Showing posts with label Rubber. Show all posts
Showing posts with label Rubber. Show all posts

Friday, February 17, 2023

PTFE Products - Unleash Industrial Efficiency with Rubber PTFE Gaskets

Rubber PTFE Gaskets are high-performance sealing solutions used in a variety of industrial applications. They are made from a combination of rubber and polytetrafluoroethylene (PTFE) materials, which provides excellent chemical resistance, high-temperature stability, and superior sealing properties. Rubber PTFE Gaskets offer improved performance and reliability compared to traditional gaskets, making them an ideal choice for industries where efficiency and safety are paramount.
WhatsApp/phone: +8619975113419
mail: info@ptfe-machinery.com

Wednesday, August 28, 2019

Reclamation and Re-resource Of Fiber Reinforced Polymer Based Composites


1.       Mposition and recycling of fiber reinforced resin matrix composites

1.1   Thermoplastic resin base

Fiber reinforced thermal plastic recycle and pure thermoplastics (FRTP) recycling some similar, but there in the FRTP enhancement phase, and enhance the phase structure and distribution characteristics of greater influence on the performance of the materials, so its recovery processing is much more difficult than pure thermoplastics, and recovery processing after the change of its mechanical properties is also a focus of concern. In the past, high industrial costs and cumbersome recycling processes meant little attention was paid to recycling, resulting in the accumulation of waste fibre-reinforced plastics in factories. With the intensification of business competition, the enhancement of environmental protection awareness and the pressure of resource depletion globally, more and more factories have processed and recycled their wastes, and great progress has been made in the recycling and utilization of fiber-reinforced plastics internationally.

1.2 Thermosetting resin base
In contrast, the separation and recovery of fiber reinforced thermosetting resin matrix composites is more difficult due to the three-dimensional network structure formed after molding. According to the recovery process, there are two methods: one recovery and three recovery. Secondary recycling refers to the use of waste materials to be mechanically crushed, used as a filler for the preparation of new composite materials, or directly used to fill thermoplastics. This process only requires mechanical action and is a physical change process. The three times recovery method means that the thermosetting resin matrix is decomposed into its low molecular substance by heating it in different media or through chemical reaction, so as to achieve the separation from the reinforcing material and realize the purpose of recovery.

A granulator is used to granulate the chip molding (SMC) fragments. The glass fiber in the granule still has the basic size (the fiber length-diameter ratio is greater than the critical value) and filling into the plastic has a reinforcing effect. In addition to the mechanical recovery of unsaturated polyester SMC, thermosetting phenolics are also commonly recovered by this method. During the crushing process, the fiber is separated from the brittle epoxy resin matrix to obtain a mixture of particles and staple fibers, and then the secondary pulverized particles are recycled according to different particle sizes and fiber lengths through screening or air separation. The results showed that the mechanical properties of long fiber reinforced plastics were improved by adding recycled materials in PA6.

The decomposition of polymer materials by supercritical fluid is a new technology developed in recent years, especially in thermosetting plastics. The liquid phase consists of medium and low molecular weight organic materials, and the solid phase is fiber. The obtained fiber has no obvious difference compared with unused fiber after electron microscope observation, and there is no organic material on the fiber surface, so it can be used again as reinforcing material. Studied the decomposition and recycling of carbon fiber/phenolic composite materials, and found that in the supercritical water reaction medium system in alkaline environment, increasing temperature, prolongation of time and increasing alkali concentration would be beneficial to the decomposition of resin matrix.

2.       Separation and recycling of fiber reinforced rubber matrix composites

Short fiber reinforced rubber composite (SFRC) is an important part of rubber products. The main recycling ways of waste SFRC are to produce recycled rubber and waste rubber powder. Taking tires as an example, at the end of the 20th century, the world produced more than 10,000,000 tons of waste tires every year, and our country was close to 10,000,000 tons of waste tires. In the process of producing recycled rubber from waste tires or other waste rubber products, at least 5 waste fibers were generally produced, and the output was very considerable. For environmental protection and security needs, most of the reclaimed rubber factory installed with waste fiber recycling equipment, but due to technical or economic reasons, such as waste fibers were used as the fuel burn more, make the fiber more than on attached vulcanized rubber produces a large number of our fleet and s02 gas, serious atmospheric pollution and the surrounding environment, and can make the fiber of recycling waste materials.

Fortunately, people have paid more attention to the research and application of this field. An earlier overseas for recycling waste fiber, carrying out the work are mainly concentrated in the field of building materials and rubber, synthetic fiber cord scrap filling on the coagulation of the tensile strength, impact strength and tensile strength increased, and the craft simple, the cost is not high, when used as waterproof tarpaulins, runway pavement materials, not only reduce the cost, and can improve the tensile strength and resistance to puncture strength. The experiment shows that although the waste rubber has been damaged to some extent during the regeneration process, it still has certain mechanical strength, especially synthetic fiber, which still has the characteristics of good elasticity, high abrasion resistance and excellent dielectric resistance. Although the surface of these waste fibers is coated with broken rubber residue and rubber powder, their potential utilization value can be fully developed through proper processing.



Friday, July 19, 2019

Polymer plastic properties

1.Definition

The main components of polymer plastics are mainly polymer compounds, whose molecular weight is about 1 000, which is only for the physical concept. At present, polymer plastics are widely used, but the daily use of plastic is synthesized by polymer compounds, usually called high or macromolecule, is synthesized by monomer raw materials or raw materials into integrated materials, and through the later development, and fusion resin, color, stabilizer and other additives. The shape of polymer plastic can be changed freely and can be designed according to the user's requirements.

2.Characteristics

Polymer plastics not only have their own unique, that is, arbitrary changes in the shape, but also have viscoelasticity. Polymer plastic, if subjected to external forces, its body will produce high elastic deformation, viscous flow, polymer plastic deformation is mainly related to time. In addition, polymer plastic also has high specific strength, low strength and other characteristics, the strength of polymer plastic is generally lower, but its density is lower, so the strength becomes higher. Polymer has many characteristics, such as high stability, high wear resistance, expansion, high insulation, so it is widely used in various fields, by many people's favor.

The types of polymer plastics are also diverse. At present, the classification of polymer plastics in China mainly includes seven categories: rubber, polymer coatings, polymer materials, matrix composites, plastics, fibers and plastics.

a.   Rubber.
The price of rubber molecular chain is small, flexible, this is from the point of view of the field of physics. Rubber with the size of the external force will change its shape, with instability, if the external force removed, the original state of rubber can be quickly restored.

b.  Polymer adhesive.
The adhesive materials of polymer adhesive are mainly natural compounds. In practice, it is usually divided into two kinds: natural, synthetic adhesive. The most widely used is synthetic adhesive.

c.   polymer coating.
The main components of polymer coatings are mainly polymers, which are made in a relatively simple way, mainly adding solvents or additives in its production process. Polymer coating is divided into 3 kinds commonly, namely grease, synthetic resin and natural resin, often use in daily life.

The commonly used high molecular weight materials mainly include high molecular enzyme and high molecular transparent materials. Polymer materials have certain functions: energy, material, information conversion, transmission and magnetism.

e.   fiber.
Fiber is common in daily life, usually divided into two kinds: natural fiber and chemical fiber. Fiber has the characteristics of small deformation force, small secondary valence force and high modulus in physical concept.

f.    Plastics.
Plastic is a kind of material that USES more at present, also be the commonest material. The main components of plastics are usually synthetic resins, natural polymers, and the integration of other additives, such as plasticizers, fillers and so on. Plastic is generally based on synthetic resin, so it can be divided into thermosetting plastic, thermoplastic.

3. Physical properties

In general, if the polymer plastic placed in isothermal conditions, easy to produce the product. In the actual processing, the crystallization temperature is not completely consistent. If the crystallization temperature difference is large, it will affect the crystallization process. At the same time, high stress is often formed in the process of spinning forming, film stretching forming and extrusion forming, which leads to the tendency of accelerating the product. In addition, plastics apply techniques in shear stress. And under the influence of tensile stress, the melt will form longer fibrous crystals. The higher the stress and strain rates are, the more elongated chains and the higher the melting point.

4. Chemical properties


Generally speaking, if the polymer plastics are placed in high stress and high temperature conditions, the molecular structure will have some changes. In this reaction, polymer plastics usually release a large amount of degraded substances, thus releasing more harmful substances. To this end, in the processing should be clear raw material indicators, choose high-quality raw materials. At the same time, a small amount of antioxidant and stabilizer can be added in the formula to improve the anti-degradation performance of the polymer.