1 Overview of the Industry Chapter 1 Professor Joe Greene CSU, CHICO August 25, 1999MFGT 144

2 Chapter 1: Introduction to Plastics Objectives –Injection Molded Plastics Applications –History of Injection Molding –Future Processes –Materials –Business Concepts –Strategic Materials

3 Automotive Plastics Use

4 Automotive Plastics and Composites Use Exterior –doors (Saturn) –fenders (Saturn, Truck Dooleys) –bumper covers (soft fascia typically injection molded TPO) Interior –instrument panels, door trim, seat clips, consoles

5 Recreational Plastics and Composites Use Snow Equipment –bindings for skis, snow boards Water Sports Equipment –water skis, water crafts, snorkel equipment, fishing gear –diving equipment –drinking containers Land Sports Equipment –roller blades, skate boards, Air Sports Equipment –plane kits, sky diving equipment

6 Commercial Plastics Usage Packaging –Wrapping, bags, bottles, blister packages, shrink wrap. Textiles –Clothing, carpets, fabrics, diapers, netting for sports Furniture, Appliances, Housewares –Telephones and other communication equipment, computer housings and cabinets, luggage, seating, components for washers, dryers, etc. –Musical instruments, CDs, VCRs, TVs, cases Construction –Moldings, counter tops, sinks, flooring, cups, paints, etc.

7 Definition of Plastics Plastics come from the Greek plastikos, which means to form or mold. –Plastics are solids that flow (as liquid, molden, or soften state) when heat is applied to material. Polymers are organic materials that come from repeating molecules or macromolecules –Polymer materials are made up of “many” (poly) repeating “units”(mers). –Polymers are mostly based in carbon, oxygen, and hydrogen. Some have Si, F, Cl, S –Polymers are considered a bowl of spaghetti or a bag of worms in constant motion.

8 Definition of Plastics All Materials Gases Simple Liquids Solids Metals Polymers (polymeric molecules) Ceramics Thermosets Heat Setting Thermoplastics Heat Forming Elastomers

9 History of Plastics 1868 John Hyatt developed a plastic material called Celluloid for billiard ball competition to substitute for ivory he and his brother Isaiah invented the first injection molding machine to mold celluloid for billiard balls, combs, buttons, and collar stays. –By 1920 the injection molding industry began. –1940s the plastic industry had rapid growth during WWII –First machines acted like a large hypodermic needle and contained a basic plunger to inject the plastic through a heated cylinder into a mold. –1946: James Hendry invented a screw injection machine and revolutionized the plastics industry.

10 Early Synthetic Plastics Phenolics (named Bakelite by Leo Bakeland) –Phenol and formaldehyde reaction after heat –Resin could be shaped and hardened with heat –Replacement for celluloid for billiard balls (1909) Phenolics used for telephone equipment (1912) –Phenolics used for automotive electrical (1916) –Used for handles for cooking pans and electrical switches –Excellent thermal and electrical insulator –Coatings for paper and wood (Formica) and adhesive for particle board. –In 1991 US Plastics industry used 165 millions pounds

11 Commercial Synthetic Plastics Several Polymers found by mixing simple gases under extreme conditions (high heat and pressure) –Ethylene gas to form polyethylene using addition polymerization. –Modifications to ethylene gas to form PVC, polystyrene, polypropylene, and polymethyl methacrylate. –Nylon discovered by Dr. Carothers (Harvard) and a new method called condensation polymerization in 1930s with DuPont. –Polyesters, PBT and PET, produced via condensation. Post WWII boom in plastics –PTFE, synthetic rubber, polyesters, ABS, polycarbonates, polyurethanes, etc.

12 Petroleum Basis Plastics are made from small molecules (monomers) that are usually derived from crude oil. –Exception is ethylene which about 50% comes from natural gas and 50% from crude oil –Exception is some plastics can be derived from coal, corn, oats, tree sap, fish oil, and other natural oils. U.S. Petroleum Consumption in 1998 –62% Transportation –25% Industrial (excluding plastics) –11% Residential and Commercial – 2% Plastics

13 Growth Comparison, US Plastics From 1984 to 1994 growth of 5% annually In 1991, Plastics account for 11% of all Shipments in US In 1991, Plastics. account for 3% of US workforce.

14 Major Plastic Materials (1995) LDPE ($0.38/lb) 6.4 M metric tons (1000 kg) HDPE ($0.29/lb) 5.3 M metric tons PVC ($0.26/lb) 5.1 M metric tons PP ($0.28/lb) 4.4 M metric tons PS ($0.38/lb) 2.7 M metric tons PU ($0.94/lb) 1.7 M metric tons PET ($0.53/lb) 1.6 M metric tons Phenolic ($0.75/lb) 1.5 M metric tons Total28.6 M metric tons (82% of market) Nylon ($1.40/lb) 0.4 M metric tons PTFE ($6.50/lb) <0.1 M metric tons PEEK ($36.00/lb) <0.05 M metric tons

15 Price Volume Relationship of Materials Figure 1.4

16 Evolution of Injection Molding Screw –95 % of all injection molding machines –Screw is inside heating cylinder and when activated mixes the plastics well. Good for using colors, regrind. –During injection, screw stops rotating and pushes forward like a plunger to inject material in mold. Plunger Machines –Step 1: resin melts via thermal heaters and collects in a pool called injection chamber –Step 2: resin pushed forward by action of plunger (ram or piston) driven by hydraulic system at the head of the machine. A torpedo or spreader is used in barrel to improve melting and mixing. –Step 3: resin flows into mold –Step 4: part cools and is ejected

17 Evolution of Injection Molding Ram- plunger injection machine Source:

18 Evolution of Injection Molding Reciprocating screw injection machine

19 Evolution of Injection Molding Ram (plunger) injection advantages –less expensive –better for marbling of plastics because the plunger does not rotate. Reciprocating screw advantages –more uniform melting –more uniform mixing –lower injection pressures –larger permissible part area –fewer stresses in part –faster total cycle

20 Evolution of Injection Molding Industry Evolution –Table I-1

21 Evolution of Injection Molding Energy Efficiency New machines need to have higher energy efficiency and reduce the amount of electricity utilized to heat the plastic, power the hydraulic pumps and motors, and control the temperature of the mold. Innovations include internally heated injection screws, insulated molds, and insulated heating cylinders. All electric machines use 20% to 40% less electricity. Desktop Manufacturing Use of small injection molding machines with few cavities. Set-up includes large bank of small, desktop-size machines, each one with one or two cavities producing equal or greater number of parts than a traditional large machine with multicavities. More flexibility, lower energy, faster cycle times, lower repairs.

22 Evolution of Injection Molding Molds and Tooling –Larger (fascias) and smaller parts (micro molding). Lead Times –Lead time reduced from 36 weeks to 12 to 16 weeks –Computer Generated Data –Mold Materials Flow analysis software Materials Recycling Education and Training Quality

23 Organizations in the Plastics Industry SPE: Society of Plastics Engineers, SPI: Society of the Plastics Industry, SAMPE: Society for the Advancement of Material and Process Engineering, CFA: Composites Fabricators Association, CFECA: California Film Extruders & Converters Association,