RU2533718C1 - Method to process workpieces from polymer material - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: workpieces from polymer materials are treated with chemical reagent. The workpiece and cutting tool are imparted with the relative shaping motion, the workpieces are fed-in discretely and are mechanically treated by cutting tools. For the purpose of workpiece production the colloidal solution of nanodispersed boron nitride powder with particle size of from 25 nm to 80 nm is used as a chemical reagent in a plasticiser, it is mixed with rubber mix based on butadien-nitrile rubber with their further moulding and vulcanisation.

EFFECT: simplified and increased efficiency of mechanical treatment of workpieces from polymer materials.

Description

The invention relates to the field of processing materials by cutting and can be used in the machining of billets of polymeric materials.

A known method of mechanical processing of rubber, for the implementation of which on the inner and outer lateral surface of a hollow cylindrical billet, reinforcing bodies are installed followed by their fixing with an adhesive joint (Patent JPH 03184730, IPC B23P 25/00, publ. 1991-08-12).

The disadvantage of this method is the length of the process, due to the need for additional operations related to the fastening and removal of the reinforcing bodies. The method limits the technological capabilities of mechanical processing of rubber, since it is applicable only when turning. The method introduces significant limitations associated with the wall thickness of the workpiece, due to the manifestation of rubber highly elastic properties.

A known method of mechanical processing of rubber, for the implementation of which pre-freeze the rubber billet by spraying on its surface liquefied nitrogen (Patent JPS 6130344, IPC B23B 1/00, B23P 25/00, publ. 1986-02-12).

The disadvantage of this method is a significant complication of the process, due to the need for cryo equipment. The implementation of the method leads to an increase in the time of the technological process associated with freezing of the workpiece and premature wear of the cutting tool.

The closest is the method of machining plastic blanks, in which the relative motion of the shaping is reported to the blank and the cutting tool, the parts are fed discretely and the surface of the blank is pretreated with chemical reagents (RF Patent No. 23228374, IPC B29C 37/00, published on July 10, 2008 )

The disadvantage of this method is that the method significantly increases the time of the process, due to the need for long exposure of the material in a chemical reagent and subsequent re-machining. The implementation of the described method is associated with technological difficulties associated with the need to apply microdamage to the surface of the workpiece to be processed in the form of holes, the depth, diameter and pitch of which are individual and determined by the type of chemical agent used, the density of the workpiece material, and also the machining parameters. In addition, the pitch of the holes should be constant over the entire length of the surface to be treated, and should also ensure overlapping areas of the chemical agent. In addition, the method describes the use as a chemical agent of toxic substances with a maximum one-time MAC in the air of the working zone of 10 mg / m ³ .

The problem to which the invention is directed, is the manufacture of parts with high surface quality.

The technical result is to simplify and increase the productivity of machining workpieces made of polymer materials.

The technical result achieved is achieved in a method for processing workpieces made of polymeric materials, in which a chemical treatment is performed, the workpiece and the cutting tool are informed of the relative motion of the forming process, the feed is carried out discretely and the workpiece is machined with a cutting tool, and colloidal is used as a chemical reagent a solution of nanodispersed boron nitride powder with a particle size of 25 nm to 80 nm in a plasticizer, which is mixed sew with a rubber mixture based on nitrile butadiene rubber, followed by molding and vulcanization.

The chemical reagent used is a colloidal solution of nanosized boron nitride powder (TU 2-036-707-77) in a plasticizer, which is mixed with a rubber mixture based on nitrile butadiene rubbers, for example SKN-18, SKN-26, SKN-40, SKN -fifty.

As a dispersion medium, it is possible to use plasticizers of hydrocarbon origin, for example: dioctyl phthalate, dimethyl phthalate, dibutyl phthalate (DBP), orthophosphoric esters.

On the one hand, the presence of a nanosized powder of boron nitride in the vulcanizate can increase the maximum cutting speed by increasing the thermal conductivity of the material, on the other hand, the high specific surface and morphological features of the newly formed agglomerates of dispersed boron nitride particles affect the relaxation time of the material, increasing the latter. Due to the combined influence of the above effects, when the cutter contacts the workpiece, brittle destruction of the material occurs under the action of the cutting tool. Thanks to the modification of the rubber mixture with additives, the relaxation properties of the material are changed, which subsequently allows the elastomers to be mechanically processed at cutting speeds available to metal-cutting equipment under brittle fracture of the material under the influence of a cutting tool. Therefore, the formation of defects inherent in unmodified materials associated with stretching, abrasion, and also the separation of the surface layers of the material during machining is prevented. The absence of such interactions caused by highly elastic deformation of the material is a prerequisite for reducing the surface roughness of the treated part and, as a result, improving the surface quality of the product.

The method is as follows.

At the stage of manufacturing the billet, a nanosized powder of boron nitride (0.4 mh) dispersed in 5.0 mh was introduced into the rubber mixture based on SKN-18 (100.0 mph) DBF The average particle size of the applied nanodispersed boron nitride powder ranged from 25 nm to 80 nm. The remaining ingredients of the rubber mixture corresponded to the prescription map: N, N-dithiodimorpholine (1.0 m.h.), Tiuram D (1.5 m.h.), Sulfenamide C (1.5 m.h.), Zinc white ( 10.0 mph), Acetononyl H (2.0 mph), Santogard PVI (1.0 mph), TU P-324 (10.0 mph), TU P- 803 (40.0 mph). Mixing was carried out on rollers at a temperature of 40-50 ° C for 30-40 minutes, then the operation of molding and vulcanization was performed to obtain a preform. The workpiece and the cutting tool were informed of the relative motion of the shaping, the feed was carried out discretely, and the workpiece was machined with a cutting tool.

The introduction of a chemical reagent into the rubber mixture at the stage of manufacturing the workpiece allows you to achieve uniform distribution of the chemical reagent in the entire volume of the workpiece, due to which the method allows you to abandon the technological operations associated with preliminary mechanical and chemical surface treatment of the workpiece. Thus, a simplification and increase in the productivity of machining of workpieces made of polymeric materials is achieved.

Claims (1)

A method of processing workpieces from polymeric materials, in which the workpieces are treated with a chemical reagent, the workpiece and the cutting tool are informed of the relative motion of forming, the feeding is carried out discretely and the workpieces are machined with a cutting tool, characterized in that a nanodispersed colloidal solution is used as a chemical reagent boron nitride powder with a particle size of 25 nm to 80 nm in a plasticizer, which is mixed with the rubber mixture on based on nitrile butadiene rubber, followed by molding and vulcanization.