Compounding
KPM specializes in custom rubber compounding — engineering precise blends of chemical ingredients tailored to your exact performance requirements. Rubber compounding is the science of integrating chemicals into rubber molecules to achieve targeted material properties, and every compound we design accounts for polymer behaviour, cure chemistry, mixing methodology, molding process, part geometry, service environment, and cost. With 400+ proprietary formulations across 125+ polymer grades and over two decades of in-house compound development, we translate your performance specifications into tailored recipes — collaborating closely with universities and testing laboratories across South India for advanced analyses.
We formulate compounds using a full range of cure technologies — Sulphur, Peroxide, Bisphenol, Platinum, Sulphur-less, Metal Oxide, and Di-amine — selected based on your polymer type and application demands. Mixing is carried out on open roll mills and dispersion kneaders, achieving the high degree of chemical dispersion required for superior rubber performance. Our rigorous Compound Approval Process, validated through viscoelastic property testing, ensures consistent lot-to-lot quality in every part we produce.
Surface Treatment
The quality of adhesion between metal and rubber is a key determinant of the performance and service life of every rubber-metal bonded part we manufacture. Our surface treatment process follows a best-in-class, multi-stage system — encompassing degreasing, sandblasting, automated adhesive chemical application, and oven drying — to condition every substrate to its optimal state before bonding. Surface freshness, cleanliness, and precise parameter control are critical at this stage, as they directly influence the degree of adhesion and long-term bond strength, ensuring defect-free bonding across a diverse range of polymers and metal substrates.
Beyond standard rubber-to-metal bonding, we bring broad expertise in bonding elastomers to metals, bakelite, and plastics — engineering custom composite seals that integrate the seal and mating component into a single, high-performance part. This approach improves overall assembly performance while significantly reducing assembling costs. Every bonded part is validated through rigorous testing by our skilled team, ensuring consistent adhesion strength and durability across every production lot. To further guarantee repeatability and quality, we have incorporated robotics and automation into our adhesive and primer application process — eliminating manual intervention and delivering uniform coverage, superior bond strength, and consistent results in every rubber-to-metal and rubber-to-substrate component we produce.
Molding / Vulcanizing
Vulcanization transforms raw rubber compounds into high-performance parts by inducing cross-linking under precise conditions of heat, pressure, and time — enhancing hardness, modulus, tensile strength, abrasion resistance, ageing resistance, and swell properties in direct proportion to the degree of cross-linking achieved. Our proprietary formulations are engineered to perform in the most demanding environments — extreme temperatures, aggressive media, high-pressure conditions, and stringent industry standards. Each compound is precisely weighed, accounting for overflow and shrinkage, before being placed into the mold cavity where heat and pressure cause the rubber to flow and conform to the exact geometry of the part.
We offer a comprehensive range of molding technologies, giving us the flexibility to meet diverse design complexities, production volumes, and performance requirements across a wide spectrum of rubber components:
- Compression Molding — The most widely used molding method where pre-weighed rubber is placed directly into an open mold cavity, compressed under heat and pressure, and vulcanized into shape. Ideal for high-volume, simple-to-medium complexity parts with cost efficiency.
- Vacuum Compression Molding — An advanced form of compression molding where vacuum is applied during the molding cycle to eliminate trapped air and gases. This results in void-free, defect-free parts with superior surface finish — critical for high-precision applications.
- Transfer Molding — Rubber is loaded into a pot and transferred under pressure through sprues and runners into a closed mold cavity, offering better dimensional accuracy, reduced flash, and suitability for rubber-to-metal bonded components and complex geometries.
- Injection Molding — The most precise and automated molding process, where rubber is injected directly into a closed mold under high pressure and temperature, ensuring consistent quality, faster cycle times, minimal material waste, and tight tolerances for high-volume production.
Finishing
Precision finishing is a critical step in delivering dimensionally accurate, high-quality vulcanised rubber components. We employ a range of industry-leading deflashing techniques — each selected based on part geometry, material type, production volume, and sealing requirements — to ensure every component meets exact specifications:
- Tear Trim Deflashing — Designed for both rubber and rubber-metal bonded parts, the flash is structurally engineered at its weakest section for clean, easy removal. A cost-effective solution across all part types.
- Manual Trimming — Applied selectively in areas where tear trim profiles cannot be formed, ensuring thorough finishing even on complex geometries.
- Circular Part Trimming — Widely used for forming precise, sharp sealing edges on shaft seals and sealing lips, where dimensional accuracy is critical.
- Vacuum Deflashing — Ensures clean, controlled flash removal under vacuum conditions for superior surface integrity.
- Cryogenic Deflashing — Ideal for bulk deflashing of blunt sealing rubber products, enabling efficient, damage-free flash removal across large production batches.
Packaging
Our packaging solutions are designed to protect part integrity while optimising cost and compliance across every order. Parts are packed in bulk or in custom configurations tailored precisely to customer specifications, using packaging materials free from toxic agents to ensure safe handling throughout the supply chain. For international shipments, packaging is carried out in strict accordance with industrial standards and customer requirements, minimising environmental and safety risks during transit — ensuring every rubber component arrives in perfect condition, wherever in the world it is headed.