Graco AFD announces new barrel stack designs for LSR equipment

Graco Advanced Fluid Dispense (AFD), a manufacturer of fluid-handling products and systems headquartered in North Canton, OH, announces its new barrel stack designs for Graco F-5 and F4-55 two-component liquid silicone rubber (LSR) injection molding meter, mix and dispense equipment. The updated barrel stacks are available in both multi- and single-pass designs.

The new stacks are easy to clean and assemble and have no tapered national pipe threads (NPT). End users can save up to 50% of cleaning time over older models, and spend more time producing parts, said Graco in its announcement. Enhancements have also been made to the regulator and mixer.

The new barrel stacks use plastic molded mixers, which stack upon each other. These mixers prevent the side-walling problem that may be caused by the repeated removal and installation of older stainless-steel mixer designs The plastic mixer also does not suffer from installation damage because of tight tolerances between the hosing and mixer. End users can now choose to clean the plastic mixer or dispose of it.

Greater clearance makes the new barrel stack easier to clean by reducing thread galling. The design also makes it easier to reach components to clean them. The new barrel stacks completely eliminate all tapered NPT threads, from the top of the assembly all the way through the filter and into the regulator. With all straight threads, the design keeps material out of threaded areas, reducing stress on threads as they come apart and making them easier to put together again.

The barrel stacks now come with two filter options: A 1-inch diameter filter comes standard, integrated in the stack assembly; a 2.5-inch filter is available as an option.

The new design also features an easy-to-clean regulator design with fewer bolts than conventional equipment, resulting in cost savings with no sacrifice in performance. Flow-through passages on the new regulator manifold are 225% larger, reducing pressure drop through the barrel stack.

The new multi-pass mixer can now run as many as 30 mix elements, compared with older models that run a maximum of 24. End users can configure the equipment to run as few mixers as required—8, 20 or 30.

The single-pass model has 12 elements, which now can be configured so that users only need to use as many mixers as required. The configuration saves on material costs, allowing customers to use only what they need and keep the rest on the shelf for the next batch of material.