There are basically three Coefficients of Friction (Figure 1) that take place in the feed section of the screw, (1) between the barrel and the pellet, (2) between pellet to pellet, and (3) between the root of the screw and the plastic pellet.
Screw and barrel wear is critical in all plasticating applications whether it is extrusion, injection molding, and blow molding, plus twin screw extrusion. Excessive screw and barrel wear can cause instable throughput or recovery on reciprocating screws, increased melt temperature and reduced plasticating rates.
There are two different areas of screw design for thermoplastic composites: the screw
design which is being used to make the thermoplastic compound and the screw
design which is used to process the compounded thermoplastic. This paper
mainly discusses the latter of the two types, but many of the issues are pertinent to both.
Screw and barrel wear is critical in all plasticating applications whether it is extrusion, injection molding, and blow molding, plus twin screw extrusion. Excessive screw and barrel wear can cause instable throughput or recovery on reciprocating screws, increased melt temperature and reduced plasticating rates.
There are two different areas of screw design for thermoplastic composites: the screw
design which is being used to make the thermoplastic compound and the screw
design which is used to process the compounded thermoplastic. This paper
mainly discusses the latter of the two types, but many of the issues are pertinent to both.
Rubber extruders have a varied field of application. So, when you come across a rubber profile, strip, hose, cable, wire, cord coating, tire tread, v-belt, tube, or blank remember that they are only a few handful of products manufactured using extrusion process. In this Knowledge On-The-Go Special Supplement, we bring to you a ‘collector’s edition’ on Extruders and Extrusion incorporating the fundamentals.
Screw and barrel inspection plays a very important part in achieving exceptional production performance. The screw and barrel are major components of extrusion, injection molding and blow molding processes, and should be measured for wear at least once a year (preferably twice a year). Many U.S. companies schedule preventive maintenance (PM) during the week of Independence Day and again during the week of Christmas.
This presentation includes basics of mold design, important aspects of molds and mold design that will be useful for understanding design, material aspects, and theoretical aspects of mold making and mold engineering. ProE mold design module known as Pro/MOLDESIGN is also briefly explained in the slide.
http://www.spiratex.com/ : Understand the complete process of custom plastic extrusion with step by step details of the process through this presentation. It also explains the various specialized forms of plastic extrusions.
The material handling of the feedstock is a very critical part of the extrusion process. If the feedstock is not introduced to the feedsection of screw in a smooth and uniform matter, then the likelihood of a stable and consistent output is unlikely. This is the reason why it is very important that if regrind is added to the virgin feedstock, it must be done very consistently and uniformly. It should also be mentioned here that a very important part of the extrusion equipment is the hopper and feedthroat section. If the hopper and feedthroat sections are not designed properly, inconsistent material flow to the screw can take place. For example, if the conical section of the hopper (see figure) does not have the proper transition, the resin will not flow smoothly into the feedthroat of the extruder.
Rubber extruders have a varied field of application. So, when you come across a rubber profile, strip, hose, cable, wire, cord coating, tire tread, v-belt, tube, or blank remember that they are only a few handful of products manufactured using extrusion process. In this Knowledge On-The-Go Special Supplement, we bring to you a ‘collector’s edition’ on Extruders and Extrusion incorporating the fundamentals.
Screw and barrel inspection plays a very important part in achieving exceptional production performance. The screw and barrel are major components of extrusion, injection molding and blow molding processes, and should be measured for wear at least once a year (preferably twice a year). Many U.S. companies schedule preventive maintenance (PM) during the week of Independence Day and again during the week of Christmas.
This presentation includes basics of mold design, important aspects of molds and mold design that will be useful for understanding design, material aspects, and theoretical aspects of mold making and mold engineering. ProE mold design module known as Pro/MOLDESIGN is also briefly explained in the slide.
http://www.spiratex.com/ : Understand the complete process of custom plastic extrusion with step by step details of the process through this presentation. It also explains the various specialized forms of plastic extrusions.
The material handling of the feedstock is a very critical part of the extrusion process. If the feedstock is not introduced to the feedsection of screw in a smooth and uniform matter, then the likelihood of a stable and consistent output is unlikely. This is the reason why it is very important that if regrind is added to the virgin feedstock, it must be done very consistently and uniformly. It should also be mentioned here that a very important part of the extrusion equipment is the hopper and feedthroat section. If the hopper and feedthroat sections are not designed properly, inconsistent material flow to the screw can take place. For example, if the conical section of the hopper (see figure) does not have the proper transition, the resin will not flow smoothly into the feedthroat of the extruder.
Hot runner nozzle is one of important components of hot runner system. It is very important to control temperature of hot runner nozzle in injection mold. If temperature at the gate is too high, melt will stick to valve needle when mold is opened. If temperature at the gate is too low, melt at the gate will be too cold, which will make valve needle difficult to close.
When a new extruder is installed, or a new screw mounted in an existing machine, do you know what the expected throughput rate is going to be? You should. If you don’t baseline your extruder, then how are you going to set realistic expectations for its performance? If extrusion screws are designed properly, they typically will be able to withstand the maximum torque available from the extruder and the resin being processed. The extruder should operate at approximately 90% of its full available torque, based on 100% pellet feedstock, which typically will be the worst-case scenario. By using today’s barrier screw technology, higher throughput rates, lower melt temperatures, and better power efficiencies can be obtained. This article will provide some basic insight to help processors to determine if they are obtaining the maximum production rates from their extruders, providing that they have adequate downstream cooling and handling equipment in the extrusion system.
Computational fluid dynamics simulation of single screw extruders in cable in...eSAT Journals
Abstract The flow of polymer pellets along the solid conveying screw of a single screw extruder is studied by use of a numerical model
based on the Finite Volume Method (FVM). The screw profile of existing Nokia-Malifer plastic extrusion devices (for cable
industries) was mesured.Model predictions used is the Power law for Non-Newtonian Fluid, the results are compared with
experimental data, showing a good match. The feasiability of using CFD models for designing plastic extrusion devices is
analyzed. Basic parameters such as temperature, velocity profiles and pressure show high degree of similarity to practical results.
KeyWords: CFD, Single Screw Extruder, Ansys Fluent, Numerical Simulation
Est group harbin urea conference 2014 pap paper v1 englishJim Novak (吉因龙)
An Improved Tube Plugging Technique for Ammonia and Urea Plant Heat Exchangers. Eliminates Welding, Reduces Downtime and Increases Reliability
We will provide details documenting the development of Pop-A-Plugs specifically for this service and how this significantly reduces the shutdown time required to seal tubes in such service. Everybody knows that welded plugs in high pressure heat exchangers in urea plants are prone to leaking problems as the proper quality of the welds is difficult to assure. Pop-A-Plug® System plugs promise a much better reliability than welded plugs.
Practice:
Well made, clamped, and temperature stabilized circular O-rings should be used in the design of
reliable, reusable and long life seals in vacuum sealing applications. Benefits:
Leak free flanges as well as low/undetectable outgassing of the elastomeric materials can be achieved at pressure levels as low as 10-8 Torr by using well made O-rings in a static vacuum seal environment. The use of O-rings has provided ease for running environmental tests on the ground using space simulation chambers.
Optimux globe control valves provide superior performance while permitting easy, fast, and inexpensive maintenance. Unlike diaphragm-operated control valves, the Piston cylinder-actuated OpGL™ provides stiffness, maintains high positioning accuracy control – making for the world’s most efficient and accurately responsive valve.
For more information on TrimTeck OpGL valves in Northern California, contact:
Belilove Company Engineers
21060 Corsair Blvd
Hayward, CA 94545
Phone: (510) 274-1990
Fax: (510) 274-1999
E-mail: sales@belilove.com
Almost all processes, extrusion, injection and blow molding require that regrind be used in the process. Depending on the process greatly determines the amount of regrind that is generated. Some processes produce very minimal amounts of regrind, such as an injection molding process using a hot runner system versus a flat sheet extrusion process producing thermoformed sheet and the entire skeleton has to be fed back into the process or a blow molding process which always generates large amounts of regrind.
I have written in the past about screw/barrel wear and also screw rebuilding, but there are some screw and barrel shops that offer an alternative for excessive barrel wear and that is honing the barrel oversize and then rebuilding the screw oversize also to fit.
Recently a processor installed a new screw into their 6” x 32:1 L/D extruder. Within a few weeks the hard facing that had been welded on the flight OD started to pop off. (As shown in the attached photo) The flight failure was in an isolated area, so it was then assumed that the failure was due to a poor weld bond. The screw was ultra-sonically inspected and the remaining flights showed good bore, but the entire screw was rebuilt and returned to the customer.
Extruder or Injection Molding Machine Startup and Shutdown ArticleR&B Plastics Machinery
Many companies have their own procedure for starting up and shutting down an extruder or injection molding machine and, depending on the process, there may be reasons for the specific method. But from the point of view on the effect of the screw itself, the following procedure will produce the best overall results.
I was recently asked to visit a facility that was a flat sheet producer to determine the cause of a major screw design problem. So, as always, I have to start at the beginning to gather all of the technical information to determine the root cause. This facility had 5 large extrusion sheet lines and they were issues with all 5 extruders...
Since the early 1990’s INGEO™ resins have made enormous improvements in the process ability of their bio-polymer resins. In the early days, when the resin was first being manufactured at pilot plant levels, extrusion processing of INGEO™ was very difficult.
Today, natural additives are being used to improve the process ability of these resins. Several new lubricant additive packages were tested to determine which package produced the best overall performance and process improvements. The process data was used to quantify the process ability of the various additive packages.
The data was then compared to the internal pressure data that was collected to analyze and determine the best overall additive package.
This paper will compare the total power consumption of two different means of heating/cooling systems: air and water. For a single 90mm extruder, the total power consumption, output rate, and thermal control will be used to compare the two cooling means. Four different resins will be used.
Plasticization rates can be greatly increased with the use of grooved feed extrusion. Grooved feed extruders can be used in a wide range of extrusion processes for higher output rates. This technology has doubled plasticization rates for some resins and processes as compared to smooth bore extruders.
This paper will compare the performance of three different screw geometries while processing fractional melt HDPE. One of the main methods of evaluation will be the comparison of internal pressure profiles over the entire length of the screw at eleven different locations down the length of the barrel at two L/D apart.
The effects of running different barrel temperature profiles for various resinsR&B Plastics Machinery
Differences in solids conveying, screw pressure profile generation, output, motor energy required, will vary between resins, barrel temperature profiles, and resin preheat temperatures, on a single stage low compression barrier screw design.
Melt pump performance and efficiencies will vary according to the viscosity of the resin being pumped, and the discharge pressure that the melt pump will need to overcome. Resin melt temperature differences and power requirements of the pump, will vary according to the resin, and conditions that the pump will operate under.
This paper will explore the processing differences in resins on gear pump performance at different pump speeds, at three different discharge pressures. Discharge pressures on the pump will be varied keeping the suction pressure constant, thus increasing the change in pressure across the pump. Melt temperature, and pump efficiency. melt pump motor amperage, and total output, (kg/hr) will then be measured and recorded.
From time to time it is necessary to do a complete an audit on the condition of an extruder to make sure that it is operating in top condition for maximum effectiveness and efficiency. The following some general information that should be considered to accomplish a good Extruder Audit.
The paper presents a fundamental study of the polymer flow within a “wave” type screw channel. The analysis is performed on an “unwrapped” form of a conventional screw channel and a “wave” type channel of similar size. A 3D Finite Element Method
(FEM) simulation was used to simulate the flow field and flow characteristics of the wave channel are compared relative to the plain channel.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Water Industry Process Automation and Control Monthly - May 2024.pdf
Extruder Screw Cooling
1. Screw Cooling
There are basically three Coefficients of Friction (Figure 1) that take place in the feed section of
the screw, (1) between the barrel and the pellet, (2) between pellet to pellet, and (3) between
the root of the screw and the plastic pellet.
5
Coefficient of Friction
(in the feed section of the screw)
1. Pellet to the barrel wall
2. Pellet to the root of the screw
3. Pellet to Pellet
1
2
3
Screw
Cooling
Screw cooling on the feed section core of the screw should always be installed. In most cases,
screw cooling will be a benefit to the process. It will give the operator another “zone” of control
of the extruder. The main theory of “solids conveying” is that the resin must “stick to the barrel”
and “slip on the screw”. By cooling the root of the screw it will reduce the Coefficient of Friction
between the steel of the screw and the plastic pellet.
By installing a rotatory union to an extruder screw, as shown in Figure 2, you can have many
positive affects to your processing issues.
Figure 2
Figure 1
2. One advantage to using screw cooling is when regrind is part of the feedstock recipe; there are always traces of “fines” in the regrind. These fine particles will always melt quicker that pellets and pellet-size regrind particles and therefore stick to the root of the screw in feed section. This resin that has stuck to the root of the screw in the feed section will eventually degrade and break loose and ultimately exit through the die and into the final product being made. By circulating 100˚F to 120˚F water through the feed section of the screw, this will control the temperature of the steel in the feed section of the screw and reduce the possibility of the fines building up on the root in this area.
Another advantage to using screw cooling is to increase the throughput rate of the extruder. For resins that have poor coefficients of friction in the solid phase, such as polypropylene and polyamides, by increasing the first barrel temperature zone and keeping the root of the screw cooled to 100˚F to 120˚F, the differential of the COF between the pellet/barrel and pellet/screw can be maximized and therefore solids conveying will be maximized.
The easiest way to make sure that 100˚F to 120˚F can be maintained on the screw, is to simply use tower water and control the flow so that the return water out of the screw is maintained. To do this, all that needs to be done is to install a shut-off valve and immersion thermometer on the return side of the rotary union as shown in Figure 3.
So, by spending about $500 for a rotary union, an immersion thermometer and the necessary plumbing components, many of your feeding problems may go away.
Figure 3