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435 Technical Terms You Need To Know in Rubber Industry (Part 1)

Here is a compilation of 435 Technical Terms in Rubber Industry.

Being a long list, I have split this into two posts. Here are alphabets (A-L)



  1. Abrasion : The wearing away of a surface in service by mechanical action, such as rubbing, scraping or erosion.
  1. Abrasion Resistance : The ability of a rubber compound to resist mechanical wear.
  1. Abrasion Resistance Index : A measure of the abrasion resistance of a rubber relative to that of a standard rubber under the same specified conditions, expressed as a percentage.
  1. Absorption : The physical mechanism by which one substance takes up another substance (liquid, gas or vapor) into its interior.
  1. Accelerated Life Test : Any set of test conditions designed to reproduce, in a short time, the deteriorating effect obtained under normal service conditions.
  1. Accelerated Service Test : A service or bench test in which some service condition, such as speed, temperature or continuity of operation, is exaggerated in order to obtain a result in shorter time.
  1. Accelerator : A compounding material used in small amounts, with a vulcanizing agent, to increase the speed of vulcanization.
  1. Acid Resistance : The ability to resist the action of identified acids within specified limits of concentration and temperature.
  1. Acrylic : A polymer for which resistance to air and hot oil at temperatures above 30 degrees Fahrenheit are required.
  1. Adhere : To cling or stick together.
  1. Adhesion : Tendency of rubber to bond or cling to a contact surface.
  1. After Cure : Continuation of vulcanization after the desired cure is effected and the heat source removed (also referred to as Post-Cure).
  1. Ageing : To undergo changes in physical properties with age or lapse of time.
  1. Ageing, Accelerated : Tests run on various rubbers to find out, in as short a period as possible, the destructive influence of light, oxygen, heat and ozone.
  1. Ageing, Oxygen Bomb : A means of accelerating the change in the physical properties of rubber compounds by exposing them to action of oxygen at an elevated temperature and pressure.
  1. Ageing , Air Bomb : Similar to an oxygen bomb, but used with air.
  1. Ageing, Shelf : Ageing during storage.
  1. Agglomerate, Compounding material : A cluster of particles of one or more compounding materials loosely held together. Most commonly used to describe carbon black.
  1. Air Checks : Surface markings or depressions due to trapping air between the material being cured and the mold surface.
  1. Air Curing : Vulcanization of a rubber product in air, as distinguished from in a press or steam vulcanizer.
  1. Alpha Particles : Positively charged particles composed of two protons and neutrons (often referred to simply as helium atom molecule); characterized by limited penetration.
  1. Ambient Temperature : The surrounding temperature relative to the given point of application.
  1. Aniline Point : The lowest temperature at which equal volume of pure, fresh aniline and oil will completely dissolve in one another is the aniline point of the oil.
  1. Antidioxidant : An organic substance which inhibits or retards oxidation.
  1. Antiozonant : A substance that retards or prevents the appearance of cracks from action of ozone when the elastomer is exposed under tension, either statically or dynamically, to air containing ozone.
  1. Antirad : A material which inhibits radiation change.
  1. Aromatic Oil: A hydrocarbon process oil containing at least 35%, by mass, of aromatic hydrocarbons.
  1. Atmospheric Aging Resistance : Loss of physical properties due to the normal action of its surroundings (weather).
  1. Atmospheric Cracking : Cracks produced in the surface of rubber articles by exposure to atmospheric conditions.
  1. Autoclave : A vessel used for vulcanizing rubber products by means of steam under pressure.
  1. Axial Seal : A term usually applied to an O-Ring where the squeeze is applied on the top and bottom surfaces. Another term for face seal.



  1. Backrind : A molding defect in which the rubber adjacent to the parting line shrinks below the surface of the molded product, with the parting line often being ragged and torn.
  1. Back-Up-Ring : (Anti extrusion device) A ring of relatively hard and tough material, placed in the gland between the O-Ring and groove side walls, to prevent extrusion of the O-Ring.
  1. Bake Out : A process whereby a vacuum system is heated for a given time at some predetermined temperature to degas all the components, i.e. gauges, fittings, valves, seals.
  1. Banbury Mixer : A specific type of internal mixer used to blend fillers and other ingredients with an elastomer.
  1. Bank: The reservoir of material at the opening between rolls of a mill or calendar.
  1. Batch : The product of one mixing operation.
  1. Bench Marks : Two marks of known separation, applied to a specimen to measure the strain of the specimen during extension.
  1. Bench Test : A modified service test in which the service conditions are approximated, but the equipment is conventional laboratory equipment and not necessarily identical with that in which the product will be employed.
  1. Blank : A portion of a rubber compound of suitable volume to fill the cavity of a mold.
  1. Beta Particles : Negatively charged particles or electrons, characterized by limited penetration.
  1. Bleeding : Migration to the surface of plasticizers, waxes or similar materials, to form a film or bead.
  1. Blemish : A mark, deformity or injury which impairs appearance.
  1. Blister : A raised spot in the surface, or a separation between layers, usually forming void or air-filled space in the vulcanized article.
  1. Bloom : A dusty or milky looking deposit that sometimes appears on the surface of an molded product after molding and storage, caused by migration of a liquid or solid to the surface. Not to be confused with dust from external sources.
  1. Blow : The volume expansion that occurs during the production of cellular or sponge rubber.
  1. Blowing Agent : A compounding material used to produce gas by chemical or physical action, or both, in the manufacture of hollow or cellular articles.
  1. Bond : The term commonly used to denote the attachment of a given elastomer to some other member. Bonds may be classified by types, as follows:
  1. Mechanical – purely physical attachment accomplished by such means as “through” holes, interlocking fingers, envelope design, riveting, etc.;
  2. Cold – adhesion of previously vulcanized elastomer to another member through use of suitable contact cements;
  3. Vulcanized – adhesion of an elastomer to a previously primed surface using heat and pressure, thus vulcanizing the elastomer at the same time.
  1. Break : A separation or discontinuity in any part of an article.
  1. Break-Out : Force to inaugurate sliding. Expressed in same terms as friction. An excessive break-out value is taken as an indication of the development of adhesion.
  1. Brittleness : Tendency to crack when deformed.
  1. Brittle Point: The highest temperature at which a rubber specimen will fracture under sudden impact.
  1. Buna -N : See Nitrile.
  1. Buna-S : A general term for the copolymers of butadiene and styrene. Also known as SBR and GRS.
  1. Butaprene : See Nitrile.
  1. Buffing : The grinding of a vulcanizate, producing a roughened or velvety texture.
  1. Bumping, Moulding Process : The application, release, and reapplication of pressure prior to the start of vulcanization to vent entrapped gases, thereby facilitating complete filling of the mould cavities.
  1. Butt Joint : Joining two ends of a seal whereby the junction is perpendicular to the mold parting line.
  1. Butyl : A copolymer of iso-butylene and isoprene.



  1. Calender : A machine with two or more parallel, counter-rotating rolls, with controllable roll-to-roll spacing, rotating at selected surface speeds and controlled temperatures.
  1. Carbon Black : A material consisting essentially of elemental carbon in the form of near-spherical colloidal particles and particle aggregates. It is produced by partial combustion or thermal decomposition of hydrocarbons. Primarily used as a reinforcing agent, but also affects many other dynamic properties of a rubber compound.
  1. Catalyst : A chemical that, in small quantities, accelerates a chemical reaction without itself necessarily becoming part of the final product.
  1. Cell : A single small cavity surrounded partially or completely by walls.
  1. Cell, Closed : A cell totally enclosed by its walls, hence not interconnected with other cells.
  1. Cell, Open : A cell not totally enclosed by its walls and hence interconnected with other cells.
  1. Cellular Rubber : A generic term for materials containing many cells (either open, closed, or both) dispersed throughout the mass of rubber.
  1. Cellular Material, Collapse : An undesirable densification of a cellular material resulting from the breakdown of its cellular structure.
  1. Cement, Rubber : An adhesive that is either a liquid dispersion or solution of raw or compounded rubber, or both.
  1. Chalking : The formation of a powdery residue on the surface of a rubber, commonly resulting from surface degradation.
  1. Checking : The short, shallow cracks on the surface of a rubber product, usually resulting from damaging action by environmental elements.
  1. Chemical Bonding : A method of bonding rubber to inserts by applying special adhesives to the insert prior to molding.
  1. Chemigum : See Nitrile.
  1. Closure Dimension : Dimensions of a molded rubber product that are affected by flash thickness (mold closure) variation.
  1. Coagent: A compounding ingredient used in small amounts to increase the crosslinking efficiency of certain non-sulfur vulcanizing systems (especially organic peroxides), or to modify the properties given by such systems.
  1. Coating : A uniform layer of chemical primers or adhesives to produce a chemical bond between the rubber and substrate. May also refer to special surface treatments that can be applied to rubber to achieve special properties.
  1. Coated Fabric : A flexible product composed of a textile fabric and an adherent polymeric material applied to one or both surfaces.
  1. Coefficient of Thermal Expansion : Average expansion per degree over a stated temperature range, expressed as a fraction of initial dimension. May be linear or volumetric.
  1. Cold Checks : A defect on calendered sheeting consisting of surface roughness.
  1. Cold Flexibility : Flexibility following exposure to a predetermined low temperature for a predetermined time.
  1. Cold Flow : Slow deformation, under gravitational force, at or below room temperature. Sometimes referred to as “creep”.
  1. Cold Resistance : Able to withstand the effects of cold or low temperatures without loss of serviceability.
  1. Commercially Smooth : Degree of smoothness of a surface of an article which is acceptable for use.
  1. Compound : A term applied to a mixture of polymers and other ingredients to produce a usable rubber material.
  1. Compound, Standard: A control or reference compound prepared according to a prescribed formula and mixing procedure.
  1. Compression Molding : Molding process in which the material is placed directly in the mold cavity and compressed to shape by closure of the mold, under heat and pressure.
  1. Compression Modulus : The ratio of the compression stress to the resulting compression strain (the latter expressed in the direction of force). Compression Modulus may be either static or dynamic.
  1. Compression Set : The permanent deformation experienced by a rubber material when compressed for a period of time. The term is commonly used in reference to a test conducted under specific conditions wherein the permanent deformation, expressed as a percentage, is measured after a prescribed period of time. A low compression set is desirable in molded rubber parts such as seals and gaskets, which must retain their dimensions to maintain an effective seal.
  1. Conditioning (Environmental) : The storage of a rubber, under specified conditions (time, temperature, humidity) prior to testing.
  1. Conditioning (Mechanical): The prescribed program of deformation of a specimen prior to testing.
  1. Conductive Rubber : A rubber capable of conducting electricity. Most generally applied to rubber products used to conduct static electricity.
  1. Copolymer : A polymer consisting of two different monomers chemically combined.
  1. Corona Resistance : The ability of a rubber acting as insulator to withstand the effects of high voltage discharge. Indications of failure appear as surface cracks.
  1. Corrosion (Packing) : Corrosion of rigid member (usually metal) where it contacts packing. The actual corroding agent is fluid medium trapped in the interface.
  1. Corrosive (Packing) : A property of packing whereby it is assumed (often incorrectly) to promote corrosion of a rigid member of a trapped fluid.
  1. Cracker : A heavy-duty mill having two deeply corrugated or pyramid-cut rolls for breaking down a rubber or a mix, or for cutting rubber or a mix into pieces.
  1. Crack : A fissure originating in the surface of a rubber vulcanizate or product as a result of natural weathering.
  1. Crack, Flex : A fissure originating in the surface of a rubber vulcanizate, resulting from cyclic deformation (usually bending).
  1. Crack, Ozone : Fissures originating in the surface of a rubber vulcanizate, caused by exposure to an ozone-containing environment; these fissures are perpendicular to the direction of strain, and usually occur in rubbers having main chain unsaturation.
  1. Cracking : The sharp break or fissure in the surface. Generally due to excessive strain.
  1. Crazing : Formation of a random pattern of shallow cracks on a rubber surface usually due to ageing by light. Unlike ozone cracking, crazing does not depend on the presence of a tensile strain in the rubber.
  1. Creep : The progressive relaxation of a given rubber material while it is under stress. This relaxation eventually results in permanent deformation, or “set”.
  1. Crosslink : The chemical bond bridging one polymer chain to another.
  1. Crosslinking : Formation of chemical bonds between polymer chains to give a network structure.
  1. Cross-Linking Agents : A chemical, or chemicals, that bonds the polymer chains together to form a thermoset rubber product.
  1. Cross-Section : A seal as viewed if cut at right angles to the molding line, showing internal structure.
  1. Crystallinity : Orientation of the disordered long chain molecules of a polymer into repeating patterns. The degree of crystallinity effects stiffness, hardness, low temperature flexibility, and heat resistance.
  1. Cure : The thermo process that causes a chemical change in the raw stock, turning it into the finished rubber part . Also see Vulcanization.
  1. Cure Date : The date a rubber product was molded. Normally expressed, for example, as 1Q04, meaning the first quarter of the year 2004.
  1. Cure Meter : A testing device that measures the progress of vulcanization.
  1. Curing Temperature : The temperature at which the rubber product is vulcanized.
  1. Cure Time : The preset time needed to complete the curing process
  1. Cylinder : Chamber in which piston, plunger, ram, rod or shaft is driven by, or against, the system fluid.



  1. Damping : The quality of an elastomer to absorb forced vibrational energy. That property of a material or system that causes it to convert mechanical energy to heat when subjected to deflection; in rubber the property is caused by hysteresis.
  1. Deflashing : Any of various processes used to remove the waste edge from a molded rubber part.
  1. Degassing : The intentional, but controlled, outgassing of a rubber substance or other material.
  1. Density : The mass per unit volume of a material. Also referred to as specific gravity.
  1. Desiccant : A compounding material used to irreversibly absorb moisture, particularly for the purpose of minimizing risk of porosity during vulcanization.
  1. Die Swell : The difference between the dimensions of the cross section of an extrudate, and the corresponding dimensions of the die orifice from which the extrudate was formed. It is usually expressed as the percent increase in the cross-sectional area.
  1. Diene Polymer : A polymer formed from one or more monomer species, at least one of which is a diolefin.
  1. Dielectric Properties : The ability of a material to resist puncture due to electric stress. The property is expressed in terms of “volts per MIL thickness”.
  1. Dielectric Strength: The measure of a vulcanizate’s ability to resist passage of a disruptive discharge produced by an electric stress.
  1. Diffusion : The mixing of two or more substances (solids, liquids, gasses, or combinations thereof) due to the intermingling motion of their individual molecules. Gasses diffuse more readily than solids.
  1. Dispersion : The application of shearing forces to distribute one or more compounding materials uniformly throughout the mass of a rubber compound.
  1. Dumbbell Specimen : A flat specimen of rubber having a narrow straight central portion of essentially uniform cross section with enlarged ends. Used for testing purposes.
  1. Durometer : An instrument for measuring the hardness of a rubber; measures the resistance to the penetration of an indentor point into the surface of the rubber.
  1. Dusting : The application of a powder to a rubber surface, generally to prevent adhesion to another surface.
  1. Dynamic : An application in which the seal is subject to movement, or moving parts contact the seal.
  1. Dynamic Packing : A package employed in a joint whose members are in relative motion.
  1. Dynamic Properties : Mechanical properties exhibited under repeated cyclic deformation.
  1. Dynamic Seal : A seal required to prevent leakage past parts which are in relative motion. Also means a seal which is subjected to reciprocating, rotational, or oscillating motion.



  1. Ejector Pins : Pins or blades that, when activated internally to the mold, eject the part from the mold cavity. Sometimes referred to as “knock outs”.
  1. Elasticity : The property of an article which tends to return to its original shape after deformation. A rubber’s ability to return to its original size and shape after removal of the stress causing deformation such as stretching, compression, or torsion. It is the opposite of plasticity. The term elasticity is often loosely employed to signify the “stretchiness” of rubber.
  1. Elastomer : Any natural or synthetic material with resilience or memory sufficient to return to its original shape after major or minor distortion.
  1. Electron Volt : Unit of energy in atom calculations equal to 1.602 X 1012 ergs.
  1. Elongation : Extension produced by a tensile stress.
  1. Elongation, Percent : The extension of a uniform section of a specimen expressed as percent of the original length.
  1. Elongation, Ultimate : The elongation at the time of rupture.
  1. EPDM : Terpolymer of Ethylene-Propylene-Diene (noted for excellent ozone resistance).
  1. Erg : Unit of energy (C.G.S.) equal to one dyne centimeter, or approximately equal to the work done by force of One (1) milligram, causing a movement of one (1) centimeter.
  1. Evaporation : The direct conversion from liquid to vapor state of a given fluid.
  1. Explosive Decompression : The rupture of a rubber article caused by the rapid reversal of pressure, causing dissolved gases in the rubber to escape quickly to the surface of the vulcanizate.
  1. Extender : A material (usually organic) used to augment the polymer in a compound.
  1. Extensometer : A device for determining elongation of a specimen as it is strained.
  1. Extrudate: The material that issues from an extruder.
  1. Extruder : A machine designed to force rubber through an orifice, which is shaped to the geometry of the desired end product.
  1. Extrusion : The continuous shaping of a material during passage through a die.
  1. Extrusion (seal) : Distortion, under pressure, of a portion of a seal into the clearance between mating metal parts.



  1. Face Seal : A seal between two flat surfaces. In an O-Ring, this means it seals on the top and bottom, not the ID and OD. Also referred to as an axial seal.
  1. Fatigue Breakdown : The deterioration of an elastomeric product during repeated deformation.
  1. Fatigue Life : The number of deformations required to produce a specified state of fatigue breakdown in a test specimen or product that is deformed under a prescribed set of conditions.
  1. Feather Edge : The sharp, thin edge on parts, such as wiper seals and cups. (Also called “Knife Edge”).
  1. Filler : A solid compounding material, usually in finely divided form, which may be added in relatively large proportions to a polymer for technical or economic reasons. The most commonly used filler is carbon black. Most fillers also function as reinforcing agents.
  1. Filler, Inert : A filler having no reinforcing effect.
  1. Fixed Dimension : Dimensions on a rubber product that are not affected by flash thickness or mold closure variation.
  1. Flame Resistance : The resistance to burning of material that will not withstand combustion under ordinary conditions.
  1. Flash : Excess rubber left around a rubber part after molding, due to space between mating mold surfaces; removed by trimming.
  1. Flex Cracking : A surface cracking induced by repeated bending or flexing.
  1. Flex Life : The number of cycles required to produce a specified state of failure in a specimen that is flexed in a prescribed method.
  1. Flexometer : A machine that subjects a test specimen to repeated deformation by compression, tension, shear, bending, torsion or any combination thereof.
  1. Flex Resistance : The relative ability of a rubber article to withstand dynamic bending stress.
  1. Flexural Strength : The ability of a material to flex without permanent distortion or breaking.
  1. Flock : Fibrous filler sometimes used in rubber compounding.
  1. Flow : Ability of heated plastic, or uncured rubber, to travel in the mold and runner system during the molding process.
  1. Flow Cracks : Surface imperfections due to improper flow and failure of stock to knit or blend with itself during the molding operation.
  1. Flow Marks : Marks or line on a molded product, caused by imperfect flow of the raw compound during forming.
  1. Fluid : A liquid or a gas.
  1. Fluorocarbon : A polymer designed to meet the most rigid requirements in oils, solvents, synthetic lubricants and corrosive chemicals, at elevated temperatures.
  1. Friction : Resistance to motion due to contact of surfaces.
  1. Friction (Break Out) : Friction developed during initial or starting motion.
  1. Friction (Running) : Constant friction developed during operation of a dynamic O-Ring.
  1. Frosting : The formation of a matte, whitish appearance on a rubber surface exposed to air, resulting from the action of ozone. Often confused with bloom.
  1. Fuel (Aromatic) : Fuel which contains benzene or aromatic hydrocarbons; causes little swell of rubber.
  1. Fuel (Non-Aromatic) : Fuel which is composed of straight chain hydrocarbons; causes little swell of rubber.
  1. Furnace Carbon Black : A type of carbon black produced by the decomposition reaction of hydrocarbons, when injected into a high velocity stream of combustion gases under controlled conditions.



  1. Gamma Radiation : Electromagnetic disturbance (photons) emanating from an atomic nucleus. This type of radiation travels in wave form, much like X-Rays or light, but has a shorter wave length (approx. 1 Ado or 107 mm). It is very penetrating.
  1. Gasket : A deformable material clamped between essentially stationary faces to prevent the passage of matter through an opening or joint. A static mechanical seal.
  1. Gas Permeability : The degree to which a substance resists permeation of gas under pressure.
  1. Gates : The openings in an injection or transfer mold that ensure the even flow of material into the cavity.
  1. Gate Mark : A raised spot or small depression on the surface of an injection or transfer molded part, where the gates interface the cavity. (Also called “Sprue Mark”)
  1. Gland : The cavity into which an O-Ring is installed. Includes the groove and mating surface of the second part, which together confine the O-Ring.
  1. Glass Transition Temperature : The approximate mid-point of the temperature range over which a reversible change in a polymer occurs from (or to) a viscous or rubbery condition to (or from) a hard and relatively brittle one.
  1. Grain : The unidirectional orientation of rubber or filler particles in a rubber strength: the resistance to deformation of rubber stock in the uncured state.
  1. Groove : The machined recess into which a seal is fitted.ground vulcanized rubber: vulcanized rubber in particulate form; used as an extender or filler.
  1. Guayule Rubber: A form of natural rubber, cis polyisoprene, obtained from the shrub, Parthenium Argentatum.
  1. Gum Compound : A rubber compound containing only those ingredients necessary for vulcanization and small amounts of other ingredients for processing, coloring, and for improving the resistance to ageing.



  1. Hardness : Resistance to a disturbing force. Measured by the relative resistance of a material to an intender point of any one of a number of standard hardness testing instruments. (Also see Durometer).
  1. Heat Aging : A test for degradation of physical properties as a result of exposure to high temperature conditions.
  1. Heat Build-up : The accumulation of thermal energy generated within a material as a result of hysteresis, evidenced by an increase in temperature.
  1. Heat Deflection Temperature : The temperature at which a standard plastic test bar deflects 0.010 in. under a stated load of either 66 psi or 264 psi.
  1. Heat History : The accumulated amount of heat a rubber stock has been subjected to during processing operations. Incipient cure or scorch can take place if heat history is excessive.
  1. Hermetic Seal : An airtight seal having no evidence of detectable leakage.
  1. Homogeneous : A material of uniform composition throughout.
  1. Homopolymer : A polymer formed from a single monomer species.
  1. Hydrocarbon Solvents – Aromatic : Solvents having basic benzene structure, usually coat tar types such as benzene, toluene orxylene.
  1. Hysteresis Loss : The loss of mechanical energy due to hysteresis.
  1. Hysteresis : The conversion of mechanical energy to heat in rubber undergoing strain.


  1. Identification : Colored dots or stripes on seals for identification purposes; seldom used.
  1. Immediate Set : The deformation found by measurement immediately after removal of the load causing the deformation.
  1. Immersion : Placing an article into fluid, generally so it is completely covered.
  1. Impact : The single, instantaneous stroke or contact of a moving body with another, either moving or at rest, such as a large lump of material dropping on a conveyor belt.
  1. Impact Resistance: Resistance to fracture under shock force.
  1. Impact Strength : A measure of the toughness of the material, as the energy required break a specimen with a single blow.
  1. Inhibitor : A material used to suppress a chemical reaction.insert: typically, a metal or plastic component to which rubber is chemically and/or physically bonded during the molding process.
  1. IRHD (International Rubber Hardness Degrees) : International Rubber Hardness Degrees. An alternate method of measuring rubber hardness. IRHD units are approximately equivalent to Shore A durometer units, although a different apparatus is used.
  1. Injection Molding : Molding in which the rubber or plastic stock is heated and, while in the flowable state, is forced or injected into the mold cavity.
  1. Insert : Typically, a metal or plastic component to which rubber or plastic is chemically and/or physically bonded during the molding process.
  1. Isoprene-acrylonitrite Rubber : A low-plasticity copolymer with around 34 per cent ACN.



  1. Knit Line : An internal or external defect in a vulcanizate, where raw stock did not unite into a homogeneous mass during vulcanization.
  1. Knuckles : Small tough rubber pieces scattered throughout a bale of raw rubber that do not disperse easily or accept carbon black and other compounding materials during mixing.



  1. Leakage Rate : The rate at which a fluid (either gas or liquid) passes a barrier. Total Leakage Rate includes the amounts that diffuse or permeate the material of the barrier as well as the amount that escapes around it.
  1. Life Test : A laboratory procedure used to determine the amount and duration of resistance of an article to specific sets of destructive forces or conditions.
  1. Linear Expansion : Expansion in any one linear dimension, or the average of all linear dimensions.
  1. Liquid Curing Medium (LCM) : A molten phase, generally a mixture of sodium nitrate, that is used as a heating medium for the continuous vulcanization of a rubber mix, usually following extrusion.
  1. Logy : Sluggish, low snap or recovery of a material.
  1. Low Temperature Flexibility : The ability of a rubber product to be flexed, bent or bowed at low temperature without cracking.


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Practical Solutions On Equipment Simplified – A Know Your Supplier Special

At Rubber Machinery World, we understand your information requirements. Our effort on this portal to share authentic information to help you source your machinery wisely remains incomplete without notes on equipment suppliers from whom you source your rubber and tire equipment.

Hence, ‘Know Your Supplierseries is one of our advertorial initiatives to bring to you information on the machinery supplier ecosystem – Manufacturers, OEM Suppliers, Machine Rebuilders, Used and Pre-Owned Equipment Buyers & Suppliers, and Agents.

In Know Your Supplier editions, we cover an equipment supplier’s Competency, Capacity, Commitment, Culture, Communication, Market Presence, Technology, Solutions, amongst other details that you seek; so you know these organizations better and reach them quicker.

In this post, I introduce you to an equipment supplier based in India but wired globally. Read on to know why.

Pracsol Chemicals & Machinery is into trading of Machinery, Raw Materials and Chemicals since 2007 and is growing in reputation in machinery business. We understand from our conversation with Harish Nene, Chief Executive, that in the last 4 years they have secured landmark orders for Used Machinery from Indian Rubber and Tyre industry.

Pracsol is now fast building on this rising confidence and customer trust to extend practical equipment solutions to the industry in new machinery as well.

Flip through this Special Edition using the link –

In this conversation, Harish Nene outlines on a wide array of his business aspects right from the genesis of his company name to his experiences in rubber and tyre industry, partnership with JM Machinery USA, recent successes and new products on the anvil. Harish also informs us the unique service proposition Pracsol offers to their customers, their competence and comprehensive range of machinery offered to buyers.

I reproduce for you a few snapshots of our conversation here. (For full story, please do read and download here, this special edition of Know Your Supplier)

  • Pracsol is a strange name. What is the story behind this name?

Pracsol is derived from the words ‘Practical Solutions’. Through my experience of last 20 years in International Business, I would state that solution for a problem is possible if looked at it practically not by just following procedures.

Pracsol Logo

  • Having started in 2007 how has been your experience so far in this industry?

Business Ethics, Honesty, Transparency and Hard work is important. Customers who do business with me recognize that they can expect these from me and have helped me succeed in the rubber and tyre industry. I also have good support from my principal company. This makes things simple and gives me time to focus on delivering value to customers. From my last 7 years experience, I would opine that doing business with Private Companies is easier than doing business with Public Limited Companies.

  • Purchasing machinery is a major investment for most buyers and they would need technical inputs and customization. What level of pre-sales support do you offer?

We provide all the important technical details about the machinery with photographs. Through JM Machinery, we can aid in design and engineering from concept thru completion of the desired machine. If the customer insists on Physical Verification Report then physical verification is carried out by our principals’ engineers and a report is provided. The client has the liberty to visit for physical verification if the machines are available at our warehouse in USA.

  • Are you launching any new products?

We are targeting the rubber industry in Europe & USA to export our range of new machinery from India. We have recently bagged an order to design, manufacture and supply a NEW BATCH OFF for Europe. This is expected to be despatched by end of September 2015.


For full conversation and other details of Pracsol, access this special edition of Know Your Supplier in PDF here.

Meanwhile, here is a quick overview of industries covered by Pracsol and Harish Nene’s contacts if you would like to reach him quickly.


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There Is Lot of Innovation In The Rubber Machinery – Prof. Dr. Andreas Limper

There is a lot of innovation in the rubber machinery and its adaptation in the industry, says Prof. Dr.-Ing Andreas Limper, Member of the Board of Management, Harburg-Freudenberger Maschinenbau GmbH in an exclusive interview with Rubber Machinery World.

Prof. Dr.-Ing Andreas Limper is a dynamic and well-respected business leader steering HF Mixing Group for over a decade now. A tall technical authority on rubber and polymers, acclaimed author of a few books on rubber, key-note speaker, educationist and much more, Dr.Limper is an inspirational figure.

Hence, this opportunity to present before you his interview, is a privilege to me and a prestigious addition to “Know A Rubber Leader” series.

Know A Rubber Leader

In this engaging interview, you will find him speak passionately about success, challenges, customer frustrations, plans of HF Mixing Group, innovations for tire and non-tire industry, quality and tackling piracy.

Here is  Prof. Dr.-Ing Andreas Limper’s complete interview.

  1. Hello Dr. Limper. First of all thank you for accepting an interview with Rubber Machinery World and sharing your thoughts. The journey from a Mechanical Engineer, specializing in Polymer processing (1981) to Member of Board of Management (2004) of an Organization with 155+ years of legacy is a remarkable one. So let me start with a personal question – What would you say was a key to your success and how you reached the very top spot?

Everybody who has passion for his kind of job will be successful. When I started my career at the IKV (Aachen University), rubber processing was a focal point of activities. It has been very fascinating to transfer methods of engineering to the rubber industry. At that point of time (beginning of the 80’s) the rubber industry was dominated by chemists and a lot of process understanding had to be developed. Being a part of this paradigm change had been very inspiring and motivating. To the new generation, my advice is whatever you do, stop doing it if you do not like it (or can’t change it). The Rubber Industry is an attractive field of work, since it requires multi-disciplinary thinking (chemistry, physics, mechanical engineering, electrical engineering, product design, etc).  

  1. Through organic and inorganic growth (acquisitions), HF currently enjoys an enviable leadership status for its portfolio of products. What’s a challenge you spend a lot of time thinking about these days?

Excellent solutions require holistic thinking in the mixing room. We could show that, for example, by the tandem technology it is possible to save considerable mixing time and even mixing stages in some cases. The integration of the abilities of modern control systems, drives, hydraulics and machine concepts is necessary to achieve lowest possible costs at highest quality. Many customers are still ignoring these facts and tend to keep buying mixing lines as in the old times. In those days, steel and iron, controls and peripheral aggregates have been sourced individually and there have not been a lot of synergistic interactions.

It is a challenge for us to convince customers to leave the archaic way of purchasing and to go for holistic “turnkey” offers.  With our investment into a first class technical center, the building up of a big group of system engineers and control system specialists, we are today well prepared for widespread offers.

HF Tandem Mixer

HF Tandem Mixer

  1. Recently, a reader wrote to me saying “Ever since the inventions of Banbury® and Intermix®, rubber mixing machinery have not witnessed any spectacular invention”. Would you agree with this statement? Where do machinery stand today vis-a-vis the progress (or lack of progress) in rubber technology?

This reader was definitely wrong! Imagine, somebody saying: “Cars today still have four wheels, a motor , a brake and an autobody, I cannot see any new technical concept..”  Would you agree??

Only out of a very big distance the mixers from 1920 and today look similar. We have

  • hydraulic instead of pneumatic rams
  • a controlled ram pressure and a controlled ram position
  • dust stops , which have far less leakages as in the past
  • machines running at least with double speeds as 100 years ago
  • have rotors being at least 250% more productive
  • a tight process control, which uses to control the process parameters to achieve a very high batch-to-batch uniformity
  • a wear protection, which has doubled the lifetime of the mixer components

Apart from the common feature, many people address to the rubber industry, I see a lot of progress in the mixing room. Tangential mixers are offering new rotors with enhanced capabilities for cooling and a higher productivity. Tyre producers are using mixers as reaction vessels (silica compounding) and are introducing intermeshing mixers. The tandem technology is getting an increasing importance and a steep rising market share. Twin screws have conquered the downstream area in many mixing rooms. I have seen a mixing room for final mixing without any roll mill.

Summarizing these shows, there is a lot of innovation in the rubber machinery and its adaptation in the industry!

HF Twin Screw Extruder

Twin Screw Sheeter

  1. What is the biggest frustration today for buyers of tire machinery? How are HF Tire Products and Services addressing this?

As I already mentioned, a missing “holistic view” can be very frustrating. Customers seem to save money, when they purchase their mixing lines “in slices”. This is only a short-term thinking. Normally their own engineering work is not taken into costing consideration or valued to be for free. Also the cheapest product can have the highest “costs of ownership”, since in many times the availability of low-price solutions can be poor. Availability is not only reached by robust and well-engineered products, it is also a function of service. This means customers should also value, what would be the reaction of a supplier, when it would come to problems. By installing a network of own service stations and service partners all around the world, we show a high commitment to achieve highest possible availability for our customers.

To allow our customers the look to a complete line, we have installed two lines in our technical center, where customers can use all components of a mixing line (material feeding, mixer, peripheral aggregates, different downstream solutions, a complete automation system including material and recipe management, process control, lab data etc.) to analyse his personal advantages in practical tests.

Such a detailed practical test had not been possible in the past. Often customers had to use industrial field installations for complete studies, which had a lot of limitations.

  1. How does HF propose to change the rubber and tire industry in the years to come?

I would be very happy, if a broader view on solutions would take place. In our case this would be an entire look at a mixing line – including controls, order and material management. It could be that the rubber industry will lose a part of its market to the TPE industry. In such cases, rubber processors could think about own compounding facilities for these materials.

In the tyre industry, we expect even new challenges from newer materials, as functionalized polymers or surface activated fillers. To develop solutions, which will assure the ability to compound these new recipes at acceptable costs, remains to be a real challenge.

Energy Efficiency will be a big theme in mixing. The relative costs might be only a few cents per Kg, but the absolute costs are approaching very high values in practice. We have developed new drive solutions with considerable higher efficiencies. Besides this we have a quite big research work in which we have analysed the complete energy flow in the mill room. The first results are very promising! By the optimisation of processes, the more intelligent process control (for example the ram-position control possible by iRam), a better use of hydraulics, we see specific energy-saving potential of up to 40%.

All in all, these examples show again, that we should be prepared to look in the bigger scope to the mixing line – then a lot of substantial optimizations are possible.

Know A Rubber Leader - Dr. Andreas Limper

Read PDF

  1. Can “superior-technology” and “low-cost” ever go hand-in-hand in rubber and tire machinery/equipment?

If we are speaking about high quality demands, it is a must!! Look at the major tyre producers. They have analysed the total costs of ownership and keep buying high quality machinery.  For low-quality products, which have to fulfill low requirements, perhaps a cheap solution also works. But for me, even this way is questionable.  A rubber mixing line has a high investment and a very long lifetime. Customers, serving today a low-requirement market, might see the demand for higher sophisticated solutions in a few years. With a line of sight at a low-standard, they are limiting their ability to follow market trends.

  1. Most analysts opine that the production has shifted from west to east in case of rubber goods production. However the customer awareness levels on advances in machinery and its availability, superior technology and its adoption is seen to be better in the west. So, on a scale of 1 to 10 (low to high), where do you rate the practices of manufacturers of the east? What do you think of this disparity and how is HF working to expand your market on newer technologies in the East?

We are actively supporting our customers wherever they go. We have own service activities at our new facility in Slovakia and an own service station in Qingdao/China. The higher personal costs are producing a higher pressure for modernization on western facilities. So in general terms, there is a certain routine for optimizations and process improvements. In eastern facilities, which in many cases are much younger, these skills must first be developed.However, I see eastern European facilities learning very fast. If the western companies in best cases are at a scale of 10, eastern facilities today are achieving results of at least 7.

If I look at Asia – which means predominantly India, China and Southeast Asia, conditions are comparable. These countries have been used by OEM’s, for example car manufacturers as source for easy and inexpensive parts. Companies being active in such business fields are working with very simple and inexpensive solutions. I am deeply convinced, with increasing quality demands there will be a strong requirement for modernisations and upgrades. New technologies, a wide use of automation concepts and new mixing procedures create the necessity to qualify as well the operators and people responsible for the mixing room. By installing our own training center, we are preparing our customer operators for the use of new technology. We see that this is as important as the technology itself.

Rubber Mixing Room

A Rubber Mixing Room

  1. One of the greatest threats to any business is copying of design and features from original manufacturer and offer at a fraction of price. Some politely call it “re-engineering” but any imitation can be quite intimidating. As a respected industry pioneer, I am sure you too would have your share of concerns and challenges. How does HF face this and protect your revenue or profitability?

I like the general thoughts of John Ruskin, who said, “There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man’s lawful prey”.
A mixer is – with a superficial view – not a complicated machine. Its geometry can be copied simply. What “pirates” ignore?  A lot of secrets are in the production methods! Think about hard coating, high precision machining of hardened surfaces, sophisticated controls for ram hydraulics, etc. Also, the correct assembly involves a lot of manual skills which need a lot of experience. If we apply our quality demands, a production of a key component is usually not decisively cheaper in a low-cost country. This means the production of this key components in own premises is the best know how protection.

  1. What do you envision for HF Group in the next 10 years?

I am convinced the market will ask more and more for “solutions” instead of “machines”. This means our group has to be able to deeply understand our customers’ requirements. Our understanding has to include not only the mill room but as well the general product specifications and the value chain of its production. The HF Mixing Group is preparing itself by building up more engineering power and more engineering competence. Our production of key components will be further developed to achieve lowest costs at highest quality. We will as well develop and use our world-wide purchasing network to accomplish the best costs for our customers.

  1. Great! And one last question, what would you advice on machinery selection to buyers and users of rubber and tire equipment?

Let me again answer with a worldly wisdom of John Ruskin. “It’s unwise to pay too much, but it’s worse to pay too little. When you pay too much, you lose a little money – that is all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do. The common law of business balance prohibits paying a little and getting a lot – it can’t be done. If you deal with the lowest bidder, it is well to add something for the risk you run, and if you do that you will have enough to pay for something better”.


Download the full interview in PDF here.

A highly influential persona up to First World War, John Ruskin’s ideas and concerns are today widely recognized as having relevance in environmentalism and sustainability. Significantly, both are key challenges for the rubber machinery industry as well.  And continued innovation in rubber machinery, I think, is the best way to protect environment and also ensure overall sustainability. With this food for thought, I look forward to hearing from you on this chat with Prof. Dr. Andreas Limper.

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Injection Moulding Machinery Is All About Reliability – Dr. Hans-Joachim Graf

Injection Moulding Machinery is all about reliability. If you assess well and decide now to stick with one (maybe two) machinery suppliers, then this time spent is a very good investment by itself, says Dr. Hans-Joachim Graf, Rubber Industry Consultant at H-JG Consulting, Germany in an exclusive interview with Rubber Machinery World.

Esteemed readers, as you know, I started “Know A Rubber Leader” series with Jacob Peled, the renowned Executive Chairman at Pelmar Engineering. The interview was widely read for some rare nuggets that Jacob chose to share on this site.

In this post, I present you an intensely thoughtful chat with Dr. Graf.

Dr. Graf was awarded with the Erich-Konrad Medal for commendable achievements in rubber-technology instituted by DKG (German Rubber Society) during DKT’12 edition. With over thirty years experience in the rubber industry, he has authored over 60 publications and paper presentations. He has over 15 patents in his name. A member of the American Chemical Society, Deutsche Chemische Gesellchaft and Deutsche Kautschuk Gesellschaft (DKG), Dr.Graf received his diploma degree from University of Mainz and his doctorate in polymer chemistry from University of Freiburg, Germany.

Know A Rubber Leader

Here is Dr. Hans-Joachim Graf’s full interview reproduced for you.

  1. Hello Dr. Graf. First of all thank you for accepting an interview with Rubber Machinery World and sharing your thoughts. Your journey started from pharmaceuticals and subsequently moved to rubber industry. Was this a planned move?

After finishing my PhD in macro-molecular science I decided I did not want to stay in university and become a researcher. I am more of a hands on person. My first job was with the owner of a small company as I felt that fit me best. I put my nose in almost everything from tooling to compound development. I even established the first manufacturing quality control system in this company. There were new challenges every day and I had fun. I cannot say it was planned. It happened.

  1. From Design Process (at Kloeckner Desma) to Director of Materials (at Cooper Standard Automotive) and now as an active educationist has been a long and varied one. Which is the position that you enjoyed the most?

There were two positions I enjoyed most. The most innovative group I worked with was at Desma. We developed many innovations, which you can find even today in different publications. I utilized my group’s expertise from mechanic to engineer, and electrician to chemist. The group did not depend on anybody else in the company. My boss protected me from the administration. We achieved the respect of a lot of customers and that was our motivation.
The second position I enjoyed most was with Cooper Standard in Canada. I was the elder in a very young dynamic group, but the most multi-cultural I have ever seen in any company. We had Asians, Europeans, North Americans and even Canadians in the group. Whenever I come to Canada, I still get together with many friends. Here, I utilized my engineering and chemist expertise in this group. This group created one the most advanced mixing centres in industry. The bad thing is, upper management never recognized it.

  1. Would you say that rubber compounding has undergone change in the last 3.5 decades that you have been with rubber industry? What were the drivers for this change?

The 50’s and 70’s saw the big polymer and ingredient suppliers work out the basics of compounding. Significant technological advancements were seen and a large amount of literature was produced at this time. It was needed because of the tremendous growth of the rubber industry after World War II. Following the first economic crisis, along with early retirement programs and more crises – for example, the breakdown of the Comecon (specifically Europe) – technical knowledge to a large extent was lost and polymers became commodities. Leadership in the supplier industry changed from technical to sales. From this time forward, rubber parts manufacturers had to take the responsibility of development in their own hands, but with limited resources.

  1. What role has machinery played in this change?

This is a difficult question for me. The machine industry has followed the same trend as the polymer industry. We had sophisticated machines in the 80’s but slowly this position has worsened. This is very different with the technology for the machines used in the thermoplastic industry. At one K’show, machines were presented that had a cycle time of less than 3 seconds! It is different with rubber parts – because of its inherent slow heat transfer qualities; the major influence on the cycle time is the rubber. As a result, engineers believe that machine time does not play a big factor. There is no real optimization of compounds going on to accommodate machine and mold necessities. Engineers and Chemists do not work together. Both parties see more differences than similarities between rubber and thermoplastic processing.

  1. Design of Experiments [DoE], though being a standard tool in optimization of materials and processes in many industries, has not many takers in rubber manufacturing industry. Why?

In my opinion, it is the fear of failing. If an experienced compounder is doing a DoE, he has to design the experiment and leave it up to a series of mathematical equations. He cannot interact with the experiments as he is used to do when performing trial and error procedures. The DoE results of the experiments may be a confirmation of his existing knowledge, but it may not. It may challenge and force him to question that longstanding knowledge.

  1. How does rubber compound development benefit with software? Do you see a trend of increased use of software in this field?

Around the time the Design of Experiment was invented some companies (Cabot, Bayer beside others) performed some superficial trials on filler / oil designs. After more than four decades this tool has not penetrated the field of compounding as it should have. Its growth is much too slow, and I would not call it a trend. Software exists today (like FEA), for the engineering of rubber parts. This is standard. However, interaction between part design and compounding is still trial and error. While properties of a compound are an input for the FEA calculation, it is rare to design a compound to fit the FEA requirements for the part.

On the other hand, compounding groups have created a lot of recipes, but most of it is based on trial and error. From my perspective, it is lost knowledge, because DoE Software cannot make any use of it. I felt that I had to help to somehow utilize this data not only for my benefit but for others. This is the basic idea behind the “GrafCompounder” software. I have the experienced compounder in mind, who would like to use his company’s historic compound date base instead of filing it away.

  1. What are the various tools and methods of recipe development and its advantages? Which of these is the most optimized method that has clear economical advantages?

Preferably, the strategy for initial recipe development should be the analysis of the compound in various machines and during its part life. We call that: data analysis, time series analysis, correlation of root cause and effect via observations. You have to work with the compound – process system. This can only be done successfully if the statistic experimental design approach is taken. The economic advantage of this is clearly superior when you take into account the reduced costs for statistical design experimentation versus trial and error, minus the cost of the final result.  A second development area of similar importance is to ensure secure supply. This needs material replacement and multiple approval strategies. It depends on raw material, process and service life knowledge. This knowledge is attained only again, through experimentation.

Upper management needs to understand that development sometimes means failure and they have to allow for this. We all learn from failed experiments. We never learn if everything is running at a steady state.

  1. In 2004, you had stated that the extruder has been around for some time and changed very little. And you viewed the extruder as a black box analyzing the energy and mass (input and output). Is the extruder different today?

I have been out of the extruder industry for some time and have not followed the ongoing developments here close enough to comment. What I can say is: the combination of an extruder and gear pump truly has its advantages, because it is a volumetric pump and it pressure dependence is zero. This provides superior straining of a compound without changing its properties. Is a gear pump is useful for compounds with very high viscosity? I do not know its limits.

  1. What are the key changes and trends happening in injection moulding?

We have been quite successful in decreasing energy consumption during moulding. Next we need to focus on developing a much faster process to stay competitive with TPE. The technique to induce heat into the compound by shear is developed, but control of the vulcanization process is urgently needed. We have come a long way with heating time regulation (Barber Colman) to inline temperature history and heating time close loop control (CAS-Jidoka) and its linkage to cross-link density, but injection molding machines should be faster. Hopefully we see more development as seen in the machine industry for thermoplastic processing.

  1. Great! And one last question. What advice on “machinery selection” would you give to buyers in rubber industry?

I can comment on injection molding machines only. One topic in my “Injection Moulding” seminar is about machine assessment. With a couple of experiments one can analyze the capability of an injection molding machine. It is not rocket science. It needs about two days of intense experimentation. Another topic I would like to comment on is maintenance and spare part management. This is all about reliability. If you decide now to stick with one (maybe two) machine suppliers, then this time spent is a very good investment.

Download the full interview in PDF here.

I would love to hear your thoughts on this interview.

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