Nordson_EFD_Medical_Device_Assembly_White_Paper.pdf - 第6页

www.nordsonefd.com 6 If your dispense valves are not cycling fast enough, the valve control system may not be compatible with the dispense valve. Most automatic assembly machines use PLCs (Programmable Logic Controllers)…

100%1 / 12
5 www.nordsonefd.com
3. Does your application require valves that must meet CIP
or SIP standards?
Proper coating placement, coverage, and thickness are critical in medical applications.
Manual tools and spray systems that allow only coarse adjustment may not provide
the controlled, consistent coverage needed to achieve predictable process results and
reliable device performance.
Aseptic valves feature a smooth fluid flow path that is free of any entrapment areas.
FDA-compliant wetted parts make the valve suitable for CIP (Clean-In-Place) and SIP
(Sterilize-In-Place) medical assembly processes.
Aseptic dispense valve wetted components can be made of 316L stainless steel or
PTFE, to conform to biopharmaceutical regulations in medical assembly processes.
Internal threads can be removed to provide a smooth, easily cleaned fluid flow path,
free of entrapment areas and the valve fluid body can be made electro-polished to
increase corrosion resistance.
Aseptic valve shot sizes can range from 0.5 microliter deposits to a continuous flow
rate of 60 milliliters per second. These dispense valves close after each cycle with a
fast, clean cut-off that eliminates drips.
Similarly, aseptic spray valves also feature a fluid flow path that is free of any
entrapment areas—a critical consideration in sterile and aseptic fluid applications
that use low- to medium-viscosity fluids. An aseptic spray valve works best with a
small gauge dispensing tip to produce uniform round spray patterns. Alternatively,
some aseptic spray valves can be fitted with fan air caps for a wider area of coverage.
Aseptic valves and aseptic spray valves offer medical device manufacturers an
accurate, cost-effective coating method that can increase yields, reduce production
costs, and improve process control.
Aseptic valves meet FDA regulations while
providing accurate consistent shots.
The unique design of the aseptic spray
valve is critical for sterile fluid applications.
•Salinesolutions
•OpticalMonomers
•Pillcoatings
•Stentcoatings
•Siliconeoils
•Solvents
•Reagents
•Pharmaceuticalfluids
Compatible Fluids
www.nordsonefd.com 6
If your dispense valves are not cycling fast enough, the valve control system may
not be compatible with the dispense valve.
Most automatic assembly machines use PLCs (Programmable Logic Controllers)
to sequence machine functions, but a PLC’s primary purpose is not to control
dispense valves.
A PLC also may or may not offer online programming of dispensing functions.
Without this capability, entire production lines have to be shut down just to make
simple adjustments to deposit size, and even if a PLC can program valve functions,
the valve may not be within the line of sight of the engineer or operator trying to
adjust it.
A dedicated controller mounted at the dispensing station will simplify initial valve
setup, make it faster and easier to purge the valve after refilling the fluid reservoir,
and allow adjustments to be made and checked “on the fly” without shutting down
the production line. A devoted valve controller with a fast-acting solenoid and a
digital timer can be a simple and cost-effective way to achieve faster cycle times
and more precise control of deposit size. The valve controller can also be interfaced
with the PLC if desired.
Smaller details in the valve system can also make a big difference. A tapered
polyethylene tip, for example, can shorten dispense time by reducing resistance
and providing a faster flow rate than a straight metal tip of the same size. Using a
fluid line with a larger internal diameter is another way to reduce cycle time in
certain applications.
A dedicated valve controller at the dis-
pensing station simplifies setup and
helps valves cycle faster.
Jetting valves can dispense a wide
range of fluids in volumes as small as
0.5 nanoliters at continuous speeds of
up to 1500Hz, or 1500 shots per sec-
ond, with exceptional process control.
4. Is Your Dispensing Line Running as Fast as it Can?
5. Would High-Speed Jetting Fit Your Application Needs?
Non-contact jetting systems are capable of dispensing a wide variety of fluids
at speeds of up to1500Hz, or 1500 shots per second. By combining high speed
with exceptional accuracy, these systems allow medical products to be built more
cost-effectively with consistently high quality.
Additionally, since jet valve systems are non-contact, it is possible to apply fluid in
hard-to-access areas or onto uneven or delicate substrates where dispensing
needles cannot be used.
Jetting can be used with a wide range of fluids. Applications include:
• Syringes • Endoscopes
- Lubricating interiors with - Bonding lenses with optical
silicone oil adhesives
 -BondingneedleswithUV • Teststrips
adhesive - Jetting or dispensing protein
• Bloodbags   solution
- Sealing bags with - Insulin/blood sugar test strips
cyanoacrylate - Veterinarian test strips
7 www.nordsonefd.com
6. Do Your Valves Leak and Drip?
Leaking is a common problem with valves that have complex designs, or seals
andO-ringsthatwearoutovertime.
The most reliable diaphragm designs entirely eliminate the need for seals and
O-rings.Thebestvalveswilleasilyhandlemanydifferentfluidapplications,and
provide tens of millions of cycles without maintenance.
Carefully choosing the valve seat materials will also prevent many problems.
UHMW (Ultra High Molecular Weight) polyethylene, for example, provides excep-
tional wear characteristics and chemical compatibility with a wide range of medi-
cal assembly fluids, keeping the valve system working longer without downtime or
maintenance.
When valves are too large or heavy to be mounted at the dispensing station, extra
time must be spent on design and fixturing. If extra lines and fittings must be
added to transfer the fluid from the valve (where cutoff takes place) to the point of
deposit, it increases the risk of dripping and drooling.
Using a compact, fast-acting valve that is small enough to be mounted directly at
the dispensing station will provide several advantages: greater flexibility in system
design, a neater installation that takes up less space, and a cleaner cutoff.
Using valves small enough to be mounted
at the point of fluid application reduces the
risk of drooling.
A digital controller allows for programmable
settings that allow for consistent, repeat-
able deposits.
7. Is It Difficult to Produce Consistent Shots?
Valves that require time-consuming manual or mechanical adjustments to
establish shot size can make it difficult to dispense a specific amount of fluid.
When several valves are used on the same machine or production line without
the proper control systems, it is nearly impossible to get each valve to produce an
identical shot.
If your valves are taking too long to set up and you cannot obtain consistent
results, a valve system with a dedicated controller is a more efficient approach
to establish shot size and regulate valve operation. Another advantage of using a
controller is that settings can be recorded and saved for the next time that spe-
cific job is run, or after maintenance has been performed.
Valve open time is the most precise way to adjust shot size. With a digital valve
controller, open time can be adjusted in increments as small as 0.001 seconds,
for exceptional control over the amount of material applied.
Onproductionlineswithmultipledispensingstations,usingadedicatedvalve
controller at each station can make it simple to adjust each valve’s open time
independently, and obtain an identical shot from each valve.