CAD/CAM used in Quality Control • Virtual Testing: Modern computer aided design and manufacturing software systems (CAD/CAM) have voluminous data on material specifications and behaviors (such as plastic shrinkage rates or the heat tolerance of various grades of molding steel), which can be used to simulate the molding processes and “virtually test” a product to identify potential problems in design, construction and/or materials before the first cut is made for the actual mold. • Precision Measuring: To implement quality control, China Array uses the three most prominent precision measuring systems: CMM (coordinate measuring machine), optical and laser. As a mold is machined and polished, first by the CNC machining center and later with more precision by the EDM machining center, it will be repeatedly measured to insure complete accuracy. • Sampling: When a mold is complete, a test run yields preliminary samples for evaluation, which will provide information as to any possible modifications to the mold. As important as the dimensional integrity of the part, which can be determined through precision measuring, will be lab tests of the product in the US to determine if there are any signs of stress or weaknesses in the part due to the injection molding process or the product’s design that may need to be changed to eliminate stress points etc. If such processing problems are found the mold may be altered (increased gate size, additional cooling channels etc.) or the process altered (temperature, cycle time etc.). After this evaluation and adjustments to the mold and/or the process, another batch of samples will be run and sent to the customer for approval. • Pre & Post Molding Sampling: Prior to molding, resin samples will be set aside, dated and labeled to track materials with the appropriate production run. First and last samples of finished goods produced will also be inventoried. • Field monitoring: Once products are in the field, the QC function will shift to the applications engineers, who will monitor the performance of a product over time and make recommendations for future improvements. The quality control process outlined above combined with customer feedback at each step maximizes on time deliveries of defect free products.

Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM)

Provides Information Before a Part is Molded

Infinite Reference Points

High Performance Thermoplastics (HPTP) require extensive upfront engineering: the nature of the materials places a premium on good design and processing. Once the proper material has been selected for an application, CAD/CAM plays a vital role throughout the product and mold design phase of production in matching the mold's cavities and mechanics to the material's characteristics.

3D Database

When China Array receives a design, drawing, or sample part from a customer, its CAD Department creates a two dimension (2D) drawing and three dimensional (3D) data base for review and modification by the customer. Once the drawing and data base are approved, the information is fed through a CAM program (China Array uses MasterCam9), to create a virtual mold for the product.

The CAM program incorporates information into the mold design based on the specific plastic material to be used for the finished good: for example, the program recommends the type of steel for the mold depending on estimated volumes, it makes dimension adjustments to the cavities according to the shrinkage factor of a specific resin, it integrates the mechanization of the mold adding hot runner systems, cooling channels, ejection methods etc. The CAD/CAM program can even simulate the mold's operation to assist in anticipating potential problems.

CAM Rendered Virtual Mold

Improves Quality and Cuts Costs

Properly used, a CAD/CAM system can save a customer money (e.g. by reducing cycle times, minimizing material wastage, eliminating false starts to production, improving finished goods quality etc.) before a finished part ever drops out of the injection molding machine. Plus, the systems can accelerate future product development as it stores a wealth of information regarding the product, mold and processing of a particular part, which can serve as a starting point if creating a new virtual part as the process goes through future iteration

Renders a Dimensionally True Mold

Finished Product

The complete 3D CAD/CAM Database is then fed to a Cincinnati Milacron Machining Center, which cuts the mold. The Database has infinite reference points allowing exact rendering of the most sophisticated cavities: capturing complex radii and intricacies of design, as well as the mechanics of the finished mold. Once the mold is completed, mold testing may turn up some necessary tweaks that need to be made. The CAD/CAM data, which is stored electronically, speeds the process along by providing possible solutions for these minor tweaks. And, of course, all CAD/CAM data is stored for use on future product development as the product evolves overtime. Customer that already have CAD drawings for a product need only transfer the files to China Array. The files will then be put through the system and the mold produced directly from the customer’s information.

Compatibility with Various Formats

China Array's US and Chinese offices are outfitted with identical CAD systems: ProEngineering CAD software, considered the best in the industry, and MasterCam9, also a recognized industry leader. Collaborative web conferencing allows engineers at different sites to work simultaneously on CAD/CAM files. The firm also utilizes digital video and photography to communicate product development, mold construction and injection molding processing issues between parties.

Prototype Molds

Prototype Molds: Fully functional Dimensionally accurate Mechanically Simple Made from low cost steel. Produce up to 1,000 prototypes

High quality molds are prerequisite for molding High Performance Thermoplastics. The steel, heat treatment, mechanical operation etc. for HPTP molds are several cuts above those required for standard plastics molds. However, for a customer needing a simple, inexpensive prototype mold, China Array can move in the opposite direction and provide a manually operated mold made from low cost domestic, non-hardened steel at a very competitive price. Everything else in the process described above for making a high quality HPTP mold is the same, the only difference is the low cost steel for the mold and the simplified mechanics. China Array's sophisticated CAD/CAM capability and quick turn around on mold production coupled with its location in China and access to low cost domestic steel for molds makes it an ideal partner for Prototype Molding.

Precision Cavity

Basically, the customer gets a precision cavity mold that faithfully renders dimensionally accurate prototype parts (up to 1,000 pieces depending on the mold material) at a very competitive price. As with all CAD/CAM projects, data relating to product and mold design, and processing is retained electronically for future reference: as the prototype product moves through multiple iterations given feedback from marketing and field testing, the stored CAD/CAM information allows for quick, accurate, inexpensive changes to the product, mold or injection molding process to perfect the finished good before large scale production.

Prototype Molds versus Rapid Prototyping

Making a mold for prototypes has several advantages over Rapid Prototyping a single part. First, the mold can produce up to 10,000 pieces for large scale in field testing: and the parts coming out of the mold are made from the same material the actual production model will be made from, which is not always the case with Rapid Prototypes. Second, by actually having a mold built, the customer gains a wealth of information on mold design and injection molding processing, which can be invaluable when taking manufacturability into account in product design. Third, by having electronic data related to the product, the mold and the process stored in-house, the probability of having large scale production go smoothly increases enormously, and gives the company a jump on designing the next generation of product.

State-of-the-art Equipment

China Array maintains an independent department for Computer Aided Design and Manufacturing. State of the art ProEngineering CAD (Computer Aided Design) and MasterCam9 CAM (Computer Aided Manufacturing) software integrated with Cincinnati-Milacron CNC (Computer Numerically Controlled) and Mitsubishi EDM (Electrical Discharge Machines) and EDM Wire machine centers to convert customers’ original designs, drawings and/or samples into completely accurate, high quality, precision molds. Zeiss CMM (Coordinate Measuring Machines) and laser inspection technologies used at each stage in mold production insure Quality Control of the mold and precise tolerances.

Zeiss Coordinate Measuring Machine		Cincinnati Milacron Sabre 12 Machining Center		EDM (Electric Discharge Machine) Wire Cutter

Cooperation with Universities

China's CAD (Computer Aided Design) and CAM (Computer Aided Manufacturing) capabilities are often underrated in the West. In fact, these capabilities are sophisticated and developing rapidly. Fortune 500 Companies, such as GE, Bell Laboratories, Microsoft, Hewlett Packard, and Texas Instruments, have recognized this phenomenon and have set up design centers across China over the last few years.

Proficiency in CAD/CAM is a prerequisite for engineering students at top ranked Universities, several of which offer graduate programs in these disciplines. Chinese Universities have a long tradition of working with businesses through research centers established within Universities. China Array, in addition to having an in-house CAD/CAM Department, cooperates extensively with one of the leading Engineering Universities in Wuhan,which maintains state-of-the-art facilities and personnel to handle complex product/mold development, as well as ongoing Quality Control measurement and testing.