Tuesday 27 November 2012

Fine Mist Precision Spray Valves

Spray valves for coating, marking, lubricating and bonding.

High precision spray valves are used in production and assembly processes to apply a wide range of low to medium viscosity fluids, adhesives, inks, paints, oils, primers, conformal coatings and activators.

The compact spray valve takes a direct pressurised feed of liquid from a standard pressure pot, cartridge reservoir or a syringe barrel.  A separate air feed to the spray nozzle atomises the fluid to create the fine spray. Both fluid feed and atom air are timed to create pulses of spray. The fluid pressure, atom air pressure can be adjusted to turn the output from a jet to a fine mist spray.

Spray valves are available with 3 different size spray nozzles and in either round pattern spray or fan spray nozzles. A fan spray nozzle creates an oval type pattern that benefits applications where a wider coverage is required. A small nozzle can achieve a spray diameter of less than 7mm. 

To control the spray valve, the TS500R controller is used. This has an adjustable digital timer to make rapid repeat deposits or a steady mode for continuous spray. It allows the timer to be set to control pre-spray atom air duration, dispense time and post-spray atom air duration. So the pre-spray clears the nozzle, the spray deposit is made then the post-spray clears the nozzle. The TS500R allows the atom air pressure to be adjusted from a jet to a fine mist. The TS500R has digital LCD timer display, a timer memory storage for 10 programs and an I/O port for direct link to a PLC. It also is supplied with a foot switch for manual control.

Our range of pressure pots are in sizes 0.5 litre to 19 litre. All valve systems supplied, (valve, controller and pressure pot) come with fluid lines and connector fittings.

For a simple and cost effective method of spraying fluids whether as part of a production cell, assembly line or by hand at a workbench, use the spray systems from Adhesive Dispensing Ltd, with full technical support and assistance. All products are CE certified and covered by a 1 year warranty.

Sunday 23 September 2012

Adhesive Dispensing Ltd now on Facebook and Twitter

We will be using Facebook to announce new products, special offers, technical bulletins, etc. 

Some of us at Adhesive Dispensing will be using Twitter to release links to blogs and technical articles for application solutions, etc.

The Facebook site also will feature a small selection of products that can be ordered online.

Please click below and sign up to us to receive regular updates. 


Adhesive Dispensing Ltd move to Bletchley Park.

September 2012, Adhesive Dispensing Ltd move to the Science & Innovation Centre at Bletchley Park, Milton Keynes, Buckinghamshire. 

This historic site was top secret during WW2 and home to the Bletchley code breakers. It is now a tourist attraction as well as using the old buildings as refurbished offices and light production facilities.

Situated at A Block, the new location allows us to hold even more stocks of fast moving consumable parts such as syringe barrels, dispensing tips, nozzles and cartridges.

We've added 2 new phone numbers. +44 (0) 1908 363432 and +44 (0) 1908 363433. All other contact numbers remain the same.

Sunday 29 January 2012

Syringe Barrels for Air Powered Dispensers

700 series syringe barrel components are compatible with all air powered dispensers, syringe guns or our hand plunger rods. These high quality barrels are suitable for use with most fluids from watery liquids to thick pastes. In sizes 3cc, 5cc, 10cc, 30cc, 55cc and in natural (clear), amber (UV tint) and black (UV block). 700 series air-powered barrels are safe to 100 psi and are certified silicone free. Barrels are available with a range of wiper pistons, air adapter assemblies, o-rings, cap seals and accessories.

Improving Grease Dispensing Process

Automotive parts manufacturers as well as other manufacturers have been challenged with dispensing liquids and pastes while assembling components in their facilities throughout the world. Part of the manufacturing process has included the application of small quantities of grease into these assemblies. Initially the parts manufacturers gave little thought to the dispensing of grease. Often the preferred technology was a thin stick, or a small brush. The amount of grease applied varied widely depending on the tool used to apply the grease and the operator. Contamination of the grease was another concern as the supply of grease was usually an open cup or can that was left open to collect any debris that happen to be in the air.
These two issues became costly to the manufacturers. When too much grease was applied, it tended to end up on other surfaces within the assembly creating performance and warranty problems. Additionally, too much grease needlessly added un-intended additional costs. Too little grease caused assemblies to fail prematurely creating additional warranty issues. Debris found in the grease also had a negative impact on the performance and longevity of the assembly.
As different manufacturing processes have been examined to improve product quality and reduce operating costs, manufacturers have tested several different processes to improve the dispensing of small, precise amounts of grease onto their assemblies. Several manufacturers have reported, they have been successful in identifying several different technologies that meet their requirements for improvement. These different technologies either include the use of valves as part of their automated process improvements or for less automated and less precise dispensing, the use of time/pressure dispensers has been employed.

What Are the Factors To Consider
Grease is lubricating oil that has had a thickening or gelling material added to cause the grease to stay where it was deposited and to release the oil onto the surfaces as intended. Grease can be found in various thicknesses ranging from under 400 Cps (low viscosity) to over 100K Cps (high viscosity). Therefore different dispensing technologies are required when addressing different viscosities.
Several dispensing factors need to be considered when dispensing fluids and these are equally true when dispensing grease. Dispensing tip size, dwell time, and pressure are the main factors to be considered. Additional factors to be considered are, the type of packaging the grease is supplied from, the viscosity of the grease to be dispensed, and some types of grease may contain a filler material that may need to be considered.
Different applications will require different techniques and equipment to meet expectations. Some of the factors to consider are shot size, shot size repeatability, shot frequency, level of automation, and the length of the overall project life.
When considering the correct dispensing tip size, the following factors need to be considered. Dispensing tip inner dimension (ID) should be a minimum 25% smaller than the desired dot size. This will allow for better material control when producing very minute dot sizes. Keep in mind when dispensing material filled grease, the tip ID needs to be a minimum of 3 times the material particle size. This consideration is important in eliminating tip clogging. Filled materials have a greater tendency to clog and using a larger tip will eliminate this concern. When dispensing materials with higher viscosities, the use of a straight walled (cannula) dispense tip may be ineffectual and a smooth flow taper walled dispense tip should be considered. Taper tips are designed to have the same ID at the outlet point as a straight walled dispense tip but reduce resistance and material separation due to the tapered wall. The taper tip will give better accuracy and repeatability when dispensing grease. When dispensing less viscous grease a straight walled dispense tip may be the better selection.
Dwell time and pressure are linked as they are usually controlled by the same device. Increasing the dwell time or pressure will increase the dispensed amount. Decreasing the dwell time or pressure will decrease the dispense amount. This rule is equally true when using a time/pressure controller with a valve or when using a manual held plunger with a syringe.
The type of packaging needs to be considered when addressing the dispensing of grease. Grease is available in many different types and sizes of packaging from very small syringes to large barrels. Depending on the dispensing method to be used, care will need to be used while handling and possibly repackaging of the grease. With the goal of increasing accuracy while dispensing small dot sizes, great care will be required to eliminate all air from the grease as air pockets will have a negative effect on accuracy and repeatability of the deposit size.
While there is a cost associated with using smaller packaging many companies elect to use smaller pails or cartridges when concerned with accuracy to eliminate the introduction of air pockets into the process. Just with a syringe, manual syringe dispensing may be acceptable when applying small dots or lines of grease without care for repeatability. The use of a syringe barrel with a piston and manual plunger will allow an operator to place dots and lines. Unfortunately this technique is not ergonomically friendly to the operator causing fatigue. The fatigue increases the difficulty to the operator while dispensing the same dot size or line thickness multiple times. After a short time the operator becomes unable to repeat the dots or lines.

Time and Pressure
Many of the grease dispensing applications can be addressed using the Time/Pressure Dispensing (TPD) systems. The TPD is acceptable when the application does not require the speed or accuracy of automation. The TPD consists of an electronic dispenser, syringe head adapter assembly and syringe assembly. The dispense tip is selected based on material and dot size. The syringe head adapter assembly connects the electronic dispenser to the syringe. When activated the dispenser releases a measured amount of air pressurizing the syringe head assembly and syringe of material. Naturally the material in the syringe wants to escape this pressure causing the material to flow through the dispense tip.
The TPD method is the most widely used method. The primary advantages of TPD are it is an inexpensive dispensing method and that it is simple to set up and use. The disadvantages of TPD relate to consistency. When the syringe is full of material and the operator starts the dispensing process, there is very little air in the syringe as compared to the grease. During this time the dispensing is very repeatable because the grease does not compress when pressure is applied. As the grease leaves the syringe and is replaced by air, the repeatability falls off. This is caused when air pressure is applied, the air does compress while under the same situation the grease does not. When the compression takes place the dot sizes become inconsistent.

Valve technology is the most accurate and repeatable dispensing method while dispensing grease. For this discussion applications will be divided into two classifications - Higher flow/ larger dots and Lower flow/ smaller dots.
Spool valves are capable of dispensing materials ranging from 5K Cps to 3000K Cps and are perfectly suited for dispensing grease. Spool valves are selected when dispensing dots at a high rate of speed. When input air pressure is applied the spool assembly drives forward opening the material path, allowing material to flow from the material inlet to the material outlet. Closing off the input air causes the spring to reverse the spool assembly closing off the flow of material. This design also ensures a quick “fail-safe” shut off of material flow.
When manufacturing management determines automation is required many applications require the use of spool valves. Many spool valves are capable of 400+ dots per minute when part of an automated system. The spool valves deposits small dots at high speed with excellent repeatability. Spool valves can be found dispensing grease in small mechanical assemblies used in industrial and automotive applications.
Auger valves are capable of dispensing materials ranging from 5K Cps to 1300K Cps and are also suited for dispensing grease. The auger valve employs a feed screw that when rotated in one direction very precisely creates a shot and when reversed, creates such back to eliminate dripping. Spool Valve shot size is determined in-part by the material dispensed and the size of the dispense tip. Some auger valves create 0.010” (0.25 mm) shots and are extremely repeatable. These valves are found in automated systems where electro mechanical or electronic assemblies are manufactured. While the auger valve is slower than the spool valve, it is the valve relied on for the smaller more precise shots. When dispensing grease, delivering the correct amount of grease to the correct location is the primary goal while minimizing costs. Several different approaches can be taken to satisfy this goal.

Using suitable dispensing tips for handling Cyanoacrylate glues and adhesives.

Cyanoacrylate (CA) adhesives and glues will generally bond rubbers, metals, certain plastics, card, felt and other materials in seconds. When dispensing these "superglue" adhesives, great care must be taken to handle correctly to avoid damage to persons or parts.

One frustrating area for concern is usually where the needle tip clogs during a dispensing process. To avoid clogging, try to use Teflon, Teflon Lined or Polypropylene plastic tips. Metal tube tips do not work as efficiently and therefore can be a false economy. These lower cost tips might need to be replaced much more frequently than Teflon, Teflon Lined or Polypro tips. With small bore metal tips, the tubes can block due to the moisture content on the metal surface which the CA adhesive will quickly react to. Small bore metal tips can block quite quickly.

Use Teflon Tips in either 0.5" or 2" long tubes here.
Use Teflon-Lined Tips in either 0.5" or 1" long tubes here.
Use Polypro Tips in either 0.5" or 1.5" long tubes here.

We recommend using the above tips for longer 'clog-free' dispensing but it is also worth considering the quality, age and grade of the Cyanoacrylates being dispensed and how and where they are stored. Also, changes in temperature/ humidity, etc can affect the performance of these glues. We can provide samples of both suitable tips and CA adhesives.

Saturday 28 January 2012

Hot melt dispensing systems

High performance Hot Melt glue dispensing systems for manual hand controlled or fully automated use. A range of robust melter units with heated hoses, pattern controllers, nozzles and accessories. For product assembly or carton packaging as well as many other applications.

THERMADOSE® Positive-displacement, all-electric Hot Melt systems are designed to provide the ultimate in temperature controlled thermoplastic delivery and dispensing for industrial applications using pressure sensitive adhesives, contact adhesives, waxes and sealants. 

Machine options are available for non-adhesive processing applications that require ultra-clean delivery, these systems are designated as “NA.” Products are RoHS compliant and CE approved.

Selecting a hot melt system.  A simple six step approach in selecting a complete hot melt system that help make the right decision for your application. And of course our engineers are available to discuss your application in more detail by phone or email.

Knowledge Base

As part of our new website www.adhesivedispensing.net, we've added a knowledge base section. This allows customers to search a growing database of solutions, datasheets, graphics gallery, user guides, applications and part codes. Find alternative compatible products to current major brands in parts comparison. Search for answers to application problems. This section to our website is being added to daily by our application specialists.

Repackaged Dispensing Components

Put simply, repacking is a contract service that allows us, Adhesive Dispensing Ltd, to provide you with your specified adhesives, pastes, gels, epoxies, coatings, primers, inks, silicones, RTVs, etc in ready to use industrial dispensing components.

We can take your tins, drums, pails, tubes and packs of manufacturers supplied materials as free issue supply and provide them back to you filled in convenient 'air-free' cartridges, syringes, dual cartridges, hinge-packs, Techkit/ Semkit cartridges, etc. Or using our relationships with material manufacturers and formulators, we can also supply the same materials with us buying them direct and in many cases using preferential pricing.
Eliminate filling syringes by hand. Remove the labour costs of mixing and blending epoxies by hand. Receive filled cartridges ready to use. Get the exact mix ratio, the right volume, the perfect packaged system every time.

No mess, No Waste ... No Problem !   

Friday 27 January 2012

Adhesive Dispensing Systems

Global supplier of adhesive dispensing equipment and accessories, manual syringe guns, cartridge guns for Techcon and Semco cartridges, 2, 3 and 4 axis dispensing robots, micro syringe dispensing machines, hot melt packaging solutions, meter mix equipment, metering valves, pressure tanks, syringe barrels, tips, epoxy cartridges, nozzles, luer bottles, felt pens, industrial fittings, fluid lines, static mixer nozzles, adhesives and fume extraction units from Adhesive Dispensing Limited in Milton Keynes, Bucks, UK.

Providing adhesive dispensing solutions for manufacturers & assemblers in most manufacturing industries including aerospace, electronics, medical device, automotive, defence, engineering shops, construction, packaging, food processing & speakers/ audio.