LDPE (Low Density Polyethylene), Warpage analysis, plastic molding, injection moulding, toolmaking CAE services, gas injection, fibre filled, mpi, fusion, midplane models

Specialised Moldflow Analysis
 Imtech Moldflow Analysis



LDPE materials

LDPE (Low Density Polyethylene)

Typical Applications

Closures, bowls, bins, pipe couplings.

Injection Molding Processing Conditions

Drying

Not usually necessary
Melt Temperature 180 - 280 C (355 - 535 F)

Mold Temperature

20 - 70 C (68 - 158 F)

For uniform and economic heat removal, it is recommended that the cooling channel diameters be at least 8 mm and the distance from the surface of the mold to the edge of the cooling channel be not more than 1.5 times the diameter of the cooling channel.

Material Injection Pressure

Up to 150 MPa

Pack Pressure

Up to 75 MPa

Injection Speed

Fast speeds are recommended; profiled speeds can limit warpage problems of large surface area parts.

Runners and Gates

All conventional types may be used; LDPE is well suited for hot runner molds. Insulated hot tip runners are preferred for frequent color changes.

Chemical and Physical Properties

Low density polyethylene is produced by the polymerization of ethylene at high pressure and temperature. The material is semicrystalline-crystalline. The crystallinity level is low because of chain branching. The material is tough but possesses moderate tensile properties and exhibits creep. However, it has good impact and chemical resistance. It is an easy flow material because of long chain branching.

Commercial materials have densities in the range of 0.91 - 0.94 g/cm^3. LDPE is permeable to gases and vapors. Very close tolerances are not possible with this material and its relatively large coefficient of thermal expansion makes it less suitable for long term applications.

Shrinkage is of the order of 0.02 - 0.05 mm/mm (2 - 5%) when density is between 0.91 - 0.925 g/cm^3. When density is between 0.926 -.04 g/cm^3, the shrinkage is of the order of 1.5 - 4%. Actual shrinkage values are dependent on the molding conditions.

LDPE is resistant to many solvents at room temperatures but aromatic and chlorinated hydrocarbons cause swelling. Like HDPE, it is also susceptible to environmental stress cracking.

 

LDPE (Low Density Polyethylene)Injection moulding Polymer Process Guide

Accurate and Confidential Moulding Solutions Since 1987

 
LDPE (Low Density Polyethylene) analysis, weld lines, flow lines, fiber orientation, polymer flow, rapra, part advisor t1 automotive plastic molding, injection moulding, toolmaking CAE services moldex, cadmold, gas injection, fibre filled, mpi, fusion, midplane models Imtech Design,household appliances, tooling, tools, mould, die, toolmaker, die maker, Moldflow Filling, Cooling and Warpage analysis medical device, simulation of plastic injection moulded products meiki, kawaguchi,milacron, mitsubishi, negri bossi, netstal, niigata, nissei, omf turra, oima, plastak, sandretto, stork, van dorm Moldflow, Catia, Solidworks, Inventor, SDRC, Solidedge, STEP, STL, Parasolid, iges, pro engineer, unigraphics, ideas, finite element cycle time, Cooling, analysis, production rate, fast cycle, plastic, injection moulding, molding process, efficiency CAD, CAD/CAM, CAM, Computerizes Numerical Control, CNC, Cutting Tools, Diecasting, Die casting, Diemaking, Die making, Dies, Drilling machines, Dry Machining, EDM Mold Seminars, Mold Shows, Mold Statistics, Mold Testing, Mold Training, Mould Associations Moldflow, fibre, gas, midplane analysis, plastic molding, injection moulding Filling, analysis, plastic molding, plastic consultant, plastics advice sigmasoft, cadmold, moldex 3d, cmold, moldflow, cae injection molding simulation services, plastics engineering, hot runners arburg, asian plastic machinery, atec, battenfeld, bmb, chen hsong, demag ergotech, dgp windsor, dongshing hydraulics, engal, fu chun shin, hpm, husky, jaco manufacturing, jsw japan steel works, jinhwa injection molding simulation software, plastics solutions, flow front, extrusion, trade moulder, custom molder husky, mold masters, inco, fast heat, synventive, hrs flow, polyshot, pms systems, ewikon, manner, gunther, orycon, dme, modplas, thermoplay, volastic, hasco. Mould Builder, Mould Buyers Guide, Mould Coating, Mould Components, Mould Conference, Mould Design, Mould Directory, Mould Distributor, Mouldmaker, Mould Maker, Mould Mold Making, Moldmaking Equipment, Mold Making Equipment, Mold materials, Mold Metals, Mold Polishing, Mold Products, Mold Repair Mold Components, Mold Conference, Mold Design, Mold Directory, Mold Distributor, Mold Magazine, moldmaker, Mold Maker, Mold maker magazine, Moldmaking Moldflow,moldex, cadmold, polymer , plastic, composite, hdt, gas injection, fibre filled, glass, talc, mineral, gas, blowing agent, mpi Machining Centers, Metalworking, Metal working, Milling Machines, Mold, Mold Associations, Mold Builders, Mold Buyers Guide, Mold Coating Electrical Discharge Machining, ETMM, Graphite, Grinding machines, Hot Runners, Injection Molding Molds, Injection Moulding Moulds, Machining Moldflow, Filling, Cooling, Warpage analysis, weld lines, flow lines, fiber orientation, polymer flow, rapra, part advisor

Specialised Moldflow Analysis
 Imtech Design Moldflow Analysis