Center for Research in Engineering Sciences and Technology Topic: Rotomolding method for manufacturing modular structure Center for Research in Engineering Sciences and Technology

Basic Background of idea Construction of an Automotive Body in White(BIW) [1] structure is achieved by processes stamping (making the sheet metal panel to form) , the stamped panels are joined (assembled) by welding/ bolting/ riveting/ bonding. This further goes through a painting process. This is required to protect the metal panels from corrosion. After painting the BIW goes for wiring harness fitment, usually done by fitting clips to hold the harness to the BIW. Trimming required to hide the harness and the metal body ( functions for aesthetics as well as safety of the passenger) Fitment of other aggregates done at the trim chassis final assembly line. Fig 1. shows a cut section through the BIW , A Pillar of the automotive. Fig 2. Shows electric harness which are assembled on the BIW with clips. Fig 1 Fig 2 11/7/2018

Basic Background of idea Assembly process for making any structure example Automotive & Aircraft interiors, exteriors Construction etc. has a huge scope of reduction in terms of Time and Cost. The idea is to reduce the processes , cost and time for making structures for any application in general. This can be achieved by a integrated modular structure. Example taken is the Automotive assembly line for cars 11/7/2018

Time Savings – Car Body Assembly comparison. Welding of Structure ~ 5 Hrs. Painting & Sealing ~4 Hrs. Assembly ,Wiring, Trimming ~6 Hrs. Body Assembly Time(~15 hrs.) Inside Plant Current Process * * Unaccounted Sheet metal stamping time Proposed Process Rotomolded structure with harness, trim, carbon fiber embedded and painted~ 8 Hrs. Rotomolded Body Assembly Time(~3 hrs.) Inside Plant Assembly of Structure ~ 3Hrs. Rotomolded Body Assembly Time(~8 hrs.) Outside Plant Savings of 4 hours per vehicle. Is 25% increase in productivity 11/7/2018 Sample Footer

Description of the innovation – How to make an integrated modular structure Available state of Art. Rotomolding is a process in which powdered plastic is introduced into a set of molds and is heated till the plastic powder melts to a viscous fluid which can stick to the mold walls when rotated in a biaxial direction. The mold is rotated inside a furnace for a set time period which makes the plastic form(stick) on the sides of the mold forming a hollow component which has a shape of the mold. Process advantages of rotomolding. [2] Used to reduce components by combining functions of different parts to one part. Can have painted components coming out directly from the mold. Paint is applied to the mold wall before introduction of plastic. Low cost of tooling as process requirements are not like injection molds ( does not require to withstand pressure of plastic being injected) Higher accuracy can be achieved as inserts can be used on mold to function for attachments required to interfacing part. Advantages of Carbon fiber cloth instead of metal for automotive structure.[3] High tensile strength Coverage of full area of panel not required as require to reinforce structure only in direction of load. Predetermine the strength accordingly changes can be made in 11/7/2018

Description of the innovation – How to make an integrated modular structure Continued Available state of Art Parameters Carbon Fiber Sheet metal E Modulus 300,000 mPa 210,000 mPa Tensile strength 1300 mPa 250 mPa Density 1.75 g/cm3 7.8 g/cm3 Above parameters show the strength and weight reduction that can be achieved using carbon fiber. Methods of using carbon fiber for automotive panels. [4] The BMW i3 is an electric car which uses carbon fiber body, the panels are transfer molded to contain the carbon fiber reinforcements. They use carbon fiber to make the body lightweight to accommodate weight of batteries. Using Rotomolding technology to suit requirements of strength by carbon fiber cloth, embedding of harness and trim is the proposed innovation. 11/7/2018

Description of the innovation – How to make an integrated modular structure Innovation : To have a structure which embeds the wiring harness and also the trim Brief Process: Step 1 Hold the harness in the mold M0 & M1 .Also hold the carbon cloth which reinforces the structure. Step 2 Heat the mold in the furnace and rotate it bidirectional. Allow it for cooling to a certain predefined temperature. Step 3 At predefined temperature remove Mold M1 and replace with M2. Before closing introduce the Material 2 for trim. Allow the cooling cycle for rotomolding process. Step 4 Remove the Molds and eject component. We obtain a integrated structure which can be assembled together to interfacing parts. Stage 4: Ejected Component after cooling. Trim Structure Electric Harness Carbon Cloth 11/7/2018

Description of the innovation – How to make an integrated modular structure Turret Moving Oven 11/7/2018

Description of the innovation – How to make the Harness The harness should be such that it does not move in the lateral direction when material flows on it embedding it. 11/7/2018

Applications of the idea Reduction of time for manufacturing, assembly Reduction of Manufacturing Costs Modularity of Design Smart Structures Alternate Materials for Manufacture of structures Integrated modular structures Recyclability Reduction of Environment footprint of Manufacture Construction Medical Devices The idea focuses towards finding solution to mentioned technological challenges. The idea proposed has many areas of application where rotomolding has been used as a manufacturing method. Automotive structures FMCG Automotive interiors Aerospace structures Railway interiors Heavy Commercial Vehicles 11/7/2018

Advantages and Disadvantages Sr. No Advantages Impact to Industry Impact to Customer 1 Reduced Assembly time Time for Production, Cost of Production. Cost of ownership 2 Reduced Tooling cost by more than 50% 3 Part Count 4 Weight Reduction 5 Reduce Processes like ED Coating, Corrosion protection. Thus Reduced part cost. 6 Easy Accident Repair Cost of Warranty/insurance Cost of Ownership 7 Tamper proof Wiring in Structure Safety & Planning of Design Safety 8 9 Ease in change of Styling as low tooling cost of Rotomolded structure More Styling Options for Automotive. More Options in styling. 10 Improved NVH and reduction in squeak and rattle Improves Quality of build Satisfaction on Build Quality Sr. No Disadvantages Impact to Industry Impact to Customer 1 Pre Planning of wiring harness is required Planning of harness in case of variant's of vehicle None 2 Cannot tamper the harness to attach external connections. Product tampering can be detected Stricter Warranty norms. 11/7/2018

Related literature survey Patents US8690226 US 2009/0224421 US. Pat. No. 7287797 Led by Belloso et al US. Pat. No. 5,286,080 led by Ringdal et al. US. Pat. No. 6588785 by Monary et al. United States (12) Patent Application Publication, Ellis et al. US 2012/0068496 A1 Notes: All patents searched and found near to the idea do not mention on embedding wiring harness in structure and also method for strengthening structure using carbon fiber cloth. This is a New method of Producing modular structures which can be Patented and then allowed to be used for the industries across sectors where such a structure is required. It can be provided as a service for design and manufacturing and charged on case to case basis. 11/7/2018

Results A section of the structure embedded with the harness. 11/7/2018

References [1] http://www.bmwgroup.com/e/0_0_www_bmwgroup_com/produktion/fahrzeugfertigung/automobilfertigung/erlebnis_produktion/prod_prozesse.shtml [2] http://www.theplasticprofessionals.com/why-rotational-molding.htm [3] http://www.automotiveworld.com/megatrends-articles/carbon-fibre-the-fabric-of-the-future/ [4] http://www.bmwgroup.com/bmwgroup_prod/e/0_0_www_bmwgroup_com/produktion/BMW_I/index.html 11/7/2018

Thank you 11/7/2018