June, 2012
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Adhesion of Dimer-Based Polyurethanes to Various Substrates
Dimerized fatty acids are expected to have a high affinity for low-energy surfaces, since the long alkane chains show a structure similar to polyethylene.Polyurethane adhesives were prepared from a variety of polyether and polyesters diols and pure MDI in an NCO:OH ratio of 2.5.These materials were tested as adhesives for two polyethylene substrates and for steel after full cure.It should be realized that these tests were performed to quantify the difference in adhesion of the PU resins to polyethylene forRead More …
Four different chemical methods can be used against plastics deterioration
Theoretically, there are four different chemical methods that can be used against plastics deterioration. The first technique is to introduce additives that absorb light before they can contact the degradation-initiating center and the energy is dissipated as heat. The second way consists in deactivating the excited state of the initiating center.Again, such reactions produce energy, which is generated either in the form of heat or as fluorescent radiation. In the third method, the hydroxyperoxides that have been formed are transformedRead More …
Some Important factors to polyester coating degradation
Polyester degradation is affected by solar radiation, photocatalytic admixtures, water and moisture, chemicals, oxygen, ozone, temperature, abrasion, internal and external stress, and pigment fading.Out of all these, the following factors, all present in outdoor weathering, are the most important to coating degradation: moisture, temperatures, oxidation ,UV radiation. Moisture Hydrolysis occurs when a plastic is exposed to water or humidity.This chemical reaction may be a major factor in the degradation of condensation polymers such as polyesters , where the ester groupRead More …
Eliminating Agglomeration Resulting from the Grinding Process
The investment in a liquid nitrogen cooling system has proven to be a very cost-effective solution to the powder agglomeration problem. The grinding of solid materials to produce powders is a common manufacturing step found in many industries.In the coatings industry,grinding may be used in the preparation of pigments and of powder coating.Of particular focus in this article is an application solution successfully deployed in the production of powder coating. In the powder coating industry,several different types of polymeric matricesRead More …
TEST METHOD-CROSS-CUT TAPE TEST-ASTM D3359-02
10. Apparatus and Materials 10.1 Cutting Tool9—Sharp razor blade, scalpel, knife or other cutting device having a cutting edge angle between 15 and 30° that will make either a single cut or several cuts at once. It is of particular importance that the cutting edge or edges be in good condition. 10.2 Cutting Guide—If cuts are made manually (as opposed to a mechanical apparatus) a steel or other hard metal straightedge or template to ensure straight cuts. 10.3 Rule—Tempered steelRead More …
Procedure for X-CUT TAPE TEST METHOD-ASTM D3359-02
Related Articles: Testing Methods for Powder Coating Standard Test Methods for Measuring Adhesion by Tape Test 7. Procedure 7.1 Select an area free of blemishes and minor surface imperfections. For tests in the field, ensure that the surface is clean and dry. Extremes in temperature or relative humidity may affect the adhesion of the tape or the coating. 7.1.1 For specimens which have been immersed: After immersion, clean and wipe the surface with an appropriate solvent which will not harmRead More …
ASTM D3359-02-TEST METHOD A-X-CUT TAPE TEST
5. Apparatus and Materials 5.1 Cutting Tool—Sharp razor blade, scalpel, knife or other cutting devices. It is of particular importance that the cutting edges be in good condition. 5.2 Cutting Guide—Steel or other hard metal straightedge to ensure straight cuts. 5.3 Tape—25-mm (1.0-in.) wide semitransparent pressuresensitive tape7 with an adhesion strength agreed upon by the supplier and the user is needed. Because of the variability in adhesion strength from batch-to-batch and with time, it is essential that tape from theRead More …
Standard Test Methods for Measuring Adhesion by Tape Test
This standard is issued under the fixed designation D 3359; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision.A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 These test methods cover procedures for assessing the adhesion of coating films to metallic substrates by applying and removing pressure-sensitive tapeRead More …
Low Temperature Cure Powder Coatings is developed to heat-sensitive substrates
For application on heat-sensitive substrates like MDF, the powder must cure below 302°F (150°C) or even 212°F (100°C). Several approaches have been developed to achieve this goal, ranging from low-temperature-cure conventional chemistries to radiation-curable evolving chemistries. A vast number of published articles and patents have confirmed the ability of UV-curable technologies to produce glossy, smooth coatings on MDF within three to five minutes of process time.8The main advantages of UV-cured powders include higher productivity and space savings due to shorterRead More …
Adhesion On Wood And Intercoat Adhesion for wood coating
Since the early 1970s when radiation-curing technology started to develop, mainly in the field of printing ink, the technology has known considerable success. One of the most successful areas has been wood coating, specifically the furniture and parquet flooring industries As with conventional coatings, it is necessary in radiation-curing systems to apply several layers of coating to get a satisfactory finish. Consequently, in addition to considering adhesion on wood, intercoat adhesion and substrate preparation must be considered. Sanding of theRead More …
D5 Creation