"Gasketing" technology has been in development at Cannon since 1994. Three and a half years is a significant period in which to set up and improve a reliable and cost effective solution for manufacturing polyurethane gaskets; a team of Cannon people dedicated their time throughout this period to presenting the market with a well proven solution.
"Gasketing" technology is also known, from the material point of view, as "Foam in Place Material" (FIPM) technology. A Foam-In-Place Material is a foam which is applied to a substrate as a liquid or semi-liquid and cures to a solid on the substrate. The foams can be single-component, such as hot melt or urethane moisture cure; or two component, such as polyurethane or silicone. Single-component foam gaskets are produced by mechanically mixing air into the resin, whilst two-component gaskets are formed using the production of gas by a "blowing" reaction in the blended material. In both cases, the liquid, or semi-liquid material must be applied to the substrate very accurately since curing will occur wherever the material is applied, in most cases robotically.
FIPM (Foam-In-Place Material) products are used as seals or gaskets. These terms are often interchangeable; a seal however, usually implies that the surfaces separated by the material do not come apart, while a gasket implies that the surfaces can be opened and closed. Both seals and gaskets can be used to insulate, dampen out vibration or sound, and prevent the passage of air, particles, or water. These functions find application in many industries and with many products. Examples can be found in automotive sub-assemblies, electrical boxes, white appliances, drum lids, filters, light fixtures, etc.
FIPM products are applied robotically and not manually, so their use is usually accompanied by a reduction in labour costs. Since labour costs are often a high proportion of the total cost of a seal or gasket, the overall cost of the part can be reduced dramatically. FIPM products can also offer superior performance in that the resulting seal or gasket is continuous; ie, there are no seams to pose the possibility of leakage. In addition, since the material cures on and adheres to the substrate, no separate adhesive is required.
FIPM products offer economic advantages over other gaskets, particularly where compression and recovery are desirable. The economic benefits are achieved through reduced labour, stock, and material costs. When compared with one-component moisture-cure FIPMs or hot melts, they are superior in performance as well.
FIPM systems can replace die-cut, strip, or moulded gaskets. Strip gaskets are straight lengths of material with a uniform cross-sectional dimension. They are usually supplied in rolls with a pressure-sensitive adhesive (PSA) and release paper on one side. Strip gaskets are cut to length, applied to the part and have joints where the ends meet. When the strip gasket is a foam material, the three sides without adhesive have exposed cells.
Die-cut gaskets are cut from sheets of gasket material by stamping the desired shape of the gasket with a metal die. Again, the cut sides have exposed cells if the material is a foam.
Moulded gaskets are produced by foaming and curing the material in a fully-enclosed mould. When the material is a foam, all sides usually have an intact exterior surface (skin).
Other benefits of the Foam-In-Place Material technology when compared to the use of strip gaskets are:
- the material sets and cures at room temperature; this means that the process does not require any additional heat whilst heat-sensitive substances can be used with no problems;
- the continuous bead eliminates or minimises leakage which can occur at the connection points of strip gaskets;
- it is a COST-EFFECTIVE alternative to standard gasket materials because all costs for glue in place gaskets are eliminated as well as the stocking of a variety of gasket sizes;
- the FIPM technology has been well proven over a period of many years, especially in Europe and the USA.
The automated system offered by Cannon for a complete gasket production cycle consists of a "Cannon b2G Plus" metering unit, a manipulator, pick-and-place equipment and all safety features as required by ED and EN775 norms (Manipulating Industrial Robots Safety Norms).
Cannon has designed and built a new dosing unit for micro-shots with a closed-circuit thermal control station which allows accurate monitoring of the temperature of the components; insulated piping and jacketed tanks equipped with agitators ensure the best conditions for homogenisation and thermal control.
A manipulator specifically designed for the gasket application has been incorporated within the range, with linear and circular controlled movements of "X -Y" axes and a pneumatically operated "Z" axis (50 mm, which can be manually placed at a distance of 100 mm by means of a slide).
The loading capacity of the manipulator is 20 Kp and the working area can reach: X=2500, Y=1200, Z=100 + 50 mm. The maximum velocity of the manipulator is 0.6 m/sec in approach, with a maximum working velocity of 0.3 m/sec when pouring. The minimum bend radius is 10 mm.
A new mixing head has been designed, to accommodate the stringent requirements of gasket production allowing flow rates from 0.1 gr/sec upwards. The mixing head is fitted with a purpose built drip-stop system controlling both the start/stop pouring cycles and the lay down of the foam.
The applications in which the "Cannon b2G Plus" system can be successfully used are many. Just some of them are detailed here:
- heating ducts;
- head and tail lights;
- steering column fire wall plate;
- air filter housing;
- auto bodies;
- fire wall plates.
- filter gaskets;
- interior air filters (residential, commercial, white room,...).
- electrical boxes;
- electronic systems;
- electric control cabinet doors.
- lamp housings and fixtures.
Container lids & packaging
- drum lids.
- cabinets and housings;
- rear and internal panels;
- cover panels.