1. Overview
hollow blow molding machine is mainly used to produce bottles, pots, cans, buckets and other small shaped pieces of single, double, (double) visible level line of blow molding hollow articles especially suitable for PVC, PE, PC, PP, PS, PA and other raw materials Blow. Market prospects.
hollow blow molding machine principle to "squeeze - blow" molding. Extruders are used frequency motor speed, speed range can be large in order to meet the requirements of different products, but also allows fairly stable parison extrusion to ensure uniform weight. Plasticization of the melt extruder plastic extrusion head through the formation of parison, blow molding parison into the mold, which completed a cycle. Currently on the market there are large hollow blow molding machine models and small models. Was divided into small type in a single station and double station. Double work, around the station to complete a cycle count of a working process.
hollow blow molding machine from the mechanical, electrical, hydraulic, pneumatic, water, and servo oil source (optional) and other parts:
mechanical parts, including: extrusion device; nose; shift mode and clamping mechanism; rack; lifting mechanism; blowing device; billet electric cutter; lift die device; addition overflow device and so on.
Gas path components: the work and products for the cylinder part blow molding, etc..
Waterway parts: cooling water for the mold, barrel, blow pin, gear box and other parts of the cooling.
2. System Description
hollow blow molding machine with variable frequency motor speed control system; head and extruder heating and temperature control systems; action process control system (PLC) and the corresponding security systems. Man-machine interface with touch screen input.
feeding extruder high starting torque, high torque converter series by Schneider ATV58, ATV71 series, PLC by Twido 40 points plus extension body; generally due to temperature heating section 6 -8 paragraph 8 by Schneider-specific temperature input modules. Schneider s XBTG touch screen with touch screen call the shots stop, PLC to do from the station, communication using the Modbus protocol. Inverter speed setting given by the external potentiometer.
process: heat insulation barrel Die - Start extrusion materials - forming tube - [mold - blowing the needle - Electric slice tube segments - the head lift mold - mold shifted to the right - blow pin down - blowing cool setting - Blow pin micro pumping - pull the bottom - mold - mold blowing the needle - mold left - the end of the pull - mold] automatic cycle. Which mold the finished product.
3. to solve the temperature drift
hollow blow molding machine as Twido PLC to achieve automatic control, and hollow blow molding machine of plastic particles by heating "squeeze - blow" molding machine, in which temperature plays in the realization of product quality a very important role, so the temperature control requirements is relatively high, generally require control of temperature -4 to 4 degrees, for which we use Twido PLC to achieve this requirement. The main control thought is: the temperature module by Schneider PLC every 0.1s (one can artificially change the acquisition time) collected the first signal, when to collect ten times the time to sort, take the middle of a value, the first boot, as the temperature output value, also sent to the intermediate variables to save, save up to 5 times, except for two maximum, remove the two minimum, take the middle of a value as the normal temperature of the output value. PLC programming ideas are as follows:
the temperature of heating, with temperature range (ie, the temperature control area) to control the heater when the open, when relevant, rather than point to determine the heater temperature control switch. Once heated to this temperature, set temperature, that is in a stable range of heating, while heating device is not very frequent contact with the work, not only guarantee the life of the contact device, and ensures the temperature stability, and improve product quality and productivity of great help. Specific programming ideas are as follows:
In order to minimize temperature drift, pull the heater for 2 seconds, so that the temperature module does not capture the signal, thus reducing the contactor is timely because current on the temperature.
4. Conclusion <BR> Blow electrical control system with touch screen Twido PLC control, all the time, pressure, temperature adjustable parameters blossoms,A police inquiry, for a variety of functions can be matched. High degree of automation: expect to complete the qualifying products from the automatic cycle work. By Schneider with a comprehensive plan, the system is very stable, temperature drift is very small, improved product quality and output, and has received high praise.