Tag: injectrion molding

clamp, injection mold, Moldflow, Terminology of Injection Molding

CAE analysis of injection molding

Nowadays there are mechanical engineering softwares that help the mold makers and molding professionals to understand to evaluate the part design for plastic injection molding and also check the tool design before cutting the steel. Although the simulation software’s results are not 100% reliable, it saves time and cost by predicting the week area of the design.

Although the results are not reflecting 100% accurate results, it gives an idea to the designers to observe the tool functionality and evaluate their design before cutting the tool. Also, it will reduce development time and save money for companies. Moldflow and Moldex are two examples of software that are very useful to simulate injection molding of plastic.

Below you can see two graphs produced by Mold Flow analysis.

 

 

 

 

 

 

Materials

Injection Molding Materials

There are two types of materials(resins) which can be used in the injection molding industry; Thermoplastic and Thermoset. A thermoplastic, or thermo-softening plastic, is a plastic material, a polymer, that becomes pliable or moldable above a specific temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight[1].  A thermoset also called a thermosetting plastic, is a plastic that is irreversibly cured of a soft solid or viscous liquid, prepolymer or resin.[1]

large.png

Figure source: http://www.bbc.co.uk/guides/z9tysg8

Resin selection is a very critical step for the injection molding. There are many material suppliers offering quality materials for the injection molding.

They can formulate a plastic to meet the consumer needs properly. For example, the applications of the product play a key role in the choosing material properties. For High voltage connector, the resin has to provide chemical resistance, excellent tracking defense and heat& humidity resilience. For a Fluid Engineering Components, the resin has to have a good hydrolytic stability, excellent resistance to water and FDA approved. The formulated resin has the processability and consistent properties after molding process and in the final use.

Reference :

  1. https://www.wikipedia.org/
Materials

Injection Molding Materials

There are two types of materials (resins) which can be used in the injection molding industry; Thermoplastic and Thermoset.

A thermoplastic, or thermosoftening plastic, is a plastic material, a polymer, that becomes pliable or moldable above a specific temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight.[1]

A thermoset also called a thermosetting plastic, is a plastic that is irreversibly cured of a soft solid or viscous liquid, prepolymer or resin.[1]

large.png

Figure source: http://www.bbc.co.uk/guides/z9tysg8

Resin selection is a very critical step for the injection molding. There are many material suppliers offering quality materials for the injection molding.

They can formulate a plastic to meet the consumer needs properly. For example, the applications of the product play a key role in the choosing material properties. For High voltage connector, the resin has to provide chemical resistance, excellent tracking defense and heat& humidity resilience. For a Fluid Engineering Components, the resin has to have a good hydrolytic stability, excellent resistance to water and FDA approved. The formulated resin has the processability and consistent properties after molding process and in the final use.

 

 

Reference :

  1. https://www.wikipedia.org/
Terminology of Injection Molding

Y

Yellowness Index: A measure of the color on the yellow scale.

Yield Point: In tensile testing, the yield point is the first point on the stress-strain curve at which an increase in strain occurs without an increase in stress.

Yield Strength: The stress at which a material exhibits a specified limiting deviation from the proportionality of stress to strain.

Young’s Modulus: The ratio of tensile stress to tensile strain below the proportional limit

Terminology of Injection Molding

W

Warpage: Distortion caused by nonuniform internal stresses.

Water Absorption: The amount of water absorbed by a plastic article when immersed in water for a stipulated period of time. All plastics will absorb moisture to some extent.

Weld Line: Where melted material flows together during molding to form a visible line or lines on a finished part that may cause weakening or breaking of the component.

Wisps: Similar to stringing but smaller in size. These also may occur as slight flashing when the mold is over packed or forced open slightly. Mold-parting-line wear or misalignment can also cause wisps.