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What Makes Cryogenic Deflashing Method a Cut Above The Rest?

November 16th, 2018 by

Before the final inspection and packing, moulded rubber parts must undergo a finishing process to remove excess flashes. “FLASH” is an excess amount of rubber that oozes out between the two halves of a mould during the moulding of rubber parts.

 

The flash occurs in areas where different sections of the mould join together and are called the ‘parting line flash’. The remaining part of the mould flash traces around where the different sections of the mould join together.

 

Flashes cannot be avoided no matter what technique has been used to manufacture these rubber products. While manufacturing high-performance materials for growing markets like electronics and automotive, intricate finishes, consistency and strict tolerance must be met.

 

Importance of Cryogenic Deflashing

 

 

This is the only method that makes it possible to eradicate complex flash at the inner dimensions. Parts with a thin flash can be removed through cryogenic deflashing quickly. The traditional deflashing methods generally deliver a poor deflashing effect as it is done manually with the help of blades, scissors or knives. The manual trimming method has a high variability in quality and the production rate due to the geometry of the parts. Since the finish quality is not up to the mark, it leads to high rejection rates. Unevenly deflashed products when used can affect and damage the machine it is used in.

 

The Process of Cryogenic Deflashing

 

 

Cryogenic Deflashing is a combination of rapid rotation, nitrogen and plastic blast media is used to get rid of the flash in an extremely precise and economical way. The rubber parts are arranged in a perforated container which is then inserted in a blast enclosure.

 

The containers rotate and evenly expose all sides towards the blast media. The enclosure is insulated with firm polyurethane foam for stable temperatures. The liquid nitrogen decreases the temperature inside and freezes the flashing to make it fragile.

 

With the use of pure nitrogen with zero moisture the requirement of a dryer is eliminated. A fast-moving impeller shoots the polycarbonate pellets in the container. These high-speed pellets trim the inner as well as the outer diameter flashing neatly in a single operation. The effective lubricity and hardness lessens the impeller’s wear and increases its durability.

 

Parting- line flash thickness determines the capability of the system to finish the moulded part in concurrence with the cycle time and LIN consumption. A thicker flash is more difficult to get rid of and requires lengthier deflash cycle time which results in higher LIN consumption. The optimum parting-line flash thickness is 0.001” to 0.005”. Optimum finish quality and LIN consumption are based on the mould design and condition.

 

 

Advantages of Cryogenic Deflashing

 

 

Cryogenic deflashing offers numerous advantages over other traditional or manual deflashing methods:

 

● This process maintains an element of integrity and precision and ensures greater productivity.

● Due to this using a batch process, the cost of per piece is lesser as the number of parts processed in a specific time increases. This makes the manufacturing process economical and cost-efficient.

● Repairing or replacing a mould rises up the expenses bracket. In this method, the moulds can bede-flashed which extends their durability.

● It delivers consistent results in every lot.

● This technique is completely non-abrasive.

● The entire procedure is highly automated which eliminates the need of a human operator.

● This method eradicates the use of any toxic chemicals and is enclosed to a minimum sound which proves it to be environmental-friendly.

 

Harkesh Rubber uses cryogenic deflashing which is the most advanced deflashing process, unlike most of the other OEM’s. This method polishes the parts (typically O-Rings) and minimizes any sign of the flash or parting line delivering an efficient and precise product.

 

With this process, we ensure precision and fulfill our commitment of delivering a quality product. This technique not only improves the performance of the product but also saves the time and effort invested which eventually reduces the cost of production as well.

   

Custom Seals That Provide Trusted Results for the Automotive Industry

August 29th, 2018 by

The exteriors and interiors of the automotive transit vehicles portray a variety of sealing challenges. In many cases, the o-ring does not suffice as a definite sealing solution, which can prove to be fatal. And that itself cannot be allowed to happen since people invest their trust in automobiles with their life.

 

Therefore, Harkesh Rubber with their specialized technical skills and empowered knowledge about the industry manufactures customized rubber seals as a solution to these common problems.  We make sure that the custom seals are of the highest quality with equal priority given to each of them individually.

 

Oil Seals:

 

The oil seal is an element used for excluding dirt, dust, water or other such contaminants while retaining the lubricity in the rotary shaft equipment. It is extremely useful as it offers protection to the bearings of rotating shafts. The basic principle of an oil seal is that the flexible rim is held against the rotating section while the shell is pushed into the cover as it confines it. The sealing edge requires some manner of lubrication to evade overheating and is frequently energized with the help of a garter spring.

 

There are the two main types of oil seals:

 

  • Dynamic Oil Seals

 

Dynamic oil seals are used between surfaces that have relative motion, such as, a shaft and a case. The dynamic oil seals keep gases and liquid in and prohibit contaminants. Oil seals should be smoothly placed against the moving parts to reduce surface wear and provide minimal friction or drag.

 

A seal is selected after taking the chafing speed, operating temperature, fluid pressure, space available and the shaft surface requirements into consideration. A few dynamic seals like the piston rings are designed to endure extreme pressure, while others seal against little pressure. Seals that are used around rotating shafts in an engine are known as radial positive contact seals.

 

Dynamic seals that are used in automotive engines are generally made from rope packing or synthetic rubber. Rope packing is the less expensive type of dynamic seal and has incredibly low friction and wear characteristics.

 

Lip-type dynamic seals that are used in automobile engines are prepared from synthetic rubber. They have the ability to withstand additional shaft eccentricity and run-out when compared to the rope type seals. They are capable of operating at higher shaft speeds. However, they need a finer shaft finish for a longer sealing life. Lip seals put more load on the shaft than the rope type seal.  Therefore, they seal in a better way.

 

  • Static Oil Seals

 

Static oil sealing is the operation against two surfaces that have no relative motion between each other. Depending on the direction of compression, static seals can be either axial or radial. In accordance to the working pressure, it can be divided into low voltage static sealing and high-pressure static sealing.

 

In a static sealing function, they are located in a groove and there is no movement between the sealing surfaces or between the seal surface and its mating surface. Static oil seals are the universal sealing elements that impress with easy installation, small footprint, and versatile application. Due to these qualities and convenience, they are used frequently.

 

Examples for static oil seals include seals for plugs, flanges, and tubing. As the pressure increases, it deforms and reshapes the seal so that sealing pressure increases to withstand the larger containment requirements.

 

 

An oil seal consists of three simple components which are the sealing element, the metal case, and spring. As the function of an oil seal is to preclude leakage along the shaft, this challenge is mainly achieved by the sealing element. The metal case flexes and grips the seal when it is held at the low-level channel. The spring ensures that the sealing element operates smoothly.

 

This proves that custom seals are a boon to the automotive industry. They have not only benefited the automotive industrialists but have also been a great help to the consumers.