Polypropylene
Polypropylene - A tough, light-weight polyolefin plastic made by the polymerization of high-purity propylene gas in the presence of an organometallic catalyst at relatively low pressures and temperatures.
Polymerization
Polymerization - A chemical reaction in which the molecules of a monomer are linked together to form large molecules whose molecular weight is a multiple of that of the original substance.
Polymer definition
Polymer - A high-molecular weight organic compound whose structure can be represented by repeated small units.
Polyethylene processing
Polyethylene - A polyolefin composed of polymers of ethylene. Exists in three classes: low, medium and high density.
Polycarbonate Resins processing
Polycarbonate Resins - Polymers derived from the direct reaction between aromatic and aliphatic dihydroxy compounds with phosgene or by the ester exchange reaction with appropriate phosgene- derived precursors.
Rotary Clamp
Rotary Clamp - A clamp in which the platens and mold are moved to close about an extruded parison and then said molds are rotated away from the parison center line. More than one platen is moved and the rotation can be horizontal or vertical, with the blowing devices rotating with the clamp.
Programmed Parison
Programmed Parison - Changes in shape and wall thickness of a parison at predetermined points along the length of the parison.
Preform Rod Holder
Preform Rod Holder (Core) - One for each station of injection blow molding machine = holds preform rods.
Preform Rod (Core Pin, Core Rod)
Preform Rod (Core Pin, Core Rod) - Internal member of preform (injection) cavity which is used to transfer preform to blow mold.
Preform Cavity (Injection Cavity)
Preform Cavity (Injection Cavity) - Together with preform rod, forms preform.
Pre pinch
Pre pinch - Closing off an open end of the parison, before the molds pinch is together. Often used in connection with pre blow.
Pre Close
Pre Close - Closing the molds (platen) to some point nearer the closed position before final closing on the parison.
Pre blow in extrusion blow molding
Pre Blow - The injection of a medium into a closed parison before the molds close.
Injection machine platen speed
Platen Speed - The closing/opening speed of a platen movement in inches per second (or cm/sec).
Polyethylene processing
Polyethylene - A polyolefin composed of polymers of ethylene. Exists in three classes: low, medium and high density.
Programmed Die Head
Programmed Die Head - A die head with provision for variation of orifice opening at specific points during parison ejection so as to program the parison.
Injection molding machine platen daylight
Platen Daylight - Open - Maximum and Minimum open distance; closed - Maximum and Minimum shut distance.
Injection molding machine platen
Injection molding machine platen - The plates on which the mold assembly is mounted. Large metal blocks on clamping ends of a molding machine used to support the mold.
Polymer plasticize
Plasticize - To soften a material and make it plastic or moldable, either by means of an extruder or by heat or both.
Plastic Shut Off Valve
Plastic Shut Off Valve - A valve used to shut off plastic flow, usually mounted in a manifold.
Screw pitch
Screw pitch - Distance in an axial direction from the center of a flight at its periphery to the center of the next flight. In a single flighted screw “pitch” and “lead” will be the same, but they will be different in a multiple flighted screw.
Pinch off
Pinch off - Those sections of a parison which are not taken within the cavity of a mold, and which are removed after blowing.
Pin (Mandrel) and Bushing (Die) Banks
Pin (Mandrel) and Bushing (Die) Banks - The maximum pin (mandrel) size and minimum bushing (die) size supplied unfinished.
PET - Polyethylene Terephthalate
PET - Polyethylene Terephthalate, known as a thermoplastic polyester. Has the unusual ability to exist in either an amorphous or highly crystalline state.
Pearlescent Pigments
Pearlescent Pigments - A class of pigments consisting of particles that are essentially transparent crystals of a high refractive index. The optical effect is one on partial reflection from the two sides of each flake. When reflections from parallel plates reinforce each other, the result is a silvery luster, iridescent effects and metallic sheen resembling natural pearl.
Plastic parting line
Parting line - Line, visible on the molded part, where the mold separates to release the molded part from the cavity.
Parison ejection rate
Parison ejection rate - The rate of plastic flow through the die body in cubic inches per second, or pounds per second.
Parison extrusion blow molding
Parison - The plastic tube formed by ejecting plastic through the die head or by injecting over a core within and injection cavity sometimes called preform.
Polymer orientation
Orientation - The alignment of crystalline structure in polymeric materials so as to produce a highly aligned molecular structure.
Olefins
Olefins - A group of unsaturated hydrocarbons and named after the corresponding paraffins by the addition of ene or ylene to the stem. Examples are polyethylene, polypropylene, etc.
Needle blow
Needle Blow - A system of blowing whereby the blowing medium is introduced into a mold through a needle inserted into the parison and which is frequently a part of the mold construction.
Moving Mandrel Die Head
Moving Mandrel Die Head - A die head whose mandrel of die pin can be moved vertically so as to vary the orifice opening.
Plastic mold components
Plastic mold components - Parts that make up a mold and determine how a mold will be operated.
Plastic mold
Mold - The cavity or matrix of cavities into which plastic melt is placed and takes form.
Metering section of screw
Metering section of screw - A relatively shallow portion of the screw at the discharge end with a constant depth and lead, usually three to four turns of the flight in length, at which the melt is advanced at a uniform rate to the screw tip.
Melt Flow Index/Rate
Melt Flow Index - The amount, in grams, of a thermoplastic resin which can be forced through a 0.0825 inch orifice when subject to 2,160 grams force for ten minutes at 230°C, per ATSM D1238
Melt decompression
Melt decompression - Reducing pressure of melt during molding cycle, usually by reverse movement of screw.
Melt accumulator
Melt accumulator - A cylinder equipped with a ram in which the plastic is stored between shots. Its capacity is variously given in cubic inches, or in maximum shot weight. The ram is actuated by hydraulic pressure, either variable or constant to allow for programming weight and thickness of the parison through the die opening.
Parison mechanical or electronic Programming
Mechanical or Electronic Programming - A method of changing the shape and wall thickness during formation of the parison.
Setting up manual cycle in injection molding
Manual cycle - A manual cycle requires that each machine function be controlled manually by an operator.
Manifold
Manifold - A structure containing flow passages that carry the plastic to the accumulator head or die heads.
Lubricants in polymer processing
Lubricants - Prevent materials form sticking or improve processability.
Low pressure injection mold close
Low pressure mold close - Low pressure mold closing is a provision in the machine to lower the clamp closing force during the clamp closing cycle. The lower clamp forces minimizes the danger of mold damage caused by parts caught between the mold faces.
Linear molecule
Linear molecule - A long chain molecule of two-dimensional structure which may contain side chains or branches.
Lead In
Lead In - Initial clearance through an initial angle or chamfer that helps align two close mating parts.
Knockout injection molding
Knockout - Any part or mechanism of a mold used to eject the molded article.
Interference Fit
Interference Fit - The mating of two points, lines, or surfaces, the dimensions of which cause negative clearance between them.
In-Mold Decorating for extrusuion and injection molding
In-Mold Decorating - The process of applying labels or decorations to plastic articles simultaneously with the molding operation.
Injection molding pressure
Injection Pressure - Pressure exerted on plastic to flow through a manifold and die head tooling.
Injection Blow or Injection Transfer Technology
Injection Blow or Injection Transfer - A type of blow molding in which the parison is first injection molded and is then transferred to the blow molding mold for blowing.
Polymer properties: Hardness, Heat Deflection
Hardness - The resistance of a material to compression or indentation. Among the testing methods Brinell, Rockwell, and Shore
Heat Deflection or Distortion Point - The temperature at which a standard test bar deflects 0.010 inches under a stated load of either 66 or 264 psi. Indication of maximum temperature that you can eject a part from a mold..
Heat Deflection or Distortion Point - The temperature at which a standard test bar deflects 0.010 inches under a stated load of either 66 or 264 psi. Indication of maximum temperature that you can eject a part from a mold..
Guide pins & rods
Guide Pins - Devices to maintain proper alignment for molds.
Guide Rods - Rods which guide the platens but take no clamp force.
Guide Rods - Rods which guide the platens but take no clamp force.
Fluorescent effect in plastics
Fluorescent - Organic dyes or pigments which may be blended into inks to provide a luminescent or fluorescent appearance typical of the "neon" colors.
Flash plastic part
Flash - The thin, surplus web of material which is forced into crevices between mating surfaces during a molding operation, and which remains attached to the molded article.
Plastic filler
Filler - A substance added to the plastic to make it less costly. Some fillers also improve mechanical properties.
Extruder Feed Throat
Extruder Feed Throat - The section of the extruder supporting the feed hopper, frequently water cooled, through which plastic is introduced into the extruder by the feed opening.
Extruder Length to Diameter Ratio = L/D - The distance from the forward edge of the feed opening to the forward end of the barrel bore divided by the
Extruder Length to Diameter Ratio = L/D - The distance from the forward edge of the feed opening to the forward end of the barrel bore divided by the bore diameter and expressed as a ratio wherein the diameter is reduced by 1, such as 24:1 or 30:1.
Impact strength for polymers
Impact Strength - The ability of a material to withstand shock loading.
Gel Permeation Chromatography
Gel Permeation Chromatography - A device used to determine the molecular weight distribution of a polymer.
GPC - An abbreviation for Gel Permeation Chromatography.
GPC - An abbreviation for Gel Permeation Chromatography.
Extrusion feed zone
Feed zone - Zone on the screw directly below hopper. Plastic is pre-heated in this zone, not melted.
Exhaust time extrusion blow molding
Exhaust time - The length of time required to relieve the blowing medium pressure in the molded part before opening the mold.
EVOH - Ethylene-vinyl alcohol co-polymers
EVOH - Ethylene-vinyl alcohol co-polymers. Used for barrier to gases.
EVA (Ethylene-Vinyl Acetate)
EVA (Ethylene-Vinyl Acetate) - Co-polymers from these two monomers retain many of the properties of ethylene, but have considerably increased flexibility, elongation, and impact resistance.
Polymer Environmental Stress Cracking
Environmental Stress Cracking (ESC) - The susceptibility of a plastic to crack or craze under the influence of certain chemicals, stresses, or other agents.
Polymer elongation
Elongation - Lengthwise stretching of a material usually denoted as a % of original length.
Polymer elasticity
Elasticity - The property of a substance which enables it to return to its original shape and size after removal of a deforming force.
Polymer elastic deformation
Elastic deformation - The part of the deformation of as part under load which is recoverable when the load is removed.
Ejection system injection molding
Ejection system - System used to eject the molded part from the mold after it cures.
Plastic part ejection
Ejection - That part of the molding cycle in which the finished part is removed from the mold mechanically.
Dry coloring
Dry coloring - A method commonly used for coloring plastics by tumble-blending uncolored and colored particles of the plastic material with selected dyes and pigments.
Draft plastic molding
Draft - The degree of taper of a side wall or the angle of clearance designed to facilitate ejection of parts from the mold.
Die adjustment extrusion blow molding
Die Adjustment - Means for moving the die relative to the die pin ( lower mandrel).
Subscribe to:
Posts (Atom)