Society of Plastics Engineers Rotational Molding Division

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TECHNOLOGY NEWS:



MOLDS

The Versatile Mold Exchange (VME) is claimed to be the first quick mold change mechanism that allows removal of an individual mold without disassembling the whole spider. The VME allows one person to change molds in about three minutes.

For information, please contact Norstar Aluminum Molds, Cedarburg, WI, USA.
Ph: (414)375-5600, Fax: (414)375-5660.



PATCH KIT

A new patching kit allows molders to salvage polyethylene parts with blow holes, voids, and bubbles. The water based liquid polyethylene based compound can be colored to match a molded part.

For information, please contact Mold-In Graphic Systems, Clarkdale, AZ, USA. Attn: Tom Innis.
Ph: (928)634-8838, Fax: (928)634-9036
E-mail: tinnis@moldingraphics.com



FOAMED PARTS

Multi-layered, multi-color, and foamed parts can now be molded without a drop box. The material for the inner layer is placed in a polyethylene bag that is put into the mold along with the material for the outer layer. A third layer can be provided by placing a second bag inside the first bag.

For additional information on the Foama-Bag System, please contact Chroma Corp., McHenry, IL, USA.
Ph: (815)385-8100, Fax: (815)385-1518



MATERIAL HANDLING

Plastic material can now be automatically charged into a mold to an accuracy of ±3% by simply scanning a bar code on the mold.

For additional information, please contact EAP Machinery Systems, Erie, PA, USA.
Ph: (814)455-6117, Fax: (814)455-5818.



UV Stabilizer

Cytec announced their hindered amine stabilizers (HAS) to protect polyolefins. HALS are Essential components in formulations developed for outdoor use and have been proven to be effective thermooxidative stabilizers. The physiochemical properties of hindered amines have a profound effect on the hindered amine's performance as a stabilizer, and will also influence the reactivity of the HAS with other formulation components, environmental agents, etc. Some of these interactions can have a deleterious effect on end product aesthetics and service life.

Studies on the relationship between HALS structure and performance have led to the development of new products which provide optimal light stabilizing efficiency while minimizing the tendency to undergo undesirable side reactions with system components or external agents. These new products have been used in PP fiber, PE film and other applications. For the details, please see the paper presented on February 23, 1999 at International Conference on Polyolefins XI in Houston, Texas. The SPE presentation is titled "What's Structure Got to Do with It: New Breakthroughs in Hindered Amine Stabilizer Performance". The paper covers the role of hindered amine stabilizers (HAS) in the protection of polyolefins and its continued role expansion.

For more information, please contact: Cytec Industries Inc., Five Garret Mountain Plaza, West Paterson, NJ 07424-3360.
Ph: (888) 298-3272, Technical Service: (800) 486-5525.



Rotational Molding Works Better in a Vacuum

During the rotational molding process, vacuum hastens part densification during processing, leaving fewer air voids in the part and thereby enhancing mechanical properties. Vacuum also provides a wider processing window. Limited tests to date yielded 17% shorter cycle times and a 58% boost in low-temperature impact strength.

- "Plastics Technology", June & July, 1998, p. 23, p. 56-57, by Kent Evans, Equistar Chemicals

Evacuating a rotational mold before you make a part may sound like a strange idea, but it's also a simple way to achieve faster cure times and improved part properties. For this reason, rotomolders should give serious consideration to switching form the standard "vented" process in favor of the vacuum process.



Free Service for Rotational Molding Professionals

PLASTICS TECHNOLOGY Magazine has launched a free daily online news service that's linked to five years of archived articles. The news service provides stories on a wide range of the topics, including technology, business and the economy, mergers and acquisitions, resin pricing and more. PLASTICS TECHNOLOGY Today will also feature occasional company profiles of leading North American processors.

PLASTICS TECHNOLOGY Today will also be linked to an archive of articles that have run over the past five years in PLASTICS TECHNOLOGY Magazine. Users will be able to access these articles by a key word search. Key words could identify a specific process on equipment type, company name, trademark, individual's name, etc.

Access to PLASTICS TECHNOLOGY Today and the archives is through http://www.plasticstechnology.com



Easy-running MDPE & LDPE

Nova Chemicals has two new experimental rotomolding resins in the Surpass line made with the new Advanced Sclairtech dual-reactor solution process and non-metallocene single site catalysts. The two grades are EX-RMs539 and EX-RMs244. EX-RMs539 is an octene MDPE with a 5.2 MI for easy flow and a density of 0.939 g/cc. The resin has low viscosity and extremely broad processing window.

Tensile yield strength is 2900 psi, and flexural modulus (1% secant) is 117,000 psi. ARM impact strength at -40 deg.C for a 0.25" thickness sample is 180 ft.lb. EX-RMs244 is an octene superrigid HDPE with 1.7 MI and 0.944 density. It has broad processing window to allow for lower process temperatures as well as faster sintering. It has a flex modulus of 142,000 psi, tensile yield strength of 3400 psi, and ARM impact strength (0.25") of 180 ft.lb.

Need to know more about these two materials, please contact Nova Chemicals Inc., Moon Township, PA.
Ph: (412)490-4000
www.surpassresins.com



Nylon 11 natural powder

Atofina Chemicals rolled out a new natural grade of Nylon 11 powder for rotomolding. Rilsan Roto 11 mplements a black grade previously available. Suitable for molding fuel, coolant, and hydraulic-fluid tanks in agricultural vehicles and lawn/garden or marine uses, this translucent grade makes the fill level visible. It is also pigmentable.

Need to know more about this material, please contact Atofina Chemicals Inc., Philadelphia.
Ph: (800)932-0420
www.atofinachemicals.com



ABS rotomolding compound

A new ABS rotomolding compound from Chroma Corp. is formulated for improved heat stability and practicle coalescence. Grade AG-9000 NA is a natural-color compound with an MFR of 6 g/10 min, density of 1.04 g/cc, tensile strength of 3300 psi, and flex modulus of 110,000 psi.

Need to know more about this material, please contact Chroma Rotational Molding Div., McHenry, ILL.
Ph: (815)385-8100
www.chromacolors.com



Tek Tuff CE HDPE

Teknor Color has developed a new variation of its Tek Tuff CE HDPE compound for rotomolding that is 5-10% less expensive than earlier formulation. It offers a broad processing window and contains a UV stabilizer for outdoor weatherability. MI is 3.0 with a density of 0.948. The materials has tensile strength of 2975 psi, ultimate elongation of 460%, and flex modulus of 130,500 psi. ARM impact at -40 deg.F is 60 ft.lb.

Need to know more about this material, please contact Teknor Color Co., Pawtucket, R.I.
Ph: (401)725-8000
www.teknorcolor.com



Special-effect colorants

More concentrated special-effect colorants with loading up to 50% are available from Jericho Plastic Industries. These cost-saving masterbatches can be formulated with high-flow LLDPE carriers.

Need to know more, please contact Jericho Plastic Industries Inc., Akron, OH.
Ph: (330)836-9617.





For More Information Contact:
SPE Rotational Molding Division
Ph: (847) 549-9970
Fax: (847) 549-9935
E-mail: rmd@rotomolding.net




Contacts : General Comments & Questions / Newsletter / Membership / Sponsorship    Email : rmd@rotomolding.net