Food EPT rubber filter-pressing plate and method for preparing same

Abstract

The invention discloses a food-grade EPDM pressure filter plate and manufacturing method thereof. The pressure filter plate adopts the EPDM as the major raw material, which is the high-purity white or colorless EPDM raw rubber that is synthesized by adopting the solution polymerization method, wherein, the ENB content of a third monomer is 4 to 6 percent; and the content of ethylene is 50 to 55 percent. The manufacturing method is that the raw materials are firstly mixed according to the mixing ratio by the parts at weight, the conventional ethylene-propylene rubber mixing process is adopted for preparing the mixed rubber, the mixed rubber is heat bodying on a mixing roll machine and then sheet making to obtain rubber sheets and rubber strips, then a rubber material middle temperature upper mold gradually increases the temperature and the pressure for stamping and pressure keeping, and a flat vulcanizing machine is adopted for vulcanization, so as to obtain the food-grade EPDM pressure filter plate. The pressure filter plate of the invention can be applied in the pressure filters of the food industry, thereby meeting the food hygienic standard requirements and having good product elasticity, heat resistance, anti-aging property and long service life.

Description

technical field [0001] The invention relates to the field of rubber industrial products, in particular to a food-grade EPDM rubber filter plate and a manufacturing method thereof. Background technique [0002] The size of the filter plate applied to the filter press in the brewing and food industry is usually between 1.2m×1.2m and 2m×2m, the thickness of the product is usually between 10-20mm, the weight of the product is between 12Kg-30kg, and the structure is relatively complicated . Since EPDM has good aging resistance, hot water resistance, and ethanol resistance, EPDM is usually used to manufacture rubber filter press plates. [0003] There are several difficulties in the manufacturing process of EPDM rubber filter plates: (1) The size of the product is large, and the semi-finished rubber material cannot be preformed into a whole by a conventional extruder, and can only be spliced ​​in pieces; (2) ) The flat plate vulcanizing machine with a plate size of 1.5m×1.5m to ...

AI Technical Summary

Problems solved by technology

[0003] There are several difficulties in the manufacturing process of EPDM rubber filter plates: (1) The size of the product is large, and the semi-finished rubber material cannot be preformed into a whole by a conventional extruder, and can only be spliced ​​in pieces; (2) ) The flat plate vulcanizing machine with a plate size of 1.5m×1.5m to 2.5m×2.5m can vulcanize such large-sized products. The clamping force of this type of vulcanizing machine is between 1500 tons and 2500 tons. After pressing, the pressure applied to the rubber material of the filter press plate is only 5-8 MPa, which is obviously low. Generally speaking, the pressure applied to the rubber material for molded vulcanized dense rubber products must not be lower than 24 MPa; (3 ) The self-adhesive properties of ethylene-propylene rubber are very poor, and it is difficult to bond and form unvulcanized rubber.

Due to the combined effects of the above three factors, it is difficult for the common formulation of EPDM rubber and the conventional vulcanization process to meet the process needs of manufacturing filter plates.

The products prepared according to the existing methods are prone to quality problems such as fracture, delamination, local lack of glue, and air pockets, and also have performance problems such as poor elasticity and short service life, and the food hygiene performance is general or unqualified, and precipitates and Much soaking residue

These shortcomings cannot meet the requirements for the use of filter plates in the brewing and food industries.