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AN OVERVIEW OF THE ROLLER INDUSTRY. Why are rollers used What is a roller Where are rollers used How are rollers manufactured Where is the roller market going. Why Roll Coverings?. Virtually all industries use rollers of some type
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AN OVERVIEW OF THE ROLLER INDUSTRY • Why are rollers used • What is a roller • Where are rollers used • How are rollers manufactured • Where is the roller market going
Why Roll Coverings? • Virtually all industries use rollers of some type • Elastomer covered rolls provide performance factors not possible with rigid materials • Large number of polymer types and compounding ingredients allow tailoring of the roller to meet specific service requirements
Rubber Covered Roll Composition • Core • Metal (Steel, Al, Bronze) • Nonmetal (FRP) • Bonding layer • Bonding agent • Cover • Rubber, Polyurethane, Resin
Polymers Thermoset plastics Thermoplastic elastomers • Phenolic or melamine resins • epoxy and polyester resins (UP) • etc. • copolyesters • polyether block amides • TPU • TPO/TPV • SBS, SEBS Thermoplastics Elastomers • PP • PE • PS • PVC • etc. Natural rubber synthetic rubber • SBR • NBR • EPDM • Silicone • etc.
What is a Roll Cover? • Rollers are covered with elastomeric compositions to allow the creation of a uniform pressure area called the “NIP” • “NIP” region dynamic performance must remain constant • Roller compounds must be stable over time in the service environment
Feed Meter Emboss Insulate Conduct Electricity Drive Squeeze Stamp Isolate Dissipate Electricity Functions of Roller Coverings
Roller Design Factors • Solvents & Chemicals • Temperature • Pressure • Rotational Speed
NBR NBR/PVC XNBR HNBR EPDM CSM CR ECO AU, EU NR SBR MQ MQ/EPDM FKM Thiokol Wide Range of Elastomers
Hardness Modulus Tear Strength Cut Resistance Compression Set Permanent Set Resilience Smooth surface Abrasion resistance Hysteresis Chemical Resistance Ozone Resistance Heat Resistance Co-efficient of friction Non-glazing surface Good printability Some Important Properties forRubber Rollers
Rubber Roller Dynamics - The “NIP” area HARD ROLL A Entrance - compound relaxed B Entry Bulge - high extension & speed C Nip Center - high compression D Exit Bulge - high extension & speed E Exit - compound recovered C B D E A ELASTOMERIC ROLL
Must be resistant to the chemicals and Oils,,, High elasticity with abrasion resistance Eccentrical property during working Changeable raw polymer rely on changeable service condition Wringer rollers Squeeze rollers Coating rollers Insulation rollers Deflector rollers Tension bridle rollers Brake rollers Support rollers Steel mill Rubber Rollers
Paper industry Steel / metal industry Furniture Industry Wood Industry Plastic Industry Food Industry Leather Industry Circuit Board Industry Industrial Roller Markets
Roller Manufacturing Processes Selection • Manufacturing process is selected based on: • Size of the roller • Elastomer type • Compound processibility characteristics
Rubber covered roll Recipe selection approach • Select a typical roll recipe and various chemicals • List down the requirement of properties • Eg . least chemical affect. • Design experiments - “Ideal recipe”
Various methods of covering rolls • Casting- rollers used in Steel Mill, Pulp and Paper, and General Industrial. • Molding - small rollers used in Offset printing and Business Machines • Calender Building - medium rollers used in a majority of applications • Strip Building - rollers used in Graphic Arts, Pulp and Paper, Steel Mill, Textile and General Industrial
Rubber Roll Manufacturing 1. Mixing process
Rubber Roll Manufacturing 2. Covering machine and roll
Rubber Roll Manufacturing 3. Rubber covered roll-Autoclave for curing
Rubber Roll Manufacturing 4. Rubber covering - Cured roll maturing
Rubber Roll Manufacturing 5. Rough Grinding at Grinder
Rubber Roll Manufacturing 6. Grinding
Rubber Roll Manufacturing 7. Failure phenomenon - Hair crack
Rubber Roll Manufacturing 8. Failure phenomenon - Destruction
Industry Trends • Increasing environmental scrutiny • New equipment designs • Competitive pressure has led to evaluation of alternative production technologies • Changes in industry will demand higher performance standards, and the roller industry must keep pace with these technical advances
Hardness Hardness stability Chemical and Solvent resistance Hysteresis loss Dimension stability Permanent set resistance Rollers are used in nearly every industry Rollers utilize nearly all polymer types because of the diverse applications Successful players in the roller industry will be those who are successful communicators and are able to meet the current & future requirements, and adapt to the industry changes Summary