Originally Published MPMN May 2001

Equipment News: Fillers and Dispensers

Dispenser and Filler Suppliers Seek to Reduce Waste and Increase Efficiency

Accuracy and repeatability are primary concerns for device OEMs sourcing dispensers and fillers. When one of these machines is integrated into an assembly line, it must consistently deliver precise shots of the required fluid or the entire manufacturing process may be compromised. In response to this requirement, suppliers of fillers and dispensers have developed new ways to maintain accuracy while keeping costs down. Read on to learn more about these products; for additional information, please refer to the Product Information box below.

Dispensers handle a variety of fluids

A new liquid dispenser is designed to apply most types of fluids including adhesives, pastes, solvents, lubricants, greases, and inks. The JB1113, offered by I & J Fisnar Inc., incorporates digital timers to control a high-duty-rate solenoid valve. The dispensing cycle time, between 0.01 and 31 seconds, is operator adjustable. A configurable barrel suck-back feature prevents low-viscosity fluids from dripping. Each dispenser comes equipped with hardware, fittings, hoses, a foot switch, a barrel stand, adapters, and barrels and tips. Some benefits of the JB1113 include hygienic conditions and safeguards to prevent the operator from coming into contact with toxic materials. The dispenser's automatic deposit controls ensure reliable production and a reduction of waste, whether the device is dispensing microdots or being used for large potting and filling applications.

Also from I & J Fisnar is the PPD-119 peristaltic pump dispenser that delivers material directly from a bottle or can. This method reduces the risk of material contamination and operator contact by eliminating the need to transfer the material from its original package. The dispenser offers selectable and preset flow rates and reversible flow options. Shot sizes can be as low as 0.006 cm³. Because it dispenses without the use of air, the PPD-119 is suited for cyanoacrylates, solvents, and other low-viscosity materials. Dispense amounts can be controlled manually or by using a built-in timer. Fluids do not come in contact with the dispensing mechanism, ensuring simple cleanup and maintenance. The material tube can be emptied between work cycles with the use of a reversible pump.

A benchtop system is capable of metering, mixing, and dispensing two-component epoxies, urethanes, silicones, inks, and acrylics. The Portionator III from Glenmarc Manufacturing Inc. is an electric machine that can deliver a 3-cm³ mixed shot in as little as 1.75 seconds. "This electrically driven system offers smoother reconfiguring of dispense speeds in a linear direction than an air-driven machine," says David Greenwood, the company's president. "This gives the Portionator III more flexibility and a range of dispense-time capabilities." A disposable 1-, 3-, or 6 1/2-in. static mix tube has an electric motor-driven mix head. Reservoirs are either polyethylene cartridges or stainless-steel tanks. The machine can provide variable dispense amounts in full or partial strokes, independently adjusts resin and hardener pistons for wide ratio ranges, and features a hand-operated knob that allows the shot size to be dialed down without interfering with the preset mix ratio. Options include stainless-steel construction, preselected counters for multiple shots, fully or semiautomatic solvent flushing and purging systems, heated material feed lines, and a material degassing function. The Portionator III can be used as a benchtop machine by an operator or can be fully automated. The variable-speed electric motor drives the pistons and allows production of quick shots and slow lines. The mix ratio can be weighed manually via two nozzles that dispense into a cup on the front of the machine.

A 5-L capacity pressure pot from Techcon Systems is designed for automated fluid-dispensing systems. The TS1258 can accommodate solvents, epoxies, cyanoacrylates, and UV cure adhesives. It can be configured with black fittings and tubing in 1/4-in., 3/8-in., and 4-mm sizes with stainless-steel compression fittings. The Pot's airtight seal minimizes leak points and air entrapment problems. According to director of marketing Marc Cortez, "The main benefit of the pressure pot is that it allows users to dispense potentially aggressive materials without handling them." The TS1258 provides fittings and tubing for a continuous fluid path from the reservoir inside the pot to the valve or point of use. Features include a fluid outlet port and a pressure gauge on the lid for easy access and reading. Three knobs that open and close the lid create a positive and uniform seal. A relief valve with a pull ring depressurizes the pot after usage. The ferrule is disposable after application to reduce cleanup, and a clip holds the air hose line steady.

Packet-dispensing system features air-actuated cutting

Suited for desiccant and oxygen-absorbing packet applications, a system features a PLC and servomotor drive for accurate dispensing. According to George Gordon Associates Inc., the system was designed to operate directly on a production line and is automated for optimum speed and efficiency. In lieu of stepper-motor cutting, the system uses air-actuated cutting that ensures cut-off repeatability. Other features include casters for portability and an adjustable bottle escapement. Precise pouch sensing allows easy adjustments during product changeovers. An electromechanical sensor enables precise cut positioning and reduces accidental packet cutting. The unit can be quickly adjusted with simple hand tools. A driven infeed pull roll, dancer, and infeed belt support the string for consistent delivery.

Dispenser offers noninvasive filling for sterile products

A liquid dispenser uses a noninvasive cassette-load pinch valve to provide precision filling. The Gen 3 Grav/Tronic from Oden Corp. features a unique product reservoir system that requires minimal system volume, making it appropriate for small batches or production runs. The operator interface is housed in a sealed NEMA-4 stainless-steel enclosure and is available as a 4 x 20-line backlit LCD or a PC-based industrial workstation with an active-matrix touch screen. A bottom-up filling system offers toolless setup, 14-in. adjustable dive distance, and nozzle kickout safety. The sanitary stainless-steel conveyer is 10 ft long with a 4 1/2-in. Delrin chain and a variable-speed dc motor drive. The diagnostics package includes a fault alarm system and a display that describes the fault and prompts troubleshooting sequences. Product-contact parts are made of 316 L stainless steel, Teflon, and silicone, and product feed can be performed by means of a peristaltic pump or actuated valve. The Grav/Tronic's PLC computes automatic fill volumes after the user enters the trial weight and target. The Grav/Tronic comes in tabletop and fully automated versions. "The main feature of the Grav/Tronic is that it can be integrated directly from the lab into a fully automated production line without changing any settings," says Bryan Ferry of technical sales.

Solvent dispensers reduce environmental risks

A new dispenser applies a uniform coating of solvent to the outer diameter of tubing and minimizes the amount of solvent that accumulates at the tip. The EZO-B dispenser from Lakeview Equipment Inc. is designed to prevent solvent from blocking tube passages. The dispensing process does not require dipping or blotting, which reduces fumes and solvent usage. The EZO-B incorporates a high-density polyethylene bottle that may be used with solvents such as cyclohexanone. A dispensing wick can be easily replaced for cleaning or to change sizes. Wicks are customized to predetermined outer diameter specifications. A stainless-steel frame can be oriented in three positions and comes with rubber suction feet to attach it to a smooth work surface.

A precision solvent dispenser engineered to provide safe, accurate, and uniform dispensing is available from Ventrex Inc. The SD7200 can treat a product's outer and inner diameters simultaneously or separately without requiring part rotation. The solvent delivery rate is adjustable regardless of the size or shape of the part. The dispenser is pneumatically driven, minimizing combustion hazards associated with solvent dispensing. "Traditionally, solvent bonding has been problematic because of volatile fumes and other environmental risks," says general manager Bob Guthrie. "However, the SD7200 is completely sealed and contains the fumes within the unit, controlling environmental exposure." Tight tolerances, PTFE seals, integral fluid pathways, and solvent-impervious gaskets reduce solvent vapor without the need for external cleanup systems. The SD7200 features a self-cleaning applicator and a high-capacity reservoir that holds 1 L of solvent to minimize refilling.

UV adhesive dispensers decrease material waste

Fitted with a 1-L reservoir like the SD7200, the UV8350 dispenser applies UV adhesives on cylindrical components consistently and rapidly while avoiding material waste. Also from Ventrex, the machine applies adhesive to a part that is inserted into the applicator, reducing wasteful stringing or oozing. This eliminates the need for foot switches, dispensing needles, and syringes. The UV8350 can be integrated into a semi- or fully automated production line. Applicators are available for individual or simultaneous OD and ID dispensing. The porous materials in the applicator are selected specifically for the viscosity of the UV adhesive being applied. This allows the correct volume of adhesive to be held on the transfer surface. The UV8350 incorporates positive light protection during operation and idle time to help eliminate unwanted curing and to maintain consistent adhesive flow. According to Guthrie, "the UV8350 provides a cost-effective alternative to solvents because it bonds quickly, does not damage plastics, and takes the labor inefficiencies out of applying UV adhesive to parts."

A UV adhesive dispenser from TechnoMed Inc. consists of an electric pumping system that provides continous circulation through custom-made removeable dispensing bushings. The bushings are designed to precisely dispense adhesive externally or internally on medical tubing or components. Tubing or components are inserted into the relevant bushing, then immediately pulled back for assembly operation. The bushing can dispense adhesive on 1.3- to 8-mm external surfaces. The DUV dispenser is suited for repeatable dispensing of UV adhesive on PVC, ABS, and other medical polymers. The adhesive stream is housed in a closed configuration shielded from extraneous UV light sources, preventing unwanted evaporation or polymerization of the adhesive. An optional vapor conveyor can be added to the system to vent adhesive fumes and create a safer work environment without the need for external discharge systems. "Current dispensing technology for UV bonding materials relies upon the use of operator-dependent applicators," says company president and CEO Ken Patti. "TechnoMed identified the need for a more efficient and reliable way to dispense precise amounts of medical-grade UV bonding materials to all types of medical-grade plastic tubing and components independent of operator control or experience."

Reagent dispenser controlled by a touch screen

A dispensing module applies reagent onto lateral-flow test-strip products. The Matrix 1600 from Kinematic Automation Inc. features a dispense tip mounting assembly that allows toolless tip-spacing adjustment and replacement and provides simple line configuration while maintaining accuracy. All dispense parameters and process variables are programmed directly into the machine and controlled using scroll-through screens on a touch panel. Closed-loop control of the bed speed and dispense rate allows for precise setup and minimum waste of expensive reagents. A 100-µl syringe draws reagent from a 5000-µl reservoir. Dispensing capabilities include 0.05-µl dot volume, 2-mm dot spacing, 5-mm minimum line spacing, and 2-12-cm/sec platen speed.

Lubrication devices offer reliable performance

A programmable lubrication station is suitable for rolling and spraying in metal-forming, machining, metal-cutting, and stamping applications. Unist Inc. created the SPR-2000 with a mechanical cam pump configuration that releases fluids under pressure to rollers. A controller opens valves at predetermined intervals. Menu-driven software allows users to create up to 60 setups for future use, alerts operators with an audio alarm wired to the press control, and monitors fluid level, pressure, and flow. Each die can be preprogrammed for fluid delivery and changed quickly. The SPR-2000 can be used in ferrous and nonferrous metal- forming and -piercing operations with either coiled or blank stock in a variety of thicknesses and widths. Lubricant coatings are accurately and consistently applied through porous covers or by being sprayed into the die, and may be applied to a part's top, bottom, or both. The system can be retrofitted on existing Unist systems to provide more-effective fluid control, statistical process control, and fluid usage. According to marketing manager Bryce Hoff, the SPR-2000 "reduces the amount of fluid used by 50-80% by using a controlled panel to precisely spray or roll lubricant to a specified area."

Designed to dispense small amounts of lubricants such as oils, greases, or single-component sealants, a dispense valve's internal components are designed for high-cycle operations. The Micro-Kiss valve from Sealant Equipment & Engineering Inc. offers 2000-psi inlet pressure and measures 1 x 4 in. long without the nozzle. The double air-operated valve includes stroke adjustment to control the material flow rate. Single, stand-alone, or multiple valves are available mounted to a common feed manifold. The Micro-Kiss accepts most small, needlelike nozzles. It features a snap-action opening and spring-assisted closing and integrates into an x-y-z fixture.

Precision pump integrates valveless technology

A precision pump that incorporates stepper motor control and valveless piston technology is suitable for pumping, dosing, and dispensing. The STQ dispenser from Fluid Metering Inc. features one moving part--a ceramic piston that rotates and reciprocates within a precision ceramic liner--and an inert fluid path of ceramic and fluorocarbon. According to the company, metering and dispensing accuracy is better than 1%. The pump features >=0.1% repeat accuracy and displacement of 0 to 1.28 ml per revolution. The Model STQ achieves dispense rates from 0.002 to 1.28 ml per stroke. It can be controlled using the company's 1.8° stepper motor drivers or other commercially available models. Six standard models as well as custom configurations are available.

Compact filler processes various shapes, sizes

A filling and stopper placement machine, designed to accommodate limited space requirements, measures 41 x 38 in. Accurate positive-displacement liquid filling is followed by precision stopper placement at up to 120 units per minute. Supplied by Chase-Logeman Inc., the Model FS-12 features a sanitary conveyor for sterile applications and a choice of filling systems. Also available is servo adjustable pump control, nondestructive check weighing with pump feedback, and complete validation document packages. The low-silhouette monoblock design keeps the area above open vials free from mechanical or structural objects prior to stopper insertion, preventing obstruction from vertical laminar airflow. The FS-12 is suitable for glass and plastic containers in a variety of shapes and sizes. It can insert rubber stoppers, plastic plugs, and snap caps. A vibratory bowl feed system is held in place by a vacuum attachment that enables rapid toolfree release of parts.

Motorized pipette fillers offer liquid handling, precision, and comfort. Jencons Scientific's Powerpette and Powerpette Plus allow fingertip control of three aspirating and dispensing speeds. Comfortable concave triggers allow variable speed control in many settings. Nickel-metal hydride batteries provide 8 hours of continuous use and will not develop memory from multiple charges. Powerpette and Powerpette Plus weigh 6.1 and 6.7 oz, respectively, and are suitable for 1- to 100-ml pipettes. Powerpette Digital, which is can be used with 1- to 25-ml pipettes, provides programmable functions including multidispensing, series dispensing, and conventional pipetting controlled via an LCD. No calibrating or memorizing of volumes is required. Volume selection on the LCD produces repeatable results.

--Katherine Sweeny

Copyright ©2001 Medical Product Manufacturing News