DME Molding Supplies (Madison Heights, MI) has expanded its already extensive line of MRO products to include new Mini-ShutTM Automatic Nozzle Tips. These low-cost tips shut off the flow of plastic into a mold to prevent drooling and stringing without requiring mold decompression.
There are several methods molders currently use to prevent drooling and stringing, but they’re often expensive, complicated and unreliable. The patented, simple design of the Mini-Shut enables molders to eliminate the variables and produce consistent shots without drooling, every time.
Typically, when plastic is injected into a mold and the mold opens, plastic continues to drool out of the nozzle. This presents significant challenges to a molder as it can create imperfections in the next part.
A common method of counteracting drool is with mold decompression – retracting the screw to relieve pressure at the nozzle tip. However, this process drops the pressure in the barrel and creates the potential for short shot. When the molder tries to make the next part, there is often not enough plastic in the barrel to fill the mold completely.
The Mini-Shut eliminates the need for mold decompression by the simplicity of its design. After a molder shoots the part, the nozzle itself doesn’t have enough pressure to continue drooling plastic. There is no need to retract the screw, but there is plastic waiting at the tip to shoot the next part.
Another method molders often use to eliminate drooling is with spring-loaded shut off nozzles. Typically costing between $1,000 and $2,000, these parts use an internal pin that wears over time and must be replaced. The Mini-Shut’s simple design with internal springs arranged in a certain pattern shuts off the flow of plastic to that tip. The Mini-Shut is a better alternative because it contains no moving parts, minimizing maintenance and downtime.
Mini-Shut is available in two different sizes, fitting 80 percent of systems. The small bore variety is 1.5” long, with radii ranging from 0.5-0.75” and orifices ranging from 0.125-0.375”. The large bore variety is 1.1735” long with radii ranging from 0.5-0.75” and orifices of 0.25”.