The integrated technology of restoring the food equipment parts with use of MODENGY coatings has been developed

Urgency of restoring operability of the dough dividing machines

Vacuum-and-piston dough dividing machines are used to divide dough into workpieces of the certain same weight at the bread baking industry enterprises.  

The construction is represented by two basic mechanisms: sucking and dividing ones.

Fig.1. Dough dividing machine construction.
I – sucking mechanism; II – dividing mechanism; 1 – drum, 2 – mensural piston, 3 – sucking chamber body, 4 – cutoff knife, 5 – top part of the sucking chamber, 6 – sucking piston, 7 – throttles

Accuracy of dividing on weight depends directly on state of the sucking system parts.

As the elements of the sucking system mechanism get more and more worn, loss of vacuum occurs, and accuracy of dough dividing on weight get broken.

Since cost of the dough dividing plants themselves, and expenses for their repairs by replacing the components is quite high (30 to 40% of the new plant price), the methods to restore operability of the worn parts are being developed.

One of the most effective ways of repairing the dough dividing machine sucking block components has been developed as a part of the thesis to get science degree of a technical sciences candidate named The Development of the Repairing Technology of the Vacuum-and-Piston Type Dough Dividing Machines by Using the Electrical Discharge Machining Method. This paper was performed at the Department of Machines Maintenance of the Mordovsky National Research State University named after N.P. Ogaryov, the federal state budget institution of higher education (MNR SU named after N.P. Ogaryov, FSBI of HE).

Successes in developing methods to restore dough dividing machines

The method to restore operability of the dough dividing plant sucking block was developed as a part of a thesis paper. Prime price of the new technology of repairing is not higher than 5 to 10% of the new machine cost.

To restore the worn parts the method of electrospark discharge treatment was chosen which creates a coating having high functional features on the parts surface.

According to the results of tests on the CMT-1V friction machine with a pad-roller pair, the pre-scuffing load, and friction coefficient of tribological conjunction were detected, estimate of friction pairs wear intensity was held on the pairs with electrospark discharge treatment, without it, and on the samples with electrospark discharge treatment and covered with MODENGY PTFE-A20 coating after that.

Fig.2 CMT-1M friction machine

Three cast-iron pads were used including one without treatment, one with electrospark discharge treatment, and one with electrospartk treatment followed by applying MODENGY PTFE-A20. The cast-iron rollers were not treated.

Fig.3. Pre-scuffing load in the friction pairs under research. 1 – friction pair: ЧН19Х3Ш cast iron / ЧН19Х3Ш cast iron; 2 – friction pair: ЧН19Х3Ш cast iron + Х15Н60ЭИО alloy / ЧН19Х3Ш cast iron; 3 – friction pair: ЧН19Х3Ш cast iron + Х15Н60ЭИО alloy + MODENGY / ЧН19Х3Ш cast iron

According to the test results on detecting the pre-scuffing load, it was determined that using electrospark discharge treatment reduces pre-scuffing load by 11% while additional applying MODENGY PTFE-A20 coating increases this index by 20% (see Fig.3).

Fig.4. Friction coefficient of tribological conjunction. 1 – friction pair: ЧН19Х3Ш cast iron / ЧН19Х3Ш cast iron; 2 – friction pair: ЧН19Х3Ш cast iron + Х15Н60ЭИО alloy / ЧН19Х3Ш cast iron; 3 – friction pair: ЧН19Х3Ш cast iron + Х15Н60ЭИО alloy + MODENGY / ЧН19Х3Ш cast iron

Use of MODENGY PTFE-A20 coating together with electrospark treatment has enabled to reduce friction coefficient of the mated parts (see Fig.4).

Fig.5. Wear intensity of the samples. 1 – friction pair: ЧН19Х3Ш cast iron / ЧН19Х3Ш cast iron; 2 – friction pair: ЧН19Х3Ш cast iron + Х15Н60ЭИО alloy / ЧН19Х3Ш cast iron; 3 – friction pair: ЧН19Х3Ш cast iron + Х15Н60ЭИО alloy + MODENGY / ЧН19Х3Ш cast iron

Wear intensity of each sample separately (the pad and the roller) as well as total wear intensity of the friction pair at electrospark discharge treatment and applying MODENGY PTFE-A20 coating reduce significantly (see Fig.5).

The author of the thesis paper supposes that increase of roller wear, and total wear intensity of the friction pair at performing electrospark discharge treatment without using MODENGY PTFE-A20 is conditioned by high hardness of the applied coating, unregular roughness, and low continuity.

So, applying MODENGY PTFE-A20 product onto the electrospark coating enables to reduce total wear intensity of the parts by 1.28 times.

Use of the given technology enables to lower prime price of the dough dividing machine repairs by 5.6 times in comparison with the costs of sucking block parts replacement.

Average overhaul life of the dough dividing machines repaired according to the new technology has extended by 12% in comparison with the general average service lifetime.