Thank You for Asking:

“What are Eastman’s recommendations for sonic welding of thin-walled parts?”    

In general, small thick-walled parts made with Eastman Tritan copolyester can be ultrasonically welded by
following the welder’s recommendations for other amorphous thermoplastics.


Mold design—critical factor #5

Tips for a clean release 

Tips for clean releaseThe coefficient of friction of copolyesters such as Eastman Tritan™ copolyester is at its highest near the heat deflection temperature (HDT) of the material-and competitive materials generally freeze at a higher temperature than Tritan. Keep this in mind if you're repurposing a mold that was originally designed for the cooling temperature of another plastic. Parts molded with Tritan must be adequately cooled to withstand ejection forces during demolding.

Three mold design and maintenance factors can also help ensure a clean and efficient release: 

Draft—Part design features with minimal draft, such as long cores and deep ribs, often result in high ejection forces. The Eastman Design Services team recommends that all wall​ surfaces have a minimum draft angle of 1° in the direction of draw. 


Are the devices you design ready for aggressive medical disinfectants? 

The designer is the point where innovative creativity crashes head-on into the real-world needs of durable functionality in a health care environment.
Unfortunately, many device housings and hardware designed just a few years ago were made with materials that lack the right combination of impact strength and chemical resistance. They crack, craze, and ultimately fail when challenged by the increased use of aggressive medical disinfectants-combined with the applied stress of greater portability.
Connecting the dots between design flexibility, chemical resistance, and impact strength is critical for selecting the best material for reliable clear and opaque medical devices. That’s why Eastman created a 60-minute webinar to provide new information about: 

Patient safety and HAI prevention

Mold design — critical factor #4

Gate style, location, and size  

Gate style location and sizeThe gate is where it all comes together in injection molding. Mold design and part design. The molten resin and the solid molded product. Aesthetics and mechanical performance.
Skillful decisions about gate style, location, and size early in the mold and part design process can pay big dividends when it is time to start molding parts. And the benefits pay off in greater part performance and reliability.

Overriding considerations—aesthetics and mechanical properties
Regardless of gating type, location, or size, these two factors will drive most decisions made regarding gating:
The gate on an injection molded part leaves a "witness," or a vestige, where the part is separated from the runner system. This is considered an appearance defect and is typically hidden in an area of the part where it will not be obvious.

Overmolding for soft-touch designs

New self-bonding LSR technology created to optimize Eastman Tritan copolyesters

The medical industry has a great and growing demand for innovative soft-hard designs in devices, housings, and other equipment. A recent advance in liquid silicone rubber (LSR) technology makes it easier to satisfy this demand with medical grades of Eastman Tritan copolyester. 

The advantages of Tritan are well-known to readers of this blog. Medical grades of Tritan offer a unique combination of properties including:
      •  Outstanding resistance to medical disinfectants and solvents
      •  Excellent impact strength and durability
      •  Made without BPA and halogens
      •  Excellent clarity and color retention after sterilization by ethylene oxide (EtO),
         e-beam, and gamma irradiation

Mold design — critical factor #3

Fill pressure and fill pattern 

Fill pressure and Fill patternTo design greater manufacturability into molds-and parts-it's critical to achieve the most effective fill pressure, to anticipate the fill pattern, and to predict volumetric shrinkage. Eastman Design Services uses mold-filling simulation to evaluate the "moldability" of the part design and engineering resin combination.

Fill pressure and fill pattern go hand in hand
Just as mold design is inextricably linked to part design, reasonable fill pressure and reasonable fill pattern should be evaluated together. 

Reasonable fill pressure—excessive fill pressure can create several problems:
• 锁模力要求过高
  •   Reduced life of mold components—due to high stress loading

Polymer selection for durables applications

Selecting the best grade for food contact and non-food contact applications

Brand owners and design engineers continue to find new ways to use Eastman Tritan copolyesters in a wide range of food contact and non-food contact applications. 

Its unique combination of clarity, durability, hydrolytic stability, and heat and chemical resistance makes Tritan ideal for many applications, including:
Food contact applications
• 商用型食品器皿
• 运动水壶
• 小家电
• 婴儿护理
• 水过滤

Non-food contact applications
• 家电
• 娱乐与安全产品
• 光学应用
• 口腔护理
• 工具
• 模内装饰

Starting with your specific needs, Eastman can provide technical expertise and support to help determine the best grade of Tritan for your application.

Mold design—critical factor #2

Thermal control of cavity surfaces

Thermal control is critical for injection molding Eastman Tritan copolyester. Keeping temperatures cooled below the heat deflection temperature (HDT) of Tritan helps ensure successful demolding with no dragging or sticking of parts. Preparing a cooling strategy early in the tool design process can pay big dividends in cycle time and processability. 

One key to keeping it cool—just add water.     
It's not that simple. But providing ample and well-positioned cooling water channels is critical to controlling the temperature of the cavity surface and the resin in the mold. Here's why controlling resin temperature is important: as the resin approaches HDT, it becomes sticky (the coefficient of friction increases) and parts cannot be ejected efficiently.

Why specify medical grade polymers

Two words: confidence and compliance
Image of Tritan Medical Device

It is critical for designers of innovative medical devices and packaging to have access to high-performance medical grade materials.
To ensure patient safety and long-lasting reliability, manufacturers depend on medical grade material suppliers like Eastman—not only to provide advanced, high quality raw materials but also to have capabilities and systems that help comply with medical protocols and regulations. 

Manufacturers who specify medical grades of clear or opaque Eastman Tritan copolyester* know that Eastman will provide a high level of support throughout the regulatory journey to commercialization of a new product. Eastman’s world of experience helps ensure confidence and compliance in the areas of:
•  Biocompatibility—selected tests from the FDA-Modified ISO-10993, Part 1 “Biological Evaluation of Medical Devices”

Mold Design- critical factors #1

Factor #1—Polymer melt residence time

Mold design goes hand in hand with part design to determine the manufacturability of a product. One factor that is critical to manufacturability-as well as to preserving the performance characteristics of the material being used-is polymer melt residence time.
In this blog, the first of a five-part series discussing critical factors of mold design, we answer these questions about melt residence time: 
      •  What is melt residence time?
      •  How does it affect the integrity of a polymer?
      •  How does this relate to Eastman Tritan copolyester?
      •  What is the residence time recommendation for Tritan?

Melt residence time—know when enough is enough (and why)