Side Gate Hot Runner System Nozzles Improve Usability for Moldmakers

Side gate nozzles from Barnes Molding Solutions offer customers ease of use and reliability, even with challenging plastics.Toolmakers often hesitate, preferring inefficient cold runners or even placing cylindrical components sideways in the cavity. However, the side gate nozzle THS has proven that cosmetic injection points, easy assembly and consistent reliability can be smoothly combined even on difficult parts and with difficult materials.

The homogeneous temperature profile is crucial because, especially with technical materials, the risk of freezing increases when the melt is first redirected to the side. During development, Barnes Molding Solutions focused on heating design, using patented heating elements from Thermoplay.

Additionally, sufficient space was provided for nozzles near cooling channels, which can also be used for heat supply if needed. A circular seal between the nozzle tip and the tool ensures thermal separation which leads to reduced energy consumption and allows for shorter cycle times and barely visible injection points with diameters measuring fractions of a millimeter.

Medical disposables such as pipets, syringes, caps, or medical cannulas are among the products where side gating (with standard polymers like PP) is already widespread. With wall thicknesses of less than a mm, low part weight, and the highest demands on concentricity, precision work is required to produce in-spec parts. But side gating can also be beneficial for technical applications such as socket inserts and decorative frames made of PC or ABS, as it helps avoid markings in visible areas.

Barnes Molding Solutions offers three nozzle variants for different component geometries. The maximum part weights for sizes 12, 17 and 23 are 6, 20, and 40 grams (polyolefins/low-viscosity materials), respectively, or 1.5, 7 and 16 grams (technical plastics). Even fiber-reinforced and mineral-filled materials can be processed with high stability.

The nozzles are available in both linear (THS-linear) and radial configurations (THS-Radial). The latter is currently used in a series application for the elongated cover of a car battery. Three radial nozzles in a row, each with two opposing nozzle tips, serve two cavities with a shot weight of 640 grams. The THS-Radial can be equipped with up to eight nozzle tips, while the linear version features 2+2 or 4+4 parallel nozzle tips. The minimum distance between injection points here is 16 mm (about 0.63 in), ideal for multi-cavity tools, with temperature control available for each individual tip.