Title of Invention

A NOZZLE AND A METHOD FOR FEEDING THERMOSETTING PLASTIC AND HACDENER

Abstract (A NOZZLE AND A METHOD FOR FEEDING A MIXTURE OF THERMOSETTING PLASTIC AND HARDENER) The present invention relates to a nozzle for feeding a mixture of thermosetting plastic and hardener from a mixing chamber, to which feed lines for supply of thermosertable plastic as well as the hardener are connected, characterized in, that the mixing chamber communicates with at least two beam channels (14) having a diameter (b) of 0.5-1.5 mm, which converge in an angle (a) of 70-140° towards a point outside the nozzle. The present invention also relates to a method for feeding a mixture of thermosetting plastic and hardener.
Full Text The present invention refers to a nozzle and a method for feeding a mixture of thermosetting plastic and hardener from a mixing chamber, to which feed lines for supply of thermosettable plastic as well as hardener are connected.
Thermosetting plastics, for instance polyester, urethane and epoxy can be mixed in fluid state and are fed out by means of a spray-gun, which is equipped with a nozzle providing a defined spray image. In this way, the plastic can be applied, e.g. in a mould for casting plastic products.
Generally, solvent agents are needed as gelling agent in the plastic, to allow it to receive correct viscosity for spraying through the nozzle.
This known technic involves drawbacks, as one generally has to calculate with a certain amount of spillage, when plastic due to an uncontrollable spray image wrongly lands in the mould or next to it. This spillage results in consuming an unnecessary large amount of plastic and also solvent agents. For environmental reason such a spillage should be minimized. Furthermore, it becomes difficult to maintain an even and high production quality, if one does not have control over the amount of plastic fed out per unit area.
The amount of the spillage will not be reduced, if the spray-gun, when spraying according to prior art, is moved closer to the surface to be covered with the thermosetting plastic, as drops of thermosetting plastic hitting a surface with a great force, tend to brake into smaller drops, which rebound back towards the spray-gun.
An object of the present invention is therefore to provide a nozzle of a type described initially, which makes it possible to hold the spray-gun closer to the surface to be covered without risk for back-spray, and which provides a stable and well-defined spray image with distinct edges.

For this object the nozzle according to the invention is characterized in that the mixing chamber communicates with at least two beam channels having a diameter of 0.5-1.5 mm, which converge in an angle of 70-140" towards a point outside the nozzle. The method according to the invention is characterized in that the mixture of plastic and the hardener has a viscosity between 150 and 75,000 cpois, and that the mixture is extruded from the nozzle with a pressure of 75 to 100 bar. Through the present design of the nozzle small plastic drops having unifomi size are produced, which move with low speed towards the surface to be covered. In this way a surprisingly well-defined spray image is obtained, without risk for back spray.
Accordingly, the present invention provides a nozzle for feeding a mixture of thermosetting plastic and hardener from a mixmg chamber, to which feed lines for supply of thermosettable plastic as well as the hardener are connected, characterized in, that the mixing chamber communicates with at least two beam channels having a diameter (b) of 0.5-1.5 mm, which converge in an angle (a) of 70-140" towards a point outside the nozzle.
Accordingly, the present invention also provides a method for feeding a mixture of thermosetting plastic and hardener via a nozzle that includes a mixing chamber, to which feed Imes for supply of thermosettable plastic as well as hardener are connected, and which chamber communicates with at least two beam channels (14) characterized in that the at least two beam channels have a diameter (b) of 0.5-1.5 mm, which converge in an angle (a) of 70-140° to a point outside the nozzle, and that the mixture of plastic and hardener has a viscosity of between 150 and 75,000 cpois, and that the mixture is extruded from the nozzle with a pressure of 75 to 100 bar.
The invention will be described with reference to an embodiment, which is shown on the
enclosed drawings, wherein:
Fig. 1 shows a section along Ime I-I in Fig. 2 through a nozzle according lo the
invention,
Fig. 2 is a bottom view of the nozzle, and
Fig. 3 shows the nozzle schematically in perspective under use.


The nozzle in Fig. 1-3 is made of a metallic cylinder 10 with mounting flange 11 formed through turning. The end of the cylinder closest to the flange exhibits a concentric turned space 12. The opposite end of the cylinder is provided with two towards each other inclining plane surfaces 13, sloping towards the longitudinal axis of the cylinder, with a mutual divergent angle. The angle between said plane surfaces can be between 70° and 140°.
A beam channel 14 is bored in each plane surface 13, substantially perpendicular to each plane surface. The two channels 14 are consequently drilled with such a mutual angle a that they converge towards a point outside the nozzle. The angle a between both beam channels is between 70° and 140° and channels extend into the space 12. Each channel 14 has a diameter b of 0.5-1.5 mm and the distance a between the downstream mouth of the beam channels is 2-5 mm.
The nozzle is used mounted on the outlet from a mixing chamber on the spray-gun, which mixing chamber is fed with plastic and hardener via separate feed channels. Mixture of plastic and hardener should have a viscosity between 150 and 75,000 cpois and feed pressure is suitably between 75 and 100 bar.
The nozzle with this equipment can be used, e.g. in combination with the nozzles for feeding cut reinforcement fibres, to spray composite laminate directly in a mould, for example, by means of an industrial robot. The nozzle can also be used without addition of fibres, to cover a surface with a layer of thermosetting plastic, for example a floor area. The spray image has a narrow elliptical form with distinct edges.
The invention is not limited to the above described embodiment, but variants may occur within the scope of the

attached claims. For instance the nozzle may be equipped with more than two spray channels. By using more spray channels the spray image can be affected.


WE CLAIM:
1. A nozzle for feeding a mixture of thermosetting plastic and hardener from a mixing chamber, to which feed lines for supply of thermosettable plastic as well as the hardener are connected, characterized in, that the mixing chamber communicates with at least two beam channels (14) having a diameter (b) of 0.5-1.5 mm, which converge in an angle (a) of 70-140" towards a point outside the nozzle.
2. The nozzle according to claim 1, wherein the distance (a) between the downstream outlets of the beam channels (14) is 2-5 mm.
3. The nozzle according to claim 1, wherein each beam channel (14) extends towards and discharges substantially perpendicular to a plan surface (13).
4. The nozzle according to claim 1, wherein the surfaces (13) are shaped with mutual divergent angle of 70-140 towards each other inclining plan.
5. A method for feeding a mixture of thermosetting plastic and hardener via a nozzle that includes a mixing chamber, to which feed lines for supply of thermosettable plastic as well as hardener are connected, and which chamber communicates with at least two beam channels (14) characterized in that the at least two beam channels have a diameter (b) of 0.5-1.5 mm, which converge in an angle (a) of 70-140° to a point outside the nozzle, and that the mixture of plastic and hardener has a viscosity of between 150 and 75,000 cpois, and that the mixture is extruded from the nozzle with a pressure of 75 to 100 bar.
6. A nozzle for feeding a mixture of thermosetting plastic and hardener substantially as herein described with reference to the accompanying drawings.

7. A method for feeding a mixture of thermosetting plastic and hardener substantially as herein described with reference to the accompanying drawings.


Documents:

1765-mas-1996 abstract.pdf

1765-mas-1996 claims.pdf

1765-mas-1996 correspondence others.pdf

1765-mas-1996 correspondence po.pdf

1765-mas-1996 description (complete).pdf

1765-mas-1996 drawing.pdf

1765-mas-1996 form-1.pdf

1765-mas-1996 form-26.pdf

1765-mas-1996 form-4.pdf

1765-mas-1996 others.pdf

1765-mas-1996 pct search report.pdf

1765-mas-1996 petition.pdf


Patent Number 197932
Indian Patent Application Number 1765/MAS/1996
PG Journal Number 10/2005
Publication Date 25-Mar-2005
Grant Date 02-Feb-2006
Date of Filing 07-Oct-1996
Name of Patentee M/S. APLICATOR SYSTEM AB
Applicant Address METALLVAGEN 6 S-435 33 MOLNLYCKE,
Inventors:
# Inventor's Name Inventor's Address
1 KJELL SAND, VITLINGGATAN 8 S-421 58 VASTRA FROLUNDA,
PCT International Classification Number B05B/7/08
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 9503304-9 1995-09-25 Sweden