Difference in resin. The advantages our HDLPE resin has over other rotomolded linear resins in tank applications Over XLPE
1. Over Linear, Medium and Low Density Polyethylene:
superior impact and stress-crack resistance

• Improved weatherability
• Broader chemical resistance
• Lower notch sensitivity

2. Crosslink versus Linear:
"The most important advantage that crosslinkable polyethylene (XLPE) tanks have over linear polyethylene (LLDPE) tanks is that XLPE has a much higher molecular weight than LLDPE. In general, as the molecular weight of polyethylene increases, the environmental stress cracking resistance (ESCR), part impact strength, elongation, weathering, toughness, and tensile at elevated temperatures are improved."

This in fact is a true statement; however Snyder is using a TRUE HDLPE and not a LLDPE. In fact, during the molding cycle the density of resins changes and testing has shown us that we end up with a higher density with our HDLPE than with the CL200 XLPE.

We feel very confident that our studies and case histories can help us to determine the best resin for the application. Sii has always taken pride in our ability to get the full development of the physical properties of the resins which translate into chemical resistance and tank life.

Crosslinked vs. linear Advantages:
The most important advantage that crosslinkable polyethylene (XLPE) tanks have over linear polyethylene (LLDPE) tanks is that XLPE has a much higher molecular weight than LLDPE. IN GENERAL, as the molecular weight of polyethylene increases, the environmental stress cracking resistance (ESCR), part impact strength, elongation, weathering, toughness, and tensile at elevated temperatures are improved.
Wall thickness is not the only factor relevant to determining the strength of the tank. Proper material cure is more important than wall thickness in determining tank strength. Material cure is highly dependent upon the time of exposure to heat conducting through the tooling and the plastic material. Excessive exposure to high temperature will degrade the plastic material and cause a weak part. The ideal cure cycle is to reach the proper curing temperature as fast as possible, maintain that temperature for the correct period of time, and to cool the part and tooling at the proper rate of part temperature decrease. The superior Sii manufacturing process and oven capacity makes it possible to reach the proper cure temperature quickly and avoid the material degradation caused by slow oven temperature rise. Therefore, it is improper manufacturing technique to compensate for poor material cure with excessively thick tank walls.

“We answer our phones, we return phone calls, faxes, and emails, and we are the fastest trained responders in the industry! Try us, compare us, dare us, to deliver when the traditional tank suppliers take your orders and put them on the PILE! ”