, high aspect ratio, non-toxicity, and abundant availability, the application of CNCs in composite materials is gaining increasing attention. In this thesis, the inclusion of CNCs in emulsion-based PSAs was carried out through in situ emulsion polymerization and blending technique. To the best of our knowledge, there is limited information about the synthesis of CNC/PSAs nanocomposites via in situ emulsion polymerization and the evaluation of their mechanical performance. The addition of CNCs to the polymerization formulation caused latex instability due to the negatively charged surfaces of the CNCs. After numerous attempts to overcome the stability issues, a stable polymerization formulation and protocol were developed. CNC/PSAs were synthesized via in situ seeded-semi batch emulsion polymerization, which is a common commercial production pathway for PSAs. The mechanical performance of the resulting PSA nanocomposite films, namely, shear strength, tack, and peel strength, was evaluated at several CNC loadings. All three PSA adhesive properties were simultaneously enhanced with increasing CNC loading. The inclusion of CNCs into the films increased their hydrophilicity. Consequently, the PSA films’ improved wettability on a stainless steel substrate imparted greater tack and peel strength. The blending of the CNCs with a base latex also led to improved adhesive properties. However, the property modification through blending was not as effective as that for the CNC/PSA films synthesized via in situ emulsion polymerization. Thus, CNCs are safe nanomaterials that have been shown to provide remarkable property enhancement of emulsion-based PSA films at low loadings (1wt%).

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.<br>Includes bibliographical references.<br>A large-format CNC router has been stored in the Pappalardo Laboratory wood shop for several years in an unusable state. A need assessment determined that it would be cost effective to bring the router online for use in the mechanical engineering curriculum. The router was cleaned and inspected; it was determined that the router was in sound mechanical condition. The stepper motors, control system, and power supply were also functional, but the CNC interface software was outdated. To ensure the long term viability of the router as an effective teaching tool the most cost effective solution was to upgrade the motors, control system, and CNC interface software using a package provided by the original supplier, Techno-Isel Inc. The motors, control system, and software were installed, bringing the router to a fully functional state. Dust and ejected cuttings cause a safety hazard and cleanliness problem when operating the router. An enclosure was designed and installed in order to trap the majority of debris and reduce noise levels in the workspace, and a brief user guide has been compiled to ensure safe and effective usage.<br>by Aaron L. Doody.<br>S.B.

The diploma thesis clarifies the issue of creating inscriptions on stone slabs. It describes some types of sensors, actuators, their physical principles and possibilities of their use. The work mentions the limitations and specifics of sandblasting, design solutions and implementation of equipment for patternless sandblasting.The functionality of the device is demonstrated and verified on illustrative examples.

This diploma thesis serves as a design and implementation of a hobby CNC milling machine, for the modeling community. The work is conceived as an overview of the most common machining technologies. The following is an introduction to the construction of CNC milling machines and an introduction to the basic components used. Furthermore, the actual design proposals and a description of the implementation of two of them are presented. When designing the machine, emphasis was placed on the lowest possible price and availability of individual components.

In today’s society, CNC machines are used for various purposes.In this project, a CNC plotter is created to analyzehow the performance of the plotter differs when using twodifferent motors: a DC motor controlled by a potentiometerin the horizontal direction and a stepper motor in thevertical direction. A CNC plotter is built and used to dotests in order to answer the research question. The resultsshow that a DC motor with a potentiometer is more precisethan a stepper motor and the mean value of the relative errorsin the vertical direction is always higher. The valuesdiffer with 1 percentage point to 3 percentage points. Thedifference in the performance of the two motors depend onseveral factors and one of the main factors is considered tobe the fact that the stepper motor sometimes skips steps.<br>I dagens samhälle används CNC-maskiner för olika ändamål.I detta projekt skapades en CNC-plotter för att analyserahur plotterns prestanda skiljer sig vid användning avtvå olika motorer: en DC motor kontrollerad av en potentiometeri horisontell riktning och en stegmotor i vertikalriktning. En CNC-plotter byggdes och användes för genomförandeav tester för att kunna svara på forskningsfrågan.Resultaten visar att en DC motor med en potentiometer ärmer exakt än en stegmotor och medelvärdet av de relativafelen i vertikala riktningen är alltid högre. Värdena skiljersig från 1 procentenhet till 3 procentenheter. Skillnaden iprestanda för de två motorerna beror på flera faktorer ochen av huvudfaktorerna anses vara det faktum att stegmotornibland hoppar över steg.

This diploma thesis deals with rebuild of manual drill-mill machine BF20L into CNC mill machine, 3D model of that and eventual control using PLC. All axes are powered by stepper motors, with encoders, connected to control cards and industrial computer from company Beckhoff. For this control is made full switchboard, supplemented by electrical wiring diagram. Program control along with visualization is made in software TwinCAT 3. Drill-mill machine can be controlled manually or automatically by program.

This thesis deals with safety of the CNC grinding machines. The first part of this thesis is focusing on legislative requirements of EU and Czech Republic, which concern with topic of this thesis. The second part of the thesis is focusing on the safety of the chosen grinding machine. The main parts of the machine which are important for safety are described and then the checklists for verification of the safety requirements are made.

In today’s society, CNC machines are used for various purposes. In this project, a CNC plotter is created to analyze how the performance of the plotter differs when using two different motors: a DC motor controlled by a potentiometer in the horizontal direction and a stepper motor in the vertical direction. A CNC plotter is built and used to do tests in order to answer the research question. The results show that a DC motor with a potentiometer is more precise than a stepper motor and the mean value of the relative errors in the vertical direction is always higher. The values differ with 1 percentage point to 3 percentage points. The difference in the performance of the two motors depend on several factors and one of the main factors is considered to be the fact that the stepper motor sometimes skips steps.<br>I dagens samhälle används CNC-maskiner för olika ändamål. I detta projekt skapades en CNC-plotter för att analysera hur plotterns prestanda skiljer sig vid användning av två olika motorer: en DC motor kontrollerad av en potentiometer i horisontell riktning och en stegmotor i vertikal riktning. En CNC-plotter byggdes och användes för genomförande av tester för att kunna svara på forskningsfrågan. Resultaten visar att en DC motor med en potentiometer är mer exakt än en stegmotor och medelvärdet av de relativa felen i vertikala riktningen är alltid högre. Värdena skiljer sig från 1 procentenhet till 3 procentenheter. Skillnaden i prestanda för de två motorerna beror på flera faktorer och en av huvudfaktorerna anses vara det faktum att stegmotorn ibland hoppar över steg.

The master's thesis deals with the basic parts and principles of CNC machines with a focus on a CNC milling machine. There are also comparisons of several CNC machines sold. Furthermore, the project deals with the description of the manipulator, which is situated in laboratory E-132 in area Kolejní 4, Brno. The work also includes a description of the device, which is located in the manipulator model. We can find there a description of the program generating G-code from the image that you create in the editor. The next section describes possible modifications of the manipulator for its reconstruction on a CNC milling machine. The last chapter deals with the description of program developed for controlling the manipulator as a CNC milling machine.