QCC PRESENTATION

Injection Mold A and B Plates and Inserts 3D solid models which I created from the part model drawing file. They contain the various features from which I generated the CNC programs to machine 90% of the entire mold. They include the geometry for the runner system, sprue bushing hole, ejector pin holes and return pin holes and inserts with blade ejector channels. Also the ejector and return pin plates were machined on the CNC. The rest was completed by manual machining.

Part Model of Component in Cosmetics Display Assembly This is a graphic image file of the part drawing from which the above injection mold solid models were extracted. The part model was created by the Engineering Department in Mechanical Desktop 4.0. An SLA rapid prototype model is then generated and the customer signs off for approval. I then receive the drawing file from which I begin working on the mold design and components.

Injection Mold Core Detail This image shows the detail of the seal-off parting line surfaces and the round runner system and the fan gates. The seal off surfaces and the curved parting line are all the open areas depicted in the part model below. They all have to be machined to precision tolerances of +.002"/-0.00 or better so that when the mold halves meet, they won't produce any flash. I produced the core and cavity solid models and exported the IGES file of the core into MasterCAM for my co-worker to program.

Injection Mold Cavity Detail This also shows the detail of the seal-off surfaces and parting line with the runner system in the center. The toolpaths for the cavity half were programmed with NC Polaris, my current system. The mold is being programmed this way in 2 separate CAD/CAM systems due to the impending deadline. It is currently in process and it will be interesting to witness how accurately the seal-off and parting line surfaces will meet when it's finished.

Part Model of Cosmetics Display Component This is the plastic part for the above mold. The original drawing had to be revised several times to make this part moldable. As a stimulating exercise for anyone skilled in mold making, see if you can devise another way to design this mold which has ribs drafted smaller toward the bottom and the 7 front posts drafted the opposite way with multiple draft angles. Sorry, I can't send the drawing file until product launch is completed.

Vacuum Form Tooling With Removable Inserts This tooling image graphic shows the solid models from which CNC programs were generated to machine these surfaces and wells. The part drawing was, as always, created in MDT 4.0 in Engineering and I manipulated the 3D objects to produce the final solid models. First I scaled the model for vacuum form shrinkage and then performed boolean subtractions to offset the surfaces for the finished wall thickness. In production it is vacuum formed in clear sheet PETG.

DME Mold Base Drawing Often when tight deadlines are looming we purchase the mold base and components from DME. They have a full on-line catalog of stock mold base sizes. This saves a great deal of time in squaring up and facing blocks, drilling, boring and threading the various holes. On the other hand, we sometimes opt to purchase raw aluminum blocks and machine the mold components ourselves to save cost since we have plenty of manual machinists and mold makers on hand in the Toolroom.

POP DISPLAYS INC.
POP Displays is the world's leading manufacturer of promotional point-of-purchase displays. From initial design through engineering and mass production POP is a complete manufacturing facility and captive injection molder primarily servicing the cosmetics sector. Look in any Walmart, Genovese or any other major department store and you will see Revlon, Almay, L'Oreal wall systems with hundreds of our plastic molded components. In Sears you will see our Circle of Beauty counter systems. In any store you will see multitudes of our promotional displays working on the concept that the customers' impulsive buying habits override their brand loyalty when they see attractive and creative product displays. With 20 injection molding machines, from a 750 ton Husky to 250 ton Goldstars, several roll-fed in-line and sheet fed open end vacuum forming machines, wood working production facilities, plastic fabrication including 4 large bed CNC routers, silk screening, hot stamping, sonic welding and many others, POP has full capabilities for producing a vast array of creative display systems. POP also owns a mold and die shop in Portugal. The design and engineering departments utilize the latest rapid prototyping equipment including Stratasys FDM 1600 and SLA 5000 systems. The process starts with the design department delivering to the customer concept models and detailed graphic presentations of the display assemblies rendered in 3D Studio Max and Photoshop. Then the engineering department creates 3D CAD parametric models of the individual component parts and the complete assembly in AutoCAD 2000 and MDT 4.0. Then rapid prototype SLA models are produced to evaluate and confirm the accuracy and functionality of the engineering models. Manufacturing engineers direct production to assure the most cost effective and rapid process. Finally the approved CAD drawings are sent to the Toolroom and to various mold shops for tooling production. The last step is to mold the plastic parts in the required quantities and assemble and distribute the complete display systems. 5 million pounds of plastic raw material in pellet form is injection molded annually. The common plastics used for molded parts are Crystal Styrene (GPPS), Impact Styrenes (MIPS/HIPS), ABS, Polypropylene and some special formulations such as NAS. Polystyrene, PVC and PETG are used for vacuum forming and Acrylics and Styrene sheet are used for fabrication.

THE TOOLROOM
I work in the Toolroom together with a staff of top notch mold makers and manual machinists. I have also worked in the engineering department modeling parts. Mold making is a very demanding craft with critical tolerances and precision shut-offs and seal offs and slide action cams. We have 5 CNC vertical machining centers. We have an old Hurco conversational knee mill that we are upgrading the control to a 4 MB capacity PC based system which is capable of inputting large G code part programs. We have a new Hurco VMC capable of both conversational and G code programs which is networked via FTP link. There is a 5 year old Bridgeport VMC 760 with a DX-32 control that has negligible look ahead such that it is often necessary to run 3D programs slow at feeds of 20 IPM or less. We also have 2 new Fadal VMC's, a 4020 and a 4525. They are both DNC linked to networked PC's which drip feed the program data via RS 232 cables at baud rates of 38,400 kbs. The 4525 has the newer feature of a vertical tool turret so that chips wont fly in. The Fadals have a sufficient look ahead for high speed machining including the Fadal Analyzer software which speeds up the feed to a maximum of 300 IPM on linear moves and slows it down to a crawl on sharp turns. We have found the Fadal to be an all around better machine than the others, stronger and more rugged and easier to operate. Most of the molds are machined in 7075 aluminum and 6061 is used in vacuum form tooling. Sonic welding horns and hot stamping fixtures are also designed and machined here. Recently due to the need for higher volume production for part quantities in the millions we have been using P-20 steel for many molds. Special multi-flute roughers are used and 4 flute carbide cutters are used for finishing, running the CNC programs at much slower feeds and speeds than for aluminum. There are 2 CNC programmers who work on the Fadals and the Bridgeport VMC and occasionally the Hurco's. There is one mold maker who keeps the Hurco VMC busy programming it conversationally. We have 2 set-up men who maintain and operate the CNC machines. There are also about 20 additional men who complete the Toolroom staff whose functions include manual machining, turning, grinding, mold making, polishing and maintenance.

CNC PROGRAMMING AND MOLD DESIGN
Mold making is a very demanding and challenging craft that takes many years to master. It is far different than production CNC machining. CAD/CAM systems have made the job faster and more efficient and can create curved surfaces formerly impossible with manual machining. However, today there is a much greater demand for experienced people skilled in mold making and CAD/CAM than there are opportunities to learn and become proficient in it. For precision mold manufacturing It is necessary to factor in such conditions as heat expansion of the spindle (+.005 in the Bridgeport), warping and bending of the metal after roughing (.003-.005 with aluminum), off-concentricity of the tool holder (+/- .001), tolerance and wear of the cutting tools, over-travel and look ahead, and other factors. Many of these factors are not that critical for production CNC machining but precision mold fabrication is a whole new ballgame.

I work in a small glass enclosed office looking out on the shop floor together with another programmer. My co-worker uses Mastercam to design the tooling and drive the toolpaths. I use AutoCAD and MDT to design the molds and tooling and NC Polaris which works inside AutoCAD to create the CNC programs. I will describe the process that I use to design the mold components to produce machinable surfaces to drive the toolpaths. I first receive the approved part drawing and use AutoCAD tools to manipulate the part model and create the mold design. The part model is a 3D parametric solid model created in Mechanical Desktop. I create core and cavity blocks as solid models with the proper dimensions, add center holes, leader pin and return pin holes if necessary. I study the part and after determining the parting lines and which side the core and cavity will be, I lay out the part model or multiples of the part in the blocks and perform boolean subtractions and additions to leave the inside mass standing on the core block, generally speaking, and the outside surfaces cut out of the cavity half. This is of course is an oversimplification of the process whose difficulty is determined by the complexity of the part. I now have 3D solid models of the core and cavity halves of the mold. I then add ejector pin holes on a different layer in AutoCAD. I create the geometry for the runner system, the gates and air vents if necessary. Waterlines and other external features are drilled and machined manually. There is mold design software on the market which automates this process and has catalogues of standard DME, Hasco etc. mold bases and components. Mastercam has a C-hook called Mold Plus which separates core and cavity surfaces from the part model. Once I have the machinable surfaces ready to program I fire up NC Polaris and start to drive the toolpaths. We always take our reference from the center holes in the CAD geometry and on the machine. I use a combination of 2-1/2D and 3D cutting techniques to program the mold geometry. I use such cutting strategies as 3D Z-level roughing for complex surface roughing and 3D Z-level finishing for bosses, hills and valleys and 3D XZ horizontal cutting for flatter curved surfaces. We have recently purchased a 2nd seat of Mastercam for me to use and we are in the process of migrating over to Mastercam for all our CNC machining needs.