CD75/135

The CD70, CD75, CD130, and CD135 are so similar that their design and features will be covered together below. But first, a brief description of the few differences among them.

The CD75 and CD135 cabinets contain two seventeen gallon material hoppers, pumps to pressurize the products, and can be heated.

The CD70 and CD130 cabinets on the other hand do not include material hoppers or pumps. Rather, they depend upon an outside source of material and pumps for supply. The reason for the option is that some contractors will obtain resin in drums or totes, leaving them no need for the hoppers.

The only other difference is capacity. The CD130 and CD135 have a much higher volumetric delivery than the CD70 or CD75 due to larger air motors and metering cylinders.

CD70/130

Piston Displacement
Piston displacement of both resin components assures ratio accuracy. Regardless of the resin pressure, the flow rate, the ratio, the viscosity of the components combined or separately, the volumetric proportioning remains precise.

The piston displacement is the same as the bore of the metering cylinders. This leaves no void for air bubbles to become entrapped and corrupt ratio. Pistons assure the most positive displacement of a fluid. There is no slippage of low viscosity materials between metal to metal surfaces as with gear displacement for example.

Fixed Ratio
Ratio is determined by the relative diameter of the base and catalyst metering cylinders. If both cylinders are the same diameter, the ratio is 1:1. The ratio is changed by exchanging the catalyst metering piston and cylinder with a different size: a ten minute task.

Because both pistons travel the same distance within the cylinders, the ratio cannot possibly vary — if, that is, both metering cylinders are fully charged with material before the dispense cycle commences. Read on to see why that cannot happen with any CD Dispenser.

If filling of a cylinder should be sluggish due to a viscous component, the sensor will prevent the system from cycling until the lagging piston has fully extended. Due to this feature, ratio is not corrupted by temperature changes that alter the viscosity of many fluids.

The resin components enter the proportioning device under pressure from pumps or pressurized vessels. (a). Under pressure, the separate components flow through open inlet valves (b) into metering cylinders (c), exerting pressure against the metering pistons (d). The pistons extend under the fluid pressure until they reach the main air cylinder end cap (e). As the pistons bear against the end cap, urethane pads on the piston ends seal off the flow of air venting from two holes. Once both of these vents are sealed, the Fill Sensor sends a signal allowing the dispense cycle sequence to continue.

This signal energizes the Coco™ Module to close the inlet valves (b) and open the outlet valves (f) to allow the resin components to exit under the pressure exerted by the main air cylinder (e) pushing against the metering pistons (d). The components merge at the Tempest Mixer (g). When the dispense stroke is completed, the Coco module closes the outlet valves (f) and opens the inlet valves (b) to allow the metering cylinders (c) to refill as the main air cylinder returns.

The system is not able to continue the dispense cycle sequence unless the Fill Sensor confirms that both metering cylinders are filled. Both of the vents in the end cap must be sealed by the arrival of the material pistons to confirm the complete filing of both of the metering cylinders This function is important, because if either metering cylinder does not fill completely, the proportioning will be off ratio.

This signal energizes the Coco™ Module to close the inlet valves (b) and open the outlet valves (f) to allow the resin components to exit under the pressure exerted by the main air cylinder (e) pushing against the metering pistons (d). The components merge at the Tempest Mixer (g). When the dispense stroke is completed, the Coco module closes the outlet valves (f) and open the inlet valves (b) to allow the metering cylinders (c) to refill as the main air cylinder returns.

The performance of the fluid valves that orchestrate the flow of the resin components to and through the metering cylinders is crucial to the reliability of a proportioning dispenser. If any of these inlet or outlet valves do not seal promptly and tightly, the ratio will be flawed. Ball check valves work well for this purpose – sometimes. They work well if the resin contains no fillers that can build and compact on the ball seat, and if both components are of the same viscosity so that they close at the same time, and if the ratio is 1:1. If the ratio is other than equal, the higher surge of the one component will seat its ball before that of the other component. Few epoxies are without fillers, have components of the same viscosity, and are 1:1 in ratio.

So, Lily Corporation has opted for Mechanically Actuated Ball Valves rather than those actuated by fluid or spring pressure. Four such valves control the flow of the resin components through the metering process: two inlet valves, and two outlet valves. The bodies are stainless steel investment castings, and the balls are hardened steel under an electroless nickel plating. The valves are rated for 3,500 psi.

Proper sequencing of the fluid valves is vital to the performance of a dispenser. If the valves open or close out of sequence, unmetered resin will pass, corrupting the ratio. The Coco module orchestrates the opening and closing of the inlet and outlet valves in precise sequence.

This is how Coco works: The base and catalyst inlet ball valves (A) are linked to a common flipper, and the outlet valves (B) are commonly linked to a second flipper. A reciprocating rod cams the valves open and closed in sequence.

To begin, the valves are positioned as shown in the left frame. The resin enters the lower entry port, pass ing through the open ball valve to fill the metering cylinder. When both metering cylinders are filled, the rod retracts to first close the inlet valves, and continue to open the outlet valves as shown in the frame to the right. The linkage makes it virtually impossible for the outlet valves to open until the inlet valves have been closed.

With the valves positioned as shown in the right frame, the resin will flow from the metering cylinders to the exit ports. The sequence repeats itself.

If all of this does not happen just right, valve overlap, a stage when both the inlet and outlet valves are cracked open, will corrupt ratio. A number of devices have been used to minimize this occurrence, but non have been utterly reliable; until that is, Coco™ Valve Sequencing was introduced and patented by Lily Corporation. Coco™ prevents valve overlap.

Flow Management Kit

The Flow Management Kit consists of a remote trigger assembly, a dual fluid valve, and a rigid stem that joins and supports the two. A long stem is used in paving and a stubby model is used for work close at hand. The trigger assembly has two switches. The left switch releases a pre-set dosage selected to fill but not flood the socket. The right switch aborts the flow, allowing the operator to dispense a small dollop for touch up. The system then resets for the next cycle.

The fluid valves at the outlet clode off the flow of both components instantly and simultaneously upon the operator's signal via the remote trigger. The threads of the mixer mounting nozzle are tool steel -- not likely to be damaged in routine service. The Twin Valves are the lightest, fastes, and toughest in the industry.

Shot Sizing

Shot sizing enables the operator to select an ideal dosage and repeat it. This feature is invaluable when setting anchors or similar applications requiring a repetitive dosage.

A set of spacer blocks offers a selection to arrive at a desired dosage. Each time the operator triggers the unit, the selected dosage is dispensed. An abort switch allows the operator to deposit short shots for touch up.

The cabinets and lids of the CD75 and CD135 are coated with a ceramic insulation. Although heaters are not included in the purchase, thermostatically controlled fin heaters can be added at the time of purchase or at a later date. The heaters warm the material in the hoppers as well as the equipment.

Two eighteen gallon material hoppers are built into the cabinets of the CD75 and CD135. Stainless steel gratings support pails of material while they drain, stainless steel screens filter construction site debris from the material, and weather proof lids keep your product dry.

At the end of a project or when the product must be changed, the hoppers need to be emptied. Two bypass valves on the downstream side of the Graco transfer pumps enable the operator to pump the hoppers empty in a jiffy. Nylon tubing is inserted into the press-to-connect fittings so that the material can be directed into appropriate containers. These fittings also make it easy to flush the hoppers clean by cycling a solvent or other agent.

The brakes on the DC-10 don't fail. This is because routine maintenance replaces worn parts as they wear rather than as they fail. The same will be true of a CD dispenser. For this reason CD dispensers have a cycle totaling counter so that service personnel do not have to guess as to when it is time to lubricate, inspect, or otherwise service the equipment. They can know without a doubt when the steps that assure ratio accuracy and stamina are to be taken.

The counter is not only used to schedule maintenance. It also monitors material consumption so that timely additions to reservoir vessels can be made. The counter clicks off each cycle of the dispenser, and with a simple calculation, the number of cycles per gallon is known. This knowledge is also helpful in controlling the rate of application when coating a deck for example. The counter is easily reset.

The faucet is used to employ a CD dispenser as a hydrant. The material is on tap from a disposable mixer so there is no clean-up. The faucet is used for filling caulking guns with two component sealants, dispensing epoxy for sealing cracks prior to injection, saturating carbon fibers, or plastering bridge segments with epoxy. Fresh, precisely proportioned, and thoroughly mixed resin is always on tap. When quality control is important, the hydrant is the obvious selection.

For filling control or expansion joints in pavement, an adjustable wand is installed between the Switch and Valve Module. It mounts a guide roller to keep the mixer tip on the joint. Lily inventories a large variety of Disposable Static Mixers for virtually every construction application. The use of the Weasel Mixer Tip, assures complete filling of narrow joints. It fits within an 1/8” wide joint and directs the resin against the bottom of the joint to assure full depth filling with minimal waste.