Modern cars have very flexible painted surfaces stretched across the bumper surfaces which are specially designed to withstand minor impacts with impunity. The idea is that a vehicle’s bumpers will absorb many of the minor impacts routinely encountered in parking lots and during everyday driving without being damaged. Unfortunately, the bumper paint is ultimately damaged, marred or scraped off when the bumper absorbs too great of an impact.
The bumper paint used on modern flexible bumpers is unique and is designed to be applied on flexible surfaces. The paint is specifically designed to be fully cured but still flex to a much greater degree than the paints which are applied to the much more rigid surfaces such as metal and high-impact plastic. The reason for these unique qualities is the existence of a chemical flex agent in bumper paint.
When procuring primer and paint products to be used for bumpers it is important to purchase and utilize products which are specifically designed for this specialized application. These paints are chemically designed for adhesion to plastic surfaces. The paint formulas are essentially the same as the materials which are sprayed onto non-flexible surfaces, but will include additives to give the paint its flexible qualities. Therefore, bumper paint is somewhat more expensive when purchased.
Bumpers are painted in basically the same manner as the rest of the vehicle. For new bumpers, the surface must be somewhat more thoroughly cleaned using specific products to remove any traces of the mold release agents which are applied inside the molds used when the plastic parts are manufactured. Presence of such mold release agents will negatively affect adhesion of the paint to the plastic surfaces. The bumper’s surface must be thoroughly chemically cleaned to remove any waxes, oil, road film, mold release agents or fingerprints so the bumper paint will adhere properly. Primers or sealants are sprayed first, followed by the basecoat paint and finally topped with clearcoat, all of which contain the flex agent. After fully curing, the flexible bumper paints may be buffed and waxed in the same manner as any other automotive paints.
https://www.msplasticmold.com/product/cratesbaskets/
The bumper paint used on modern flexible bumpers is unique and is designed to be applied on flexible surfaces. The paint is specifically designed to be fully cured but still flex to a much greater degree than the paints which are applied to the much more rigid surfaces such as metal and high-impact plastic. The reason for these unique qualities is the existence of a chemical flex agent in bumper paint.
When procuring primer and paint products to be used for bumpers it is important to purchase and utilize products which are specifically designed for this specialized application. These paints are chemically designed for adhesion to plastic surfaces. The paint formulas are essentially the same as the materials which are sprayed onto non-flexible surfaces, but will include additives to give the paint its flexible qualities. Therefore, bumper paint is somewhat more expensive when purchased.
Bumpers are painted in basically the same manner as the rest of the vehicle. For new bumpers, the surface must be somewhat more thoroughly cleaned using specific products to remove any traces of the mold release agents which are applied inside the molds used when the plastic parts are manufactured. Presence of such mold release agents will negatively affect adhesion of the paint to the plastic surfaces. The bumper’s surface must be thoroughly chemically cleaned to remove any waxes, oil, road film, mold release agents or fingerprints so the bumper paint will adhere properly. Primers or sealants are sprayed first, followed by the basecoat paint and finally topped with clearcoat, all of which contain the flex agent. After fully curing, the flexible bumper paints may be buffed and waxed in the same manner as any other automotive paints.
https://www.msplasticmold.com/product/cratesbaskets/
When you have a large business to run, it is important to select and buy your tools carefully. It can be hard sometimes because you have limited time and cannot inspect every piece of machinery. Therefore, finding a good machine maker will solve most of your problems, especially when it comes to plastic molding. There are many mold makers in China. You can find experienced mold makers in other countries, but China offers the lowest prices. You can get a great deal, but having a qualified mold maker is important for a successful business.
You can ask for a sample too, but it can be time consuming, so a better way is to see the terms and conditions of the mold maker along with their warranty clauses. These plastic molds are used for manufacturing various parts, especially in the automobile industry. Therefore, you need to be careful and keep certain things in mind before associating with a mold maker.
Some of these tips are:
Always have complete inquiries: Inquiring about your machine is always advisable. These include product specifications, mold specification and small details.
Draft or design of the injection mold: A draft of the mold is important because it is essential to know the structure of the mold.
Data of the mold: The Chinese company should provide a video, sample photos and mold designs before closing the deal.
It is important to test your mold since it can cost you much more in order to find cheaper mold. It is suggested to check your molds along with the terms and conditions. Buying molds from a Chinese company has many advantages as it not only provides a high quality mold, but also at a cheaper rate. The only problem can be that due to large manufacturing, the quality of some molds can vary. It is ideal for a complete inquiry since you cannot be physically present to test the product. Always see to it to study the product and try to have as close an inspection as possible.
Also, check what types of molds are required for your company and look for a variety of options before you buy the right kind. There are different types of China injection mold manufacturers available in the market. It is ideal to approach many companies before buying in order to get the best deal for your needs. Since the market is quite large, speak to as many manufacturers as possible with complete inquiry.
China provides the top quality molds at a very reasonable price. This is the main reason for their popularity. Every company is looking for a great deal at an affordable price which is why they approach Chinese manufacturers for injection molds. Most of the time they do get their desired molds whenever they undergo a thorough inspection. But sometimes when they don’t study the product enough, it has cost them at a very high price.
basket mould https://www.msplasticmold.com/product/cratesbaskets/
You can ask for a sample too, but it can be time consuming, so a better way is to see the terms and conditions of the mold maker along with their warranty clauses. These plastic molds are used for manufacturing various parts, especially in the automobile industry. Therefore, you need to be careful and keep certain things in mind before associating with a mold maker.
Some of these tips are:
Always have complete inquiries: Inquiring about your machine is always advisable. These include product specifications, mold specification and small details.
Draft or design of the injection mold: A draft of the mold is important because it is essential to know the structure of the mold.
Data of the mold: The Chinese company should provide a video, sample photos and mold designs before closing the deal.
It is important to test your mold since it can cost you much more in order to find cheaper mold. It is suggested to check your molds along with the terms and conditions. Buying molds from a Chinese company has many advantages as it not only provides a high quality mold, but also at a cheaper rate. The only problem can be that due to large manufacturing, the quality of some molds can vary. It is ideal for a complete inquiry since you cannot be physically present to test the product. Always see to it to study the product and try to have as close an inspection as possible.
Also, check what types of molds are required for your company and look for a variety of options before you buy the right kind. There are different types of China injection mold manufacturers available in the market. It is ideal to approach many companies before buying in order to get the best deal for your needs. Since the market is quite large, speak to as many manufacturers as possible with complete inquiry.
China provides the top quality molds at a very reasonable price. This is the main reason for their popularity. Every company is looking for a great deal at an affordable price which is why they approach Chinese manufacturers for injection molds. Most of the time they do get their desired molds whenever they undergo a thorough inspection. But sometimes when they don’t study the product enough, it has cost them at a very high price.
basket mould https://www.msplasticmold.com/product/cratesbaskets/
As far as versatility is concerned, plastic injection molding is one of the best production methods. The reason is that it offers a lot of advantages over other traditional methods of injection molding. This method is simple, reliable and more efficient. That’s the reason most manufacturers use it to make parts. In this article, we are going to discuss the 5 primary advantages of using plastic molding.
1. Complex Geometry and Detailed Features
We know that molding involves extremely high pressure. So, this high pressure allows manufacturers to add a lot of details to the components. Aside from this, the extreme pressure helps make complex shapes. Other methods can also help achieve the purpose but the cost and complications will be too high.
2. High Efficiency
After the designing of the molds, the molding process becomes quite quick, unlike other molding methods. Actually, plastic injection molding doesn’t take much time. Moreover, it allows the making of a lot more parts in a short period of time.
That’s the reason this method is a lot more efficient. Usually, these parts are more consistent as far as quality is concerned. However, it won’t be easy to make changes to the colors.
3. Enhanced Strength
As far as plastic injection molding is concerned, fillers can also be added. They can cut down on the plastic density during the molding process. Plus, they can help add more strength to the components. Plastic molding can help make parts that can meet the strength needs of a specific application.
As a matter of fact, enhanced strength is one of the main advantages of this process that appeals to most manufacturers.
4. The use of Multiple Types of Plastic
Another main advantage of this technique is that it allows the use of the different types of plastic at the same time. And one way of doing so is to use co-injection molding. So, manufacturers are not limited to only certain types of plastic anymore.
5. Automation for Cost-Reduction
Since this process is automatic, it’s possible to save a lot of money. Most of the process is done by robotics and machines. These machines are controlled by only one operator. As a result, the cost of manufacturing comes down significantly.
Apart from this, the overall manufacturing cost comes down. So, the price tag is also lower, which makes it possible for even an average buyer to place their order. Automation also allows for accurate and precise injection molds. Both CAM and CAD enable close tolerance while the molds are made.
The Bottom Line
To cut a long story short, plastic injection molding helps make parts that don’t require a lot of post-production work. In fact, parts are complete from all aspects once they have been taken out of the molds.
Nowadays, this process is quite common as it’s eco-friendly. The scrap plastic is collected for reuse. Therefore, there is almost no waste left behind. So, this was a description of some of the most common advantages of plastic injection molding.
basket mould on https://www.msplasticmold.com/product/cratesbaskets/
1. Complex Geometry and Detailed Features
We know that molding involves extremely high pressure. So, this high pressure allows manufacturers to add a lot of details to the components. Aside from this, the extreme pressure helps make complex shapes. Other methods can also help achieve the purpose but the cost and complications will be too high.
2. High Efficiency
After the designing of the molds, the molding process becomes quite quick, unlike other molding methods. Actually, plastic injection molding doesn’t take much time. Moreover, it allows the making of a lot more parts in a short period of time.
That’s the reason this method is a lot more efficient. Usually, these parts are more consistent as far as quality is concerned. However, it won’t be easy to make changes to the colors.
3. Enhanced Strength
As far as plastic injection molding is concerned, fillers can also be added. They can cut down on the plastic density during the molding process. Plus, they can help add more strength to the components. Plastic molding can help make parts that can meet the strength needs of a specific application.
As a matter of fact, enhanced strength is one of the main advantages of this process that appeals to most manufacturers.
4. The use of Multiple Types of Plastic
Another main advantage of this technique is that it allows the use of the different types of plastic at the same time. And one way of doing so is to use co-injection molding. So, manufacturers are not limited to only certain types of plastic anymore.
5. Automation for Cost-Reduction
Since this process is automatic, it’s possible to save a lot of money. Most of the process is done by robotics and machines. These machines are controlled by only one operator. As a result, the cost of manufacturing comes down significantly.
Apart from this, the overall manufacturing cost comes down. So, the price tag is also lower, which makes it possible for even an average buyer to place their order. Automation also allows for accurate and precise injection molds. Both CAM and CAD enable close tolerance while the molds are made.
The Bottom Line
To cut a long story short, plastic injection molding helps make parts that don’t require a lot of post-production work. In fact, parts are complete from all aspects once they have been taken out of the molds.
Nowadays, this process is quite common as it’s eco-friendly. The scrap plastic is collected for reuse. Therefore, there is almost no waste left behind. So, this was a description of some of the most common advantages of plastic injection molding.
basket mould on https://www.msplasticmold.com/product/cratesbaskets/
Plastic molds are important industrial products in order to shape and mold plastic before it results to a more viable and feasible product in the market. It commonly undergoes injection molding in various forms but the most popular technique is forcing a plastic liquid into a metal mold. The molding is made through the use of molten plastic that cools while it is inside the mold.
Plastic molds are used in order to lessen down the costs related to various manufacturing processes. This technology is favored because of the quick turnaround time in the procedure. A variation known as reaction injection molding is also used for fiberglass, epoxy and polymer plastic. Here are ideas on the services, processes and equipment design employed in the manufacture of these products.
Plastic molding services
Plastic molding services result from rotational molding, blow molding, thermoforming and compression molding. Other services include mold prototyping, insert molding, micro-molding, two-shot injection molding, machining and hot stamping. These services have characteristics that make them distinct from one another.
Machining, for instance is that phase where the molds are removed through drilling, milling or turning. Micro-molding is known to use special and mini molding machines in order to produce small parts out of the process. The parts produced out of these services are commonly less than two grams in weight. In a two-shot injection, a plastic product is produced from two sets of raw materials through the use of only one operation.
Plastic molding processes
Plastic molds cannot be completed without undergoing some processes. First on the list is the development of a three-dimensional or 3D CAD model. The making of a computer model is that point when a manufacturer may ask a consumer for concepts and prototypes to see if they are good enough for the production of plastics. During the consultation phase, manufacturing processes will also be considered. Production rate, number of parts, type of materials, cost and precision are used in the selection of the manufacturing process.
Plastic mold equipment design
This important aspect in manufacturing plastic molds is the fabrication of machineries to create the output. Barrels, liners, component and feeders are also created out of the equipment design. Along the process, special forms of equipment for different plastic mold services are formed. Machines for injection molding, blow molding and thermoplastic injection are a few examples of plastic mold equipment designs. The basic outputs from these machines include insulated runners as well as CAM, encapsulating, stack and insert molds.
Basket mould on https://www.msplasticmold.com/product/cratesbaskets/
Plastic molds are used in order to lessen down the costs related to various manufacturing processes. This technology is favored because of the quick turnaround time in the procedure. A variation known as reaction injection molding is also used for fiberglass, epoxy and polymer plastic. Here are ideas on the services, processes and equipment design employed in the manufacture of these products.
Plastic molding services
Plastic molding services result from rotational molding, blow molding, thermoforming and compression molding. Other services include mold prototyping, insert molding, micro-molding, two-shot injection molding, machining and hot stamping. These services have characteristics that make them distinct from one another.
Machining, for instance is that phase where the molds are removed through drilling, milling or turning. Micro-molding is known to use special and mini molding machines in order to produce small parts out of the process. The parts produced out of these services are commonly less than two grams in weight. In a two-shot injection, a plastic product is produced from two sets of raw materials through the use of only one operation.
Plastic molding processes
Plastic molds cannot be completed without undergoing some processes. First on the list is the development of a three-dimensional or 3D CAD model. The making of a computer model is that point when a manufacturer may ask a consumer for concepts and prototypes to see if they are good enough for the production of plastics. During the consultation phase, manufacturing processes will also be considered. Production rate, number of parts, type of materials, cost and precision are used in the selection of the manufacturing process.
Plastic mold equipment design
This important aspect in manufacturing plastic molds is the fabrication of machineries to create the output. Barrels, liners, component and feeders are also created out of the equipment design. Along the process, special forms of equipment for different plastic mold services are formed. Machines for injection molding, blow molding and thermoplastic injection are a few examples of plastic mold equipment designs. The basic outputs from these machines include insulated runners as well as CAM, encapsulating, stack and insert molds.
Basket mould on https://www.msplasticmold.com/product/cratesbaskets/
The Multiple Functions of the Mould Steel
2020年8月12日 日常As far as we know, the mould is a primary machining tool in many industrial sectors, such as machinery manufacturing, radio meter and electric appliance. What’s more, the quality of the mould has a direct effect on the production cost, accurate output and the quality of the processing technology. Thus, it is quite clear that the quality of the mould should be concerned by people. In recent years people make their effort to research the factors that determine its quality. They find that apart from the proper structure design and processing accuracy the quality of a mould mainly depends on its material and the way of heat treatment.
Owing to the multiple functions of the mould, the working conditions for the moulds are quite different. Therefore, the material for the mould has a broad range of choice. Among so many materials, the mould steel is the most widely used by the mould. Just as its name implies, the so-called mould steel refers to a type of tool steels that are used to make the moulds, such as the cold-punching mould, hot-forging die and so on. According to the functions of the mould steel, it can be grouped into three types, namely cold-working type, hot-working type and plastic type. Now the following article will introduce them in detail.
What comes first is the cold-working type. This material is mainly used by the moulds which are suitable to operate in the clod condition. They include cold punching die, cold stamping die, cold extruding die, thread pressing mould, powder pressing mould and so on. The cold-working mould steel is very wide in ranges, from various carbon tool steel, alloy tool steel, rapid tool steel to diverse powder alloy mould steels.
The next type is hot-working Mould steel. This steel is mainly applied in the moulds which are suitable to work in the high-temperature state. Hot-forging mould, hot pressing die, die mould and hot upset forging die are the good example for the above-mentioned mould. There are several hot-working mould steels, such as the alloy mould steel with a great amount of carbon and some alloying agents (such as Cr, W, Mo, V and so on). For the special hot-working type, sometimes the austenite heat-proof alloy mould steel will be used.
The third type is plastic mould steel. Because there are great differences for the requirements of the plastic products, correspondingly there are a lot of requirements for the material of the plastic mould. At present a great number of developed countries have formed the wide range for the steel of the plastic mould. This steel includes the following types, namely carbon construction steel, corrosion-proof type, age hardening type and so on.
cat litter mould on https://www.msplasticmold.com/product/pet-products/
Owing to the multiple functions of the mould, the working conditions for the moulds are quite different. Therefore, the material for the mould has a broad range of choice. Among so many materials, the mould steel is the most widely used by the mould. Just as its name implies, the so-called mould steel refers to a type of tool steels that are used to make the moulds, such as the cold-punching mould, hot-forging die and so on. According to the functions of the mould steel, it can be grouped into three types, namely cold-working type, hot-working type and plastic type. Now the following article will introduce them in detail.
What comes first is the cold-working type. This material is mainly used by the moulds which are suitable to operate in the clod condition. They include cold punching die, cold stamping die, cold extruding die, thread pressing mould, powder pressing mould and so on. The cold-working mould steel is very wide in ranges, from various carbon tool steel, alloy tool steel, rapid tool steel to diverse powder alloy mould steels.
The next type is hot-working Mould steel. This steel is mainly applied in the moulds which are suitable to work in the high-temperature state. Hot-forging mould, hot pressing die, die mould and hot upset forging die are the good example for the above-mentioned mould. There are several hot-working mould steels, such as the alloy mould steel with a great amount of carbon and some alloying agents (such as Cr, W, Mo, V and so on). For the special hot-working type, sometimes the austenite heat-proof alloy mould steel will be used.
The third type is plastic mould steel. Because there are great differences for the requirements of the plastic products, correspondingly there are a lot of requirements for the material of the plastic mould. At present a great number of developed countries have formed the wide range for the steel of the plastic mould. This steel includes the following types, namely carbon construction steel, corrosion-proof type, age hardening type and so on.
cat litter mould on https://www.msplasticmold.com/product/pet-products/
Custom Rubber Mouldings and front bumper mould
Compression mouldings are the simplest, cheapest, and probably the most widespread of the three basic moulding techniques. They are ideally suited to custom rubber mouldings, small quantity production, say, from around fifty to a few thousand of each product annually.
One of the keys to successful moulding is adequate removal of air while the mould cavity is filling up with rubber. The uncured pieces of compound placed in the mould are known variously as preforms, billets or load weights. For a ball, one might use an elliptically shaped extrusion, cut to an appropriate length from a Barwell. This shape is important and deliberately chosen so that air in the mould cavity will have a free path of escape when the mould begins to close.
Normally the weight of this preform will be chosen to be a few percent (from two to ten percent) above the weight of the final product, to ensure a fully formed product and to give an extra ’push’ for expulsion of any residual trapped air. The preform is placed in the bottom cavity and the top mould section placed on it.
by hand. If a significant number of custom rubber moldings are to be made, it is often advantageous to fix the two halves of the mold to their respective press platens, thus reducing manual handling and therefore labour costs.
The mould is continuously heated to a temperature, typically between 120 °C and 180 °C. A cure time for a smaller part might be 20 minutes, at 150 °C, for thin cross sections (6 mm). In this case, temperatures above 150 °C could reduce the cure time to 10 minutes or less.
At independent custom rubber moulders, the chemist plays his part in achieving a smooth flow of material in the mould, by striving to control the uncured compound viscosity. This needs to be high enough to create the backpressure required to expel air efficiently as the mould closes, and low enough to permit completion of flow into all parts of the cavity before vulcanization begins. If we look at a low cured-hardness rubber, it usually contains little or no filler (NR & CR), or alternatively fillers plus a large quantity of oil. This can often make its viscosity too low for successful compression mouldings and the compounder may strive to increase its viscosity, by choosing a raw gum elastomer grade with a high Mooney viscosity.
At the other end of the scale, high vulcanized-hardness compounds with lots of highly reinforcing fillers will need specialized process aids and low Mooney viscosity raw gum elastomers, to reduce viscosity, in order to promote the flow of the compound in the mould.
As the press platens close the mould, excess compound begins to squeeze out into the flash grooves, taking air with it. Often, residual air remains and various methods have been devised to remove it. One method is to bring the mould pressure back down to zero and then return to full pressure by quickly lowering and raising the press platens a number of times. This `shock’ treatment is called `bumping’. An additional line of attack is to find where air is being trapped in the final cured product and drill a small diameter hole through the mould cavity in the equivalent area; these are called bleeder holes. They permit an alternative escape route for the trapped air (together with some rubber). The shape of the preform and also its placement in the mould is important. The uncured rubber, placed in the cavity, might be a single piece or a number of pieces. This method is very much an art for the independent custom rubber moulders.
Since flash often spills over the land during compression, it is possible that a large land area between the flash groove and the outside of the mould might ’fine tune’ backpressure control. A large land distance restricts flow at the time when the mold is almost closed and thus might increase backpressure, which would be of assistance with low viscosity compounds. For high viscosity materials the opposite might apply, i.e., a small land area and deep flash grooves would be desirable. This would also promote greater pressure at the moment before full mould closure for the same force exerted by the press ram. Radial grooves connecting the flash grooves with the outside of the mould should also assist in high viscosity compounds exiting the mould.
The press needs to exert a certain amount of pressure to allow the compound to flow into the cavities and for the mold to properly close. The objective is to obtain a thin flash, `ideally’, around 0.05 mm.
The area of the press rams, divided by the projected area of rubber and flash between the mold halves, multiplied by the line pressure at the press, will give the pressure exerted on the product in the mold at closure. The required pressure is typically 7-10.5 MPa and will vary according to such things as the viscosity of the compound and the complexity of the mould cavity. The mould is designed to take the high stress involved.
The area of projected rubber can be smaller at the beginning of mould closure, since the rubber has not yet fully spread over all of the mold cavity. More of the force from the ram might briefly act on delicate inserts or parts of the mould, depending on the exact set up involved. This sometimes has the potential to cause damage if not taken into account.
The flow of material in a mould is a complex process, especially in compression mouldings. The rubber in the cavity is undergoing large temperature changes, which translate to viscosity variations thus continuously altering the flow characteristics of the compound. In recent years finite element analysis packages, which describe the material flow patterns in the mould, have become available to mould designers. The use of such design aids is at an early stage in most of the rubber industry.
Once the compression mould has closed, the compound continues to heat up and attempts to thermally expand. Its coefficient of expansion can be a least fifteen times greater than that of the steel mould. For custom mouldings with large cross sections or high volume to surface area ratios, such as a ball, phenomena such as backrind can occur. When the product is taken out of the mould, it looks chewed up and torn in the area of the flashline; this is described as backrind. If this occurs there is likely to be a flurry of activity between the shift foreman, chemist and engineer. These are the skill of independent custom rubber moulders.
Front bumper mould on https://www.msplasticmold.com/product/automobile-parts/front-bumper-2.html
Compression mouldings are the simplest, cheapest, and probably the most widespread of the three basic moulding techniques. They are ideally suited to custom rubber mouldings, small quantity production, say, from around fifty to a few thousand of each product annually.
One of the keys to successful moulding is adequate removal of air while the mould cavity is filling up with rubber. The uncured pieces of compound placed in the mould are known variously as preforms, billets or load weights. For a ball, one might use an elliptically shaped extrusion, cut to an appropriate length from a Barwell. This shape is important and deliberately chosen so that air in the mould cavity will have a free path of escape when the mould begins to close.
Normally the weight of this preform will be chosen to be a few percent (from two to ten percent) above the weight of the final product, to ensure a fully formed product and to give an extra ’push’ for expulsion of any residual trapped air. The preform is placed in the bottom cavity and the top mould section placed on it.
by hand. If a significant number of custom rubber moldings are to be made, it is often advantageous to fix the two halves of the mold to their respective press platens, thus reducing manual handling and therefore labour costs.
The mould is continuously heated to a temperature, typically between 120 °C and 180 °C. A cure time for a smaller part might be 20 minutes, at 150 °C, for thin cross sections (6 mm). In this case, temperatures above 150 °C could reduce the cure time to 10 minutes or less.
At independent custom rubber moulders, the chemist plays his part in achieving a smooth flow of material in the mould, by striving to control the uncured compound viscosity. This needs to be high enough to create the backpressure required to expel air efficiently as the mould closes, and low enough to permit completion of flow into all parts of the cavity before vulcanization begins. If we look at a low cured-hardness rubber, it usually contains little or no filler (NR & CR), or alternatively fillers plus a large quantity of oil. This can often make its viscosity too low for successful compression mouldings and the compounder may strive to increase its viscosity, by choosing a raw gum elastomer grade with a high Mooney viscosity.
At the other end of the scale, high vulcanized-hardness compounds with lots of highly reinforcing fillers will need specialized process aids and low Mooney viscosity raw gum elastomers, to reduce viscosity, in order to promote the flow of the compound in the mould.
As the press platens close the mould, excess compound begins to squeeze out into the flash grooves, taking air with it. Often, residual air remains and various methods have been devised to remove it. One method is to bring the mould pressure back down to zero and then return to full pressure by quickly lowering and raising the press platens a number of times. This `shock’ treatment is called `bumping’. An additional line of attack is to find where air is being trapped in the final cured product and drill a small diameter hole through the mould cavity in the equivalent area; these are called bleeder holes. They permit an alternative escape route for the trapped air (together with some rubber). The shape of the preform and also its placement in the mould is important. The uncured rubber, placed in the cavity, might be a single piece or a number of pieces. This method is very much an art for the independent custom rubber moulders.
Since flash often spills over the land during compression, it is possible that a large land area between the flash groove and the outside of the mould might ’fine tune’ backpressure control. A large land distance restricts flow at the time when the mold is almost closed and thus might increase backpressure, which would be of assistance with low viscosity compounds. For high viscosity materials the opposite might apply, i.e., a small land area and deep flash grooves would be desirable. This would also promote greater pressure at the moment before full mould closure for the same force exerted by the press ram. Radial grooves connecting the flash grooves with the outside of the mould should also assist in high viscosity compounds exiting the mould.
The press needs to exert a certain amount of pressure to allow the compound to flow into the cavities and for the mold to properly close. The objective is to obtain a thin flash, `ideally’, around 0.05 mm.
The area of the press rams, divided by the projected area of rubber and flash between the mold halves, multiplied by the line pressure at the press, will give the pressure exerted on the product in the mold at closure. The required pressure is typically 7-10.5 MPa and will vary according to such things as the viscosity of the compound and the complexity of the mould cavity. The mould is designed to take the high stress involved.
The area of projected rubber can be smaller at the beginning of mould closure, since the rubber has not yet fully spread over all of the mold cavity. More of the force from the ram might briefly act on delicate inserts or parts of the mould, depending on the exact set up involved. This sometimes has the potential to cause damage if not taken into account.
The flow of material in a mould is a complex process, especially in compression mouldings. The rubber in the cavity is undergoing large temperature changes, which translate to viscosity variations thus continuously altering the flow characteristics of the compound. In recent years finite element analysis packages, which describe the material flow patterns in the mould, have become available to mould designers. The use of such design aids is at an early stage in most of the rubber industry.
Once the compression mould has closed, the compound continues to heat up and attempts to thermally expand. Its coefficient of expansion can be a least fifteen times greater than that of the steel mould. For custom mouldings with large cross sections or high volume to surface area ratios, such as a ball, phenomena such as backrind can occur. When the product is taken out of the mould, it looks chewed up and torn in the area of the flashline; this is described as backrind. If this occurs there is likely to be a flurry of activity between the shift foreman, chemist and engineer. These are the skill of independent custom rubber moulders.
Front bumper mould on https://www.msplasticmold.com/product/automobile-parts/front-bumper-2.html
In the injection molding production process, what are the reasons for the residual glue in the mold?
Mainly analyze and judge the reasons for the defects of the current molded products. Provide reference factors in the molding machine, mold and raw materials to effectively control the defects and reduce production costs.
Content:
1 Sores: (Silver streaks) The
surface of the finished product, centered on CATE, has many silver-white streaks, which are basically produced along the flow direction of the raw materials. This phenomenon occurs after many bad conditions have accumulated, and sometimes it is difficult to grasp the real cause.
1.1 If there is moisture or other volatile components in the raw material, and it is not fully dried, a lot of silver bars will be produced on the surface.
1.2 When other raw materials are accidentally mixed into the raw materials, sores will also form, and the shape is mica-like or pinpoint-like, which is easy to distinguish from the sores caused by other reasons.
1.3 This situation is also prone to occur when the raw materials or the material pipe are not clean.
1.4 The injection time is long, and the temperature of the raw materials injected into the mold cavity is low at the initial stage. As a result of curing, the volatile components will not be eliminated, especially for the temperature-sensitive raw materials, this situation often occurs.
1.5 If the mold temperature is low, the raw material solidifies quickly and easily occurs (1.4), so that the volatile components will not be discharged.
1.6 When the mold is poorly exhausted, the gas cannot be easily removed when the raw materials enter, and sores will occur. In this situation, the top of the finished product will often burn black.
1.7 If moisture adheres to the mold, the heat from the filling material will evaporate it and fuse with the molten material to form a sore, which is in the form of an egg white mist.
1.8 There is cold material in the cold material cavity of the glue channel or small. When it is injected, the cooled material is brought into the mold cavity, and a part of it will quickly solidify to form a thin layer. When the mold temperature is low at the beginning of production, it will also cause sores.
1.9 During the filling process of raw materials, a thin layer is formed due to the rapid cooling of the contact part of the cavity surface, which is melted and decomposed by the following raw materials to form a white or stain-like shape, which is more common in thin-shell products.
1.10 When filling, the raw material becomes turbulent, which can extend the flow path of the raw material, and is affected by the structure of the cavity to produce friction. The filling speed is faster than the cooling speed of the raw material. The gate position is at the bone or small, which is easy to cause sores. Sores are also prone to occur where the thickness of the finished meat increases sharply.
1.11 The gate and flow channel are small or deformed, and the filling speed is fast, and friction occurs instantly, which causes the temperature to rise rapidly and causes the raw material to decompose.
1.12 The raw materials contain recycled materials, which are not fully dried and decompose during injection, causing sores.
1.13 The raw material stays in the material pipe for a long time, causing partial overheating and decomposition.
1.14 Insufficient back pressure, entrapped air (insufficient compression ratio).
Choose basket mould to https://www.msplasticmold.com/product/cratesbaskets/
Mainly analyze and judge the reasons for the defects of the current molded products. Provide reference factors in the molding machine, mold and raw materials to effectively control the defects and reduce production costs.
Content:
1 Sores: (Silver streaks) The
surface of the finished product, centered on CATE, has many silver-white streaks, which are basically produced along the flow direction of the raw materials. This phenomenon occurs after many bad conditions have accumulated, and sometimes it is difficult to grasp the real cause.
1.1 If there is moisture or other volatile components in the raw material, and it is not fully dried, a lot of silver bars will be produced on the surface.
1.2 When other raw materials are accidentally mixed into the raw materials, sores will also form, and the shape is mica-like or pinpoint-like, which is easy to distinguish from the sores caused by other reasons.
1.3 This situation is also prone to occur when the raw materials or the material pipe are not clean.
1.4 The injection time is long, and the temperature of the raw materials injected into the mold cavity is low at the initial stage. As a result of curing, the volatile components will not be eliminated, especially for the temperature-sensitive raw materials, this situation often occurs.
1.5 If the mold temperature is low, the raw material solidifies quickly and easily occurs (1.4), so that the volatile components will not be discharged.
1.6 When the mold is poorly exhausted, the gas cannot be easily removed when the raw materials enter, and sores will occur. In this situation, the top of the finished product will often burn black.
1.7 If moisture adheres to the mold, the heat from the filling material will evaporate it and fuse with the molten material to form a sore, which is in the form of an egg white mist.
1.8 There is cold material in the cold material cavity of the glue channel or small. When it is injected, the cooled material is brought into the mold cavity, and a part of it will quickly solidify to form a thin layer. When the mold temperature is low at the beginning of production, it will also cause sores.
1.9 During the filling process of raw materials, a thin layer is formed due to the rapid cooling of the contact part of the cavity surface, which is melted and decomposed by the following raw materials to form a white or stain-like shape, which is more common in thin-shell products.
1.10 When filling, the raw material becomes turbulent, which can extend the flow path of the raw material, and is affected by the structure of the cavity to produce friction. The filling speed is faster than the cooling speed of the raw material. The gate position is at the bone or small, which is easy to cause sores. Sores are also prone to occur where the thickness of the finished meat increases sharply.
1.11 The gate and flow channel are small or deformed, and the filling speed is fast, and friction occurs instantly, which causes the temperature to rise rapidly and causes the raw material to decompose.
1.12 The raw materials contain recycled materials, which are not fully dried and decompose during injection, causing sores.
1.13 The raw material stays in the material pipe for a long time, causing partial overheating and decomposition.
1.14 Insufficient back pressure, entrapped air (insufficient compression ratio).
Choose basket mould to https://www.msplasticmold.com/product/cratesbaskets/
Dog training is something any dog owner has to go through. Most people now get their dog training through a dog trainer. But there are some aspects of dog training that can’t be done with a dog trainer.
This is because this type of dog training occurs at your home. Not sure what kind of dog training I’m talking about?
I’ll give you a hint... this kind of dog training takes place 24 hours a day, seven days a week.
Give up?
What I’m talking about is potty training or house breaking your dog or puppy. This part of dog training is often the most hated and dreaded of all dog training. This is because house breaking often takes the longest for your dog or puppy to learn.
For those of you who need help with, house breaking your dog, help has arrived.
House breaking your dog often starts when you get your dog as a puppy. But there are adult dogs that need this type of dog training as well. Dog training has come a long way in recent years.
It has recently been decided that crate training is the best way to get your dog house broken. Dogs do not like to sleep where they have gone to the bathroom. So, in theory, if you keep a dog in a crate for small periods of time, they will learn to hold it. This is because they would rather hold it than lay in it.
Most people think that this form of dog training is cruel to the dog. But in reality, this form of dog training is not cruel in any manner, in fact, many dogs like the idea of sleeping in a crate.
Dogs naturally like to sleep in a den like environment. Using a crate for your dog training
helps create this environment. Dogs feel safe and comfortable in their "den." Many people find that their dogs often go to their crate on their own when tired.
Using a crate does take time for a dog to get used to, so be sure to start out in small intervals when beginning this type of dog training.
House breaking your dog can be a difficult part of dog training. But crate training has been proven to be the most effective way of house breaking your dog. In fact, most dog training classes and dog training books pet products recommend it for house breaking.
For more information about this type of dog training, you can go online and type in "Crate Training" into the search engine. You will soon see for yourself how effective a crate will make your dog training easier!
wholesale pet products mould on https://www.msplasticmold.com/product/pet-products/
This is because this type of dog training occurs at your home. Not sure what kind of dog training I’m talking about?
I’ll give you a hint... this kind of dog training takes place 24 hours a day, seven days a week.
Give up?
What I’m talking about is potty training or house breaking your dog or puppy. This part of dog training is often the most hated and dreaded of all dog training. This is because house breaking often takes the longest for your dog or puppy to learn.
For those of you who need help with, house breaking your dog, help has arrived.
House breaking your dog often starts when you get your dog as a puppy. But there are adult dogs that need this type of dog training as well. Dog training has come a long way in recent years.
It has recently been decided that crate training is the best way to get your dog house broken. Dogs do not like to sleep where they have gone to the bathroom. So, in theory, if you keep a dog in a crate for small periods of time, they will learn to hold it. This is because they would rather hold it than lay in it.
Most people think that this form of dog training is cruel to the dog. But in reality, this form of dog training is not cruel in any manner, in fact, many dogs like the idea of sleeping in a crate.
Dogs naturally like to sleep in a den like environment. Using a crate for your dog training
helps create this environment. Dogs feel safe and comfortable in their "den." Many people find that their dogs often go to their crate on their own when tired.
Using a crate does take time for a dog to get used to, so be sure to start out in small intervals when beginning this type of dog training.
House breaking your dog can be a difficult part of dog training. But crate training has been proven to be the most effective way of house breaking your dog. In fact, most dog training classes and dog training books pet products recommend it for house breaking.
For more information about this type of dog training, you can go online and type in "Crate Training" into the search engine. You will soon see for yourself how effective a crate will make your dog training easier!
wholesale pet products mould on https://www.msplasticmold.com/product/pet-products/
