Industrial Rubber Roll Amit Gupta Modinagar Rolls Limited March 5, 2014 AT ETDS

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

Thermoplastic elastomers 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

Functions of Roller Coverings Feed Meter Emboss Insulate Conduct Electricity Drive Squeeze Stamp Isolate Dissipate Electricity

Roller Design Factors Solvents & Chemicals Temperature Pressure Rotational Speed

Wide Range of Elastomers NBR NBR/PVC XNBR HNBR EPDM CSM CR ECO AU, EU NR SBR MQ MQ/EPDM FKM Thiokol

Some Important Properties for Rubber Rollers Abrasion resistance Hysteresis Chemical Resistance Ozone Resistance Heat Resistance Co-efficient of friction Non-glazing surface Good printability Hardness Modulus Tear Strength Cut Resistance Compression Set Permanent Set Resilience Smooth surface

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

Roller Market Segmentation

Steel mill Rubber Rollers 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

Industrial Roller Markets Food Industry Leather Industry Circuit Board Industry Paper industry Steel / metal industry Furniture Industry Wood Industry Plastic Industry

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

Summary Rollers are used in nearly every industry Hardness 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 Hardness Hardness stability Chemical and Solvent resistance Hysteresis loss Dimension stability Permanent set resistance