A book of "Mold Standards" is a detailed description of what is required to match the mold with the molding factory, their equipment, machines, clamping systems, water hook ups, hydraulics for cylinders, air hook ups and cylinders, brand and type of steels/materials that are required, Hot Runner brand, electrical hook up and wiring requirements, brand and type of components (DME, Hasco), etc. This should never come from the mold maker, he'll build you what is cheapest for him.
This technology can be very effective in eliminating or substantially reducing the stress in flatter molding. In internal gas injection, where the gas is injected into one or more gas channels. For a flattish, panel-type part such as this, this is not always the gas injection process to be recommended. The added gas channels can leave a slight witness mark on a cosmetic 'A' surface and depending on the part geometry, the gas packing pressure will probably not be equal across the whole surface area of the part, especially with thinner wall sections and wider surface areas.
Engineering plastic molded parts are made of engineering plastics, through injection molding process, the engineering plastics, such as ABS, PC, POM, are molded into parts with desired shape and measurement. Parts made of engineering plastics have better mechanical and thermal properties, it can be used as a replacement of metal in many applications, for example, plastic auto parts, medical parts, electronic parts, household parts etc.
Engineering plastic molded parts required firstly part design, then you need a mold making company to fabricate an injection mold, at the end, you need an injection molder to mold it. To achieve a good result, it is important to make sure that both the mold maker and molder understand the property of the engineering plastic. Unlike other ordinary plastic parts, the parts made of engineering plastic are supposed to be applicable on many aspects besides dimension or appearance; you need to do some test to make sure there are functional.
Finding the right software is not easy. So the best is to do a benchmark of the software systems, cause it depends a bit of what you want get out of the simulation. It depends on if your company wants to simulate for part design, or is a mold manufacturer or a plastic part producer. Also is depends on the size of parts. Big Parts, small parts, flat parts. Big parts like bumper is hard to do in 3D, cause it takes too much time in simulation. It also depends on if you want to do simulation of assemblies with mold inserts or part inserts like core shift analysis. Not everybody needs everything.
Amorphous resins such as ABS, Polycarbonate, and Polystyrene have much lower shrinkage values than the polyolefins. The higher shrinkage of polyolefins is due to the fact that, in their molten state, they take up more volume than in the solid state because polyolefin resins are semi-crystalline. When the resin solidifies, the chains in the crystalline regions pack tightly together resulting in a reduction in volume. In general, the polyolefins can be ranked for shrinkage:
HDPE ≥LLDPE ≥LDPE ≥PP
Once a resin has been selected, shrinkage can be controlled, to some extent, through mold design and processing conditions.
The differences between the two styles:
- Toggles generate tonnage via tie bar stretch, Hydraulics based on ram diameter and hydraulic pressure. Toggle injection machines tend to increase tonnage as they run due to thermal expansion of the mold, tie bars, toggle links and plattens. Without a tie bar strain gauge, you never know what the true tonnage is! Hydraulics remains the same as long the pressure stays the same.
- Toggle machines open with near full close tonnage ratings. Great for deep draw parts. Hydraulic machines are limited due to the ram design as the pressure is exerted against the shaft seals and wiper. For that reason, the opening pressure is limited. Now with newer clamp designs, the hydraulics is faster and more efficient than ever. Engel uses a smaller high speed cylinder to open and close the clamp; the ram is for clamp tonnage only. That is true of their Duo and Tie Barless machine design. With a Duo the small tie bar mounted clamping cylinders are used to break open large or deep draw parts.
In a fast-paced market, it is critical for a company to get new custom products into the market quickly, in most of the cases, it could be just a market-testing product with 10,000 units' volume or even less. But the plastic parts still need to be customized by injection molding to achieve the specified tolerance, finish, function. Traditionally, a hardened steel injection mold would requires a very high investment before you get a piece of sample, and it usually take 8-12 weeks to complete, which are unacceptable for a new product developing at the earliest phrase.
We need a solution to reduce the cost of injection molding and shorten the lead-time of for companies to launch new custom plastic products. Low volume plastic injection molding is what you are looking for, which means low cost, quick turn around and on budget.
Some glossary of terms related with plastic parts design, mold making and plastic injection molding.
Antistatic Agent: Additive used to help eliminate or lessen static electricity from the surface of the plastic part.
Boss: Protuberance on a plastic part designed to add strength, facilitate alignment, provide fastening, etc.
Clamping Plate: A plate fitted to a plastic mold and used to fasten the mold to a platen.
Co-injection Molding: A special multilateral injection process in which a mold cavity is first partially filled with one plastic and then a second shot is injected to encapsulate the first shot.
Undercuts: in plastic injection molding industrial, it refers to part features that prevent straight ejection at the parting line, which cause much mold complexity and lead to higher mold construction and maintenance costs. Whenever it's possible, redesign the part to avoid undercuts. Minor part design changes can often eliminate undercuts in the mold. For example, adding through holes can give access to the underside of features that would otherwise be undercuts, simple modifications enable the mold to form a hole in the sidewall rather than with a side-action mechanism. See below figure.
Two plate mold is the easiest injection mold structure and has many advantages. It's consist with A side and B side 2 main parts, when it is load in ejection machine to do molding, A side is fixed and held still, B side is movable.
Usually 3 plate mold is not recommended as there are some disadvantages, it's not just because of a much more complex structure but much higher scrap rate, it's also lack of stability because of complex mechanism. It's random to use for high volume production because it required longer cycle time and bigger injection molding machine as the run distance is longer comparing with 2 plate mold.
Clear plastic injection molding parts usually made in PC, POM, PMMC, AS, PET, these clear plastic kits used widely in different application, such as auto light, medical devices, cosmetic packing, food container, water tank etc.
Comparing with other colored parts, strict requirements for appearance is a must for transparent plastic parts, which makes the injection molding processing more complex. Mold design and injection molding condition are all determined factors to the final result, there are a few problems happen frequently in clear plastic molding process, we provide some solutions as below.
Overmolding is also called 2 times injection molding in China. Compared with the third-party material bonding, overmolding process makes the process faster and more cost-effective, it has been widely employed in plastic design.
Over molding are categorized into 3 types: insert molding, double shot molding, co-injection molding.
Insert molding: The most commonly used to mold soft elastomers to rigid plastics, insert molding is the most economical way to do overmolding. In the insert design, the hard segment has been separated into tools in advance, and then eject the soft materials in.
Elastomers are adhesion bond, which can be mechanical locks, chemical and other methods. In order to achieve chemical adhesion, the elastomer must be sufficiently heat to melt the surface of the hard segment to achieve chemical bonding.