ESCR (ENVIRONMENTAL STRESS CRACK RESISTENCE)
Environmental stress cracking (ESC) of thermoplastics when they are subjected to a constant tensile load in the presence of chemical agents. It is applicable to test specimens prepared by moulding and/or machining and can be used both for the assessment of ESC of plastic materials exposed to different environments, and for the determination of ESC of different plastic materials exposed to a specific environment. This is essentially a ranking test and is not intended to provide data to be used for design or performance prediction.

 

AIR FLOW AMPLIFIERS
Used to increase the flow of air into difficult-to-heat areas on the surface of the mould by moving larger volumes of air with a compressed nozzle. Can be used effectively to control wall thickness on parts.

 

ANTISTAT
Chemical added to polymers to eliminate or reduce the effect of static electricity during moulding.

 

KISS-OFF
Design feature in a moulded part used to connect or almost connect two surfaces. This technique can add considerable strength to the finished part.

 

MELT FLOW INDEX
The term “g/10 minutes” refers to the weight of molten resin moving through an orifice of a predetermined size in 10 minutes. The higher the melt index, the better the flow. Most rotomolding resins have melt indices ranging from 2g/10 minutes to 10g/10 minutes. The melt index is also a rough measure of the molecular weight or the chain length of a resin. A resin with a high melt index has shorter chains and a lower molecular weight or smaller molecules. A resin with a low melt index has longer chains and a higher molecular weight or larger molecules.

 

LINEAR LOW DENSITY POLYETHYLENE LLDPE
Linear Low Density Polyethylene has better mechanical properties than LDPE as well as higher stiffness, excellent low temperature impact strength and excellent environmental stress crack resistance

 

CROSSLINKABLE POLYETHYLENE XLPE
Crosslinkable Polyethylene (XLPE) contains a crosslinking agent that reacts with the resin during the molding cycle, forming a crosslinked molecule similar to a thermoset plastic. This reaction improves the stress crack resistance of the rotomolded part.

 

CROSS LINKING
Describes the chemical reaction that connects polymer chains together during the moulding.This typically occurs at elevated temperature and creates an interconnected structure with improved physical properties.

 

VENTING
Because of the inherent build-up of gas in the heating cycle of the rotational molding process, most rotational molds require a venting system. A vent reduces flash and piece or mold distortion. It also prevents blowouts caused by pressure and permits the use of thinner-walled molds

 

BLISTERING
Blisters can be defined as raised defects on the surface of a molded part caused by trapped gases in the part that could not escape before the surface began to "skin" during the molding process.

 

UNDERCUTS
Undercuts are internal or external protrusions that can impede the removal of the part from the mould. Compared to other plastic material manufacturing processes, rotational moulding is less restricted by the presence of undercuts..

 

WARPAGE
Warpage can be defined as a dimensional distortion in a molded product after it is ejected from the mold at the end of the injection molding process.