This document discusses compounding ingredients used in rubber products. It describes the main categories of ingredients like elastomers, vulcanizing agents, accelerators, fillers and their various functions. Elastomers include natural rubber and synthetic rubbers for general and special purposes. Vulcanizing agents like sulfur form cross-links between polymer chains to convert rubber from a thermoplastic to an elastic state. Accelerators help speed up the vulcanization process by activating sulfur. Fillers are added to reinforce properties or adjust color. Proper selection and blending of ingredients allows rubber to be compounded for specific applications and desired performance characteristics.
Biopolymers for Paperboard Extrusion Coating and Converting - SPE FlexPackCon...C. Carey Yang, Ph.D.
Biopolymers have shown promising options for sustainable packaging applications. This article presents an overview of challenges and opportunities in biopolymers for paperboard extrusion coating and converting processes. Material properties, extrusion coating process and equipment requirements, regulatory compliance, and downstream converting are reviewed. The latest developments and emerging trends in biopolymer technology and innovation are discussed.
The objective of this presentation is to give an overview of rubber compounding. We will briefly focus on:
Elastomer System
Filler System
Protection system
Process Aids
Cure System
Biopolymers for Paperboard Extrusion Coating and Converting - SPE FlexPackCon...C. Carey Yang, Ph.D.
Biopolymers have shown promising options for sustainable packaging applications. This article presents an overview of challenges and opportunities in biopolymers for paperboard extrusion coating and converting processes. Material properties, extrusion coating process and equipment requirements, regulatory compliance, and downstream converting are reviewed. The latest developments and emerging trends in biopolymer technology and innovation are discussed.
The objective of this presentation is to give an overview of rubber compounding. We will briefly focus on:
Elastomer System
Filler System
Protection system
Process Aids
Cure System
poly styrene is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed. General purpose polystyrene is clear, hard, and rather brittle. It is an inexpensive resin per unit weight. polystyrene is in a solid (glassy) state at room temperature but flows if heated above about 100 °C, its glass transition temperature. It becomes rigid again when cooled .
Rubber Processing and Profiting: Compounding, Mixing, Vulcanization, Extrusio...Ajjay Kumar Gupta
Methods for processing rubber include mastication and various operations like mixing, calendering, extrusion, all processes being essential to bring crude rubber into a state suitable for shaping the final product. The former breaks down the polymer chains, and lowers their molecular mass so that viscosity is low enough for further processing. After this has been achieved, various additions can be made to the material ready for cross-linking. Rubber may be masticated on a two-roll mill or in an industrial mixer, which come in different types.
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Basic compounding and processing of rubber, Business guidance for rubber processing, Business guidance for rubber compounding, Business guidance to clients, Business Plan for a Startup Business, Business plan on Rubber, Business start-up, How is rubber made?, How to Start a Rubber business?, How to Start a Rubber Production Business, How to start a successful Rubber Processing business, How to Start Rubber processing Business, How to Start Rubber Processing Industry in India, Manufacture of Rubber Products, Most Profitable Rubber Processing Business Ideas, Natural Rubber Processing Line, Natural rubber processing method, Natural Rubber Processing, New small scale ideas in Rubber processing industry, Opportunities in Rubber industries for new business, Processing and Profiting from Rubber, Processing methods for rubber materials, Profitable Rubber Business Ideas Small Scale Manufacturing, Profitable small and cottage scale industries, Profitable Small Scale Rubber Manufacturing, Rubber and Rubber Products, Rubber based Industries processing, Rubber Based Small Scale Industries Projects, Rubber business plan, Rubber Chemistry, Rubber compounding, Rubber Compounding & Mixing, Rubber compounding ingredients, Rubber compounding method, Rubber compounding process, Rubber compounding technology, Rubber Extrusion, Rubber mixing process, Rubber Mixing, Rubber Principles, Rubber processing, Rubber Processing & Rubber Based Profitable Projects, Rubber Processing and Profiting, Rubber Processing Business, Rubber Processing Industry in India, Rubber processing methods, Rubber Processing Projects, Rubber processing technology, Rubber Products manufacturing, Rubber Products, Rubber technology, Rubber Technology and Manufacturing Process of Rubber Products, Rubber Vulcanization, Rubbers processing technology, Setting up of Rubber Processing Units, Small scale manufacturing business in rubber industry, Small Scale Rubber Processing Projects, Small scale Rubber production line, Small Start-up Business Project, Starting a Rubber Processing Business, Start-up Business Plan for Rubber Processing, Steps in processing of rubber, Vulcanization of rubber, Vulcanization of rubber compounds, Vulcanized rubber properties, Rubber processing and compounding
Short Description related to the rubber filler properties and Rubber filler types ( Reinforcing fillers, Semi- reinforcing fillers and Non-reinforcing fillers). e.g.:- Carbon Black, Silica, Calcium Carbonate, Clay and Miscellaneous Fillers
poly styrene is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed. General purpose polystyrene is clear, hard, and rather brittle. It is an inexpensive resin per unit weight. polystyrene is in a solid (glassy) state at room temperature but flows if heated above about 100 °C, its glass transition temperature. It becomes rigid again when cooled .
Rubber Processing and Profiting: Compounding, Mixing, Vulcanization, Extrusio...Ajjay Kumar Gupta
Methods for processing rubber include mastication and various operations like mixing, calendering, extrusion, all processes being essential to bring crude rubber into a state suitable for shaping the final product. The former breaks down the polymer chains, and lowers their molecular mass so that viscosity is low enough for further processing. After this has been achieved, various additions can be made to the material ready for cross-linking. Rubber may be masticated on a two-roll mill or in an industrial mixer, which come in different types.
See more
http://goo.gl/jMs5qF
http://goo.gl/eUrr6y
http://goo.gl/MxxyTW
http://www.entrepreneurindia.co/
Tags
Basic compounding and processing of rubber, Business guidance for rubber processing, Business guidance for rubber compounding, Business guidance to clients, Business Plan for a Startup Business, Business plan on Rubber, Business start-up, How is rubber made?, How to Start a Rubber business?, How to Start a Rubber Production Business, How to start a successful Rubber Processing business, How to Start Rubber processing Business, How to Start Rubber Processing Industry in India, Manufacture of Rubber Products, Most Profitable Rubber Processing Business Ideas, Natural Rubber Processing Line, Natural rubber processing method, Natural Rubber Processing, New small scale ideas in Rubber processing industry, Opportunities in Rubber industries for new business, Processing and Profiting from Rubber, Processing methods for rubber materials, Profitable Rubber Business Ideas Small Scale Manufacturing, Profitable small and cottage scale industries, Profitable Small Scale Rubber Manufacturing, Rubber and Rubber Products, Rubber based Industries processing, Rubber Based Small Scale Industries Projects, Rubber business plan, Rubber Chemistry, Rubber compounding, Rubber Compounding & Mixing, Rubber compounding ingredients, Rubber compounding method, Rubber compounding process, Rubber compounding technology, Rubber Extrusion, Rubber mixing process, Rubber Mixing, Rubber Principles, Rubber processing, Rubber Processing & Rubber Based Profitable Projects, Rubber Processing and Profiting, Rubber Processing Business, Rubber Processing Industry in India, Rubber processing methods, Rubber Processing Projects, Rubber processing technology, Rubber Products manufacturing, Rubber Products, Rubber technology, Rubber Technology and Manufacturing Process of Rubber Products, Rubber Vulcanization, Rubbers processing technology, Setting up of Rubber Processing Units, Small scale manufacturing business in rubber industry, Small Scale Rubber Processing Projects, Small scale Rubber production line, Small Start-up Business Project, Starting a Rubber Processing Business, Start-up Business Plan for Rubber Processing, Steps in processing of rubber, Vulcanization of rubber, Vulcanization of rubber compounds, Vulcanized rubber properties, Rubber processing and compounding
Short Description related to the rubber filler properties and Rubber filler types ( Reinforcing fillers, Semi- reinforcing fillers and Non-reinforcing fillers). e.g.:- Carbon Black, Silica, Calcium Carbonate, Clay and Miscellaneous Fillers
Natural Rubber - Sources, Coagulation & Processing of Coagulate, Structure & ...Geevarghese George
Sources, Plantation Economy
Coagulation & Processing of Coagulate
Structure & Composition
Properties of raw NR
Compounding, Processing of NR
Properties of NR vulcanizates
Uses of NR
Competitive products of NR
Additives of Polymer, Additives of plastic, Improve properties of Plastic, Ty...Jaynish Amipara
additives of plastic.
uses of filler in plastic.
types of a heat stabilizer.
types of lubricant.
types of plasticizer in plastic.
plastic in antioxidant.
About different types of pultrusion resinsSugamPolytech
Also, a typical type of polyester resin is quite resistant to water. As a result, it is assumed to be one of the most beneficial for manufacturing products, usually done in small sarcastic configurations.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Le nuove frontiere dell'AI nell'RPA con UiPath Autopilot™UiPathCommunity
In questo evento online gratuito, organizzato dalla Community Italiana di UiPath, potrai esplorare le nuove funzionalità di Autopilot, il tool che integra l'Intelligenza Artificiale nei processi di sviluppo e utilizzo delle Automazioni.
📕 Vedremo insieme alcuni esempi dell'utilizzo di Autopilot in diversi tool della Suite UiPath:
Autopilot per Studio Web
Autopilot per Studio
Autopilot per Apps
Clipboard AI
GenAI applicata alla Document Understanding
👨🏫👨💻 Speakers:
Stefano Negro, UiPath MVPx3, RPA Tech Lead @ BSP Consultant
Flavio Martinelli, UiPath MVP 2023, Technical Account Manager @UiPath
Andrei Tasca, RPA Solutions Team Lead @NTT Data
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Welocme to ViralQR, your best QR code generator.ViralQR
Welcome to ViralQR, your best QR code generator available on the market!
At ViralQR, we design static and dynamic QR codes. Our mission is to make business operations easier and customer engagement more powerful through the use of QR technology. Be it a small-scale business or a huge enterprise, our easy-to-use platform provides multiple choices that can be tailored according to your company's branding and marketing strategies.
Our Vision
We are here to make the process of creating QR codes easy and smooth, thus enhancing customer interaction and making business more fluid. We very strongly believe in the ability of QR codes to change the world for businesses in their interaction with customers and are set on making that technology accessible and usable far and wide.
Our Achievements
Ever since its inception, we have successfully served many clients by offering QR codes in their marketing, service delivery, and collection of feedback across various industries. Our platform has been recognized for its ease of use and amazing features, which helped a business to make QR codes.
Our Services
At ViralQR, here is a comprehensive suite of services that caters to your very needs:
Static QR Codes: Create free static QR codes. These QR codes are able to store significant information such as URLs, vCards, plain text, emails and SMS, Wi-Fi credentials, and Bitcoin addresses.
Dynamic QR codes: These also have all the advanced features but are subscription-based. They can directly link to PDF files, images, micro-landing pages, social accounts, review forms, business pages, and applications. In addition, they can be branded with CTAs, frames, patterns, colors, and logos to enhance your branding.
Pricing and Packages
Additionally, there is a 14-day free offer to ViralQR, which is an exceptional opportunity for new users to take a feel of this platform. One can easily subscribe from there and experience the full dynamic of using QR codes. The subscription plans are not only meant for business; they are priced very flexibly so that literally every business could afford to benefit from our service.
Why choose us?
ViralQR will provide services for marketing, advertising, catering, retail, and the like. The QR codes can be posted on fliers, packaging, merchandise, and banners, as well as to substitute for cash and cards in a restaurant or coffee shop. With QR codes integrated into your business, improve customer engagement and streamline operations.
Comprehensive Analytics
Subscribers of ViralQR receive detailed analytics and tracking tools in light of having a view of the core values of QR code performance. Our analytics dashboard shows aggregate views and unique views, as well as detailed information about each impression, including time, device, browser, and estimated location by city and country.
So, thank you for choosing ViralQR; we have an offer of nothing but the best in terms of QR code services to meet business diversity!
1. TECHNOLOGY OF ELASTOMERS
Module I
Compounding Ingredients
Course Outcome :
To Comprehend the preparation , properties and applications of compounding
ingredients.
2. To Comprehend the preparation , properties
and applications of compounding ingredients
1.1.1 Classify the compounding ingredients.
1.1.2 State the functions and characteristics of compounding ingredients with examples.
1.1.3 Explain different vulcanising agents and their roles in a recipe.
1.1.4 Describe the functions of activators and retarders.
1.1.5 State the function of accelerators and their classifications.
1.1.6 Explain the classification and role of antidegradents, processing aid, (plasticiser, softener, and extender).
1.1.7 Classify fillers with respect to colour, reinforcement, origin
1.1.8 Describe the preparation, characteristics and application of nonblack fillers like inorganic, fibrous, organic.
resinous fillers.
1.1.9 Explain the classification and method of manufacturing carbon blacks.
1.1.10 State the properties of carbon black, and classification according to ASTM D 1765.
1.1.11 Describe the procedure for the determination of particle size and structure.
1.1.12 List the special purpose additives and their functions.
3. • Rubber products are divided into
Tyres
Industrial goods (motor vehicle, rail road transportation, construction
etc.)
Consumer goods ( footwear, mats, inner tubes, O –rings etc.)
4. Rubber Compounding
Compound – refers to a specific blend of ingredients used in the manufacturing
of products in order to achieve a definite set of mechanical properties.
Rubber Compounding – science of selecting and combining elastomers and
additives to obtain the desired properties (physical as well as chemical) for a
finished product.
It is through compounding that the specific rubber is designed to satisfy a
given application in terms of properties, cost, and processability.
6. Elastomers/ Rubber
Single elastomer / blend of two or more different rubbers.
Elastomers can be general purpose or special purpose synthetic rubbers.
General purpose rubbers
Used in the production of articles in which the basic property of
vulcanized rubbers, i. e high elasticity at ordinary temperatures—
is desirable
Example, tires, conveyer belts, and footwear.
Special purpose rubbers
Used in producing articles that should be resistant to the action
of solvents, oils, oxygen etc. i. e , able to retain high
elastic properties over a broad range of temperatures.
8. Vulcanizing Agents/Curatives
Vulcanization –
Cross linking process in which individual molecules of rubber
(polymer) are converted into a three dimensional network of
interconnected (polymer) chains through chemical cross links
Vulcanizing agents are necessary for the
formation of crosslinks and rubber
changes from the thermoplastic to the
elastic state
9. History of Vulcanization
• Discovered in 1839 by the U.S inventor Charles Goodyear .
• Thomas Hancock , a scientist and engineer, was the first to patent
vulcanization of rubber.
• Hancock awarded British patent in 1844.
• Goodyear received United nations patent also in 1844.
10. • As long as the molecules are not tied to each other, they can move more
or less freely, especially at higher temperatures.
Plastic behaviour , exhibits flow characteristics
• By cross linking, rubber changes from thermoplastic to elastic state.
• As more crosslinks , vulcanizates becomes tighter and force necessary to
produce a given deformation increases.
Effect of vulcanization
Improved elasticity, tensile strength, hardness and weather
resistance etc..
11. VULCANIZING AGENTS
TYPE COMMON USE
Sulphur or Sulphur bearing
materials
Natural Rubber, Isoprene, SBR, IIR,
Poly Butadiene, EPDM, Nitrile
Organic Peroxides Urethane, Silicone, Chlorinated
Polyethylene, PVC/Nitrile
Metal Oxide Polychloroprene, Chlorosulphonated
Polyethylene, Polysulphide
Organic Amines Acrylic, Fluorocarbon,
Epichlorohydrin
Phenolic Resins IIR
13. • Rubber + Sulphur : Vulcanization time 8 hrs @ 141 °C
Organic Chemicals
Vulcanization time 4 hrs @ 141 °C
metallic oxides
Reduced to 30 minutes or lesser
14. Accelerators
• Sulphur exists as S8 ring and stable.
• Splitting sulphur ring needs considerable amount of activating energy.
• Process of activation occurs at higher temperature, promoted by
organic substances called Accelerators
An accelerator is usually a complex organic chemical which takes part in the
vulcanization, thereby reducing the vulcanization time considerably
Used to increase the speed of vulcanization.
15. Characteristics of an accelerator
• Should give flat cure
• Should provide scorch safety
• Should give good storage properties for the uncured compound
• Should give good physical properties to vulcanizates
Vulcanization
rate
Delayed
action
Slow
Medium
Fast /
Ultrafast
16. Activators
• Used to increase the efficiency of accelerators.
• Additives that activate sulphur cure and improve the efficiency of sulphur based
cure systems.
• Commonly used - Zinc fatty acid ester which is often formed in-situ by reaction of
fatty acid with zinc oxide.
• Fatty acids include stearic, lauric, palmitic, oleic and naphthenic acid.
• Fatty acid solubilizes the zinc and forms the actual catalyst.
• Zinc oxide can also act as a filler or white colorant in rubber products whereas the
fatty acid improves filler incorporation and dispersion.
17. Classification of accelerators
• An accelerator is a complex organic chemical which takes part in the vulcanization, thereby
reducing the vulcanization time considerably.
• Vulcanization accelerators classified as (based on their role in a given compound)
Primary Accelerators
Secondary Accelerators
• Based on the vulcanization rate, classified into
Slow Accelerators
Medium Accelerators
Ultrafast Accelerators
Delayed Action Accelerators
Cross-link density and the cure speed depend on the type and dosage of accelerator used.
18. Primary accelerators provides
long scorch time
medium to fast cure
good modulus (crosslink density) development.
Dosage : 0.5 to 1.5 phr
Examples : Sulphenamides and thiazoles.
Secondary accelerators (used at much lower concentration)
activates primary accelerators
increases speed of vulcanization (increases cross links density)
reduces scorch safety
Dosage : 10-40% of primary accelerator (0.05 to 0.5 phr)
Examples : dithiocarbamate, thiurams, guanidines
19. Thiazole Accelerators
• Medium fast accelerator
• Improved scorch safety
• Need higher temperature for vulcanization
Examples :
2-mercaptobenzothiazole (MBT)
Zinc salt of mercaptobenzothiazole (ZMBT)
Dibenzene thiazyl disulphide (MBTS)
MBT & ZMBT – fast onset of vulcanization and lower processing safety
Zinc salt (ZMBT) is used mainly with latex compounds
MBTS provides safe processing
20. Sulphenamide accelerators
• Primary accelerator
• Delayed action accelerator as well as provides faster cure rate
• Can be boosted with small amounts of secondary accelerators like DPG,
TMTD, TMTM etc.
• Provide good resistance to reversion.
Examples
Cyclohexyl benzothiazole/ thiazyl sulphenamide (CBS)
Tertiary butyl benzothiazyl sulphenamide (TBBS)
Dicyclo hexyl benzothiazyl sulphenamide (DCBS)
21. Thiuram accelerators
• Fast accelerator
• Faster curing rate, higher crosslink density
• Lower processing safety
• As secondary accelerator with dithiocarbamates, sulfenamides, or thiazole.
• As primary accelerator for sulphur cured low unsaturated rubbers
Examples
Tetramethyl thiuram disulfide (TMTD)
Tetraethyl thiuram disulfide (TETD)
Tetramethyl thiuram monosulfide (TMTM)
22. Dithiocarbamate Accelerators
• Ultra fast accelerator
• Mostly used in latex based compounds
• Functions both as primary as well as secondary accelerators
• low scorch safety
• faster cure rate
• higher crosslink density
• Vulcanized in a short time at low temperature (115 - 120°C)
Examples
Zinc diethyl dithiocarbamate (ZDEC)
N-dimethyl dithiocarbamate (ZDMC)
Zinc N-dibutyl dithiocarbamate (ZDBC)
23. Guanidines
Examples :
diphenyl guanidine (DPG) and N, N’-diorthotolyl guanidine
(DOTG).
• Slow cure rate and require the use of zinc oxide for activation
• Used for thick walled rubber products
• As secondary accelerators in combination with thiazoles
• Results in relative high crosslink density and good physical-mechanical
properties such as high modulus and good compression set.
• Cause a brown discoloration, not suitable for light coloured products
24. Xanthates
• Ultra fast primary vulcanization accelerators
• Used for vulcanization of rubber latex and rubber in solution.
• Employed for low vulcanization temperature applications.
• Examples :
Zinc (ZIX) and sodium isopropyl xanthate (NaIX). The later is
water soluble, and ideal for latex vulcanization.
25. Thioureas
• Ultrafast primary or secondary accelerators.
• Examples
Ethylene thiourea (ETU)
dipentamethylene thiourea (DPTU)
dibutyl thiourea (DBTU)
Mainly used for the vulcanization of chloroprene rubbers.
26. Sulphur donors
• Capable of providing active sulphur during the vulcanization process
thereby generating sulphidic cross links.
• Classified as those that are applied as a direct substitute for free
sulphur and those that act simultaneously as vulcanization
accelerators.
Examples
Caprolactam disulphide( CLD)
Tetramethylthiuram disulphide (TMTD).
27. Retarders/ Prevulcanization inhibitors (PVI)
• Reduce accelerator activity during processing and storage.
• Prevent scorch during processing and prevulcanization during storage.
• They should either decompose or not interfere with the accelerator during
normal curing at elevated temperatures.
• Acts as organic acids that function by lowering the pH of the mixture, thus
retarding vulcanization.
Examples
Benzoic acid
phthalic anhydride (up to 2 phr)
maleic acid
Cyclohexylthiophthalimide (CTP)
29. Peroxide Curing
Curing saturated as well as unsaturated rubbers
Used for curing EPDM, Chlorinated PE, Hypalon, Silicone rubbers.
Examples - diacyl peroxides, dialkyl or diaralkyl peroxides, peresters and
peroxyketals
Curing takes place by thermal decomposition into oxy and peroxy free radicals
and abstracting hydrogen atoms from the saturated elastomer to generate
elastomer chain radicals.
Cannot be used with butyl rubber because they cause chain scission and
depolymerisation.
30.
31. Metal Oxide Curing
Used for curing as polychloroprene rubber (CR), halogenated butyl rubber, and
chlorosulfonated polyethylene rubber.
Curing agents - ZnO, MgO and Pb2O3
Mixtures of (ZnO and MgO) are used because ZnO alone is too scorchy , MgO
alone is inefficient.
Zinc oxide and lead oxide combination for improved water resistance.
32. Resin Curing
Used for curing unsaturated rubbers, used with butyl rubber for high temperature
applications.
Certain di-functional compounds form crosslinks with elastomers by reacting with two
polymer molecules to form a bridge.
Resin cures are slower than accelerated sulphur cures and high temperatures are
required, activated only by zinc oxide and halogen atoms (SnCl2 ).
Resin has got adhering capacity, low molecular weight resin molecules diffuse into
rubber thereby stiffen the rubber.
Examples :
Epoxy resins - NBR
Quinone di-oximes and phenolic resins -butyl rubbers
dithiols and diamines - fluorocarbon rubbers.
33.
34. Radiation Induced Crosslinking
Physically induced chemical reaction, which is easier and preferable for continuous
curing.
Includes electron beam crosslinking, photo-crosslinking, microwave crosslinking,
ultrasonic crosslinking etc.
Upon irradiation free radicals are formed in rubber molecules.
Free radicals can combine to form crosslinks as in the case with peroxide crosslinking.
In radiation crosslinking of rubbers, kneaded rubber is placed in an aluminium die and is
pressed at 100-200° C for 5-10 minutes, allowed to cool under pressure and then
exposed to radiation.
Use of sensitizers can reduce the required dose and radiation time.
Examples : Halogen compounds, nitrous oxide, sulphur monochloride and bases
like amine, ammonia etc.
35. Antidegradants
Degradation of Rubber
Chain scission resulting in shorter chains and lower molecular weight ( NR & IIR – softened stock
showing tackiness ).
Cross-linking resulting in three dimensional structures and higher molecular weight (SBR & NBR – brittle
stocks with poor flexibility and elongation)
Chemical alteration
Factors affecting degradation
• External factors – oxygen, ozone, pro-oxidants, heat, light and fatigue
• Internal factors – type of rubber, degree and type of vulcanization accelerators used, compounding ingredients
and protective agents
36. Factors contributing to degradation
Oxygen Mode of attack oxygen on unvulcanised rubber is different from vulcanized rubber.
Unvulcanised stock – initial induction period followed by rapid up-take of oxygen
Vulcanised stock- no induction period
Pro-oxidants Cu , Mn, Co, Ni and Iron ( increase the rate of oxygen attack) in NR ; Iron – SBR
Cu salts – increases rate of chain scission ; Co salts – increases rate of crosslinking
Ozone Ozone concentration in atmosphere 0-6 ppm
Ozone reacts with unsaturated rubber forming ozonides which decompose into products of lower molecular
weight
Ozone degradation occurs in two ways
In rubber under stress cracks appear perpendicular to stress
In unstressed rubber , silvery film appears on the surface of the article in hot humid weather
Heat Combination of crosslinking and increase in rate of oxidation
Fatigue Weakening of rubber due to continuously repeated distortions
Cause of failure due to :
Stress breaking of chain or cross links
Oxidation accelerated by heat build p in flexing
Light and
weathering ( UV
radiation)
Light promotes action of oxygen at the surface producing a film of oxidised rubber
Oxidised film reacts with water vapour and heat to produce crazing (fine cracks), exposing filler by washing of the
oxidised layer
Exposed filler can be rubbed off , a condition known a s Chalking.
37. Antidegradants are used to protect the rubber from degradation so that a
longer service life is obtained.
Includes antioxidants and antiozonants.
Selection of antidegradants is based on
Type of protection desired
Environment in which the product is exposed.
Chemical activity
Persistence (volatility and extractability)
Nature of end use
Discoloration and staining
Toxicology
Cost
Antidegradants classified into
• Amines - strong antidegradants , discolour and staining in nature
• Phenolic compounds – less effective, non –discolouring and non-staining
38. Chemical Name Oxygen Heat Flexing Pro-oxidant Ozone
N- phenyl-N-isopropyl P- phenylene diamine Good Vey good Excellent Excellent Excellent
N- (1,3-dimethylbutyl) N-phenylenediamine Good Vey good Excellent Excellent Excellent
Phenyl-β-naphthylamine Good Good Good Moderate --
Substituted phenol Poor Poor Moderate No No
Blend of arylamines and diphenyl-p-
phenylenediamine
Good Good Excellent Poor Fair
39. FILLERS
Fillers are materials used to
Extent the range of physical properties
Reduce compound cost
Modify the processing properties
Influence the chemical resistance of the compound
The effect of a filler on rubber depends on-
• Structure
• Particle size
• Surface area
• Geometrical characteristics
40. Diluents or extenders
Non-reinforcing filler/ inactive fillers
Primarily to occupy space and used to lower the formulation cost.
Particle size : 1,000 and 10,000 nm (1 to 10 μm)
Functional or reinforcing fillers
Functional or reinforcing fillers/active fillers
Particle size range : 10 to 100 nm (0.01 to 01 μm)
Improve the modulus and failure properties (tensile strength, tear resistance and
abrasion resistance) of the final vulcanizates.
Semi- reinforcing fillers
Moderately improve the tensile strength and tear strength, but does not improve the
abrasion resistance
Particle size range : 100 to 1000 nm (0.1 to 1μm)
41. Reinforcing Type` Carbon Black (listed in
order of increasing
particle size)
N220 (ISAF)
N330(HAF)
N550 (FEF)
N762 (SRF-LM)
N990 (MT)
Non-black Silica
Zinc Oxide
Magnesium Carbonate
Aluminium Silicate
Sodium Aluminosilicate
Magnesium Silicate
Extending Type Calcium Carbonate
Barium Sulfate
Aluminium Trihydrate
42. Reinforcement by fillers
Condition for filler reinforcement is the interaction between the filler
particles and the polymer.
Interactions can be strong, for example in the case of covalent bonds
between functional groups on the filler surface and the polymer, or
weak as in the case of physical attractive forces.
When carbon black is blended with a polymer, the level of physical
interaction is high.
But interaction between silica particles and the polymer is very
weak, and only by the use of a coupling agent a bond is formed
between the filler and the polymer.
43. Factors influencing elastomer reinforcement
There is an optimum loading of filler indicating that there
are two opposing factors in action when a reinforcing
fillers such as carbon black is added.
• First, there is an increase of modulus and TS, which is
dependent on the particle size of filler. ( smaller PS,
greater SA, interaction between polymer and filler
surface)
• Secondly, the reduction in properties at higher loading
is a simple dilution effect, generally to all fillers, due to
a diminishing volume fraction of polymer in composite.
If there is not enough rubber matrix to hold the filler
particles together, strength rapidly approaches to zero.
44. Carbon black
Chemical process Manufacturing
method
Raw materials
Thermal –oxidative
decomposition
Furnace black process Aromatic oils on coal tar basis or mineral
oil, natural gas
Lamp black process Aromatic oils on coal tar basis or mineral
oil
Channel Black process Coal tar distillates
Thermal decomposition Thermal black process Natural gas or mineral oils
Acetylene black process Acetylene
Carbon blacks are produced by converting either liquid or gaseous
hydrocarbons to elemental carbon and hydrogen by partial combustion
or thermal decomposition.
45. Depending on the process adopted for the preparation,
carbon blacks are classified as
• Furnace blacks- produced by incomplete combustion of natural gas or
heavy aromatic residue oils from the petroleum industries (particle size 20
nm – 80 nm).
• Thermal blacks – decomposition of natural gas or oil at 1300 oC in the
absence of free air (particle size 20 nm – 80nm).
• Acetylene black is a thermal type. Decomposition of acetylene gas is
exothermic, so heat is supplied only to start the reaction.
• Channel blacks - produced by feeding the natural gas or oil into thousands
of small burner trips where the small flames impinge on to a large rotating
drum
• Lamp black - made by burning oil and allowing the black formed to settle
out by gravity in series of chambers.
46. Properties of Carbon black
Composed from three colloidal particles morphological forms existing in rubber compounding
includes (primary particle, aggregate, and agglomerate).
Sizes of these morphological forms have the following order:
particle < aggregate < agglomerate.
85 – 500 nm
15 – 300 nm
1 – 100 µm
47. Important properties of carbon black
Particle size
Structure
Physical nature of the surface
Chemical nature of the surface
Particle porosity
48. Particle size
• The particles of carbon blacks are not discrete but are fused clusters
of individual particles.
• It is the fundamental property that has a significant effect on rubber
properties. Finer particles lead to increased reinforcement, increased
abrasion resistance, and improved tensile strength.
• Transmission electron microscope and surface area by adsorption
methods are used to determine particle size .
49. Determination of particle size
• Surface area measurements give an indirect characterization of carbon black
particle size.
• Surface area determination using
Iodine adsorption (expressed in mg/g of carbon) measures the amount of iodine which can
be adsorbed on the surface of a given mass of carbon black.
BET (Brunauer, Emmett and Teller ) method / Nitrogen adsorption surface area is a
measurement of the amount of nitrogen which can be adsorbed on a given mass of carbon
black.
Iodine and nitrogen molecules are sufficiently small to be adsorbed in the narrow slits or
pores which can be formed in CB by oxidation at higher temperatures.
Rubber molecules are much bigger than these imperfections, so the extra surface area is not
available for rubber- CB interactions.
Overcomed using cetyl trimethyl ammonium bromide molecule (CTAB) .CTAB (m2/g) gives
best correlation with primary particle size.
50. Structure
Carbon blacks do not exist as primary particles.
Primary particles fuse to form aggregates, which may contain a large
number of particles.
The shape and degree of branching of the aggregates is referred to as
structure.
51. Structure
Increasing carbon black structure increases modulus, hardness,
electrical conductivity, and improves dispersibility of carbon black,
but increases compound viscosity.
Thermal process produces blacks with little or no structure
Some particle agglomeration in channel process
Oil furnace process gives blacks with high structure.
The structure is measured by determining the total volume of the air
spaces between the aggregates per unit weight of black (DBP
absorption method).
52. Determination of structure
Dibutyl-Phthalate (DBP) oil absorption test measures the amount of DBP absorbed on
100g of carbon black.
Involve measuring the absorption of oil by the carbon black and they indicate the
internal void volume present in both the primary and secondary aggregate structure.
DBP is added by means of a constant-rate burette to a sample of the Carbon Black in the
mixer chamber of an absorptometer.
As the sample absorbs the oil the mixture changes from a free-flowing powder to a semi-
plastic continuous mass, leading to a sharp increase in viscosity, which is transmitted to
the torque-sensing system of the absorptometer.
The endpoint of the test is given by a pre-defined torque level.
The result is expressed as the oil absorption number (OAN), in ml/100 g.
A high OAN number corresponds to a high structure, i.e. a high degree of branching and
clustering of the aggregates.
53.
54. Physical nature of the particle surface
• The physical form (beads or powder) can affect the handling and
mixing characteristics.
• Highly oriented layers – regular spacing- large layers -less
reinforcement
• Less crystalline orientation – irregular spacing – small layers - high
reinforcement
55. Chemical nature of particle surface
• This is a function of the manufacturing process and the heat history of a
carbon black and generally refers to the oxygen-containing groups present
on a carbon black’s surface.
• 90-99% elemental carbon
• Other major constituents are (combined) hydrogen(from original
hydrocarbon) and oxygen (from reduced atmosphere during manufacture).
• The principal groups present are phenolic, ketonic and carboxylic together
with lactones. These surface groups are not physically adsorbed but are
chemically combined.
• In addition to oxygen and hydrogen it contains very small amount of
sulphur which do not cause cross linking of rubber.
56. Particle porosity
• Fundamental property of carbon black that can be controlled during
the production process.
• Surface of the carbon black is not smooth
• Oxidation at the non graphitic atoms make them pores.
• Porosity affect the measurement of surface area providing a total
surface area (NSA) larger than the external value (STSA).
• Increase in porosity also allows a rubber compounder to increase
carbon black loading while maintaining compound specific gravity.
57. Classification of carbon black
• ASTM system consists of one letter followed by three numerals.
• The first letter indicates rate of cure, N and S being used for normal
and slow respectively.
• The first numeral – surface area of the carbon black.
• The remaining two numerals are selected arbitrarily- the second
always a repeat of first numeral and the last is zero.
58. Commercially available carbon blacks
Name Abbrev. ASTM desig. Particle size
(nm)
Super Abrasion Furnace SAF N110 20-25
Intermediate Super Abrasion
Furnace
ISAF N220 24-33
High Abrasion Furnace HAF N330 28-36
Fast Extruding Furnace FEF N550 39-55
Semi reinforcing Furnace SRF N770 70-96
Fine thermal FT N880 180-200
Medium thermal MT N990 250-350
59. Application of Carbon Black
Name Nature Field of Application
SAF Highly reinforcing, gives maximum tensile
and abrasion resistance. High heat
generation during processing
Camel back, truck treads industrial
beltings and in other heavy duty
items.
ISAF Highly reinforcing, imparts high tensile
strength and abrasion resistance, better
processing properties than SAF
In high abrasion resistance
applications like treads, camel
backs, conveyer belt covers etc.
HAF Reinforcing black with good abrasion
resistance and better processing properties
In treads, camel backs, inner
tubes, off-road treads and in
mechanical goods
FEF Reinforcing black with good abrasion
resistance and better processing properties
In carcass. side walls, wire and
cables and in calendared and
extruded items requiring good
dimensional stability.
60. Name Nature Field of Application
GPF Moderately reinforcing, high loadings
can be given, gives good processing and
dynamic properties
In carcass, side walls cushion
under tread, inner liner
compounds, motor mounts and in
high speed beltings.
SRF Semi reinforcing, high loadings can be
given gives good processing and
dynamic properties.
In bead, breaker, body ply,
cushion squeeze compounds, in
bicycle tires, wire and cables and
in other extruded items.
Thermal
blacks
Low reinforcement, can be used in high
loadings
In V- belts, mats, sealing
compounds and in mechanical
goods.
Channel
blacks
Highly reinforcing, processing is easy,
retards cure.
In bonding applications
Lamp blacks Less reinforcing, gives high hardness
compounds with high resilience
In truck treads and engine
mounts
Acetylene
black
Produce high hardness compounds,
processing is easy
In compounds requiring electrical
conductivity
61. Silica
Silica is not quite reactive with rubber as carbon black.
Mostly used in tyre products due to reduction in rolling resistance and increasing hardness.
Usually exists as aggregates and agglomerates, acidic in nature, leads to poor dispersion of silica.
Addition of silane coupling agents into rubber to modification of silica particles surface and
increase the interaction between the silica and rubber.
Two types of silica - precipitated silica & fumed silica
Precipitated silica is manufactured by acid precipitation from silicate solution,, it has
average particle size (10 to 100) nm and water contains is (10-14%).
Fumed silica is produced at a higher temperature by a reaction of silicon tetrachloride with
water vapor, it has average particle size (7-15) nm.
62. Plasticisers and extenders
Functions of a plasticizer
Increase plasticity and workability of the compound
Aid in wetting and incorporation of fillers
Provide lubrication to improve extrusion, moulding or other shaping
operations
Reduce batch temperature and power consumption during mixing
Modify the properties of the vulcanized products.
63. Classified into : chemical plasticisers and physical plasticisers
Softeners (Physical Plasticizers)
• Do not react chemically with the rubbers involved, but function by modifying the physical
characteristics of either the compounded rubber or the finished vulcanizates.
• Dosage : 2 to 10 phr
• Must be completely compatible with the rubber and the other compounding ingredients
used in the recipe.
• Incompatibility will result in poor processing characteristics or "bleeding" in the final product
Examples : Mineral petroleum oils (paraffinic , naphthenic & aromatic)
Chemical plasticizers
Synthetic type (ester based), used where mineral oils are not compatible with the
rubber (polar rubbers) .
Ester plasticizers are generally used in NBR and CR compounds because they impart good
vulcanization properties
dibutyl phthalate -DBP
di isobutyl phthalate-DIB
di octyl phthalate - DOP
64. • Extenders
Added in large quantities so that the cost of the compound can be reduced, without seriously
affecting the final properties. E.g.: Reclaimed rubber, factice .
• Factices
Vulcanized vegetable oils used as plasticizers to get smooth compound in extrusion (brown) & to
reduce abrasion resistance in products like erasers (white)
• Stiffeners
Improve the plasticity of the compound in very small quantities. E.g. dihydrazine sulfate
• Peptizers
They speed up the rate of polymer break down and also control the speed of breakdown,
decreasing nerve within the compound and shrinkage during subsequent processing.
E.g. penta chloro thiophenol
65. • Flame retardants
Chemicals which can improve the flame retardency of the compound
highly chlorinated paraffins and waxes, antimony oxide, aluminium oxide and selenium
• Colors and pigments
They provide esthetic look and appearance for the product [organic and inorganic]
• Tackifying agents
They are useful in providing tackiness to the compound.
E.g. wood rosin, coumarone resins, pine tar.
• Blowing agents
They are materials which provide either open or closed cell structure by producing CO2 or
nitrous gases during vulcanization
dinitroso pentamethylene tetramene (DNPT) , azocarbonamide (ADC), baking soda
(sod.bicarbonate)
• Bonding agents
They facilitate adhesion between rubbers, fibers, fabrics, metals
chemlok, resorcinol – formaldehyde- latex for dipping of nylon cords in tyre manufacture
66. Silane Coupling Agents
• improve properties of compounds containing silica and silicate fillers by forming
chemical bonds across the filler and the rubber interface.
• bis-(3-triethoxysilylpropyl)tetrasulphane and 3-thio-cyanatopropyl triethoxy
silane.
The effect of coupling agents on the physical properties of the compound is to:
• lower compression set
• reduce heat build-up under dynamic conditions,
• reduce tan delta, improve crosslink stability
• improve tear related characteristics
• improve resistance to swelling by water.
• improve the abrasion resistance of compounds containing silica
reinforcement. The effect is dependent on the surface area of the silica.
67. Tackifiers
synthetic rubbers are less tacky than natural rubber, it is often necessary to add
tackifying substances. These should lead to improved uncured ply adhesion on assembling.
Examples include CI resin, rosin derivatives, alkyl phenol-aldehyde resins etc.
Colours and Pigments
Pigments can be classified as inorganic or organic.
Inorganic pigments are often dull and in some cases too , insoluble and thus cannot bloom.
Organic pigments - brighter shades, more sensitive to heat and other chemicals. On long term
exposure to sunlight they can fade badly.
Inorganic colours : iron oxide, chromium oxide
Organic pigments contains different chromophore groups, these are mainly amines and azo-
compounds such as phthalocyanines.