4 big impacts are plastic conduit squeezes a shaping element

Published on 2017-09-25

 1. Temperature


Temperature is crowded piece shape one of fundamental conditions that are able to go on wheels.


Begin from farinaceous or graininess solid state stock, high temperature goods is squeezed from inside nose piece, experienced a complex temperature change process. Will strictly tell, crowded piece shape the temperature that temperature should point to plastic fuse-element, but this temperature depends on greatly however the temperature of makings canister and screw, one fraction comes from the clash that produces when mixing in makings canister heat up, express to shape approximately via temperature of canister of commonly used makings so temperature.


Because expect canister and plastic temperature are in,screw is discrepant each paragraphs, to make plastic carry in makings canister, melt, leveling and squeeze the process success that give, so that efficient ground production high quality is made, crucial question is canister of control good stuff each paragraphs of temperature, expect the adjustment of canister temperature is to rely on extruder heat cooling system and temperature control system will come true.


Nose temperature must be controlled it is under plastic pyrolysis temperature, and the temperature that buccal model is in can compare nose temperature a bit a few lower, but should make sure plastic fuse-element has good liquidity.


In addition, shape the wave motion of the temperature in the process and difference in temperature, will make model each bits of generation remains stress, intensity is inhomogenous with the surface gloomy lacklustre wait for blemish. The ingredient that produces this kind of wave motion and difference in temperature is very much, if heat, cooling system is not stable, change of screw rotate speed, but the impact of stand or fall that be designed with screw and chooses is the biggest.


2. Pressure


In cramming a course, as a result of the obstruction of makings shedding, the change of screw chamfer deepness, and screen pack, cross the generation block such as filter plate and buccal model, consequently the edge expects canister axes direction, constant pressure generates in plastic interior. This kind of pressure is plastic turn into even fuse-element gets compact model one of fundamental conditions.


Increase nose pressure to be able to raise those who squeeze a fuse-element to mix uniformity and stability, raise a product to send density, but nose pressure crosses a general to affect crop.


With temperature, pressure also can produce periodic wave motion along with the change of time, this kind of wave motion is right model quality has adverse effect likewise, the change of screw rotate speed, heat, the reason that the flabby choose a site for the capital of cooling system is generation pressure wave motion. To reduce pressure wave motion, should rotate speed of reasonable control screw, assure to heat to control precision with the temperature of cooling device.


3. Extrusion rate


Extrusion rate (also say to push a rate) it is the extruder inside unit time buccal model squeezes the plastic quality that give (the unit is Kg/h) or length (the unit is M/min) . The size token that pushs a rate is worn the on any account that pushs a productivity.


The element that the influence pushs a rate is very much, rotate speed of the structure that is like nose, screw and makings canister, screw, heat cooling construction of system and plastic character. Theory and practice prove, extrusion rate follows deepness of chamfer of screw diameter, helix, leveling to end length is spent and increase of screw rotate speed, increase along with pressure of screw extreme fuse-element and screw and makings canister clearance and increase. The structure in extruder and plastic breed and model below the circumstance with certain already type, extrusion rate is concerned with screw rotate speed only, accordingly, adjusting screw rotate speed is the main measure that controls extrusion rate.


Extrusion rate also is put in fluctuant phenomenon in producing a course, this will affect model geometrical appearance and dimension precision. Accordingly, besides structure of correct affirmatory screw and dimension parameter, still answer to control screw rotate speed strictly, strict control squeezes a temperature, prevent to push a pressure and fuse-element viscosity change because of temperature is changed and be being caused, bring about the wave motion that pushs a rate thereby.


4. Drawing speed


Crowded piece shape to basically produce successive model, because this must install draw gear. Squeeze the model that give from inside nose and buccal model, drawing orientaton will happen below traction action. Drawing orientaton rate is higher, model the tensile strength of edge orientaton direction is greater also, but systole of the length after refrigeration is big also. Normally, drawing speed but with squeeze a speed to comparative. Drawing speed and the specific value that push a rate say drawing is compared, its value must is more than 1.