Author: Kenny

Glossary of Terms (2)

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FLOW LINES	See SPLAY
FREEZE TIME	The time it takes to set the molded plastic resin for a variety of functions. For example, freeze time describes the time it takes to set the molded resin, in order for ejection to occur.
FRONT CAVITY PLATE	See “A” PLATE
GATE	An opening at the end of the runner through which the material enters the cavity.
GUIDE PINS	See LEADER PINS
HARDENABILITY	The ability of a material to become harder by the addition of alloying elements and heat treatment processes. It should not be confused with hardness.
HARDNESS	The resistance of a metal to surface indentation (denting) or abrasion (scratching). Indentation hardness can be measured with the Rockwell or Brinell methods.
HEAT SINK	A heat absorber or collector. It is used as a mold component or insert into the component to collect heat in an area that is hard to reach by typical cooling design. Materials typically used are copper, beryllium copper, tungsten alloys, and gas or liquid thermal pins.
HOT RUNNER MOLD	A molding method in which the runner system is kept hot and insulated from the cavity portion of the mold. The mold parting line is typically at the gate. This runner system is not ejected to become waste or regrind material, as it is in the cold runner system.
INJECTION	The process of forcing a plastic material or a molten alloy into a mold.

INJECTION MOLDING	The process in which the plastic material is heated to a molten state in a heating cylinder, and then forced into a cooled mold to produce the desired shape.
INSERT	Integral inserts – parts which are machined separately from the basic core and cavity, and are then installed in the proper position in the core and cavity, and which become part of the molded part after the molding material has hardened.
INSERTS, MOLDED-IN	Loaded inserts – not part of the mold, but separate metal pieces placed in the mold which become part of the molded part after the molding material has hardened.
KNOCKOUT BAR	See EJECTOR PLATE
KNOCKOUT PIN PLATE	See EJECTOR RETAINER PLATE
KNOCKOUT PINS	Term given to ejector pins.
LEADER PINS	Hardened and ground steel pins pressed into one of the plates. They align the two halves of the mold base. (Also called GUIDE PINS)
LOCATING RING	Fits into a counterbore in the top clamping plate and is used to locate the mold on the platen of the press so the nozzle and sprue bushing are aligned.
MACHINABILITY	The relative ease of which a metal can be machined or worked on with tools.
MICROPROCESSOR	A computer chip integrated circuit, capable of controlling the (Integrated Circuit) input and output functions, for which it was designed – such as automatically controlling the cooling cycle of a mold.

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MIRROR FINISH	A diamond finish that shines and reflects light.
MOLD	The entire mechanism (cavities, cores, plungers, holder blocks, etc.) needed to mold parts from plastic materials or from non-ferrous alloys.
MULTIPLE CAVITY MOLD	A mold which has a number of cavities and produces more than one part in each cycle.
ORANGE PEEL	A condition caused by too much pressure, speed, or both when diamonding. When orange peel occurs the surface becomes bumpy and irregular.
O-RING	A tire-shaped, round cross-section of a synthetic rubber gasket or seal. A coolant seal can be formed by a compression fit of the O-ring and itÆs mating parts.
PARALLELS	Mounted on the bottom clamping plate under the support plate to form a space (ejector housing) which allows the ejection stroke when the piece parts are ejected. (Also called RAILS)
PARTING LINES	Marks on a molding where halves of the mold meets in closing.
PIECE PART	The article or part to be molded.
PILLARS	Bars placed between the support plate and the bottom clamping plate. Bolted or doweled to the bottom clamping plate, they are used as additional support for the core retainer plate.
PLATENS	The mounting plates of a press to which the mold assembly is bolted.

PROFILER	Profiler is a brand name commonly used to refer to any reciprocating hand piece.
PROTOTYPE MOLD	A temporary or experimental mold construction made in order to obtain information on part design, tool design, and market reactions.
PUSH BACKS	See RETURN PINS
RADIATE	Emitting rays of heat, such as a mold-base radiating heat from the molding process.
RAILS	See PARALLELS
REAMED HOLE	A round, hard, multi-cutting edge scraping tool. It is used after a hole is drilled in order to improve the hole geometry. It will produce a rounder, straighter, and smoother hole than drilling.
REAR CAVITY PLATE	See “B” PLATE
REAR CLAMPING PLATE	See BOTTOM CLAMPING PLATE
REDUCE DEFORMATION	Elements added to control the amount of change in a metal due to stress, thermal change, change in moisture or other changes.
RELEASE	The ability of a mold to eject a part.

RETURN PINS	Located in the ejector retainer plate. These pins force the ejector plate and ejector retainer plate and, therefore the ejector pins, to the bottom position as the mold closes. (Also called EJECTOR RETURN PINS, SAFETY PINS, or PUSH BACKS)
REYNOLDS NUMBER	A number used as a measure of turbulent flow for a liquid.
RUNNERS	Channels through which plastics flow from the sprue to the gates of mold cavities.
RUST RESISTANCE	The ability of a ferrous metal to resist oxidation in the presence of water (rust).
SAFETY PINS	See RETURN PINS
SCAR	An undesirable cosmetic mark left on the mold surface due to a variety of reasons, such as degating the part from the runner system.
SENSORS	A variety of devices designed to detect, measure, or record physical phenomena such as temperature.
SHRINKAGE ALLOWANCE	The additional dimensions that must be added to a mold to compensate for shrinkage of the plastic molding material on cooling.
SPACER BUTTONS	Pressed into the bottom clamping plate, they are lands for the ejector plate. (Also called STOP PINS)
SPRUE BUSHING	Butted up against the nozzle of the injection machine. Has a conical-shaped hole through which the material is forced into the mold runner.

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March 20, 2014

Glossary of Terms

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ABRASION RESISTANCE	The ability to resist localized surface damage from contact with other material in use, such as gouging, grinding, scratching or erosion.
ANSI	(American National Standards Institute) A privately funded, voluntary membership organization that identifies industrial and public needs for national consensus standards, and coordinates development of such standards. Many ANSI standards relate to the safe design and performance of equipment, such as safety shoes, eyeglasses, smoke detectors, fire pumps and household appliances; and safe practices or procedures, such as noise measurement, testing of fire extinguishers and flame arrestors, industrial lighting practices, and the use of abrasive wheels.
“A” PLATE	Part of the stationary section of the mold into which the leader or guide pins are mounted. Also used to hold core, cavity blocks, and sprue bushing.
ASTM	(American Society for Testing Materials) A voluntary membership organization with members from a broad spectrum of individuals, agencies, and industries concerned with materials. As the world’s largest source of voluntary consensus standards for materials, products, systems, and services, ASTM is a resource for sampling and testing methods, health and safety aspects of materials, safe performance guidelines, and effects of physical and biological agents and chemicals.
AUTOMATIC MOLD	A mold designed and constructed in which the material is loaded into the mold and the finished parts are ejected from the mold without an operator.
BACK TAPER	Sometimes called back draft or reverse draft.
BACK-UP PLATE	See SUPPORT PLATE
BALANCED RUNNER SYSTEM	A runner system that is designed to fill each mold cavity equally, continuously, and simultaneously.
BALL END MILL	A hardened cutter, capable of machining a half-round slot, or shape into annealed metal using the milling machine.
BENCHING	Term used to define the initial steps in polishing to prepare cavity and core blocks for the actual polishing process.

BERYLLIUM COPPER	Beryllium is added to copper to form a hard, strong alloy. It is excellent as a heat sink, or heat absorber, for a component portion of the mold that is hard to reach by typical cooling design. It can also be used to conduct heat.
BOTTOM CLAMPING PLATE	Holds the moving portion of the mold to the movable platen of the injection machine.
“B” PLATE	Top plate of the movable section of the mold. Forms the parting line of the mold with “A” plate. Used to hold the leader pin bushings as well as core and cavity blocks.
BUSHINGS	Hardened and ground steel bushings which are pressed into one of the plates. They serve as bearing surfaces for the leader pins.
CAVITY	The depression or female portion of the mold which gives the external surface to the part being produced.
CHILLER	See COOLING UNIT
CHILLING UNIT	A mechanical refrigerator designed for outgoing water of a specific temperature. Ethylene glycol can be added to the water if a temperature below freezing is required.
COLD SLUG WELL	A recess or groove, at the end of a long length that traps the leading cooled plastic. A Cold Slug Well is typically machined in a runner part of a balanced runner system, and can be used to prevent or minimize weld lines.
CONDUCTION	Transferring heat from two or more bodies that are in contact with each other, such as heat conducted by mold-base steels.
CONVECTION	The ability of a medium to carry heat from one place to another, such as coolant traveling through mold steel channels

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COOLING CHANNELS	Holes drilled into the various plates or into the various mold components, or channels machined into components, to allow the flow of a cooling medium (water) in order to keep the mold at the proper molding temperature.
COOLING TOWER	Heated coolant from a mold is pumped to a cooling tower, inside or outside of the factory, where it falls by gravity past a grid. Some cooling takes place during the fall, but fans are typically used to add extra cooling. The cooled liquid is then collected and returned to pass through the mold again.
COOLING UNIT	A mechanical refrigerator designed for outgoing water of a specific temperature. Ethylene glycol could be added to the water if temperatures below freezing were required.
COOLING UNIT	A system of cooling channels and components designed to give effective cooling to a molded part or parts.
CORE	The male portion of a mold that shapes the interior of a hollow molded part.
CORE PIN	A pin for forming a hole or opening in a plastic molded piece.
CUSTOM MOLDS	Molds owned by the customer and used by the molder.
CYCLE TIME	The total time required to produce a molded part. Cycle time includes the time from the injection of the plastic resin into the mold, to the ejection of the molded part.
DEGATING	Separation of the gate and runner system from the molded part. Degating can be done by hand, in a trim fixture, or automatically.
DEOXIDIZERS	Elements added during the manufacture of steel to control the residual amount of oxygen that remains in the steel.

DIAMONDING	Act of shining molding surfaces with diamond compound and brushes and buffs.
DIMENSIONAL STABILITY	The ability of a plastic part to keep the precise shape in which it was molded.
EJECTOR PIN	A pin (in a mold) that directly pushes the molded part out of the cavity. Sometimes called a knockout pin. A number of these pins may be used in one mold.
EJECTOR PLATE	Bolted together with the ejector retainer plate to form a unit. Contains the plate for the pins in the ejector retainer plate.
EJECTOR RETAINER PLATE	Counterbored for the heads of ejector, ejector return pins, and sprue puller pins.
EJECTOR RETURN PINS	See RETURN PINS
ETHYLENE GLYCOL	A colorless, viscous liquid used as antifreeze.
FATIGUE RESISTANCE	The ability of a metal to resist fracture from repeated application of stresses. Fatigue failure usually occurs at loads which if applied statically would have little effect, but repeated cycles of the stress or strain lead to eventual failure.
FATIGUE STRENGTH	The highest cyclic stress a material can withstand for a given number of cycles before failure occurs.
FLASH	A thin piece of plastic material that typically forms along the parting line of a molded part. Flash is a result of a parting line surface or surfaces that is not matched or is shutting off the flow of plastic resin

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March 20, 2014

Design of Runner and Gate

The runner system is the passage way for plastic material to move from the sprue to the entrance. The runner technique is extremely important with respect to filling cavities. In the event the runners are extremely small in size the mold cavities will not likely fill properly. If the runners are too big, then the cooling time will probably be increased and cycle time reduced. Suitable runner design can reduce the negative impacts of stress, sink and weld spots.

Runner

[ezcol_1half] The illustration reveals a well-balanced H layout runner system employed to mold four rectangular chips. The arrows display the plastic material move from the sprue via the runners, entrances, and directly into the cavities. What’s so great about the proper H layout will probably be discussed afterwards.

Two of the most common runner types available today are the full spherical and the trapezoidal. The entire spherical style is used in most cases.

The sketch shows a cross section view of a entire spherical runner produced directly into the P/L(parting line) of a mold base. Be aware that half of the runner is in the top plate and the other half of the runner is incorporated in the bottom plate. The runner is stripped out of the mold base with the molded part.

A skin of plastic material gets frozen against the cooled mold surface and causes melted plastic to flow via the core of the runner. The spherical runner provides the least amount of scrubbing to its volume, least pressure drop, ideal movement, and is the simplest runner to remove from the mold. Nonetheless, more works and skill matching the runner into both mold halves is needed.

[/ezcol_1half][ezcol_1half_end]This illustration represents the method employed to engrave one half of the round runner into the mold steel .A very hard ball end mill cutter and its fixer are spun in the spindle of a milling equipment. The cutter marks left over the runner surface must be eliminated through polishing with rotary abrasives.

The spherical runner dimension is decided by the species of plastic material employed to mold the component. A lot of mold developers depend on client or plastic material resin provider in order to indicate dimension. The runner dimensions vary from 3/16 in order to 3/8 . Big size runners decrease strain, bending, and sink scars. Nonetheless, runners have to be possible small in order to decrease injection dimension and cycling time.

This sketching shows a cross-section of a trapezoidal runner engraved directly into the P/L of a mold base. Be aware that the entire runner is engraved in one plate. The runner is stripped out from the mold base along with the component.

A plastic material skin gets frozen contrary to the cooled down mold surface and results in melted plastic material to move via the core of the runner. Despite the fact that trapezoidal runner is simpler to engrave because it is machined into just one plate, this particular advantages could be outweighed through the more move constraint. Choice of this runner could be for the Three plate mold or plastic mold that might not permit a entire spherical runner structure.
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March 20, 2014
Mold Base Technology

Mold Base Technology

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Cavity Plate, A Plate

This plate holds the cavity in the mold. Its thickness is normally decided by the “depth” of the part. The runner system and gating are sometimes machined (half) in the surface of the plate. This surface is also the parting line surface and “shut off” (sealing) must be obtained or flash will occur.

Core Retain Plate, B plate

This plate holds the cavity in the mold. Its thickness is normally decided by the “depth” of the part. The runner system and gating are sometimes machined (half) in the surface of the plate. This surface is also the parting line surface and “shut off” (sealing) must be obtained or flash will occur.

Top clamping Plate

This plate holds the cavity in the mold base. Its thickness is normally decided by the “depth” of the part. The runner system and gating are sometimes machined (half) in the surface of the plate. This surface is also the parting line surface and “shut off” (sealing) must be obtained or flash will occur.

Supporting Plate

The primary purpose of the supporting plate is to reinforce the mold during injection. It is actually a thicker plate that will not bows during the injection stage of the molding process. The ejector mechanism (pins) moves though the supporting plate.

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Ejector bottom Plate

The actual ejector plate stands out as the floating plate during the ejector process. Its thickness is determined with the level of pressure necessary to remove the component and the part/mold dimension. This plate furthermore fastens the ejector system (pins or plate) inside the ejector retainer plate.

Ejector top Plate

The ejector bottom plate is adopted in a mold to fix the ejector system (ejection pins, return pins, and so on) on the ejector plate. The retainer plate is head recessed for every pin. The pin bottoms change to be flush with the back on the plate and also the ejector plate then fastens straight to the retainer plate. In the course of ejection, the retainer plate “draws” the ejector system (pins) to its original position.

Stripper Plate

The stripper plate is usually an ejector system employed to aid in component stripping. This plate is mounted on the ejector return pins and actuated traditionally. The plate thickness is determined with the pressure necessary to take away the component. The cavity shape should be precisely machined in to the stripper plate to prevent extreme tool wear and enable the stripper plate to “stay” properly whenever it’s retracted.

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March 19, 2014
quickly manufacturing injection molded components

In terms of quickly manufacturing injection molded components, there are many important aspects to think about. Listed below are some from the best considerations to begin off around the proper track:

Design and style

All effective injection molding applications commence with correct design and style for the procedure, and within this case for fast production. When designing your component for speedy injection molding, probably the most crucial elements that contribute to lead time are component size and complexity. Anytime a bigger element may be broken down into smaller sized pieces then assembled, you’ll potentially shorten lead time. This really is easy, shallow cavity styles are created faster through the CNC machining method. Designing components which can be moldable having a ‘Straight Pull Mold’ is a superb spot to begin. This demands that each of the pars functions be developed in order that when the two halves in the mold are pulled from one another as well as the element is ejected, you’ll find no secondary processes needed. This really is as a result of mold material’s tendency to pull by means of component plastic ,this can be known as an ‘undercut’.Undercuts need mold pieces to pull out sideways, perpendicular towards the path in the pull. These side actions as they’re referred to as can demand hand loads for reduced volume projects or automatic/mechanical loads for larger runs.

Material

Best rapid turn projects ought to make use of regular, off the shelf supplies and colors which are either currently on hand or may be swiftly sourced from a material distributor. Typically, lack of require for name brand material doesn’t trigger problems, but this can be not the case for all projects. When a precise brand and kind of material is needed, the material could be ordered and shipped although tool cutting happens simultaneously. Must the material not arrive inside the allotted window, a substitute material can occasionally be employed in location in the production material to, in the extremely least, confirm simple design and style and function from the component. When production material arrives, a second sample run can take spot prior to proceeding with greater production runs.

Price

Obviously when there’s a lead time requirement for components faster than the regular, you’ll need price considerations. These considerations are driven by further man hours needed by the project up front and frequently outcome in overtime and extended shop hours to attain the preferred ship date. These products that may be sped up? Issues including tool style, steel or aluminum delivery towards the shop, component material ordering, and scheduling sample production runs.

March 18, 2014
How to decide a draft

Among the most typical concerns we’re asked is “How to decide a draft I want to the texture that I want”
The basic rule of thumb is the fact that you permit for 1.6 degrees of draft for every .001 inch of texture finish depth. Nevertheless, you will find other concerns that should be taken under consideration as a result of the numerous new resins and polymers, molding enhancements, and different other aspects that come into perform in contemporary plastic molding. Examples of scenarios that demand extra draft are thin wall component design and style and large strain molding.

Some essential concerns to help keep in thoughts are:
Will be the vertical wall in query an inside or outside wall? If it really is inside wall, the element will shrink onto it in the course of molding, which means you will want a lot more draft to be able to apply a texture, or apply the texture at a lighter depth.

Specific plastics have really tiny shrinkage and can consequently not shrink far from outside walls as very easily as other plastics. Thermosets, Ryanite, Glass Filled PA, Glass Filled PP, ABS, PC, and so forth. will typically demand a lot more draft as a way to mold elements without scuff or drag marks.

In the event the core is extremely easy, and there’s absolutely nothing within the core to hold the component in spot in the course of ejection, the element will have a tendency to hang onto the cavity, making scuff marks. The component might demand much more draft, or possibly texture might be utilized towards the core side. This assists hold the element onto the core in the course of ejection.

March 18, 2014
Injection Molding Method and cycle

Injection Molding Method

With injection molding , the gravity deliver the granular plastic from a hopper right into a heated barrel. Since the granules are gradually pushed forward by a screw-type plunger, the plastic is forced right into a heated chamber called the barrel where it really is melted. As the plunger advances, the melted plastic is forced through a nozzle that seats towards the mold sprue bushing, enabling it to enter the mold cavity by means of a gate and runner method. The mold stays at a set temperature so the plastic can solidify virtually as soon as the mold is filled.

Injection Molding Cycle

The sequence of occasions throughout the injection molding of the plastic component is termed the injection molding cycle. The cycle starts once the mold closes, followed from the injection of the melt polymer to the mold cavity. When the cavity is filled, a holding pressure is maintained to compensate for material shrinkage. From the following stage, the screw turns, feeding the subsequent shot to the front screw. This triggers the screw to retract since the next shot is ready. As soon as the element is sufficiently awesome, the mold opens and also the portion is ejected.

March 17, 2014
What is injection molding ?

What is injection molding and What are the features about injection molded plastics? This approach allows suppliers to create goods of more challenging and elaborate shapes that could be too hard or costly to machine. The injection molded plastics procedure furthermore facilitates a large number of items to get created all at once using the same mold. Additional advantages comprise significant processing rates, decreased workcrews expenses and higher repeat tolerance, plus there certainly is minimal require to do whatever to finalize the part once it is usually molded. The untouched plastic pellets and runners can also be reprocessed for potential future molding therefore there is virtually virtually no waste product.
if you would like bulk construction for intricate objects,the injection molding is a good determination ,and the upcoming show few already mentioned and unmentioned.* Injection molding allows for significant manufacturing output ranges.
For a few particular usage ,you could possibly fit an insert into tooling or even add in addictives for strenght consideration
you can get exactly the same dimension and outlines for objects
We might benefit from over-mold to build the items for different color choice and varied substance in the mean time.
Commonly,we’d like uncommon effort for second operation immediately after injection molding,as well as the items finish is actually very same.
*Most scrap may well be reground that can then be used again, consequently there may be little waste.
* Whole automation may be accomplished with the help of Injection Molding.

March 14, 2014
Blog

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Usually in the mold constructing procedure, it is possible to offer rapid prototypes employing 3D printing and thermoplastic technology and review all aspects of mold design along with the user, complete with procedure and plastic mold troubleshooting, to be certain a high-quality, accurate mold everytime.

March 14, 2014