Free Newsletter
Register for our Free Newsletters
Newsletter
Zones
Advanced Composites
LeftNav
Aerospace
LeftNav
Amorphous Metal Structures
LeftNav
Analysis and Simulation
LeftNav
Asbestos and Substitutes
LeftNav
Associations, Research Organisations and Universities
LeftNav
Automation Equipment
LeftNav
Automotive
LeftNav
Biomaterials
LeftNav
Building Materials
LeftNav
Bulk Handling and Storage
LeftNav
CFCs and Substitutes
LeftNav
Company
LeftNav
Components
LeftNav
Consultancy
LeftNav
View All
Other Carouselweb publications
Carousel Web
Defense File
New Materials
Pro Health Zone
Pro Manufacturing Zone
Pro Security Zone
Web Lec
Pro Engineering Zone
 
 
 
News

Thinner, lighter, faster

Bayer MaterialScience AG : 13 October, 2004  (Company News)
The
Bayer MaterialScience AG has developed a customized blend of polycarbonate and acrylonitrile-butadiene-styrene copolymer (PC/ABS) especially for this process. The qualities of the flame-retardant Bayblend® grade are demonstrated in battery covers for cellphones. Engel currently manufactures this component with a wall thickness less than 0.18 millimeter.

“Up till now, this type of PC/ABS cover couldn’t be made so thin,” says Hans-Joerg Dahmen, an expert for polycarbonates in Business Development at Bayer MaterialScience. He sees considerable potential for applications in cellphone components, for example battery covers and casings and cellphone casings. The material could also have many uses in the production of micro-precision components.

In the X-Melt expansion injection molding process, the screw exerts pressure up to 3,000 bar on the plastic melt in the cavity in front of it, compressing the melt by around 10 percent of its original volume. A special shut-off system then opens, allowing the melt to expand instantaneously into the mold. The cavity fills in a few hundredth of a second with melt front speeds of up to five meters per second.

“The mold can therefore be filled quickly and evenly without the melt setting too quickly,” explains Hans-Joerg Dahmen. Injection times are extremely short, typically ranging from 10 to 50 milliseconds depending on the size and wall thickness of the component. This results in cycle times of less than five seconds.

The Bayblend® grade has the perfect qualities for expansion injection molding. It is highly compressible, a fundamental requirement for use with this technology. Its processing stability means it is also able to withstand the long periods in the heated screw and its flowability allows the production of thin walls. A further strength is its high degree of mold surface reproduction, ensuring that even very fine, small script is replicated exactly.
Bookmark and Share
 
Home I Editor's Blog I News by Zone I News by Date I News by Category I Special Reports I Directory I Events I Advertise I Submit Your News I About Us I Guides
 
   Â© 2012 NewMaterials.com
Netgains Logo