Plastics – Application and Evaluation
Application of the right plastics and production methods can cut costs and shorten development time.
The plastics industry has gone through major changes since Dr. Leo Baekland introduced “Bakelite” in 1909. As recently as a decade ago there were perhaps 35,000 plastic formulations. Now it seems that there are specific compounds for every purpose. Today’s design challenge is to build increasingly complex and robust products fasterand at a lower overall production cost. Viable solutions can be found with the use of plastics. With thousands of possible choices, product developers need a solid knowledge of the families of plastics, and be aware of the best candidates for specific projects and applications.
We know plastics at Omnica.
The resins that account for 80% of those usedin the medical market are the commodity resins: PVC for tubing and bags, polyethylene (medical packaging), polystyrene (lab ware), and polypropylene for syringes. In the remaining 20%, the so called engineering resins, we see uniqueness and extensive cross-over from one category to another. Application requires a specialized knowledge of the materials and processing requirements to make the best use of their particular characteristics.
We work with and specify many engineering and performance plastics when prototyping molded parts.
In the last 30 years we have developed hundreds of molded parts. Before designing a part, we need to make a decision on such factors as how it will be produced, which performance characteristics are most important, the cost and availability of the material, required aesthetic values, and if it will be exposed to sterilization.
One example is how shrink rate properties can affect material selection. A handle, for instance, could be made of many materials including ABS or Delrin™. If injection molding was chosen as the preferred manufacturing process, the designer/engineer needs to be aware that the two plastics behave differently when heated. ABS probably couldn’t be used in a mold designed for Delrin™, because it won’t shrink to the same dimensions.
Metal replacement plastics
Plastics have often been used as replacements for more traditional materials like metal and glass. Performance plastics like Ryton™, Ultem™ and Valox™ weigh less than metal, and some replacement parts can be less expensive to produce.
We once designed eight plastic parts for Nellcor Puritan Bennett that replaced the same number of machined metal parts in their conserver valve. We shaved 60% from the total weight and reduced production costs by more than 30%. The prototype tools were machined in-house, where we injection molded and tested the first articles.
Rubber replacement plastics
The Omnica team can offer alternate choices that can save customers time and money. Thermoplastic elastomers like Kraton™, Pebax™, and Santoprene™ are often good rubber replacements. They can be used for over-molding buttons, keypads, and handles to get just the right “feel”. Engineering resins like polycarbonate (Lexan™) and acrylic are aesthetic plastics that take a high polish. They can be used in many applications that in the past would have required glass. Substituting plastic (which can be hardcoated for scratch resistance) for a glass lens can cut costs significantly, reduce weight, and diminish the risk of breakage.
Extensive experience with small bio-compatible parts design.
Don’t be mistaken that we specialize in only tabletop, point-of-care, and major equipment parts design. We develop ophthalmic implantables (left), high-volume consumables (center), and handheld devices (right), too.
Omnica can offer our customer choices that weren’t possible even a few years ago.
Plastics can offer lighter weight, lower cost, and consistent availability. They can be more easily manufactured and produced than traditional materials, and part production costs can be substantially lower. If you have an existing product or one that is ready to be redesigned, let’s talk about it. The Omnica team may be able to offer you some options.
Who We Are
Omnica Corporation is a privately-held design, engineering, and medical product development firm located in Irvine, California. The 28-person company is staffed with full-time employees and has been in operation since 1984. Our speciality is custom product development for the medical industry and industrial fields.
Our expertise is developing complex medical devices.Technical personnel at Omnica includes designers, mechanical engineers, electronic and software engineers, advanced R&D specialists, regulatory staff (for FDA documentation), machinists and model makers.