Gradient-oven

The gradient-oven is a test apparatus for evaluating the baking and drying behavior of liquid coatings, powder coatings, resins, plastics, etc. A production baking process can be simulated by programming heat-up speed, baking temperature and time.

• Saves time and energy
• Generates various curing temperatures on one panel
• Simulates the temperature profile of a production oven in the laboratory

Technical Specification for Gradient-oven
Temperature	Connection for temp-gard oven Recorder
86 - 482 °F (30 - 250 °C)	included
86 - 608 °F (30 - 320 °C)	included
Voltage	230 V, 50/60 Hz
Power Comsumption	3400 VA
Heating Surface	20.4 x 3.9 in (520 x 100 mm)
Test Surface	19.6 x 2.7 in (500 x 70 mm)
Heating Elements	45 pcs.
Pressure Plattform	reciprocates automatically (16 kp) for insertion and removal of panel
Linear Gradient	max. temp. difference betw. 86 and 482 (608) °F: 180 °F; 30 and 250 (320) °C: 100 °C
Step Gradient	with 2, 3 or 4 steps: max temp. difference betw. 2 steps: 50 °C (90 °F)
Heat-Up-Speed	2 °C to 30 °C/min, programmable (3.6 °F/min to 54 °F/min)
Baking Time	in sec. and min.
Memory	max. 10 gradients
Accuracy	control accuracy of the heating elements: < 3.6 °F (< ± 2 °C) surface temperatures on 0.8 mm test panels from element 3 to 43: to 392 ° ± 3.6 °F (to 200 ° ± 2 °C) to 482 ° ± 5.4 °F (to 250 ° ± 3 °C) to 608 ° ± 9.0 °F (to 320 ° ± 5 °C) measu
Dimensions	18 x 28 x 23 in (465 x 720 x 595 mm)
Weight	110 lbs (50 kg)
Comes complete with: gradient-oven exhaust tube 1 pc. glass plate 25 pcs. test panels 25 pcs. marking strips 1 set of tools gradient-oven PT-2610 with optional printer Cat. No. PT-2630

Test Panel with Marking Strip

Application Device

Printer with Paper Types

Portix

Accessories Gradient-oven
For flat bed printer, Cat. No. PT-2630
For flat bed printer, Cat. No. PT-2630; for printing reports; Set of 100 sheets for 200 reports
For flat bed printer, Cat. No. PT-2630; for printing panel marking strips; Set of 100 sheets for 200 marking strips
To facilitate application of powder
For gradient-oven, Cat. No. PT-2600 to PT-2610 to protect heating bank
For gradient-oven (old model black), Cat. No. PT-2611 to PT-2617 to protect heating bank
For application of samples for the gradient-oven; made of ST 14 O 5 steel; dimensions: 568 x 98 x 0.8 mm (22.36 x 3.86 x 0.03 in); Set of 100
Solid aluminum construction, 6 knurled screws for secure clamping of test panel during paint application, free floating slide jig holds film applicator; Recommended film applicators PA-2056, PA-2057
For gradient-oven, Cat. No. PT-2600 to PT-2610; incl. accessories
Length 2.5 m (98.4 in.); ø 80 mm (3.1 in.)
Self-adhesive strips for test panels, Cat. No. PT-2623; Set of 100
Measuring Range	-30 - 400 °C (-22 - 752 °F)
Target	5 mm diameter at a distance of 40 mm
Resolution	0.1 °C
Dimensions	7 x 2.5 x 1.5 in (175 x 60.5 x 35.5 mm)
Weight	270 g (0.6 lbs) incl. battery
Uncertainty	1 °C ± 1 digit; at e 1 and Tu = 23 °C
Comes complete with: Portix: Portix infrared thermometer; NiCrNi connection; Adaptix-C file transfer software; 9 V alkaline battery; Carrying case

Gradient-oven Applications

The gradient-oven saves time and money in R & D as well as QC testing of raw materials (e.g. additives, pigments, resins, and coatings). It allows to simulate the conditions of a production oven in the laboratory by downloading temperature profiles recorded with our temp-gard oven recorder. Thus, material properties, baking conditions and production ovens can be optimized for best quality and economical operation.

Temperature stability of iron oxide pigments:

Depending on the chemical composition the various iron oxide pigment types show different temperature stabilities:

                               Temperature stability
Red iron oxide:            up to approx. 1200 °C (2192 °F)
Yellow iron oxide:        up to approx. 200 °C (392 °F)
Brown iron oxide:         up to approx. 180 °C (356 °F)
Black iron oxide:          up to approx. 180 °C (356 °F)

In the following example, two yellow iron oxide pigments with different temperature stabilities were tested in a silicone polyester system.

Whenever low temperature stable iron oxide pigments are used in baked coating systems or composite materials, it is very critical to define the production window in which the baking temperature will not affect the mechanical, chemical or the optical specifications.

The high repeatability and reproducibility of the gradient-oven helps to accurately determine the tolerance range. Depending on the gradient-oven type coatings can be tested with temperatures up to 320 °C. By applying the coating system with a duplex frame applicator two different coating systems can be applied simultaneously on the same panel. This makes the comparison easier saving application time and material cost.

Results:

Pigment type A starts showing a discoloration at 210 °C, while pigment type B remains color stable up to 250 °C. At temperatures over 280 °C both pigments can no longer be used. The gradient-oven saves you time and money because the testing is considerably shorter than using a convection oven. In addition, the high precision and tight temperature control of the individual heating elements guarantee you reliable and repeatable results – test after test.

Temperature influence on silicone additives

Inter-coat Adhesion
In a multi-layer system, like automotive coating systems, silicone additives can diminish the inter-coat adhesion. Silicones have the tendency to migrate to the surface. As they don' t have reactive groups, they are not integrated in the coating surface of the first layer. Consequently, they would migrate into the surface of the 2nd layer during application. This type of behavior is known as silicone migration.

If the 1st coating layer is baked, reactive groups are created and the silicone additive gets embedded into the resin system of the 1st layer. The capability to migrate is gone which can result in a diminished inter-coat adhesion. The temperature stability of silicones varies depending on how they were modified. The gradient-oven can test on one panel the influence of temperature.

Test procedure:

Two differently modified silicones were tested:
Sample A: BYK®-310 – polyester modified polysiloxane
Sample B:  Polyether modified siloxane

The application and baking occurred in two steps. For ease of testing the two layers were differently pigmented – 1st layer white and 2nd layer red. The white coating was applied first and baked in the gradient-oven using the step gradient function: 130 °C – 150 °C – 170 °C – 190 °C for 30 minutes. Then the red pigmented coating was applied and baked under the same conditions.

The quality of the inter-coat adhesion can be evaluated by using a cross-cut tester with tape or knife with tape according to a Ford test specification.

Results according to Ford Test:

Sample A shows excellent inter-coat adhesion at all 4 different temperature ranges. In case of sample B the inter-coat adhesion is destroyed at baking temperatures higher than 150 °C

Rewetting of 2 coat systems:

At high temperatures silicones can cause wetting problems in a 2 coat application process.

Test procedure:

Two differently modified silicones were tested in an amino-cured alkyd topcoat:
Sample A: BYK®-325
Sample B:  Polyether modified polysiloxane

For ease of testing the two layers were differently
pigmented – 1st layer white and 2nd layer red. The 2 coats were applied wet on wet with a spray gun and each coat had a wet film thickness of 150 µm. The silicone additives were only added in the 2nd coat.
Both systems were baked in the gradient-oven using the linear gradient function:
120 °C – 190 °C for 30 minutes.

Ford Test Specification:

The coating is marked with a knife, adhesive tape is applied to the test surface, pressed on and removed.

Result:

Sample A was perfectly wetted, while in sample B the two coats "separated” – droplet formation can be seen at higher temperatures. Therefore, sample B can only be exposed to a maximum temperature of 165 °C.

Chemical etch resistance of automotive topcoat systems:

Acid rain, bird droppings, fuel, antifreeze and many other environmental factors can damage automotive finishes. Especially in summertime, some substances can be very aggressive and cause severe damage. Therefore, automotive paint manufacturers as well as auto makers need to find out how different environmental phenomena will interact with a coating system. Throughout the world panels are tested on weathering sites for years to evaluate the influence on color,  gloss as well as physical properties.

The gradient-oven has been approved by the automotive industry as an accelerated test method. It allows to predict how a particular coating system is reacting to a specific material at increasing temperature levels. This test method is specified by several automotive companies.

Test procedure:

In a standard test 5 different chemicals can be tested on one panel – e.g. H2SO4 which simulates atmosphere and acid rain, NaOH for car wash detergents, pancreatine (bird dropping), brake fluid, and tree resin. The panels are coated and baked under the specified processing conditions. Using a pipette droplets (approx. 0.05 ml) of these various materials are placed about 6 mm apart vertically on the test panel. Repeat this length down the panel with spacing about every 2-3 cm. The gradient-oven is then programmed to have a linear gradient in the range of 35 °C – 80 °C. The panels are now  baked at either 20, 30 and / or 60 minutes to allow for evaluation of the coating. After the baking process the panel is washed under running water, dried and visually evaluated. The evaluation should be done after approx. one hour and again after 24 hours to see if any additional etching has occurred.

The temperature is documented at which the first visual changes and damages occurred.

temp-gard 8p

temp-gard 8p system
• Memory card to store the temperature data: unlimited data storage, fast data download, easy file management
• Long lasting batteries – 250,000 readings or 300 hours in continuous operation
• Built-in display shows automatic functionality check and allows direct programming of operating parameters
• Robust thermal barrier made of stainless steel with absolutely safe temperature insulation
• 8 thermocouples for any application
• High accuracy guarantees for long-term reliable results
• Temperature stable results under any circumstances

Put us through the ultimate test:
temp-gard will give you the same results even after being in the oven for more than 1 hour – no drift!!!

Technical Specification temp-gard 8p
Accuracy	± 0.5 °C
Resolution	0.1 °C at 280 °C
No. of Channels	8
Memory	500 KB on memory card
Sampling Interval	1 sec up to 5 min
Temperature Range	0 - 120 °C; 280 °C; 500 °C
Trigger	start-key; time; threshold
Battery Capacity	1 sec interval = 30 h battery
Display	4 columns with green LCD
Interface	PCMCIA-card and RS 232
Thermal Barrier
Dimensions	9.6 x 8.2 x 6.3 in (245 x 209 x 160 mm)
Weight	12.1 lbs (5.5 kg)
Maximum Duration	at 100 °C, 9 h; at 200 °C,4 h; at 250 °C, 3 h
Hardware Requirements: Windows® 95; 98 or NT-computer with min. 6 MB available hard disk space; CD-Rom drive, serial port, PCMCIA slot or drive, Windows® compatible printer
Comes complete with: temp-gard instrument temp-chart software 1 Thermal barrier 1 Set of heat sinks 1 Memory card (PCMCIA) 1 Probe for air temperature, magnet, 3m 7 Probes for object temperature, magnet, 3m 1 Interface cable to PC 2 AA Alkaline batteries Operating manual Certificate included Carrying case Training

Temperature Probes for any Application

• High quality thermocouple type “K” with special limits of error 1.1 °C or 0.4 % (ANSI MC 96.1)
• Magnets or clamps do not influence measurement results
• Connection cable of 1.5 m (59 in), 3 m (118 in) and 8 m (315 in) length available (see table)
• Response time for 100 % measuring range from 5 seconds to 2.5 minutes depending on probe style

Style C Style A Style B Style D Style E   Style F Style G Style H Style I

Accessories temp-gard 8p
Style	Probe	Length	Attachment	Max Temperature
A	object	1.5 m	clamp	509 °F (265 °C)
A	object	3 m	clamp	509 °F (265 °C)
A	object	8 m	clamp	509 °F (265 °C)
B	object	1.5 m	magnet	509 °F (265 °C)
B	object	3 m	magnet	509 °F (265 °C)
B	object	8 m	magnet	509 °F (265 °C)
C	air	1.5 m	clamp	509 °F (265 °C)
C	air	3 m	clamp	509 °F (265 °C)
C	air	8 m	magnet	509 °F (265 °C)
D	air	1.5 m	magnet	509 °F (265 °C)
D	air	3 m	magnet	509 °F (265 °C)
D	air	8 m		509 °F (265 °C)
E	foil	1.5 m		509 °F (265 °C)
F	open junction	1.5 m		509 °F (265 °C)
F	open junction	3 m		509 °F (265 °C)
F	open junction	8 m		509 °F (265 °C)
F	open junction	3 m		509 °F (265 °C)
	extension	3 m		509 °F (265 °C)
	extension	5 m		509 °F (265 °C)
G	object	1.5 m	washer 2 mm	509 °F (265 °C)
H	IR	3 m	magnet	509 °F (265 °C)
I	IR	3 m	clamp	509 °F (265 °C)
heat-proof adhesive tape for attachment of foil probes
incl. 2 heat sinks, max duration at 250 °C, 3h
1 piece
lite max duration at 250 °C, 40 min
max duration incl. 2 - PT-3322 at 500 °C, 15min (400 °C = 30 min)
temp-gard 8p logger
PCMCIA-Memorycard
external card drive for PC; parallel port
Cover for heat sink to protct against penetration of water/vapors

temp-gard basic

temp-gard basic comes with everything you need to record – analyze your oven temperature.
You can download your measurement results from the memory card to EXCEL with the easy-link software – all included.

• Highly accurate and long-term reliable measurement data
• PCMCIA memory card: stores the data, guarantees fast data download and makes file management easy
• Long lasting, standard batteries – available off the shelf: Your system is always ready
• Small, robust thermal barrier made of stainless steel
• 4 thermocouples for object and air temperature included (up to 8 probes can be connected)

Training temp-gard / temp-chart
Qualitest offers you more than just an instrument. We assist you in operation of the temp-gard data logger and temp-chart Software to analyze your curing process. As a result you will be able to use the system to save time and money and at the same time improve your quality. Therefore, the instrument comes with a half day training course including:

1. Temperature Analysis, Oven Profiles Theory
   • Temperature versus time, typical process curves
   • Data interpretation: How can the oven profile be used to optimize process / material parameters
2. Operation and Software Training
   • Software overview
   • Set up a template to create a routine measurement procedure
   • Programming of temp-gard with templates and measurement in production oven
   • Data transfer to temp-chart software and saving in a file for routine process control
3. temp-gard Operation
   • Set up parameters on the instrument
4. Data analysis:
   • Oven analysis
   • Process optimization
   • Identification of problems

Technical Specification temp-gard basic
Accuracy	± 0.5 °C
Resolution	0.1 °C at 280 °C
No. of Channels	8
Memory	500 KB on memory card
Sampling Interval	1 sec up to 5 min
Temperature Range	0 °C - 120 °C; 280 °C; 500 °C
Trigger	start key; time; threshold
Battery Capacity	1 sec interval = 30 h battery
Display	4 columns, green LCD
Interface	PCMCIA card and RS 232
Thermal Barrier
Dimensions	245 x 209 x 101 mm (9.6 x 8.2 x 4 in)
Weight	4.1 kg (9 lbs)
Maximum Duration	at 100 °C 90 min; at 150 °C 65 min; at 200 °C 45 m

BYKWARE temp-chart

temp-chart is an easy-to-use software for documentation and analysis of the temperature profile. temp-chart was developed in close cooperation with leading automotive manufacturers.

• User-friendly Windows® software
• Graph of temperature profile with upper / lower limits, reference curve and tolerance range

• Professional documentation
– All important information on one page:
customer and process parameters
graph of temperature profile
critical cure data
– Product images with location of temperature probe can be imported
– 3-D-graph facilitates visual control

• All critical process parameters can be entered and saved for detailed analysis:
– Curing data
– Oven data (line speed, zone lengths, etc.)

• Porsche value, a new cure index, based on the transferred energy amount allows to optimize the curing process with a never before seen accuracy
• Compatible with data from other byko-track systems

For further information or to place an order for the Gradient-oven CLICK HERE, call us Toll-Free at: 1.877.884.TEST, or click on the "HOW TO ORDER" Button