New foaming EAs and other technologies, thermoplastic rubber has become an important area of rapid growth in the rubber and plastic industry.
People are very concerned about replacing various rubber parts with more economical thermoplastic elastic materials (TPEs).
An important category of TPE that has been developed is elastic alloys (EAs).
EAs has penetrated into the entire intersection.
Part of the rubber market application, progress continues to be made in these special applications.
The foaming of TPEs has made significant progress and has not been developed until recently, allowing the preparation of very low density rubber foam with elastic alloy Santoprene rubber.
In another area of application, the rubber cover rolls, the properties of the EAs make them ideal for use.
However, until recently, manufacturing technology has been fully developed in order to be able to be used in a variety of rubber-covered rolls.
Large rollers covered by hot-solid materials require a vulcanization time from a few hours to a day or two, because these roller covers are larger in size and the heat transfer performance of the rubber is relatively low.
However, the rollers covered with elastic alloys do not require any vulcanization.
For those hot solid rubber rollers with quality defects, the rubber must be stripped and the process repeated.
In some cases, the thermoplastic elastic plastic cover can be repaired, and in the worst case, it can be removed, re-ground and re-processed.
Similarly, due to the relatively low density of these materials, the use of EAs as a sound barrier is limited.
The demand for sound and noise control in automotive and industrial applications has prompted the development of several new grades of elastic alloys that will show better sound attenuation capabilities.
This paper reports on the progress made in pushing the East Asia Summit into these three areas.
The new developments reported here will specifically support the sustained and rapid growth of TPEs and EAs.
Rubber, including traditional vulcanization foam rubber, is used in various sealing applications.
The low force required to detect and compress foam rubber seals
makes it an ideal material for washers in automotive and mechanical rubber products applications.
The process of manufacturing these traditional vulcanization foam rubber products is susceptible to high scrap rates, which offset the advantage of low cost per volume of foam thermosolid rubber products.
The reprocessed TPE has a significant cost advantage over the conventional rubber used in foam rubber products.
In a variety of industries and applications, thermosolid elastic materials are used as roll covering materials for small and large rollers.
Due to the lack of application technology to solve practical functions and manufacturing problems, the penetration of thermoplastic rubber in this field is relatively small.
Rubber used in rolling covers represents non-
The development of TPE\'s roll cover and bonding technology opens the market for these materials, enabling them to compete with traditional rubber.
Roll paper is used in many industries, including paper, food and office equipment.
We will report three different processes used to prepare EA rubber covering rolls.
Another product application area that needs special attention is noise control.
Since sound insulation products are considered performance and high quality products, noise control has become an increasingly important issue in all industries.
Compared with traditional rubber, TPE products with enhanced noise control features provide better quality and consistency.
Compared to traditional rubber products, the products reported here will provide competitive economy and high sound barrier performance.
Foam technology has been extended to elastic alloys for use in foam rubber applications.
The foaming of Extruded is done through two processes.
The first is a chemical foaming agent.
The second is a mechanical foam process using a foaming agent.
Figure 1 shows a comparison of the reduced density that can be achieved by both processes.
Chemical foaming is a logical extension of the technology often used in conventional hot-solid rubber, which is to some extent used in thermoplastic processing.
Chemical foaming agent is an additive that can decompose gas through overheating.
A few of the jobs are Kempore 60/14 (Olin Chemicals), Expancell 0-113 and 0-157 (Thefa Corp. ), Celogen AZ-130 (Uniroyal Co. )
And Nortech XMF 1307 (USI Chemicals).
Citric acid and bicarbonate compounds such as hydrogen cerol-were also used-CLM 70 (
Nitrogen diarbon and modified nitrogen diarbon compounds form a closed cell structure that maintains this structure when the molten elastic alloy cools down.
The chemical foaming process is usually limited to a decrease in density of 15 to 25%.
Attempts were made to inject nitrogen or air directly into the melt to achieve a reduction in density of about 20% or less, but did not succeed.
The limiting factor is the ability to dissolve the gas produced by the blowing agent.
A lower density elastic alloy foam is obtained using a mechanical foaming process using ozone-safe foaming agent such as C F. sub. 3]CH[Cl. sub. 2].
Ozone-safe carbon-fluorine compounds are measured directly into the vacuum port of the 30:1 L/D extruder.
The temperature of the last barrel part needs to be carefully controlled to obtain a smooth skin and develop a closed foam structure.
By mechanical foaming of elastic alloys, the density is reduced by up to 80%.
Foam elastic alloy has excellent mechanical properties.
Figure 2 shows the tensile properties obtained in several foam elastic alloy grades, where the specific gravity is from 0. 72 of 0. 84.
The main design features of many foam rubber products are load deflection force.
Figure 3 shows the load deflection force of several elastic alloys.
As shown in figure 4, the foam elastic alloy also exhibits excellent taking performance during compression.
For the application of many foam rubber elastic materials, the foam unit structure is composed of closed units to prevent water stop or absorption of other materials.
A water absorption test characterized the number of closed cell structures as shown in figure 5.
Table 1 shows the comparison of the hardness grade of foam elastic alloy 67 Shao\'s A with the traditional hot-solid foam B-C rubber.
Under equivalent load deflection and similar density, the tensile strength of the foam elastic alloy is 58% higher than that of the foam B-C rubber.
The compression permanent deformation of foam elastic alloy is 30%.
A mechanical foam elastic alloy with three commercial foam-B-c rubber samples was tested.
Compared with Grade 67 shore A of elastic alloy, foam B-C rubber has similar load deflection properties.
The tensile strength, tear strength and compression permanent deformation of each material were determined.
Figure 6 summarizes the results graphically.
These data show that the low density elastic alloy has excellent tear strength and tensile strength
B-C rubber with considerable density.
The tear strength exceeded 0.
55 The specific gravity of B-C rubber is better than any kind of foamed B-C rubber, especially 0.
39 proportion of B-C rubber.
With the decrease of the density of foamed ethylene-propylene rubber, its tensile and tearing strength decreases.
When these low densities are reached, the elastic alloy foam has excellent mechanical strength.
Elastic alloy foaming technology provides a means to prepare low-density elastic products using low-cost thermoplastic processing.
The properties of the foam elastic alloy are similar to those of the traditional foam hot solid rubber.
The application of this foaming technology opens the application of elastic alloy in a wide range of cross sealing applications
Foam elastic alloy seals in electrical appliances, automobiles, office equipment and building and residential door and window seals are now commercialized.
The properties of elastic alloy foam make it an excellent candidate for this wide range of applications.
The economy of the process is based on relatively low thermoplastic processing costs and makes it commercially important for manufacturers and users.
Roller cover technology according to the size of the roller, the developed roller cover technology can be divided into two application areas.
Small rolls are easily covered with thermoplastic elastic materials and can be applied with traditional techniques.
Very large volumes have special handling issues that make them more difficult to cover.
Smaller rollers of length from a few centimeters to nearly 1 m are covered with an elastic alloy, formed using an insert injection, and then the roll cover is processed into a tight tolerance dimension.
In some cases, mechanical interlocking with the roller is a full guarantee of performance, however, adhesive can be applied on the roller to achieve a higher level of adhesion between the elastic alloy and the surface of the roller.
Another technique that successfully covers small rolls is the extrusion tube-shaped premade rod.
The pre-Blank can be pressed onto the roller using a lubricant or air assist technology.
For rollers with less stringent dimensional tolerance requirements, the latter technique is a highly attractive low-cost method for preparing rubber covering rollers using elastic alloys.
Two manufacturing methods have been developed to cover large rolls with a diameter of 1 m or longer, 30 cm with an elastic alloy.
The first is the melting layer technology, and the second is the cold layer technology.
The thickness technology of melting is to preheat the roller to 175 [degree]
C. Place it in the hot air oven for about an hour.
After installing the hot roller in the wind-
Up system, modified polypropylene powder adhesive (
BP chemical company, Poly bond 1016)
Sprinkle on the outside surface.
The roll is then returned to the hot air oven and heated for another 15 minutes to melt the adhesive.
The adhesive-covered rollers are then installed into the sheet extrusion line system.
The elastic alloy is extruded through a standard sheet with a thickness. 5 to 3. 8 mm at 205-215 [degree]C.
The paper is tightly wrapped around the roller and ensures good sandwich adhesion by pulling slightly to 1\'s tensile ratio. 0 to 1. 25.
Roll and rotate until the elastic alloy melt is layered to the required thickness.
Once covered, the roll is removed and cooled in water (|70 [degree C]
About an hour.
Then the roll cover of the required size is processed on the lathe.
In a series of elastic alloy grades from 73 Shore a to 53 shore D hardness, the melting layer process was successfully demonstrated.
It was found that the lid had good adhesion, no gaps, and no layering was found.
The Ply method has also been developed as a two-step process.
First, squeeze and wrap a ladder of elastic alloy.
Coating of epoxy resin based adhesive (Metallon 2108)
Applicable to volumes.
The ladder strip is coated with adhesive Primer (Renault primer 360)
And then spiral around the roller to the required thickness.
Apply the fabric tape tightly to the cold elastic alloy roller and apply the winding roller to 150-160 [degree]
A few hours.
During this period, the pressure blends these layers together, and this technology provides a solid rubber coating without void.
The rollers are removed and cooled, and then processed to the finished size according to the melting layer technology.
The performance of elastic alloys in these applications has been demonstrated in a variety of commercial applications, from office machines for paper processing to industrial rolls in the food, textile and paper processing industries.
The performance of elastic alloys for applications in these fields is rubber-
Such as friction properties, good wear resistance, moderate fluid resistance, excellent heat-resistant aging properties and excellent compression properties.
Since the elastic alloy does not require any vulcanization process, the economy of the technology described is better than that of conventional hot-solid rubber.
Therefore, the driving force is better cost/performance for rollers covered with elastic alloys.
Sound attenuation elastic alloy technology has been developed for applications that require noise and sound attenuation.
This is achieved by increasing the density of elastic alloys to take advantage of the law of mass effect.
The larger mass of the unit volume reduces the sound power transmission in number.
Several grades of elastic alloys are compared with the properties of hot-solid ethylene-propylene rubber in table 2.
The data show that the high-density elastic alloy is better than the high-density ethylene-propylene rubber and the lower-density and more traditional ethylene-propylene rubber.
These high density elastic alloys provide physical properties to meet the hot air aging and fluid resistance requirements for automotive and industrial applications, while providing better noise reduction effects.
Acoustic Chamber tests of sound transfer properties and acoustic attenuation elastic alloy grades of ternary rubber were performed using an acoustic chamber.
The device consists of a white noise source connected to a rubber tubular sample.
The total sound power transmitted through the sample was measured in the chamber.
Samples of each material are measured under two wall thicknesses.
The total sound power through a diameter of 75mm is from 2.
Figure 7 shows 5mm wall tubes for each material.
The results of these tests show that the sound transmission properties of high density elastic alloys are reduced.
Total acoustic power is reduced between 2 and 2 compared to standard elastic alloys. 5 dBA range.
These reductions are very significant and often require significant mechanical modifications through engineering or design means.
In Figure 8, the frequent failure of sound transmission is shown as 1.
5 gravity B-C rubber and a-1.
5 gravity elastic alloy.
The spectrum of sound shows that the elastic alloy has a better attenuation at a lower frequency, which is usually preferred, E. G. g.
Due to the reduction in sound transmission to car passenger cars.
High frequency sound of attenuation and thermosetting ethylene-propylene rubber quite.
An improved acoustic attenuation elastic alloy will provide significant benefits in applications in industries such as automobiles, office equipment, electrical appliances and industrial equipment, including sound barriers, seals and covers.
The competitive advantage of using low-cost options such as elastic alloys while obtaining significant sound and noise attenuation is important in applications where consumer quality is critical.
Summary and conclusion by developing the application technology in these fields, the application of elastic alloy in the special market application of foam rubber, roller cover and harmonic attenuation becomes possible.
These developments will enable the processing advantages of elastic alloys to be realized in this application.
The elastic alloy is known for its good fluid resistance, excellent thermal aging, excellent dynamic fatigue, excellent compression performance and good mechanical properties.
The capability of manufacturing products discussed here will bring these advantages to a wide range of industries including commercial equipment, automobiles, office equipment, electrical appliances and construction.
Users in these industries will be able to get better cost/performance through elastic alloys, rather than hot-solid rubber such as ethylene-propylene oxide rubber, Poly-neoprene and chloro-sulphonated polyethylene.
Figure 1-foamed EAs -
Figure 2-Comparison of densityfoamed EAs -
Photo: Figure 3-foamed EA -
Load deflection Photo: Figure 4-
Chemical foaming EAs-
Figure 5-compress settings photos
Chemical foaming EAs-
Photo of water absorption: Figure 6-
Performance Comparison with foam B-C rubber Photo: Figure 7-
Density effect of sound transmission Photos: Figure 8-
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