Understanding how to effectively eliminate mold sweat is pertinant to solving the problems facing many plastic manufacturing plants, particularly those in hot and humid climates. Simply increasing chilled water temperatures extends cooling time, slows production rates, leads to inferior products and cuts into the bottom line - profit.

Most molded products, whether injection molded, blow molded or vacuum formed (thermoformed) products are cooled by chilled water in mold cavities. The cooling time, which normally is the longest part of the total cycle time and the molding process, is an expensive and an important part of the manufacturing process. Lowering the chilled water temperature in the mold leads to a shorter cycle time.

It is suggested to use pure chilled water at a temperature not lower than 6 °C [43 °F]. Lowering the temperature under the dew point of the ambient air causes condensation on the mold surfaces adding challenges to the process.

In many manufacturing plants process engineers tend to increase the chilled water temperature in hot and humid climates to avoid mold sweat and this leads to some problems. Increasing the chilled water temperature extends the cooling time, slows the production and shrinks the profit. In many cases a longer cooling time increases the crystallization rates in the molded plastic resulting in inferior product quality.

The ideal and most profitable solution is the Mold Area Protector (MAP). This should be combined with a good ventilation system in the plant to get rid of the excessive heat radiated from the machines in the plant.

The MAP is a simple air dehumidification unit with integrated chiller (condensation dryer). It filters the ambient air sucked into the unit through a washable and replaceable filter and then chills the air to a temperature of 3 °C [37 °F] in two steps before the air is being heated to a temperature of 25 °C [77 °F]. The first chilling step requires chilled water from the plant's chiller at the same temperature used in mold cooling. The second chilling step is done by the integrated chiller of the MAP unit. A lot of the moisture contained in the air is separated from the air due to condensation on the cold surfaces of the heat exchangers (pre-cooler and evaporator). The heat extracted from the air in the second chilling step is given back to the air after it has lost the moisture in the condenser of the chiller. A blower sucks the air through the unit and blows it in a duct work to the molding areas to be protected from sweating.

The mold area protection system is a complete system in which the clamp and mold area of every machine is enshrouded and separated from the ambient air. Trained installation technicians install the custom made covers on the machines and connect the dry air duct work to every machine.