The benefits molders derive from using Porcerax II are primarily, but not limited to, the elimination of trapped gas problems that occur in inadequately vented areas within the mold. Frequently, it is difficult, if not impossible, to provide adequate venting in these hard to mold areas. Traditional methods of venting, such as parting line vents, vent plugs, and pins often do not provide sufficient surface area to accommodate the large volumes of gases that can be generated. Porcerax II provides a location-specific method of venting gas in a targeted area. Since it is 25% air by volume, one-fourth of the surface area becomes a vent. The larger the surface area of the piece installed, the greater the venting capacity.

Prevention of Burning
Burning is a condition caused by compressed gases trapped by the flow of molten resin in a cavity pocket. Using Porcerax II venting steel, gases are permitted to evacuate through the steel to the outside atmosphere, thus eliminating the burning condition.

The enhanced venting capabilities of Porcerax II are illustrated below. The illustration is taken from a current production application:

The scrap rate on this part prior to installation of the Porcerax II insert was over 45%. Upon completion of the installation, the documented scrap rate dropped to 9% and was unrelated to the previous burning problem.

Prevention of Knit Lines
Minimizing or eliminating flow and knit lines is an additional benefit for using Porcerax II. Knit lines occur at points where resin flows converge after molding around an obstruction, or protrusion within the mold, usually away from the gate area. There are two primary reasons for this occurrence:

1. The failure of resin to sufficiently fuse due to the drop in temperature after flowing over long distances.
2. The presence of residual air at the resin flow convergence point at the cavity obstruction, prohibiting the proper fusion of the flows.

The permeability of Porcerax II prevents defects arising from residual gases normally trapped inside the mold cavity. Also, using Porcerax II reduces back pressure and improves the flow rate, allowing the resin flows to merge while still hot.

Eliminates Shrink
Trapped air bubbles between the resin and mold steel surface can cause shrinkage or sink that shows as a ripple in the otherwise straight plastic surface. Using Porcerax II on the trapped air side of the cavity will eliminate shrink in most cases.

Before using Porcerax II (click to enlarge)

After using Porcerax II (click to enlarge)

   

Enhances Part Appearance
Webbed, ribbed, and other difficult to fill thin-walled designs are greatly enhanced and cosmetically defined using Porcerax II in the mold. Molding these high-detailed, thin-walled, and aesthetic parts is easily accomplished with the reduced back pressure and added venting of Porcerax II.