33results about How to "Non-toxic material" patented technology

The invention relates to a production method of triethylamine method cold core box resin suitable for high humidity environment, and specially relates to a production method of triethylamine method cold core box resin for casting; the method is as follows: first, synthesizing separately a component I and a component II, and then mixing the components I and the component II; the components I comprises the following raw materials by weight: 42%-65% of benzylic ether phenolic resin, 16.2%-25% of an aromatic solvent, 6%-12% of a citrate plasticizer, 12%-24% of a fatty acid dibasic acid ester plasticizer and 0.4%-0.8% of a silane coupling agent; the components II comprises the following raw materials by weight: 72.5% of polyaryl polymethylene isocyanate (PAPI), 27% of synthetic plant ester and 0.5% of a phosphate ester inhibitor. The method is unique, good in moisture resistant performance and high in environmental protection performance, can improve casting production conditions, achieves ''green casting'', and improves the surface quality and dimension accuracy of castings.

The invention discloses a gum-protecting device which is an integrated shell structure. The inner surface of the shell is matched with the half of the longitudinal section of a tooth drill body. The shell of the gum-protecting device is devised into a machine needle base connector, a body connector, a gum-protecting part and a positioning part. The gum-protecting part of the gum-protecting deviceis matched with the machine needle on the tooth drill; the inner diameter of the gum-protecting part is larger than the diameter of the machine needle; and a gap is remained at the fixed socket part of the machine needle of the tooth drill. The front end of the gum-protecting part is provided with a positioning part which is extruded out of the length of the front end of the machine needle; the machine needle base connector of the um-protecting device is covered at the external surface of the machine needle base of the tooth drill; the body connector of the um-protecting device is covered at the external surface of a handle of the tooth drill; the machine needle base connector and the body connector are tightly matched with the tooth drill body, so that the gum-protecting device can be stably fixed at the external surface of the tooth drill. The gum-protecting device has the positioning function in the process of polishing tooth shoulder, and effectively separates the machine needle from the gum to protect the gum.