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PP compression fittings are often used in the construction industry and are ideal for many different purposes. For example, they are lightweight, easy to install, and can be used in a variety of environments. They are also durable and strong.
Often, the difference between fabricated and molded compression fittings is not clear. Both are designed to join a pipe or pipe component. Each has its advantages and disadvantages. It is important to determine the fitting for the job at hand.
The fabricated fitting is usually a larger fitting. It is made from a pressure-rated PE4710 polyethylene resin. The process involved is more complicated. In addition, fabricated fittings must undergo a deration process in order to meet Australian standards. Fabricated fittings may be adequate for low-pressure systems. However, it may be a good idea to use moulded fittings when possible.
In terms of the quality, molded fittings are much better. This is due to the fact that the material used to mold the fitting is more accurate. In addition, the quality of the finished product is consistent, and the fitting is more likely to last. It is also a cheaper option.
The fabricated fitting, on the other hand, is less common. This is because fabricated fittings are usually larger than injection molded fittings. It is also more labor-intensive to produce. It is also likely that less common fittings may not require the creation of a mold.
The choice is to use a quality European moulded fitting. This type of fitting is a good choice because they are fully pressure rated and provide longevity. These fittings also come with a warranty.
PP/PE compression fittings are designed to connect two lengths of polyethylene pipe. They are widely used in irrigation and water supply applications. They do not require solvent welding or glue, and are resistant to UV rays. Polypropylene is the commonly used material in the production of PP compression fittings.
Polypropylene has good resistance to organic solvents and salts, and is N.S.F. 14 certified. It is also autoclavable. However, it is not suitable for use in chlorinated hydrocarbons or other strong acids.
Polyvinylidene fluoride (PVDF) has outstanding aging and fire-resistant properties, and is twice as strong as PVC. It has a semitranslucent cloudy appearance and is self-extinguable. It is also non-flammable, and is a reliable thermoplastic pipe fitting material.
Thermoplastic materials are flexible to use, and are cost-effective. Their environmental tolerance is also high. They can be recycled and colored. Thermoplastics are also resistant to corrosive materials and have resistance to sunlight. In general, thermoplastic materials have high tolerance to chemicals, heat, and cold. In addition, they have good mechanical properties. Compared with other thermoplastics, PP/PE compression fittings have good bending capacity and are easy to shape.
The mechanical properties of HDPE are dependent on the temperature and crystallization rate. In particular, the crystallization rate was positively correlated with the elastic modulus and tensile properties. The tensile properties were significantly reduced as the temperature increased, while the elastic modulus increased with increasing strain rates.
Currently, expanded plastic material mold systems are primarily confined to steam chests. In these systems, the mold is enclosed in a steam chest that limits the number of cavities and limits the part's geometry. In addition, the process requires significant steam to expand the plastic material. This steam volume is a significant portion of the variable cost of expanded plastic materials. However, direct injection methods can eliminate the need for steam chests, which also reduces the cost of steam. Consequently, the present invention reduces the cost of expanded plastic materials by removing the need for a steam chest.
One embodiment of the invention is a method for expanding polypropylene. The method includes the steps of preparing a specimen having a predetermined dimensions of at least 220 mm x 64 mm. The specimen is then compressed using a pre-injection stage. The compressed material is then turned around through a hot runner channel with a pneumatic needle valve nozzle.
