Continuous Production of Thermoplastic Honeycomb Sandwich Components for Automotive Interiors. Low Weight Low Cost Technology

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1 Continuous Production of Thermoplastic Honeycomb Sandwich Components for Automotive Interiors. Low Weight Low Cost Technology Tomasz Czarnecki, EconCore SPE, Novi, 7 9 September 2016

2 Introduction: Sandwich construction by nature The efficient use of material and energy is a fundamental principle of nature. Section of a human skull Section of a bird wing Section of an iris leaf Honeybee comb Nature set the examples let s save resources 2

3 Sandwich in Construction and Transportation Important historical examples of sandwich construction in transportation Stephenson 1830 Chanute 1894, 1903 (Wright flyer) Sandwich frame in locomotive by Stephenson Fairbairn 1845 Bi-plane wing construction by Chanute Junkers 1915 Tubular Bridge design by Stephenson and Fairbain Sandwich metal wing design by Junkers 3

4 Sandwich construction today Sandwich constructions are composed of Two thin facings (skins, liners) One thick low density core Bonding layers (adhesive) Upper skin Lower skin Adhesive Core material Adhesive Sandwich applications Aerospace Trains Recreational vehicles Building Packaging Trucks Cars 4

5 Potential of Sandwich Construction Effect of the sandwich thickness: Geometrical definitions (symmetrical sandwich materials) t h t 82.3 % weight saving 82.3 % cost saving Economic advantage depends on low core material cost and low production cost 5

6 Core material types Core types Sandwich core materials Homogeneous support of the skins Foam cores Structured (non-homogeneous) support of the skins Punctual support Regional support Unidirectional support Best material properties Bi-directional support Textile/pin cores Cup shaped cores Corrugated cores Honeycomb cores but high manufacturing costs 6

7 Conventional honeycomb production processes Thermoplastic honeycomb production by extrusion Tubular honeycombs Extruder saw Collecting the tubes Welding to a block Cutting to a honeycomb Extrusion of single tubes Out-of-plane extruded honeycombs Extruder saw Extrusion small honeycomb blocks Welding to a bigger block and cutting to a honeycomb Both processes require the production of blocks and the cutting from blocks result in a low degree of automation and in relatively high costs 7

8 Continuous production process Honeycomb cores from a continuous film through a step-by-step in-line process Aerospace Internal structure and mechanical properties New Honeycomb Cores ThermHex Thermoplastic Honeycomb Packaging Industry Production concept and machinery Best mechanical properties Major cost reduction Automatic production Low production costs Automated in-line production leading to very low production costs Direct lamination of skins allows in-line production of panels 8

9 EconCore Technology- ThermHex Continuous production of ThermHex honeycomb panels from rolls of thermoplastic films......or by direct polymer film extrusion 9

10 Value chain Sandwich production value chain core production sandwich constituents (core, skin and bonding layer) bonding / lamination sandwich panel (sandwich material) forming sandwich part assembling sandwich structure Core material producer Sandwich panel producer Part producer Assembly plant raw materials (for core and skins) In-line core Sandwich material In-line post preparation producer processing End user 10

11 Thermoformability of folded honeycomb sandwich panels 11

12 Honeycomb - Properties Thermal insulation e.g. for wall or inner cladding skins Heat flow ThermHex Thin PP cell walls PP skin strip Still air entrapped in the cells (more than 95% volume fraction) A thermal barrier against conduction created by still air and PP Air movements suppressed or rather eliminated air entrapped in the cells Radiative effects limited conductive skins separated 12

13 Honeycomb - Properties Acoustic absorption e.g. for wall cladding, separation walls Sound waves Sound waves Steel skins One or two (for separation walls) side perforated skins Air filled, one side open ThermHex cells damping of the noise (acoustic vibrations are transferred to the opposite skin panel stiffness driven) Air filled, one side open ThermHex cells Improved damping of the noise sound absorption (energy dissipated in the core structure) Tests proved good sound absorption ability of the ThermHex core Dissipation of the sound waves in the one side open honeycomb structure 13

14 Thermoplastic honeycomb panels application examples Automotive trunk trims Sandwich composition: PP honeycomb core - PP/wood flour composite skins 14

15 Vibration damping with honeycomb panels Very capable, light-weight stiffening and vibration dumping element for metal doors and roofs 15

16 Honeycomb sandwich panel for heavy duty applications Honeycomb with 0/90 UD Glass fiber / PP composite skins Honeycomb with woven carbon fiber / epoxy composite skins Honeycomb with woven glass fiber / PP composite skins 16

17 Honeycomb organosandwich mechanical performance Weight reduction (=cost reduction) Rigidity increase (at minimal weight/cost gain) 17

18 Ultra-light honeycomb sandwich parts Increased rigidity / weight reduction through replacement of conventional sandwich panels Short cycle thermo-formability into complex parts, acoustic absorption benefits Applications include automotive interior parts and small cargo van s inner cladding Massive weight reduction through replacement of plywood and conventional sandwich panels Mostly applicable for dry freight constructions but do offer enhanced thermal insulation Applications include: roofs, walls, floors, doors, inner structures, aerodynamic elements 18

19 ThermHex organosandwich thermoforming/overmolding Process integration the key to executer the cost saving potential of a sandwich material Pick up of the Organo-sandwich Preheating (e.g. with IR) Process Demoulding of the part Transfer of the Organosandwich into the mould Functionalisation/ overmoulding 1-step Forming while closing the mould 19

20 Organosandwich mechanical performance UNDER DEVELOPMENT: Trunk Compartment - thermoplastic alternative to the conventional, dirty paper honeycomb PU glass fiber sandwich panel Customized Trunk Floor load test Load (80mm diameter) 995 mm 420 mm Centered weight (Ø80mm area) in kg Load - Deflection curve ThermHex honeycomb sandwich with woven GF/PP skins ThermHex honeycomb sandwich with 0/90 GF/PP skins Glass fiber-pu - paper honeycomb sandwich panel Flexural deflection in mm All sandwich panels with a thickness of ca. 20mm 20

21 Organosandwich integration 21

22 Ultra-Light Honeycomb sandwich parts Replacement of gsm monolithic NF/PP composites and injection molded PP and ABS parts Honeycomb panel with natural fiber / PP skins = ca. 800gsm over 50% weight savings! 22

23 Summary on Continuous Honeycomb Sandwich Part Production MINIMAL ENVIRONMENTAL IMPACT MINIMAL WEIGHT MINIMAL COST 23

24 Thermoplastic honeycomb technology Let s build the future of honeycomb sandwich materials together! Thank You! 24