Device and Method for Determining Viscosity

Abstract

A device for determining the viscosity of reaction resins is provided. The device includes a sample storage unit with at least two storage containers and respectively a dosing unit, at least one mixing device, a high pressure pump, a temperature-control unit, and at least one capillary with an inlet and an outlet. A pressure measuring device is arranged at least on each capillary's outlet and on the inlet of the first capillary.

Claims

1. A device for determining a viscosity of reactive resins, comprising: a sample storage unit including at least two storage containers and in each case one dosing unit; at least one mixing device; a high-pressure pump; a temperature-control unit; and at least one capillary having an inlet and an outlet, wherein a pressure measurement device is arranged at least at each outlet of the at least one capillary and at an inlet of a first capillary.

2. The device according to claim 1, wherein the dosing unit includes a pump.

3. The device according to claim 2, wherein the pump is a double-piston pump.

4. A method for producing a device for determining a viscosity of reactive resins, the method comprising the acts of: providing an HPLC system, wherein the HPLC system includes a sample storage unit having at least two storage containers and in each case one dosing unit, at least one mixing device, a high-pressure pump, a temperature-control unit, and at least one separating column; replacing the separating column by at least one capillary having an inlet and an outlet; and arranging a pressure measurement device at least at each outlet of the at least one capillary and at an inlet of a first capillary.

5. A method for determining a viscosity of reactive resins, the method comprising the acts of: dosing and delivering a curable resin from a first storage container of a sample storage unit by way of a first dosing unit; dosing and delivering a curing agent from a second storage container of the sample storage unit by way of a second dosing unit; mixing the curable resin and the curing agent in a mixing device; setting a predefined volumetric flow rate of the mixture of the curable resin and the curing agent by way of a high-pressure pump; controlling a temperature of the mixture of the curable resin and the curing agent; delivering the mixture of the curable resin and the curing agent through at least one capillary having an inlet and an outlet; arranging a pressure measurement device at least at each outlet of the at least one capillary and at an inlet of a first capillary; and determining a pressure difference which arises between two pressure measurement devices at a given volumetric flow rate of the mixture of the curing agent and the curable resin.

6. The method according to claim 5, the method further comprising the act of: after the throughflow of the mixture of the curable resin and the curing agent, freeing the at least one capillary of residues by dosing and delivering from a third storage container through the at least one capillary a solvent for the cured resin.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0023] FIG. 1 is a schematic illustration of a device for determining the viscosity of reactive resins according to an advantageous configuration of the invention.

DETAILED DESCRIPTION OF THE DRAWING

[0024] The present invention will be discussed in detail on the basis of an exemplary embodiment. To this end, only those aspects of the invention which are essential to the invention are illustrated in FIG. 1. All other aspects have been omitted for the sake of clarity.

[0025] The device 1 according to an embodiment of the invention includes a sample storage unit 2 having four storage containers 3a, 3b, 3c, 3d. The storage containers 3a, 3b, 3c, 3d are each adjoined by a dosing unit 4 by way of which a corresponding quantity of a stored substance can be dosed and delivered. Needle valves 5 and backflow prevention valves 6 prevent the substances from flowing back.

[0026] The substances delivered from the storage containers 3b and 3c and from the storage containers 3b/3c and 3d are mixed with one another in mixing devices 7a and 7b, respectively.

[0027] The sample storage unit 2 and the mixing devices 7a, 7b are situated in the so-called low-pressure region of the device 1. This means that here substantially no pressure increase has taken place, and the substances and mixtures are generally at normal pressure.

[0028] The low-pressure region is adjoined by a high-pressure region. The latter region is reached after a high-pressure pump 8 has been passed through.

[0029] By way of example, the device 1 contains four capillaries 10 in the high-pressure region. Each capillary has an inlet 11 and an outlet 12. A pressure measurement device 13 is arranged at each outlet 12 of each capillary 10. A pressure measurement device 13 is likewise also arranged at the inlet 11 of the first capillary 10. A pressure measurement device 13 is therefore present in each case at the inlet 11 and at the outlet 12 of each capillary 10. This allows a pressure difference between the inlet 11 of a capillary 10 under consideration and the outlet 12 of said capillary 10 to be measured. It is likewise possible to determine a pressure difference over multiple capillaries 10.

[0030] The device 1 further includes a temperature-control unit 9 by way of which all the capillaries 10 can be brought to a desired temperature.

[0031] Connected downstream of the capillaries 10 is a collecting container 14 in which substances delivered through the capillaries 10 are collected for subsequent disposal.

[0032] The functioning of the device 1 will be explained on the basis of the following example: [0033] The storage containers 3a-3d are filled as follows: [0034] Storage container 3a: Solvent for a reactive resin; [0035] Storage container 3b: Curing agent; [0036] Storage container 3c: Separating agent; and [0037] Storage container 3d: Curable resin.

[0038] A predefined quantity of curing agent is dosed and delivered from the storage container 3b via the adjoining dosing unit 4. A predefined quantity of curable resin is dosed and delivered from the storage container 3d via the adjoining dosing unit 4. The curable resin and the curing agent are mixed with one another in the mixing device 7b and delivered in the line to the high-pressure pump 8.

[0039] A predefined volumetric flow rate of the mixture of curable resin and curing agent is set by way of the high-pressure pump 8.

[0040] After passing through the high-pressure pump 8, the mixture of curing agent and curable resin is delivered through the capillaries 10 at constant temperature, and this is set and maintained by the temperature-control unit 9. The pressure measurement devices 13 allow a pressure difference to be determined at an arbitrary location between the capillaries 10.

[0041] If a pressure difference which arises between two pressure measurement devices 13 at the given volumetric flow rate of the mixture of curing agent and curable resin is then determined, it is then possible from this for the viscosity of the reactive resin, that is to say of the mixture of curing agent and curable resin, to be determined via the Hagen-Poiseuille law.

[0042] Also, by way of tests and a comparison of the determined parameters, it is possible for the time which a reactive resin is still sufficiently free-flowing before it has cured completely to be determined. These findings are helpful for the process control in an injection process for the reactive resin under consideration, for example in an RTM process.

[0043] After the viscosity measurement has ended, it is possible for a solvent for the reactive resin to be delivered from the storage container 3a, for example, and pumped through the capillaries 10. This prevents blockage of the capillaries 10 with resin and allows repeated use of the capillaries 10.

[0044] It is equally also possible to supply a separating agent from the storage container 3c.

LIST OF REFERENCE SIGNS

[0045] 1 Device for determining the viscosity of reactive resins [0046] 2 Sample storage unit [0047] 3a Storage container [0048] 3b Storage container [0049] 3c Storage container [0050] 3d Storage container [0051] 4 Dosing unit [0052] 5 Needle valve [0053] 6 Backflow prevention valve [0054] 7a Mixing device [0055] 7b Mixing device [0056] 8 High-pressure pump [0057] 9 Temperature-control unit [0058] 10 Capillary [0059] 11 Inlet of the capillary [0060] 12 Outlet of the capillary [0061] 13 Pressure measurement device [0062] 14 Collecting container

[0063] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.