From The Blog
How to Make an Injection Mold
What is an Injection Mold?
An injection mold is a tool that when all the parts are assembled, fits into an injection molding machine to manufacture identical plastic parts. Injection molds start with a drawing by an engineer of the part required for an application. Next an engineer with knowledge of the injection mold making process makes a mold drawing.
How an Injection Mold is Made
Making an injection mold takes a great deal of skill and some very expensive machinery.…
What Kind of Plastic is This?
What Plastic is this Part Made Of?
There are several ways to determine what plastic the object you have is made of:
*Plastic Resin Identification Codes
*Burn Test
*Floats or sinks in water
Plastic Resin Identification Codes
The plastics identification codes were developed in 1988 by SPI Society of Plastic Industries. These codes are intended to be recycling codes. #1 is polyethylene terephthalate (PETE, PET), #2 high density polyethylene (HDPE). #3 polyvinyl chloride (PVC),…
UV Degradation of Plastics and UV Resistant Additives
Sunlight May Degrade Plastics
Many plastics will degrade in sunlight without the addition of light blockers, stabilizers or UV absorbers. Materials may discolor, crack or completely disintegrate. While the UV degradation of a polymer in sunlight is usually only .05 deep in the material’s surface the highly brittle nature of some plastics may lead to complete component failure.
Folding Chair with UV Damage
Signs of UV Degradation
*Brittle outer layer (loss of tensile elongation)
*Reduction in molecular weight
*Loss in mechanical properties
*Change in chemical properties
*Discoloration,…