History of Kemet

History of Kemet International

1938

Kemet International was set up initially as an importer of equipment for the aircraft industry, which included machinery and small tools for the fabrication of ball bearing races and other precision equipment.

1953

Manufacture started on a range of diamond abrasive pastes, which for the first time enabled precision components to be polished to a specified surface finish with guaranteed reproducible results. Developed in the first instance for use in the production of moulds and tools for the rapidly expanding plastics industry, as well as the precision polishing of hard materials and ceramics, diamond pastes now form just part of the Kemet product range.

diamond production in 1950s

1963

The Company moved to new premises which included a purpose-built laboratory for manufacturing Diamond Compounds.

1964

The Applikator was developed and patented to meter out precise quantities of Diamond Compound

applikator

1965

Kemet Europe was set up to handle sales in the Benelux countries

1968

The development of metal/resin lapping plates meant that for the first time a wide range of materials, including composites of different harnesses, could be flat lapped and polished to a higher specification than was previously achievable.

1972

Kemet Australia was set up to handle sales in Australia and New Zealand.

1975

The success of the metal/resin lapping plates led to the setting up of a new division to concentrate specifically on flat lapping. The result of this new venture was the introduction of a range of liquid diamond products and precision flat lapping machines developed for production lapping applications.

annular grooved lapping plate

1983

Kemet Far East was established to handle sales in for the Asian markets. More recently their activities have extended to serving the Chinese Market.

1985

Kemet set up a dedicated Research and Development Technical Centre to optimize customers’ processes for lapping and polishing applications, to carry out lapping services and to develop new products. Over the years the Lapping Technical Centre has been extended and it is now equipped with over 15 Kemet Lapping and Polishing Machines ranging from 15″ to 48″ Lapping Systems allowing a fast turn-round of customers’ samples. The Centre also has Spherical Polishing Machines, along with the latest Mitutoyo and Rank Taylor Hobson Surface Measuring and Flatness and Roundness Inspection Equipment.

1989

ISO 9001 Quality assurance for the manufacture of Diamond Compounds, Slurries and Kemet Composite plates. More recently this has been extended to cover Contract Lapping

kemet quality assurance

1997

In response to customers’ demands for ever tighter specifications of Diamond Compounds and Slurries, especially from the rapidly-expanding electronics industry, a new diamond research and development laboratory was built, fitted with the latest diamond particle analytical equipment, capable of measuring down to just 10 nm.

2002

Kemet Japan set up as a Joint Venture.

2006

To cope with the increasing demand for Diamond Slurries, special Lapping and Polishing Fluids and Kemet Composite Lapping Plates, new production plants were built which enable production to be increased by many times.

diamond laboratory

2007

Cleaning Technical Centre set up to develop processes for ultrasonic cleaning applications.

2008

Kemet China established. Kemet Korea set up as a joint venture

2009

New Metallographic Centre set up in the University of Oxford. Queen’s award for International Trade

2013

New process development Technical Centres were opened covering Metallographic and Petrographic sample preparation and Ultrasonic Cleaning with aqueous- based media.

2014

In Singapore new research and development facilities were set up equipped with a wide range of single and twin-wheel grinding, lapping and polishing machines to process customers’ samples and carry out pre-production trials.

biggest lapping plate

2015

In China Process development facilities were set up to duplicate the development work carried out in Singapore. Today, the Kemet International Group, with 120 employees, has its own sales organisations in eight countries worldwide – and is represented in all the major industrial countries worldwide. In the UK, 60 employees, including a field sales force of five Technical Representatives, are all committed to providing the customer with total quality and service.

research development of lapping

After over 80 years in the business, in which it has enjoyed sustained growth both at home and abroad, Kemet International continues to apply the philosophy which has provided the solid foundation for its premier position in the market: To offer top quality products with unrivalled Technical Support. This will ensure that the company maintains its established position in a market where long-term success depends on the company’s ability to meet the ever more exacting demands of its many customers worldwide

80 years of kemet international

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Larslap Exclusive Distributor’s Letter

 

Kemet Far East Pte Ltd is proud to be Larslap's sole distributor to offer and supply Larslap machines, its spare parts and after sales services to South East Asia & China.

About Larslap

Larslap was established over twenty five years. LarsLap’s biggest cornerstone is quality in everything manufacture and deliver.

LarsLap valve grinding system give your valve a fast and efficient maintenance so you can feel safe and comfortable with your valve environment.

 Applications Industries:

  • Oil & Gas

  • Petrochemical

  • Power Generation

  • Marine

We are able to provide the whole spectra (grinding material, valve maintenance classes, machines and service) to meet your valve environment.

Send us your inquiry today to meet your valve environment needs. 

larslap-exclusive-distributors-letter

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Aircraft & Aerospace Component Maintenance

Kemet Diamond Flat Lapping Systems are widely used throughout the aircraft and aerospace industries by both original manufacturers and individual airlines for maintenance. These systems offer the most efficient and reliable method of producing precision flat, polished surfaces.

Kemet diamond quality and grading enables precision lapping of aircraft components to be performed in production and service environments. Each Kemet diamond product is a special blend of diamond powder with a specific grading and concentration in a chemical carrier to give optimum stock removal and surface finish, ease of cleaning, temperature resistance and lubricity to prevent drying out.

aircraft component maintenance

Typical Areas

Pumps & Valves

Metal to metal faced seals can be lapped on Kemet Diamond Flat Lapping systems. While Fuel pump gear faces can be successfully lapped on Kemet annular grooved Plates for precision shoulder lapping.

Hydraulic Parts

Can be accurately lapped using Kemet Diamond Flat Lapping systems and Kemet annular Grooved Plates

Engine Seals & Bearings

Can be precisely lapped using Kemet Diamond Flat Lapping systems.

Landing Gear

Can be effectively lapped using Kemet Diamond Flat Lapping systems and intricate internal faces / diameters can be polished using Kemet Diamond Compound and Kemet Helilaps.

 

Seal Manufacture and Maintenance

Manufacturers for mechanical seals and engine seals use Kemet Diamond Flat Lapping Systems extensively. The most common materials processed are tungsten carbide, stellite, ceramic, silicon carbide, carbon and brass. Seal rings up to 12” diameter are successfully lapped under production conditions to have mirror surfaces with flatness to 2 or 3LB.

Pump Manufacture

Companies involved in the manufacture and reconditioning of pumps use Kemet Diamond Flat Lapping Systems for producing and maintaining / repairing flat seal faces on mechanical seals and flow control equipment

Aviation subassemblies

Kemet Portable hand Lap kits are used for lapping and polishing of small aircraft parts.

Kemet Diamond Lapping Machines and Systems used for Aircraft and Aerospace Engineering

Country Component Equipment
Belgium F100 Carbon & Metal Engine Seals Kemet Pneumatic Lift Diamond Lapping Machine with Kemet Iron/Kemet XP Composite plate
Hydraulic Parts for Landing Gears Kemet Diamond Lapping Machine with Kemet XP Composite Plate
Holland Fuel Pumps Shoulder Lapping using Kemet Diamond Lapping Machine with Annular Grooved Kemet Iron Composite plate
Hydraulic Parts, Engine Seals and Air Cabin Pressure Flaps Shoulder Lapping using Kemet Pneumatic Lift Diamond Lapping Machine with Annular Grooved Kemet Iron Composite plate
Kemet Diamond Lapping Machine with Kemet Composite Plates
Spain General engine components Kemet Lapping Machines
Singapore Metal Faced Seals are lapped on our Diamond System. Carbon Seals are lapped with Al/Ox on Cast Iron Composite plate on a Machine Kemet Large Sized Diamond Lapping Machine with Cast Iron Plate
Hydraulic Components
Malaysia Engine Seals
Thailand General
Singapore Fuel Components Medium Sized Diamond Lapping Machine with Kemet Iron Composite Plate
Hong Kong General Kemet Medium Diamond Lapping Machines
Australia Mechanical Seals and Hydraulic Parts
Seals and Carbons for the Aircraft Industry Kemet Lapping Machine and Kemet Hand Lapping Plates with Diamond Slurry / Compound
Hand Lapping, but mainly involved in the tooling side for the Helicopter Industry Kemet Hand Lap Kits
Engine and Hydraulic Parts for the Helicopter Industry
Small components for aviation sub-assemblies
High Tech Aeronautical Industries (F111 planes, etc.)
UK Constant Velocity Drive Units, General Engine Components and Hydraulic Landing Gear Kemet Medium Sized Diamond Lapping Machine with Kemet Iron Composite Plate, Kemet Small Sized Diamond Lapping Machine with Cast Iron Plate, Kemet Medium Sized Diamond Lapping Machines with Kemet Iron Composite Plate and VSA Machine
Engine Seals and Bearings Kemet Medium Sized Diamond Lapping Machines with Kemet Iron and Kemet XP Composite Plates
Engine Components Medium Sized Diamond Lapping Machine with Kemet Iron Composite Plate and Large Sized Diamond Lapping Machine with Kemet XP Composite Plate
Engine and Landing Gear Kemet Large Sized Diamond Lapping Machine with Kemet Iron Composite Plate and Cast Iron Plate and VSA Machine
Hydraulic Undercarriage/LandingGear Kemet Large Sized Diamond Lapping Machine with Kemet Iron Composite Plate and Kemet Internal Helilaps with Kemet Diamond Compound
General Components Kemet Large Sized Diamond Lapping Machine with Kemet Iron Composite Plate
Hydraulic Landing Gear
Engine Seals Kemet Land Lap Kits
Hydraulic part repairs and replacements Kemet Medium Sized Diamond Lapping Machines
Undercarriage vanes and constant speed drives
Various Maintenance Engine / Hydraulic parts
Fuel and Hydraulic Pump Manufacture
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Sapphire Lapping and Polishing Process

Single Crystal Sapphire

The use of Single Crystal Sapphire, as a high quality original opto-mechatronic material in the information age, is growing rapidly because of its excellent mechanical features such as stability and optic permeability.

Problems with processing Sapphire?

  • Sapphire has the property of extremely high hardness but very low impact strength.
  • LED chips have the above structure but because the sapphire substrate is susceptible to stress there is the fear that it can easily be damaged.
  • Because of this inherent characteristic the wafer cannot be diced with a diamond wheel. Scribing is used for this purpose.
  • In order to produce a wafer thickness suitable for scribing we must perform back-grinding, followed by lapping and polishing.
  • Because the final thickness of the wafer is about 80um it is very weak and it is very important to keep it from breaking.
  • As this back-grinding/lapping/polishing is the final manufacturing process it has a great effect on yield.
  • These final operations demand machines and processes of high accuracy, high efficiency, and high stability in the manufacturing method.

Kemet has developed a series of metal-composite lapping plates to shorten the lapping and polishing process and reduce the number of reject parts.

Kemet Copper SP2 Composite Plate

This is the most popular plate for Sapphire lapping

The Kemet Copper SP2 Plate is a metal / resin composite containing finely graded copper powders. It was developed for the sapphire lapping market to produce repeatable stock removal of up to 2μm per minute.

  • Developed for polishing and back lapping sapphire wafers
  • Metal/resin composite containing finely graded copper powders
  • Fast stock removal with excellent surface finish
  • Shortens final CMP process
  • Typically used with 3 and 6 micron polycrystalline slurries for optimum results
  • Minimises sapphire wafer chipping and fracturing
  • Can be easily grooved
  • Available in a variety of sizes from 15” (380mm) to 84” (2140mm) diameter

lapping plates for sapphie lapping

Other plates which are used for sapphire lapping are:

Kemet Copper SP3 Composite Plate

This is a harder version of Kemet Copper SP2 which gives a faster removal rate.

Kemet XJ2 Composite Plate

This gives the fastest removal rate.

Kemet XP Composite Plate

Slower removal rate than Kemet Copper SP3 but with better Ra. Polishing Plates are manufactured from a homogenous mix of synthetic resins, copper powder and other materials. The Kemet XP plate is used to polish a wide variety of materials

  • Fast stock removal with excellent surface finish
  • Shortens final CMP process
  • Typically used with 3 and 6 micron slurries for optimum results
  • Can be grooved
  • Available in a variety of sizes from 15” to 84” diameter
Kemet Plate Features Relative Removal compared to Pure Copper Typical Surface Finish (Ra)
Pure Copper Good heat transfer, Good surface roughness. Difficult to groove and care needed to ensure chips and burrs are removed before used. Replacement cost is higher than Kemet material. 1 5.6nm
Kemet Copper SP2 Good removal rate and Ra, easy to groove 1.25 6.3nm
Kemet Copper SP3 Better removal rate but worse Ra. More difficult to groove 1.6 8.1nm
Kemet XP Better removal rate and good Ra. More difficult to groove 1.5 5.5nm
Kemet XJ2 Best removal rate but worse Ra, easy to groove 1.7 10.6 nm

 

Kemet Iron SP2 Composite Plate

This plate is used as an alternative to Kemet Copper SP2 where copper must not come into contact with the sapphire wafer egg for the manufacture of blue/green LED’s

The Kemet Iron SP2 Plate is a metal / resin composite containing finely graded iron powders. It was developed for the sapphire lapping market to produce repeatable stock removal.

  • Developed for polishing and back lapping sapphire wafers and eliminates copper contamination
  • Metal/resin composite containing finely graded iron powders
  • Fast stock removal with excellent surface finish
  • Shortens final CMP process
  • Typically used with 3 and 6 micron polycrystalline slurries for optimum results
  • Minimises sapphire wafer chipping and fracturing
  • Can be easily grooved.
  • Available in a variety of sizes from 15” (380mm) to 84” (2140mm) diameter

kemet xp composite plate

Kemet XL Composite Plate

Polishing plate which gives an excellent surface finish e.g. when used with 3 micron diamond slurry Ra = 1.4nm

Kemet XL Composite Polishing Plate gives good stock removal, whilst producing high quality surface finish and flatness with Kemet Diamond Slurries.

  • Produces superb surface finish with excellent flatness.
  • Easy to machine – Free-cutting plate formula gives chip-free edges on grooved patterns.

Tests with 3 Micron diamond slurry on Sapphire produced Ra better than 2nm (see data below)

Tests with 3 Micron diamond slurry on Sapphire produced Ra better than 2nm

Typical Sapphire Polishing Processes

Sapphire Substrates

  • Double-sided lapping with Boron Carbide #240 abrasives on cast iron plates to achieve the required thickness and surface roughness.
  • Single-sided lapping with Kemet SP2 plate with either 3 or a 6 micron diamond slurries.
  • Single-sided CMP process with polyurethane or poromeric pads with colloidal silica slurries.

MOCVD

  • Single-sided diamond wheel grinding (also known as back grinding).
  • Single-sided lapping with Kemet SP2 plate with 3 or 6 micron diamond slurries, (for this application, most of the LED manufacturers stops at this process stage).

 

Phone cover glass, panels, watch faces and windows

  • Double-sided lapping with either boron carbide #400 abrasives on cast iron plates or fine grinding wheels.
  • Single or double-sided machines process with Kemet Copper SP2 plates with 3 or 6 micron diamond slurries.
  • Single or Double-sided CMP process with polyurethane or poromeric pads with colloidal silica.

 

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Celebrating 75 Years of Service to Precision Engineering

Kemet-75 large

The year 2013 marks a significant milestone for Kemet International Ltd as we have now been at the forefront of abrasive technology for 75 years.

Originally manufacturing and selling the Sanderhead, which was used in the production of the all wood Mosquito bomber (this product is still sold today, happily for more peaceful applications), Kemet is now a truly multinational organisation, our activities spanning the world, spearheaded by our companies in nine countries, all sharing the same commitment to customer support.

The company now has four divisions supplying equipment, diamond abrasives and other consumables for Lapping/Polishing, Ultrasonic Cleaning, Precision Engineering Tools and Metallography/Petrography.

Now specialising in the production of quality diamond pastes and suspensions in our ISO 9001 qualified, purpose built laboratories in Kent, the company also produces Kemet composite lapping plates and other consumables to be used in conjunction with a comprehensive range of standard and purpose built equipment. Today Kemet still services the aircraft industry but also many others – from aerospace to mould making, from oil and gas to medical implants.

So while we celebrate 75 years, industry can enjoy the benefits of our longevity with our years of experience in process development enabling us to provide you with a complete solution to all your precision lapping, polishing and cleaning challenges.

Thinking of surface finishing - Think Kemet

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