Unsaturated polyester putty is a product based on amine unsaturated polyester resin, which is hardened by a hardener from the peroxide family and has a very strong adhesion ability on iron, galvanized, It has aluminum and fiberglass. The mechanism of unsaturated polyester resin is based on the initiation of a radical reaction with the attack of peroxide free radicals on the chain of unsaturated bonds on the resin chain, and with the rapid formation of intramolecular covalent bonds and also with the underlying part, it causes adhesion and final hardening of the putty. It should be noted that this is an exothermic reaction and the heating of stone putty will be visible during the reaction with peroxide. Stone putty is mainly produced and supplied by fillers and pigments with a density of 1.76 to 1.85 grams per liter, and its task is to wave and fill the uneven surface of metal. The ratio of stone putty with peroxide hardener depending on the ambient temperature is from 1% of the putty weight in hot seasons to 4% of the putty weight in cold seasons. The operator should recognize the correct amount of mixing of hardener with putty from the final color of the putty, so if the final color of the putty becomes pale pink, it indicates that there is too much hardener. All stone putties have a useful life for polishing on the part, which is called gel time. According to Iranian National Standard 4878, a stone putty mixed with 2% by weight of hardener with 100 grams of stone putty at an ambient temperature of 25 degrees Celsius should be able to be polished for at least 5 minutes and at most 10 minutes. It should be noted that after finishing the gel time, the stone putty starts to increase in temperature and become hot, and this increase in temperature, according to the type of putty and the manufacturing technique of the manufacturer, should rise with a gentle slope to a temperature of at least 48 degrees Celsius and up to a maximum of 70 degrees Celsius, and then again with a slope gently until the ambient temperature decreases and subsequently, according to standard 4878, two pieces of 200 microns should be applied, and after 2 hours it will harden and be able to sand with 60 dry sandpaper without sticking to the sandpaper, on the other hand, the second piece of 200 microns after 24 hours by the bending test with a 14 mm rod, the putty must not crack and crack, and it must also pass the 2 mm cross cutter and no staining or burning experimentally Stone putty is produced in two main types: 1, general stone putty, or General 2, soft stone putty, both of these putties can be divided into the following three types or three terms based on their pseudoplastic properties and rheology or viscosity. be produced: 1- puffy paste 2- cream paste 3- Korean buttery paste Now the difference between the two main versatile types, general and soft, is that they are mostly versatile putties with very strong adhesion on all types of parts. especially galvanized and aluminum, and they must also pass the standard flexibility test and not crack in any way under the environmental conditions, General putties are always used for the first layer of polishing on the part and must be according to the next standard from two hours at a temperature of 25 degrees Celsius, it can be dry sanded with 60 to 100 grit, and after 8 hours with a sanding machine or orbital machine, it can be sanded with 220 grit, mainly “general gray putty thick with They produce high rheology (creamy). In the European Union, general putties are produced in gray color, and in Iran, they are sometimes sold in cream color. Soft stone putty is used as a stone putty to apply the second layer of smoothing and has a finer granularity than general stone putty, this type of stone putty is more for filling scratches and holes caused by general stone putty. The first layer or sometimes used to apply very thin layers (onion skin), the difference between soft putty and general putty is that after 2 hours of the putty hardening, it must be sanded with softer sandpaper such as 180 to 220 and are mainly supplied with the concentration or rheology of puffy and buttery, in the European Union, soft stone putty is only supplied and produced with cream color.
The difference in the physical concentration and rheology of stone putty is a matter of taste, of course, it should be noted that according to the national standard 4878, the concentration of stone putty with a penetrometer should be between 2.5 and 3.5 cm, that is, it is almost “creamy” and according to the ambient temperature and the temperature of the weather in which the operator works depends, some of the market prefer puff putty, others cream, and another group prefers Korean putty.
Now, the difference in the rheology of stone putty is that puff putty mostly has a relatively soft lick and the concentration of the putty is slightly loose or fluid, and the putty is made of filler particles with a lower mesh (larger size), but the opposite point is cream putty, which is elastic and thick, and the operator feels a kind of force or pressure on his trowel while applying the spatula. This property is because the putty does not fall during application, and it is more suitable for tropical climate and in its production, filler particles with relatively medium mesh are used.
Korean stone putty is actually a derivative of puffy and creamy putty, and in terms of rheology and fluidity, it looks similar to creamy putty, but it becomes fluid when first mixed and spooned, which gives it pseudoplastic properties. They say that in terms of smoothing, it works similar to puff putty, and they mainly make “soft putty” with cream color and butter type.
In the production of general stone putty (General) of Rangin Kimia company, which is supplied under the power brand, pseudoplastic property can be seen in it, in fact, power stone putty is designed and produced in a way that has both versatile and soft properties. so that many consumers use it both as the first layer and for scratching.
The features of power stone putty include: easy polishing, flexibility, very crisp and excellent sanding, since the gel time of this putty is set to 7 to 10 minutes, it gives the operator the necessary time to polish and with attention It has the ability to harden to an average heating temperature of 60 degrees Celsius in any temperature condition and will prevent cracking over a long period of time.
The storage period of stone putty is at least 12 months to a maximum of 18 months according to storage conditions.
