Read our April Newsletter to find out!

Read our latest newsletter for exciting news about Albright Technologies.

While it is difficult to provide one general answer to your question, if I had to limit my response to one word, “yes”, because the cost of parts is typically very dependent upon the cost of the raw materials, and the cost of raw silicone is usually more expensive than the cost of plastic resins. Even the least expensive silicones may cost $5 – $10 per pound, while plastic resins run closer to a couple dollars.

However, in the medical device market, lots of parts are very small or microscopic. Micro molding is much less dependent upon the cost of the materials since there is so little physical volume. The cost of a micro part is driven more by the processing that goes into demolding, quality control inspection, and packaging, as all of these activities will require the use of microscopes that would not be required for larger parts.

But in general, molded or extruded silicone medical parts will cost more than plastics, thermoplastic elastomers, and petroleum based rubbers. The tradeoff is the biocompatibility and implantability that you get with silicone products, as well as other contributing factors like the physical, chemical and mechanical properties required of the device. Silicone may not always be the best material for the job, but when it comes to soft, flexible parts for medical applications it is a very good place to start.

Click here to read the rest!

Silicone, especially liquid silicone will conform well to just about any mold shape that can be dreamed up, the difficulty is typically in the mold making process. In the prototyping sector, we see a lot of cutting edge design concepts that push the envelope with features that are very small and precise. Every molder has their own specialty and also their own limitations. At Albright we specialize in quick-turn micro medical device parts molded in liquid silicone rubber. One design limitation that we frequently contend with is the size and geometry of micro features, we like to use “The 3X Rule”, which basically means that if you have a microscopic opening in your part design (which would be reflective of a raised boss in the mold) the overall height of that feature shouldn’t exceed three times the diameter (or side length) of the feature. That would mean that if you wanted to form a 0.005″ diameter hole in your molded part, you wouldn’t want to go much more than 0.015″ deep into the part, from a tool making standpoint.

Click here to read the rest of this answer and our latest newsletter!

Question: When you buy a certain durometer of silicone from the manufacturers, what is the actual durometer are you getting?

Answer: Silicone is a very useful material that has been widely used in both non-medical and medical application for decades. For example, silicone has a wide range of operational temperatures (between -150 °F and -600 °F). Moreover, silicone has another interesting property that enables it to be widely used. It has a wide hardness range without additional additives. Shore A scale is typically used to identify the silicone’s hardness and liquid silicone rubber (LSR) is typically available from 01 to 80 durometers (typically in increments of 10 durometers).  Nevertheless, there is a variation in hardness when you buy silicone from the manufacturers. The industry standard tolerance for silicone is ±5 durometers. This is due to the variation in the vinyl gums and treated filler used to make them plus the ±2 potential test error in determining the durometer. As a result, you normally don’t get the exact durometer of silicone as listed from the manufacturers; you only get a range of durometers that is close to the desired durometer.

How is the “softness” (durometer) of medical grade silicone measured?

This is a question that comes up almost every day when discussing new project ideas with perspective clients. The softness or durometer of all polymers/elastomers/rubbers is measured essentially the same way and the term while commonly used to describe the material hardness, actually originated from the device used to take the measurement a duro-meter. There are lots of different designs for this device, click here to compare pricing and options and get a general feel for what they look like and how they work.

Click here to read the rest of our October Newsletter!