Master Molded Products, LLC. has experience and expertise in molding a wide range of commodity and engineering grade thermplastic resins and thermoplastic elastomers.

Specialty materials feature resins systems with a wide range of additives and reinforcements to meet your design and performance criteria.

Morphology Characteristics

Polymers can be divided into two categories according to their molecular structure — semi-crystalline and amorphous.

Characteristics Amorphous Semi-Crystalline
Low Shrinkage  *
Low Warpage *
Tight Tolerances *
Transparent *
Mold Flow Ease  *
Chemical Resistance  *
Wear Resistance  *

Amorphous Resins

Amorphous resins have randomly ordered molecular structure, do not have a sharp melt point and soften gradually as the temperature rises.

Amorphous materials change viscosity when heated, but do not flow as easily as semi-crystalline materials. They exhibit isotropic flow and shrink uniformly in both the direction of flow and transverse to the flow.  resulting in lower mold shrinkage and less tendency to warp as compared to semi-crystalline materials.

Amorphous resins exhibit rapid strength falloff above their glass transition temperatures (Tg).

Semi-Crystalline Resins

Semi-crystalline materials have a highly structured molecular structure and sharp melting points. As temperature increases, semi-crystalline materials remain solid until reaching a point where they rapidly change into a low viscosity liquid.

Semi-crystalline resins are anistropic, that is, they shrink less in the direction of flow compared to transverse to flow.

Semi-crystalline resins typically have excellent chemical resistance due to the lattice-like molecular structure.   Semi-crystalline show significant improvement in their heat deflection temperature (the temperature at which they deform under a given load) when reinforced and maintain strength and stiffness well beyond their glass transition temperatures (Tg).


ABS  AcrylonitrileButadieneStyrene

CPVC  Chlorinated Polyvinyl Chloride

ECTFE  Ethylene Chlorotrifluroethylene

ETFE  Ethylene Tetrafluoroethylene

FEP   Fluorinated Ethylene Propylene

HDPE  High Density Polyethylene

HIPS  High Impact Polystyrene

LDPE  Low Density Polyethylene

LLDPE  Linear Low Density Polyethylene

PA  Polyamide

PAI  Polyamideimide

PBI  Polybenzimidazole

PBT  Polybutylene Terephthalate

PC  Polycarbonate

PCTFE  Polychlorotrifluoroethylene

PEEK  Polyetheretherketone

PEI  Polyetherimide

PES  Polyethersulfone

PET (PETE)  Polyethyleneterephthalate

PETG  Polyethylene Terephthalate with Glycol modifier

PFA  Perfluoroalkoxy

PI  Polyimide

PMMA  Polymethylmethacrylate

POM  Polyoxymethylene

PP  Polypropylene

PPO  Polyphenylene oxide

PPS  Polyphenylenesulfide

PPSU  Polyphenylsulfone

PSU  Polysulfone

PTFE  Polytetrafluoroethylene

PVC  Polyvinyl Chloride

PVDF  Polyvinylidene Fluoride

    UHMW PE  Ultra High Molecular Weight Polyethylene  

Contact us at 847-695-9700 or to have us quote this option for your next custom molding project!