Type A Single Lip – Rubber Coated w/ Spring (Rotary Seals or Oil Seals)

[Type A Single Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: Carbon Steel Stainless Available.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only. Generally used for sealing lower pressure (up to 0.5 bar/7psi) fluids or heavy greases depending on shaft speed. If a backup ring is used, it can operate at medium pressure (4 bar/57psi).

Type ADL Double Lip – Rubber Coated w/ Spring (Rotary Seals or Oil Seals)

[Type ADL Double Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: Carbon Steel – Stainless Available.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only. Generally used for sealing lower pressure conditions with medium dirt exclusion of foreign materials. Used for lower pressure (up to 0.5 bar/7psi).

Type AW – Rubber Coated – No Spring (Rotary Seals or Oil Seals)

[Type AW Single Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: N/A.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type “Springless”. Rotary Motion Only Generally used
for sealing non-pressure medium, especially for grease or viscous fluids. Otherwise only
for less critical sealing applications.

Type B Single Lip – Metal Case w/ Spring (Rotary Seals or Oil Seals)

[Type B Single Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: Carbon Steel – Stainless Available.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only Generally used for sealing
lower pressure (up to 0.5 bar/7psi) fluids or heavy greases depending on shaft speed. If a
backup ring is used, it can operate at medium pressure (10 bar/140psi).

Type BDL Double Lip – Metal Case w/ Spring (Rotary Seals or Oil Seals)

[Type BDL Double Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: Carbon Steel – Stainless Available.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only Generally used for lower pressure conditions with medium dirt exclusion of foreign materials. Used for lower pressure (up to 0.5 bar/7psi).

Type BW Single Lip – Metal Case – No Spring (Rotary Seals or Oil Seals)

[Type BW Single Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: N/A.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only. Generally used for sealing non-pressure medium, especially for grease or viscous fluids. Otherwise only for less critical sealing applications.

Type C Single Lip – Full Metal Case w/ Spring (Rotary Seals or Oil Seals)

[Type C Single Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: Carbon Steel – Stainless Available.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only Generally used for sealing lower pressure (up to 0.5 bar/7psi) fluids or heavy greases depending on shaft speed. If a backup ring is used, it can operate at medium pressure (10 bar/140psi).

Type CDL Double Lip – Full Metal Case w/ Spring (Rotary Seals or Oil Seals)

[Type CDL Double Lip]

DIN: 3760 Standard.

Common Materials: Nitrile, Fluorocarbon, Silicone, EPDM, Polyacrylate, Neoprene.

Spring make: Carbon Steel – Stainless Available.

Pressure Rating: Max 7psi.

Mounting: Press-fit.

Comments: Common grease seal type. Rotary Motion Only Generally used for lower pressure conditions with medium dirt exclusion foreign materials. Used for lower pressure (up to 0.5 bar/7psi).

Standard O Rings

MECH Rubber offers the seal industry’s largest inventory of O-rings including every standard AS-568B size, including I.D.’s from 1/32″ (.794mm) to 26″ (66.04cm), O.D.’s from 3/32″ (2.38mm) to 26-1/2″ (67.31cm) and cross sections (widths) from 1/32″ (.794mm) to 1/4″ (6.35mm). We also carry a wide variety of metrics and non-standard sizes. Most likely the size and compound you require is in our stock of over 300,000,000 O-rings. Our O-ring inventory is constantly restocked to assure immediate delivery of any size in large or small quantities. We are the largest rubber manufacturers in India.

Simplified Reference Easy to Order:

Our Quick Reference Guide has all the information you need at a glance. All rubber O rings sizes are listed by ascending inside diameter (I.D.) in fractional AND decimal sizes. Standard AS-568B Uniform Numbering System (Order by a single number).

Choice of Seven Materials as Standard:

We offer O rings rubber compounds and options of Durometer hardness to satisfy practically any service condition. Check with our sales staff for other material needs.

Quickest Delivery on O-Rings:

We have stock of about 300,000,000 O-rings. Immediate shipments with no intermediate delays. (Remember – with MECH Rubber you buy direct.)

We highly recommend that in all cases, samples of a specific size and compound should be tested in the application before use in production.

General Applications

O-Rings from MECH Rubber are available in a choice of seven basic materials each in a range of optional Durometer (Shore A) Hardnesses. Other materials available upon request.

Buna-N:

In the Buna-N family, you will find compounds which are ideally suited for oil resistant applications of all types.

Ethylene-Propylene:

In the Ethylene-Propylene family, you will find compounds that are used extensively for outdoor, weather resistant uses, water appliances. The first choice for low torque drive belts.

Silicone:

In the Cast Polyurethane family, you will find compounds which are used predominantly in high hydraulic pressure applications and situations where highly stressed parts are subject to wear.

Cast Polyurethane:

In the Cast Polyurethane family, you will find compounds which are used predominantly in high hydraulic pressure applications and situations where highly stressed parts are subject to wear.

Neoprene®:

In the Neoprene family, you will find compounds which are the superior sealing materials for the refrigeration industry featuring resistance to ammonia and Freon®.

Fluorocarbon:

In the Fluorocarbon family, you will find compounds which make-up the preferred seals for aircraft engines, automotive fuel handling systems and hard vacuum

Fluorosilicone:

In the Fluorosilicone family, you will find compounds which make-up seals that are unparalleled for aerospace fuel systems and auto fuel emission control systems. All materials are compounded under stringent quality control for uniformity of physical properties, and to meet or exceed Government, Military, Space Program, Automotive, F.D.A., Industrial and Commercial specifications.

Metric Size Range

A wide range of Standard British, Swedish and German Metric ‘O’ Rings India are available in cross sections from 1.5 to 8.4 millimeters and inside diameters from 3 to 395 millimeters.

The MECH V-RING is a unique all-rubber seal for rotary shafts. The V-Ring provides a perfect solution to prevent the ingress of dirt, dust, water or combinations of these media while positively retaining grease. With its unique design and performance the V-Ring protects a wide range of bearing types. It can also be used as a secondary seal to protect primary seals that do not perform well in hostile environments. It has been used successfully by OEM and the replacement market world wide in a broad range of applications.

Selection of Rubber

When selecting the correct material i.e. type of rubber compound it is necessary to take the following requirements into account;

• good chemical resistance
• good resistance to high and low temperatures
• good resistance to ozone and weathering
• It is also necessary to consider the need for the following attributes;
• high resistance to wear
• low friction
• low compression set
• good elasticity

Properties

Pressure Range: up to .5 MPa (74 psi)
Temperature: -40 to +200ºC (-40 to +392ºF)
Velocity: 30 m/s (100 ft/s)

Application

The V-Ring is normally long-drawn-out and mounted directly on the shaft, where it is positioned by the inherent tension of the rubber body. It rotates with the shaft and seals axially against a stationary counter face, at right angles to the shaft. The counter face can be the end face of a bearing or a washer, stamping, bearing housing, or even the metal case of oil seal. The sealing lip is flexible and applies only a relatively light contact pressure against the counter-face and yet is still sufficient to maintain the sealing function. The low contact pressure (that varies with the fitted width) allows the seal to run dry in many applications.

Due to the centrifugal force, the contact pressure of the lip decreases with increased speed. This means that frictional losses and heat are kept to a minimum, resulting in excellent wear characteristics and extended seal life. Once breakaway torque is overcome, the power losses reduce steadily until around the 10 -15 m/s band when they reduce quite quickly. In the 15 – 20 m/s band the losses reduce to zero and the V-Ring then serves as clearance seal and deflector.

The flexible lip and hinge allow the V-Ring to function even in the presence of a certain amount of run-out, eccentricity and shaft misalignment. Contact our local company for advice on these and other application issues.

V-Rings are made entirely of rubber without fabric or sheet metal reinforcement. They are, therefore, particularly easy to install. V-Rings can be stretched and, depending on size, installed over flanges, pulleys and bearing housings without costly dismantling.

V-Rings are available in various standard cross-sections to meet various space and application requirements.

We are specialists in developing new products and we currently offer the widest range available on the market.

Our rubber sheetrange one will always find the ideal solution for any gasket sealing or abrasion protection problem, even in the most demanding industrial environments.Its used as most protective solutions to complex applications. It can be used even in dynamic applications.

All types of elastomers-natural and synthetic (SBR, Nitrile, Chloroprene, EPDM, Silicone, Viton®, Butyl and Polyurethane) always with well-defined and certified quality aimed and enhancingthe end use of the product.

Shore Hardness range from 30º to 90º A.

Finishes and presentation:

• Moulded Smooth on both sides.
• Moulded Smooth on one side + canvass impression on the other side.
• Canvass impression on both sides.
• Matt or special designs like diamond, chequered on one or both sides.
• Canvass inserted and moulded smooth finish on both the sides

Shapes and Sizes:

• Sheets available in rolls, strips, plates and tiles.
• Thickness from 1.5 mm to 50 mm.
• Widths available up to 2000 mm.
• Length up to 100 meter.

we have specialised ourselves in making of expansion joints towards following applications.

• Conveyor high temperature substances (like steam, gases etc…)
• Conveyor of high pressure or high vacuum substances
• To absorb movements
• To absorb vibrations (anti vibrations)
• Noise absorption
• Earthquake movements
• Shock absorption
• VERY HARD 90-100°

This typical joints are made as bellows of stainless steels, PTFE, Hi modulus plastics, glass fibre fabrics (we have separate section), or specialised synthetic elastomers (rubbers). A bellows are designed with single or multiple convolutions depending on length and application, with the shape of the convolution designed to withstand the internal pressures of the pipe, and to ensure flexible enough to absorb lateral , axial, and angular deflections. The higher flexibility with zero leakage are also made with multiple layers. The rubber bellows are manufactured with steel wire & high strength fibre reinforcement. The flanges are made up according to standards or non-standards provided by customers. They are made in different shapes like round, Oval, Elliptical, Conical, rectangle or octagonal.

Pressure balanced expansion joints (bellows)

We have manufactured Expansion joints mainly for industrial piping systems to adapt movement or vibrations due to thermal and mechanical changes in the production line.And some of the process has wider changes in temperature hence metal components vary in size. Expansion joints with metal bellows are designed to absorb certain movements and minimize the conveying of forces to delicate components in the system.

In some of the application pumps built pressure or gravity is used to move fluids through the piping system. Fluids under pressure follow the volume of their vessels.So we designed the unique concept of pressure balanced expansion joints to maintain a constant volume by having balancing bellows compensate for volume changes in the bellows (line bellows) which is moved by the pipe.

Rubber expansion Joint bellows

Wrapping steel wire and fabric reinforced rubber masticated sheets

Rubber expansion joints are primarily manufactured by labour-intensive wrapping of rubber masticated sheets and fabric reinforced rubber sheets around a bellow-shaped product mandrel tool.Along with rubber and fabric, reinforced rubber and/or also steel wires or metal rings are inserted for additional reinforcement. This can be made high pressure resistant. After the entire product is build up on the mandrel, it is enclosed with a winding of (nylon) peel ply to coerce all layers together before pressurization and vulcanization. Because of the labor-intensive production process, it takes longer.

Moulded rubber expansion joints

Rubber expansion joints (some types only) can also be made with a moulding process. They are of medium sized expansion joints with bead rings, which are manufactured in large quantities on a cylindrical mandrel, which is wrapped with partiality cut fabric ply. This part is finally placed in a mould and moulded into shape and vulcanized. We manufacture for automobile sector for their bulk and faster needs.

Our next project is to adopt new technology for robotic manufacturing of Automated winding of rubber expansion joints.

Mech Spares real strengths remains in the development of custom bellows. We are a world leader in the design and manufacture of bellows; we are capable of providing the best possible solution for your application. Our materials has excellent physical properties like, temperature resistance from – 40C° to 1000C°, self-extinguishing, Flame retardant, Fire proof, oil, coolant and chemical resistant, anti-abrasive, long shelf life etc…. We have expertise in chip protection, high speed cutting technology, laser beam protection, aggressive grinding coolants and moving-column machines.

With our new technology and designs bellows are vastly superior to products manufactured with traditional methods. They can be custom designed to meet and exceed your specifications.

Mech Spares fabric bellow divisions motto is to design and manufacture the products to protect customers economically, environmentally, and most importantly, employees can be even more productive, with a safer and cleaner workplace. We have adopted new technology instead of traditional methods to exceed expectations.

Our customers believe that they can rely on us for professional, individualized solutions to protect their machinery from hazardous materials such as dust, chips, weld splatter and fluids.

Thermally Bonded Bellows

Single construction and firm rigidity provide a secure cover that maintains its uniform shape even in long runs. It is also reinforced with PVC stiffeners that are thermally bonded to each fold of material to give a clean aesthetics, which will enhance the emergence of products and machinery.

Linear Guide Bellows

Mech Spares has designs and also stock of linear guide bellows for commonly used linear rails. We also have some of the special designs for tight retracted length situations as well as long extended length applications. This has been designed in standard or high temperature materials.

Stainless Steel Plated Bellows

Stainless steel bellows protect against welding splatter hot chips, and heavy chip loading. It is designed for hostile and/or extreme environments. Spring-loaded steel plates are mounted to every fold of conventional bellows, on one side or multiple sides. The steel plates push the debris off of the adjoining steel plate avoiding debris from contacting the bellows beneath. Horizontal applications work best with fixed plates and vertical applications are optimized with the hinged plate design.

Stitched Bellows

Mech Spares designed stitched bellows for severe environments. They can handle extreme temperatures, high abrasion and tight compression applications. Mech Spares uses the best chemically treated thread for the highest level of performance, Stitched bellows can be combined with rigid PVC reinforcement. They are economical solution, but it has limitation of not being liquid proof. It’s a labour intensive design.

Polygonal Laminate Bellows

Polygonal laminate bellows are aesthetically proven designs because they are available in almost any shape, and further they are attractive and practical bellows made in horizontal and vertical systems. The bellow material selection can be matched with different interior materials, and their divisional design allows for easy replacement in the case of impaired sections. It can be enhanced with, gliders and /or rigid PVC reinforce. Polygonal laminate bellows can operate in ambient temperature and humidity conditions.

Disk Rubber Bellows

This bellows are of high quality protective covers for pistons and spindles. The rubber disks are pressed out and vulcanized for added toughness and elasticity. They can be used for most regular and external applications. We recommend Nitrile & EPDM rubber covers for oil or coolant protection. We suggest alternative material for high temperature applications. They are robust in nature.

Moulded Bellows

We use moulding process to produce a wide variety of shapes and sizes. Moulded bellows are designed to resist alkalis, acids, dust and water. They are produced in large quantities.

Flange Sealing Technology Through Gaskets

Our work at the frontier of sealing technology gives us a clear understanding of the roles that gaskets must play, for example:

• If joint faces are absolutely flat and aligned true.
• If flanges do not distort under load.
• If loaded bolts do not stretch or relax…

…There is no need for a gasket, because the joint will be perfect.

In the real world, such perfection is very expensive to achieve and almost impossible to maintain. Therefore a gasket is the most practical and cost effective way to seal a bolted flange joint.

Our knowledge and experience will resolove the major problem of designers and maintenance engineers to to select the correct gaskets to ensure the integrity and safeoperation of their fluid handling plant.

Types of gaskets

• Compressed fibre Gaskets
• Cork-elastomer Gaskets
• Expanded graphite Gaskets
• Profile Cut Gaskets
• Machined/corrugated gaskets
• Spiral wound gaskets
• Semi-metallic gaskets
• Metal Jacketed Gaskets
• Other gasket products
• PTFE gaskets
• Ring joint gaskets

(caps, Grips, Bellows, Proto various sizes & shapes)

We have been manufacturing Rubber, Plastic & Vinyl caps, Grips for various applications. They can be compounded into any hardness, clarity & colour, They can be pumped & sprayed.

Some of the exclusive features are as follows:

• USP Class VI materials for medical products
• High temperature resistance,
• Anti-stat (ESD)
• Copper non staining
• Glossy or matte finishes
• Available in both custom and standard colors including fluorescent colors
• Strong & permanent environmental seal
• Available at economical rates
• Available from a minimum thickness of 0.005 inches
• Soft like skin or hard like glass
• Can to elongated up to 500%
• Weather resistance, electrical insulation, fire resistance, abrasion resistance are the other features.

We have separate unit for the designing and production of Engineering plastics especially

• Acrylonitrile Butadiene Styrene (ABS)
• Polyamides (PA)
• Polybutylene Terephthalate (PBT)
• Polycarbonates (PC)
• Polyetheretherketone (PEEK)
• Polyetherketone (PEK)
• Polyethylene Terephthalate (PET)
• Polyimides
• Polyoxymethylene (POM / Acetal)
• Polyphenylene Sulfide (PPS)
• Polyphenylene Oxide (PPO)
• Polysulphone (PSU)
• Polytetrafluoroethylene (PTFE / Teflon)
• Techtron (PPS/HPV)
• Ultra High Molecular Weight Polyethylene (UHMWPE)

Protective elements for shaft joints primarily performing angular movements. Axial movement is limited. Single convolute bellow prevent loss of lubricant while excluding contaminants. Mech has been one of the largest bellow manufacturer in India

Protective elements available in various geometrical designs for sealing axially moving rods and machine parts against dirt, dust and environmental factors. available from stock.

Fabric-reinforced moulded diaphragms in standardised geometrical moulded design for use in air cylinders for pneumatic brake systems. Depending on the level of the braking force to be transferred and the stroke length, they are divided into three design ranges for different types of cylinders: diaphragm cylinders, diaphragm spring-loaded cylinders and diaphragm tristop cylinders. The diaphragms operated in the same way for all three cylinders types.

Base material for producing flat packings and moulded parts, pressed or drilled, for all sectors of industry. Sheets and rolls are available in many elestomers and in various thicknesses and sizes.

Round mounts and buffers are designed for damping and isolating vibrations, they also have a shock-absorbing effect and compensate for stress or manufacturing differences between connected components. Mech round mounts are different from numerous other products of this kind in that they have and integrated rubber contour which reduces the high edge strain on the rubber when there is radial deflection, thus increasing the durability of the component.

Also available Spherical mounts, Instrument mounts

Flat metal ring with internally bonded, trapezoidal, elastomeric sealing torus for static sealing of Screw couplings, Flange Connections.

Depending on the gap width, operating pressure and material hardness, O-rings are fitted with backup rings to prevent gap extrusion. In addition to ourstandard range, we provide backup rings in various special materials and sizes.

Mech has a complete range of sealing solutions for applications in every sector of industry. Materials include polymers (Nitrile, Neoprene, EPDM, Silicone and Viton), rubber corks manufactured by the world’s leading cork producer, and a broad base of non-asbestos sheeting.

ultra bushings are designed for the damping and isolation of radial and axial vibrations. They are used as maintenance-free joints to balance torsional and cardianic stress. Their high level of durability relies on the bonding of the pressurised and tensioned elastomer later on both sides.

Mech rubber mouldings are used for a whole variety of applications in rubber products and include gaiters and bellows, diaphragms, anti-vibration mountings, rubber gasket seals, valve seats, rubber O rings, seals and so forth. We have large stock of Rubber O rings, Rubber gasket seals & variety of Rubber products. Each product is custom-made for a specific application and Mech can advise on the most suitable compound. Available materials include Nitrile, Neoprene, EPDM, Silicone, Fluorocarbon and Natural.

At Mech, we tailor each product to the customer’s requirements. We are one of the largest PTFE manufacturers and PTFE suppliers in India. Whether your request is for slit width, special tolerances, or custom sizes on material, you’ll always get the service and product you need. We have wide ranges of PTFE gaskets in our stock as well.

Mech is one of the only processors to reprocess virgin PTFE in house, enabling us to control the quality of reprocessed material. We also offer which is blended in our plant to offer you a larger variety of virgin PTFE materials, along with a (Ultra PTFE) which is a Virgin PTFE with Bronze & Carbonfill PTFEior physical properties.

Browse through our online catalog below, and if you have any questions, please feel free to contact us. We’re happy to help by answering any questions you have about and PTFE products or properties.

Advantages

• Excellent physical and mechanical properties
• Self-lubricating with superior bearing performance
• Good dimensional stability at operating conditions
• Superior resistance to moisture absorption
• High wear resistance
• Low coefficient of friction
• Outstanding chemical and corrosion resistance
• Light weight and reduces noise chatter
• LINEAR BEARING GRADE is oven annealed to reduce internal stresses

Method of Operation

LINEAR BEARING GRADE materials are used in dynamic load applications such as: bearings, thrust washers, bushings, gears, cams, spacers as well as in numerous other sliding or rotating components.

• Bushings: radially loaded shafts, whether Carbon or Stainless Steel, can benefit from the use of LINEAR BEARING GRADE sleeve bushings
• Thrust Bearings: under oscillating motion, these bearing materials exhibit excellent wear resistance, durability and no stick-slip. Axial- loaded shafts benefit from the reduced friction of the material
• Linear Motion: for the benefits of efficient mechanical advantage, LINEAR BEARING GRADE leadscrew nuts provide low friction, reduced noise and combinations of high speeds/low loads or moderate speeds and loads
• Pulleys: these bearing materials resist wear, self-lubricating, easily fabricated and can be incorporated into existing designs

Special Features

LINEAR BEARING GRADE was developed for general-purpose bearing applications. This grade exhibits an excellent surface finish when machined. Outstanding service life and superior chemical resistance are typical of LINEAR BEARING GRADE products. This grade excels in performance demands up to moderate loads and speeds.

LINEAR BEARING GRADE bearing grade material was developed to handle moderate loads in high-speed applications. Long service life, exceptionally low coefficient of friction with reduced noise plus high PV capabilities are some of the characteristic of LINEAR BEARING GRADE

Technical Data

MATERIAL PROPERTIES

• Tensile Strength @ Break ……… 7,600 psi 5,900 psi
• Elongation @ Break …………… 15% 19%
• Heat Deflection Temp. ………… 205°F 203°F
• Max. Continuous Service Temp…… 180°F 180°F
• Intermittent Service Temp. ……. 225°F 225°F
• Linear Coef. of Thermal Exp…….. 5.2 in/in°Fx10-5 5.2 in/in°Fx10-5
• Coef. of Friction (Non-Lub)……. 0.30 0.22
• Wear Factor …………………. 43 in/(psi*fpm*hr) 20 in/(psi*fpm*hr)*10-10 *10-10
• Limiting PV Value ……………… 7,500 psi-fpm 42,000 psi-fpm
• Warter Absorption ……………….. .20% .20%

We at MECH begin our journey as Polyurethane suppliers and turned to biggest Polyurethane Manufacturers in India to PU products designers. We did recognised that Unlike any other engineering material, Cast Polyurethanes itself have an extraordinary combination of physical, mechanical, and environmental properties.

The proportion between the resin and the curative agents can be varied to optimize some of these properties (sometimes it affects other properties). So, a proper combination will help to engineer the compound to achieve desired properties.

In most applications Polyurethane products offer following advantages.

• Resilience (high or low )
• Additional Toughness leads to Durability
• load bearing capabilities
• High Resistance to Tear and Cut
• Low Compression Set
• Impact resistance
• Outstanding Abrasion resistance
• Machinability to desired shape
• Oil, solvent, water and ozone resistance.
• Flex fatigue resistance
• Good Electrical properties
• Friction (high or low) Mechanical Properties

Rubbers are amorphous in nature hence has excellent elastic properties. And because of elastic properties and resistance to wide range of temperatures, rubber products has found many industrial and consumer applications.

We as rubber manufacturers and rubber suppliers have diverse range of materials – as varied as “metals or plastics.

There is lot of research and development has happened to have best of the rubber products and some of the properties are briefed below with instances of actual applications.

Most of the engineers and designers choose rubber (elastomers) because of its Wide Range of Properties

The properties optimised by right type of compounding. Every group of rubber has its own inherent properties and we can design to best of its application and have best of the rubber products

The development of synthetic rubbers stemmed from the need to create materials with greater resistance to fuels and oils. Aggressive chemicals, hydraulic oils, food substances and refrigerants all have to be carefully formulated and tested to ensure safe and predictable service lives.

Typical Applications

Rubber is used for seals and gaskets in almost any chemical environment and for mechanical components in machinery of all kinds. It is also suitable for parts which must be reasonably resistant to normal contaminants, such a printed circuit board components which will be solvent cleaned.

Apart from Silicone, rubbers are essentially hydrocarbon materials and perform within a limited range of temperatures. Where working temperatures are quoted, these represent the range within which the rubber’s properties are maintained more or less indefinitely. Temperatures lower than the minimum will always stiffen the material (although it will relax as the temperature rises) and extremely low temperatures may turn it brittle. Temperatures higher than the maximum will degrade the rubber, ultimately destroying it.

Typical Applications

Where service temperatures are known, the best types of material can be selected to provide adequate life under those conditions. Temperature guidelines are provided in the DataChart, covering the range from – 80°C to + 300°C.

In vehicles, under-bonnet components are required to perform reliably in a high temperature environment while being exposed to hot oil, brake fluid and other chemicals. In other countries, the same components must function even when subjected to high wind chill factors – in Scandinavia for example sometimes reaching – 50°C.

The property of hardness is easily recognised, but in design it must be specified to achieve a given objective.
Solid rubbers range from 20° to 98° Shore A, where 20° is extremely soft like foam and 98° is as hard as bakelite or nylon. As a reference, the ball of the human thumb is 25°, a Staedtler white rubber eraser 55° and a bath plug 95° Shore A.

Typical Applications

Designers use rubber in its whole range of hardnesses and each application has to be individually considered. Once a mould has been produced, it is relatively easy to make the same part in other colours and hardnesses to suit different functions.

Whatever the hardness required, it may still be necessary for a rubber component to deform in order to seal against an uneven surface or to resist abrasion.

The ability to expand greatly and to return quickly is what distinguishes a rubber from a plastic. This property not only makes possible the catapult but also allows designers to use rubbers to supply constant forces, either in tension or compression.

Typical Applications

High quality rubber compounds will remain elastic for their full design lives, virtually irrespective of the movement cycles they undergo. However, all rubbers will relax to some extent under constant deformation and this should be specified if significant.

Where rubber is to be used continuously in tension, consideration should be given to the effects of failure and trials carried out as required.

Rubbers can have a wide variety of electrical properties (including piezo electric and magnetic) and by suitable compounding can be made highly conductive or totally insulating

Typical Applications

Conductive rubber is used in electronic equipment for switching, touchpads and continuity as well as static dissipation. Insulating rubbers are used extensively in electrical termination and switchgear components, grommets and weather seals.

Resilience is the property of absorbing energy by deformation and returning a proportion of it on rebound. Depending upon the rubber type and compound, some of the energy will be converted into heat within the material. A high resilience material returns almost all the energy – for example a superball – while a low resilience material has a low rebound, “dead” feel, such as a squash ball or high performance tyre.

Typical Applications

Rubbers have always been used for energy control purposes. These range from the simple – buffers, elastic bands and sports equipment – to the complex, such as car suspension systems or keyswitches, where rubber provides that delicate, precise “feel”.

Rubber is also valued for its vibration control. It is extensively used in flexible couplings where rubber “spiders” allow misalignment, reduce jamming and have the resilience to damp out vibration.

Raw rubbers can’t be used in their natural state. The raw rubber mixed with the right type of additives will get us to the optimum properties of rubber products, rubber seal rings, Rubber O rings, Rubber gasket seals etc… Rubber processing and compounding has utmost importance.

The additives in a rubber processing and compounding may vary from application to application. The additives are added by weight and will include some or all of the following:

Curatives

Sulphur and peroxide curing are used as cross linking curatives for rubber chains and best known curatives in rubber processing and compounding. They are first to get discovered and most commonly used.

The constituents are weighed out and combined by a mixing process which must blend the ingredients thoroughly in a repeatable way. This is achieved either by an internal mixer, where the compound is mixed by two meshing rotors in an enclosed case; or by open mill mixing, adding the ingredients carefully into the “nip” between two steel rollers, typically of 30″ diameter.

The result of either process is a batch of uncured rubber compound. This is allowed to settle for a time before undergoing Quality Assurance tests. Once passed, it can be formed into suitable shapes for moulding.

A piece of uncured rubber of the correct size is placed between two halves of a heated mould. The mould is closed in a press under a pressure of around one ton/sq in and the rubber is forced into the exact shape of the cavity. The rubber gains heat by conduction from the mould surfaces and “cures”. When the rubber has had sufficient time to cure, the mould can be opened and the part removed.

Compression moulding is a relatively simple process and is often used for components required in fairly low quantities. It is also the most economic method for parts with simple shapes.

Parts moulded by this method will always have some flash because the mould surfaces are held apart by the necessary excess rubber in the “blank”.

A screw injection system delivers a metered quantity of rubber into the closed mould. The injection unit is fed from a continuous strip or a reservoir of uncured rubber and is cooled to avoid premature curing.

This process is generally used for multi-cavity moulds and can produce hundreds of components per press cycle. Because of the amount of rubber in the system, it is inadvisable to change materials frequently

Large moulds require complex feed systems to balance the pressures in each cavity. Generally these are in the heated top half of the mould and cure at the same time as the components. Unlike thermoplastics, cured thermoset rubber cannot be reground or reused and the additional waste has to be included in the material usage per piece. Where very large volumes of mouldings are required, cold runner systems should be considered. These are justified by material savings over £10,000 pa.

This process lends itself to relatively large quantities, a large number of cavities and infrequent changes of materials or moulds. Parts are repeatable and can be made to a high level of precision.

Compression moulded and some injection moulded parts require deflashing. This is done in various ways depending upon the shape and size of the component and the type of rubber used.

Sub-Zero Finishing

The most modern and efficient method of finishing uses cryogenics. Parts are frozen to temperatures as low as -120°C and then tumbled and/or bead-blasted while cold to remove the brittle flash. The machines are individually programmed with the optimum temperature and running times for each particular type and number of components, which are tested and proven during the development stages.

While every component is designed to fulfil a unique set of operational requirements, there are a number of common principles which will reduce the time and cost of obtaining an economic component. Many of these are self-evident, but some require an understanding of the differences between moulding thermoset rubber and moulding plastics. We have utmost data on Rubber Design Standards. We have developed Electric Rubber mat in accordance with IS 15652 standards. We also have been following DIN, ISO, ASTM & IS Rubber design standards. Our rubber seal rings has been tested on AS 14000. Our Electric mats are tested up to 40 Kv on IS 15652.

If we know the applications then we can design the products at much lower possible costs. Hence effective communication can play vital role here.

A single cavity prototype can be produced quickly and economically. This allows designs to be proved, materials tested and a small number of parts supplied for pre-production runs. Mech offers a priority service for prototype moulds which can generally be obtained in less than four weeks.

The following should be borne in mind at the design stage:

• Be aware of where the split line will fall
• Think about removing the part from the mould when it is hot and soft
• Rubber parts do not generally need taper
• Re-entrant shapes are practical in rubber
• Core out thick sections which would extend cure times
• Geometric shapes make for economic tools
• Combine features – such as seals, springs, logos and tolerance take-up – from other parts.

The key determinants of cost are cycle time, the number of cavities in the mould, material cost and the need for manual operations before or after moulding.

Cycle times for rubber generally range from two to ten minutes, although the cure time for heavy parts may be much longer than this. Reducing the mass of a component not only reduces the material cost, but may also reduce the cycle time. This is especially true for parts with thick sections.

Where zero defects are required, due recognition of process capability is required in order to prevent unnecessary quality inspections after moulding. Checks that are not built into the process will inevitably add to the cost (shortcut to Quality in Rubber).

Rubber gains much of its strength and its resistance to heat and light from the addition of carbon black. Hence the vast majority of rubber is black.

Coloured rubbers can be produced using other reinforcing fillers and suitable colouring pigments.

However, the changes that take place during curing, and the nature of the moulding process, make it difficult to maintain perfectly even coloration, particularly with pale colours. Silicone rubbers are the most suitable for achieving reliable and clean coloured mouldings, even with pale colours and translucents.

While selecting the base rubber for any Rubber products, we first study the application and which are the basic properties are utmost important. Some of the basic properties are designed considering temperature range, fluid resistance, Weather, Ozone resistance etc

While selecting the most appropriate rubber for rubber products, bearing seals etc… the following data is needed:

• Highest and peak temperature
• Continuous temperature
• Lowest operational temperature?
• Contact fluids and with context to temperature?
• How long the fluid will come in contact and also if any accidental contact of hazardous chemicals etc…
• Environmental or weather (ozone) application

The accompanying chart shows the different rubbers and their properties as related to these questions. The cost factor is also shown, with the rubbers arranged in order of increasing cost from left to right.

Starting at the left, check the properties of the rubber against your answers to the questions above. Keep moving to the right until a rubber is found that meets your need. (Where no particular temperature or fluid resistance is required Natural Rubber is the most widely used material and offers the greatest scope of compounds and properties coupled with the most economic cost.It is also an environmentally friendly material)

If a rubber meets most of the requirements but is borderline on a particular property, Mech Spares should be consulted for further advice with a view to testing under the relevant conditions (if necessary).

Once a rubber type has been selected, the hardness range must be determined. Hardness is measured in degrees on the Shore “A” or IRHD scale (the values are similar although Shore “A” readings are usually one to three degrees higher than IRHD readings). Hardnesses are normally based on a nominal figure e.g. 50 ±5° or as a hardness range e.g. 50-60°.

Materials below 30° are extremely soft and comparable with foams. These are available but must be regarded as a special requirement.

Additional mechanical requirements should be specified only where necessary. They can be specified simply by description e.g. “good tear resistance required” or quantified by the use of a defined test method (such as ASTM or BS test methods) giving maximum or minimum values as appropriate. These values may be obtained by calculation based on the actual requirements of the application, by comparison with known values for similar applications or materials, or by testing a material which has been proved satisfactory by trial or experiment.

Where requirements are considerably more complex than the scope of this publication, the ASTM or BS framework for specifying rubber materials can be consulted. Materials may also be selected from the BS range of standard and special application specifications, some of which are listed below.

If the properties required of the rubber are difficult to determine, the production of a prototype mould should be considered. A variety of rubber compounds can then be moulded and parts tested for suitability in the actual application. Once a material has been proved suitable, it can be tested and its properties appropriately defined.

A method for specifying rubber materials can be found in ASTM D2000 and BS 5176. These provide a full framework covering all rubbers and rubber properties. The relevant requirements for an application are selected from within the framework and are expressed in the form of a “line call out”. (The same framework is used in both ASTM D2000 and BS 5176).

An example of a line call out is BS 5176 1MBC514 F2 7Z1. This can be broken down as follows indicated in this table:

The appropriate table for Grade 1 MBC materials shows the following basic requirements:

• Test: Elongation at Break
• Requirement: 400% minimum
• Test: Heat Resistance (70 hrs @ 100°C)
• Requirement: T.S. ± 30%, E.B. -50% max, Hardness ±15° max
• Test: Oil Resistance (Oil no.3 70 hrs @ 100°C)
• Requirement: Volume change + 120% max
• Test: Compression Set (22 hrs @ 100°C)
• Requirement: 80% max

Quality is often understood as “strength for application”, but such a concept has no cost or processing considerations. A part produced using poor processes, which can be guaranteed only as the result of inspection, has no inherent quality. A fuller definition is “dependability of function at lowermost cost, consequential from good design and the use of skilled processes”.

Quality begins on the understanding application and on creating the drawing. With awareness of rubber properties and its manufacturing needs for simple design to optimize functions and avoid manufacturing difficulties towards tooling and finished product processing. Such components will have best values for money.

Using the knowledge and understanding of the rubber designer at an initial stage will enhance the design which will offer rubber’s optimum properties and avoid future problems. It will also allow considering the tolerances, differences of thermal expansion, co efficient of shrinkage etc…

The goal of all quality conscious companies is zero defects. This is achieved through the use of capable processes and statistically based monitoring; it cannot be achieved by inspection.

Continual improvement is needed to increase the capability of processes. In today’s rubber industry, this capability is relatively low and many aspects are difficult to monitor. For example, rubber is pliable and dimensions such as cylindrical diameters often cannot be gauged quickly and accurately. In mixing, dispersion cannot be easily checked; in preparing blanks, actual volume cannot easily be measured; and in moulding, the injection process is often more sensitive to material variation than any existing rheometer.

Rubber materials crosslink and are time and temperature sensitive. This results in significant viscosity variations during flow. Friction heat through mould gates and channels creates differences between material and mould temperatures which cannot easily be measured.

Despite such problems, much progress has been made in recent years through the emphasis on consistent processing and with modern computer-based injection presses which are self-adjusting, within limits, to material variations.

At present, world class levels of internal rejects should not be assumed in rubber but they can be achieved through careful design and adherence to the procedures outlined above. Across the industry, internal reject rates run at a typical but unacceptable level of 2%, but rates of 500 ppm (0.05%) – well within world class levels (Anderson Report) – can be sustained across a range of parts, materials and machines.

Clearly, any single part with well designed processes can achieve lower ppm reject levels. As more and more parts are designed on the right basis, and continuous improvement is applied to processes, capabilities will rise and reject levels fall.

It is important to consider present capabilities. The following is intended to provide a general guide using typical results, but every material, machine and process has its own capability and these can vary considerably.

Hardness is measured by pressing an indentor into the rubber and measuring penetration. Shore A is based on an immediate reading using a spring applied load. Variation from user to user can be as great as +/-2.5°. IRHD uses a dead load with a 30 second wait and is more consistent, giving user variations of +/-1.5° (3 sigma). There can be significant differences between the two types of readings.

The Tolerances Table (BS 3734) gives a brief background to rubber moulding tolerances. Tighter limits can be achieved (particularly with injection moulding) by slowing the process and moulding under minimum stress conditions. Limiting the number of cavities and shortening the flow path for the rubber also gives improvements, but clearly all these measures have a commercial cost.

Tolerances in rubber are generally less critical as the material deforms readily and accommodates variations. In fact, errors in measuring rubber can be significant and non-contact methods should be used wherever possible.

When designing tooling, critical dimensions should be taken into account to minimise the effects of tool split lines and flow. Stresses built up while the material flows can be moulded in if curing begins before the rubber is relaxed. On removal from the mould the part will distort accordingly, resulting in lower dimensional capabilities.

The Tolerance Table for BS 3734 moulding tolerances are included in this site. M2 tolerances are normal commercial tolerances and can be met by most rubber materials. M1 tolerances can be achieved through careful design and consideration. Production rates may be affected in some instances and good tooling and equipment is required. Particular attention should be given when using high shrinkage materials such as Silicones, Fluoroelastomers and peroxide cured rubbers.

Keypad force tolerances should not be considered in the same way as dimensional tolerances. Nearly all keypads are finger operated and the finger is relatively insensitive to exact loads. This is particularly true of single finger operation where loads of +/- 30% will not be noticed by a user. Examples include car switches, teletext terminals, car phones and instrument controls.

The exceptions are computer and typewriter keyboards where a tolerance of +/- 15% is required. In this case the finger rarely reaches full travel and operators are sensitive to forces because of the high frequency of use.

Capabilities depend upon membrane design and length of travel. Typical capabilities are outlined in this table.

Force variation is greatly affected by the fixing of the keypad base and by the escutcheon/keycap interface with the rubber. It is strongly recommended that early advice is sought.

The natural rubber is used since hundred years. The most extensively developed rubber with a lot many range of compounds.

Natural rubber is replenishable. During its production as a sapling (latex), it continually absorbs carbon dioxide (a greenhouse gas). At the end of their survival, the rubber trees are used for furniture and are substituted with young sapling for further production. Natural rubber is also biodegradable and non-toxic.

Properties

• the most water resistant type of rubber – also very resistant to most water based chemicals
• very inert structure, remains stable over long periods of time
• can withstand temperatures of up to 130°C for extended periods of time (months)
• very good weathering resistance
• easily compounded and processed

Properties

• resistant to a wide range of hostile environments
• resistant to oils and chemicals
• weather and water resistant
• can withstand temperatures from -30°C to 95°C
• easy to process and compound, offering cost benefits
• flame retardant
• can be produced in any colour required

Developed in the 1950s as a speciality rubber for rugged applications. Best described as a “super” Neoprene, with similar but better developed characteristics.

Properties

• resistant to oil and fluids, especially at higher temperatures (+125°C)
• extremely resistant to ozone and weathering – can withstand harsh outdoor conditions for up to 15 years

Another early development in the search for an oil resistant rubber. The most suitable rubber for applications requiring resistance to petroleum based fluids (there are rubbers with higher degrees of resistance but these are much more expensive).

Properties

• very good resistance to petroleum based fluids
• good high temperature resistance – up to 100°C (120°C with EV cure systems)
• economical to compound and produce
• very low level of permeability to gases

A synthetic rubber which is particularly resistant to hot oil.

Properties

• excellent resistance to oxidation and weathering
• particularly resistant to oil at high temperatures

Provides good oil resistance over a wide temperature range. More expensive than Nitrile but considerably cheaper than Silicone.

Properties

• good resistance to oxidation and weathering
• good oil resistance
• strong and abrasion resistant

A proprietary brand of EPDM and Polypropylene, readily available in a range of hardnesses. Flame retardant and coloured grades can also be obtained.

Properties

• easy to process
• reasonable resistance to fuels and oils
• available in hardnesses ranging from 60° to 99° Shore A

Synthetic rubber with a wide temperature range and outstanding resistance to weathering. Characterised by clean, smooth appearance with good flexibility.

Properties

• wide temperature range
• extremely good resistance to weathering
• excellent electrical properties
• good resistance to oils
• easily coloured
• low level of toxicity

Synthetic rubber with a wide temperature range and outstanding resistance to weathering. Characterised by clean, smooth appearance with good flexibility.

Properties

• wide temperature range
• extremely good resistance to weathering
• excellent electrical properties
• good resistance to oils
• easily coloured
• low level of toxicity

The best rubber to use in hostile environments where fuel, oil, chemicals or low temperatures are encountered.

Properties

• performs excellently in the temperature range -60°C to 200°C
• resistant to oils and fuels (particularly at low temperatures)
• good electrical strength

A synthetic rubber which is easy to process in large quantities. Widely used in the footwear and tyre industries.

Properties

• good physical strength
• good tear and abrasion resistance
• range of colours
• one of the cheaper rubbers

Hydrogenated nitrile rubber provides good all round performance at a compound cost between Nitrile and Fluoroelastomer. Its highly saturated main chain provides good resistance against thermal oxidation and chemical attack.

Properties

• good physical properties, including abrasion resistance, at high temperatures
• good dynamic behaviour and flex cracking resistance at elevated temperatures
• excellent heat, ageing and ozone resistance
• outstanding resistance to steam and hot water