Home Page,www.plastemart.com
 PRODUCT SEARCH     PROCESSORS     PRICES     PLACEMENTS      EXHIBITIONS       DISCUSSION FORUM       ARTICLES       NEWS      LOGIN  
Go to->Home - Technical Articles & Reports on Plastic Industry
Mineral fillers are property enhancers for thermoplastic compounds
 

Thermoplastic compounds with mineral fillers have a special position in many applications including automotive, consumer products and myriad of other applications. The mineral fillers used in thermoplastic compounds are:

Calcium carbonate

Dolomite

Barium sulfate
Talc
Wollastonite
Kaolin

Calcium carbonate is the least expensive and the largest mineral filler used in thermoplastic as well as thermoset compounds. PP and other polyolefin compounds and SMC/BMC compounds are the largest users of calcium carbonate. Besides providing economy, it reduces shrinkage and offers good surface finish. Calcium carbonate can be incorporated at a very high level of more than 70%. While SMC/BMC compounds use plain calcium carbonate, polyolefin compounds require surface modified calcium carbonate. While the surface treatment of coating has a limited role in polyolefin compounds- mainly due to non-polar polymeric nature, the functionalized polymer such as malice anhydride polymer acting as coupling agent is more efficient.

Dolomite is quite similar to calcium carbonate with the exception of the fact that it contains more of magnesium carbonate. It can be used for all the application as a replacement of calcium carbonate.

Talc or hydrous magnesium silicate has a platy structure compared to crystal structure of calcium carbonate. It helps in enhancing the stiffness of thermoplastic compounds and raises the heat deflection temperature significantly. Talc also provides better dimensional stability. PP uses talc significantly among all thermoplastics. The particle size of talc determines the impact strength, as the finer particle size enhances or maintains impact, and increases stiffness at the same time. Talc also reduces coefficient of linear shrinkage of the plastic product.

Barium sulfate being the densest mineral finds use in a few end products such as sound barrier or dampening applications. It also finds use in eraser.

Wollastonite, a calcium silicate, is basically quite similar to calcium carbonate but has a different structure. It is comparatively more difficult to disperse in a polymer matrix compared to calcium carbonate. It is used alone or in combination with glass fiber mainly to balance the cost of glass reinforcement. Additionally, it helps to improve the surface finish of glass fiber reinforced thermoplastic products. Wollastonite requires surface treatment for easy dispersion. Finer particle size is essential better dispersion. Polyamide is the major thermoplastic polymer that uses wollastonite.

Kaolin or clay or natural alumnisilicate provides good impact modification. It competes well with talc. Polyamide is one of the major thermoplastic that uses kaolin particularly for automotive applications. Clay also helps in providing cost economy. Clay also requires surface treatment for ease of dispersion. Clay also improves dimensional stability like talc. Clay provides better sound dampening effect compared to wollastonite and talc but not as well as barium sulfate.

All these minerals grow along with thermoplastic compound growth. Typically thermoplastic compounds grow slightly higher level (5-6%) compared to polymer growth of about 4-5%. In fact, the usage of mineral for plastic modification grows at higher level compared to its other usages. The main drivers of mineral fillers for plastic modification are:

Automotive sector

Consumer durable products

Forward this article to friend Forward this article to friend Print this article Print this article  
Back to list of articles
 
Advertise With Us    Home    Information Mart    Newsletter    Environment      Articles   Polymer Prices
About Us    Jobs in Plastic Industry    Manufacturers Plastic Industry   Products & Services Plastics  Terms Of Use
Plastic Exhibitions And Trade Fairs   Disclaimer   Software Solutions   Contact Us  Site Map
Be fan of Plastemart.com on Facebook Be Our Fan | follow Plastemart.com on Twitter Follow Us
Best viewed in IE 6.0+
Copyright © 2003 Smartech Global Solutions Ltd. All rights reserved.
Designed & Conceptualized by Plastemart - www.plastemart.com