The increasing demand for improved fuel efficiency and lightweighting in automobiles has resulted in many auto component manufacturers opting for engineering plastics across the automobile design value chain. Helping this cause further is the process of plastics extrusion, which has remained the preferred process for designing automotive parts over the last many years. PPAP Automotive Limited has been a leading supplier of injection moulded parts for many OEMs in India, for a wide variety of sealing systems, and interior and exterior parts. ATR met Anil Sharma, Deputy General Manager, Manufacturing, PPAP Automotive, at their Noida plant to understand the extrusion process for vehicle applications.
PPAP's core competence is in polymer extrusion and injection moulded products. The company provides complete solutions to its customers starting from product design to delivery of the finished product. The company has a design centre, tool manufacturing, special purpose machine manufacturing, and laboratory and testing facilities.
PPAP works closely with its technology partners in providing cost effective solutions to its customers. The company's experienced engineering, design and manufacturing teams are capable of designing and manufacturing products based on customer specifications, using design software like Unigraphics and Catia. Simulation software like Moldflow and extrusion software like MARK is used to validate the design in order to achieve first time right.
PPAP has the capability to extrude materials of up to four different levels of hardness, according to customer specifications, alongside the ability to process engineering polymers like PVC, PP, ABS and TPO. Today, most of the toolings and machinery required for polymer extruded parts is manufactured in-house. Some of the products manufactured here include inner and outer belt moulding, door trim, windshield moulding, roof moulding, slide rails, glass run channel and other special profiles. These products are used as sealing systems in automobiles and to enhance the aerodynamics of the vehicle.
The company focuses on acquiring the latest technology like servo controllers, electric machines, QMC and magnetic platen to provide higher quality, cost effective products to its customers. These machines have been sourced primarily from the leading manufacturers like Toshiba, JSW, Fanuc, Mitsubishi, Toyo, Nissei etc.
PPAP has an integrated development centre, which designs products using the latest software and processes. It also has a validation and testing facility to validate the designs along with a tool manufacturing facility which makes all the tools required to manufacture its line-up of products. PPAP also has extrusion lines which are capable of processing various engineering polymers required to ensure rigidity and longevity. PPAP also has EPDM rubber extrusion lines and TPV glass run channel lines at their other plants located around the country. All the lines are fully automated and use cost effective technologies.
AN IMPRESSIVE JOURNEY
Back in 2007, PPAP started its technology association with Nissen Chemitec Corporation of the US, for the design and manufacturing of components like door lining assembly, rear tray assembly, trunk lid assembly, pillar garnishes, and fender linings etc. Today, the company's injection moulding machines manufacture both gas assist as well as non-gas assist type injection moulded parts, and PPAP has also set up robotic assembly processes to ensure defect-free and cost effective assembled parts to its customers.
In order to support its manufacturing processes, PPAP set up its in-house dedicated tool manufacturing facility in 2003. Currently, the tool manufacturing facility produces all the tools, dies and fixtures, along with parts for special purpose machines required in the manufacturing processes. The tools are designed in-house, using design software like Unigraphics, and are validated before manufacturing by using simulation software like Moldflow. The design of these tools goes through a detailed 'advanced product quality planning' (APQP) approved procedure for validation. The key target for development of tools, throughout the entire extrusion process, is to get it right at the first attempt.
PPAP utilises valuable global inputs, provided by its international technology partners, to ensure robustness of its designs. The company commenced the design and development of its machinery in 1989, when the automobile sector in India was still in a nascent stage. Over the years, the company developed its capability to design and develop tools and fixtures required to manufacture required products for the auto industry.
The company has an in house testing and validation facility which started in 1997. Since then, the company has been testing and validating raw materials and finished products to ensure zero defect supply of parts to its customers. Tools and products are validated on various equipment like profile projectors, coordinate measuring machines, universal testing machines, abrasion resistance machine and window glass simulator etc.
PRODUCTION & TESTING PROCESSES
The company carries out extensive tests for all its products using state-of-the-art testing machines. Ancillary machines are designed and manufactured in-house and to test extruded and injection moulded parts, the company creates artificial atmospheric situations that replicate varied weather and temperature conditions prevalent around the world.
For polymer parts used for enhancing the aesthetic value of a vehicle, PPAP tests its products using climatic elements from the geographical location, where its product will be exported. Equally important is to test the parts for vibration, to ensure product rigidity during all driving conditions. The company uses simple and intricate moulds depending upon the nature of the product. Some moulds are produced in-house, while those requiring higher levels of precision are imported from China, Taiwan and Japan.
Many extruded parts are made of PVC with steel inserts. The company produces two varieties of moulded windshields – one type requires welded joints, and the other uses injection moulded joints. Roof parts require insert moulding as well, while trim door opening applications require slit steel for the extrusion process. PPAP is capable of making body sealing parts for all automotive requirements, be it in EPDM, PVC or TPO.
At the Noida plant, PPAP has seven extrusion lines. The first line is used to produce steel inserts with PVC, while the second line produces PVC-only products. The third line is allocated for slide rail parts and the fourth and fifth lines are used for TPO parts, which do not require steel inserts or reinforcements. Line six is used for producing moulded roofs and moulded windshields, and line seven manufacturers trim door openings.
PVC parts with steel inserts are commonly used for most reinforced parts within a vehicle. The process of producing such parts starts within an uncoiler, which feeds the extrusion line with raw materials. There is a sensor to monitor the amount of steel that enters the process, which informs the operator when the steel coil is exhausted, requiring the operator to rotate the uncoiler by 360 degrees to load the steel strips. Once this is done, the operator needs to create a welding joint with the help of a looping machine, which feeds the production line as a buffer stock for continuous material flow.
Post the welding and looping process, the gluing application takes place between the steel strip and the PVC. This is followed by the amalgamated product entering the baking oven and the roll forming puller, which pulls the moulded product from the uncoiler to be formed into a roll. The rolling puller is equipped with a siren, which warns the operator of any activity that may be hazardous, so it can be addressed immediately.
During this, there is also a water treatment process, which cools the steel and PVC compound. After this, there is an induction heater that heats the steel strip to create better bonding with the PVC. A cold steel unit will not form a strong bond with the polymer and may disintegrate during real world applications.
PPAP uses a program logical control (PLC) unit to provide standardised product development according to set specifications from the customer. It also ensures that intricate details are taken care of and variations are minimised at all levels. An hourly check is carried out to ensure consistency and seamless operations. In case of any discrepancies, the operator is required to fine tune the process as per the desired standards. Meanwhile, a fume filtering machine sucks out the harmful fumes produced during the extrusion process and releases in a manner that's safe.
Once the steel strip and PVC combination reaches optimum temperature, it is sent to the laser printing unit for traceability. It imprints the material name, along with the date and time of production and creates an individual identity for each extruded part. Any anomaly occurring later can be traced back to the production process and necessary measures can be taken to address it.
TEXT: Anwesh Koley
PHOTO: Bharat Bhushan Upadhyay