SU676377A1 - Method of activating sand under room temperature - Google Patents

Description

the sandy clay component, and because of this, the polystyrene multifunctionality increases the final strength of the molds and cores.

Polystyrene solvents or styrene copolymers are from the class of aromatic or aliphatic hydrocarbons, ketones, etc.

The use of polystyrene or its derivatives enhances the antiburning properties of mixtures, since it contains up to 52% of its carbon glitter in its composition.

The use of polystyrene or its derivatives ensures good sand regenerability, since its thermal destruction begins already at 300-350 ° C. The introduction of solutions of polystyrene or its derivatives into the filler provides for the best spreading and wetting of the surface of sand grains.

Introduction to the sand solution at the rate of more than 0.6 wt. % pure polystyrene leads to a thickening of the film on the surface of sand grains, which can cause caking of the composition, its clumping, and with a content of less than 0.2 weight. The film is very thin and fragile and does not provide an increase in the final strength of the molds and cores.

Example. Take the mixture of the following composition, weight. %

Quartz sand with clay content of 0.7-1.5% 90-95 10% solution of polystyrene brand PSV-B in toluene1-6

Binder - phenol-formaldehyde resole resin grade SF-0154

The proposed method is implemented as follows.

Model 018 roller runners are loaded with dry quartz sand at room temperature, a solution of polystyrene is poured into the sand, and mixed for 2-5 minutes until complete completion of toluene. Then, binder SF-015 is added to the obtained dry-blend blend and additionally stirred for 1-2 minutes. After that, the finished mixture is discharged from the runners and samples are made from it - eights in hot box.

The results are shown in the table.