PLASTIC BAG PRODUCTION UNIT Russian patent published in 2012 - IPC B31B37/00 B31B37/60 B31B19/26 

FIELD: process engineering.

SUBSTANCE: invention relates to production of plastic bags with rectangular bottom. Proposed unit comprises bag main part material feed device, side fold material feed device, appliance temporary attachment of one of bag main part material strips to side fold strip, main material guides, bottom fold forming devices and transverse and lengthwise welding appliances. Side fold material sheet 3 is bent in half, folded in two layers and fitted in between strips a and 2 of main part material webs. One of said webs is bent along lengthwise fold line 8 to make said webs 1 and 2 open so that open surface is produced on bad main part webs 1 and 2. One layer of side fold 3 is bent along lengthwise line 8 to make side fold material layers open together with extra fold section7 so that open surface is produced on layers of said section 7. Bottom fold material web 4 is applied on open surfaces of material 1 and 2 and section 7. Bottom fold web 4 and extra fold section 7 are heat-welded together while bag main part webs 1 and 2 and side fold material sheet 3 are heat-welded together over width of webs 1 and 2. Note here that open surfaces are retained as-formed. Bottom fold material webs 4 and, at least, one of webs 1 are heat-welded together in lengthwise direction of webs 1 and 2. Note here that open surfaces are retained as-formed.

EFFECT: simplified and perfected method.

6 cl, 5 dwg