Rotomolding, a technology that was once mainly used to produce simple plastic products, is now breaking through traditional application areas with its unique advantages and entering a broader and more cutting-edge market. From medical health to aerospace, from new energy to environmental protection, rotomolding is becoming more and more common, showing strong vitality and development potential.

1. Medical health field: safe and reliable, protecting health

2. Aerospace: Lightweight and high strength, helping to soar into the blue sky

3. New energy field: Green and environmental protection, helping sustainable development

The mold of the rotomolded product is a single-wall closed mold, which gives the outer contour of the product but cannot accurately determine the internal contour of the product. The mold material of the rotomolding mold is generally selected from ordinary carbon steel plates for welding. The cost of welding molds is relatively low, especially suitable for large rotomolded products. The rotomolding process has the following basic requirements for its mold:

Suitable for molding large and extra-large parts:

In most roto-molding processes, the plastic mold is under a very high pressure (stress) during the molding process, such as the widely used injection molding, compression molding, extrusion, blow molding, etc. Therefore, when using these molding processes to produce large plastic parts, not only must a mold that can withstand a lot of pressure be used, making the mold bulky and complicated, but the plastic molding equipment must also be designed and manufactured to be very strong, and the difficulty of processing and manufacturing the machine mold increases accordingly, and the cost increases. On the contrary, since the roto-molding process only requires the strength of the frame to be sufficient to support the weight of the material, the mold and the frame itself, as well as the closing force to prevent material leakage, even if large and extra-large plastic parts are roto-molded, there is no need to use very bulky equipment and molds. The processing and manufacturing of the machine mold is very convenient, with a short manufacturing cycle and low cost. In theory, there is almost no upper limit on the size of parts formed by roto-molding. However, it is impossible to produce such a large plastic container without very expensive and large blow molding equipment, such as blow molding.

1. Analysis of the causes of warping of roto-molded products

Although roto-molded products are non-pressure-molded, they are not easy to warp and deform compared with other pressure-molded methods.

However, roto-molded products are generally complex in shape, uneven in wall thickness, and not completely symmetrical.

This makes the cooling rate and shrinkage rate of different parts of the product inconsistent, and warping and deformation occur in large planes and parts with large wall thickness differences.

PE products have a relatively large shrinkage rate after roto-molding, generally 2% to 3%, or even as high as 3% to 5%.

The dimensional accuracy is poor, and the shrinkage rate is even higher in parts with large local linear dimensions.

The shrinkage of the product is also related to factors such as the heating temperature, cooling and setting temperature, cooling rate, and product demoulding temperature during product molding.

These factors are not easy to accurately control during roto-molding.


2. Solutions for warping and deformation of roto-molded products

When designing roto-molded products, try to avoid large planes.

Structural forms such as reinforcing ribs, steps, overlaps (bridges) or surface groove decorations can be used to reduce the plane area, thereby controlling warping.

Adjust the position of the mold on the mold frame to eliminate factors that increase the wall thickness difference and affect the uniformity of heating and cooling.

According to the structural characteristics of the product, make a shaping tooling or fixed tooling with active parts to shape the product in the post-cooling and sectioning stage.

For products with special shapes, you can also combine simple shaping tools to pass compressed air into the product to force the product to shape and shape, which has a better effect.

When conducting quality inspection of rotomolding molds, there are some precautions that need to be followed to ensure the quality and performance of the molds.

Here are some common precautions:

1. Regular maintenance of molds:

2. Check mold dimensions:

3. Check mold material:

4. Check the surface quality of the mold:

5. Check the mold accessories:

6. Perform a trial mold:

7. Check the mold cooling system:

8. Check the mold identification and documents:
What should be paid attention to when conducting quality inspection of rotational molding molds?
In short, the quality inspection of rotomolding molds needs to be carried out carefully, including inspections of mold size, material, surface quality, accessories, cooling system, etc. Through strict quality inspection, it can be ensured that the rotomolding mold has good performance and quality, providing guarantee for the production of high-quality plastic products.

New Year, New Atmosphere, Draw a New Chapter for the Company

Dear colleagues:
As the New Year's bell rings, we usher in 2025, which is full of hope and challenges. At this moment of bidding farewell to the old and welcoming the new, on behalf of the company's management, I extend my most sincere New Year's blessings and good wishes to everyone. May everyone be healthy, happy in family, and smooth at work in the new year!

‌Looking back on the past, we are grateful. In 2024, in the face of many challenges, we united as one, worked together, and achieved remarkable results. Under the leadership of Director He Shaochun, the Tianwei Production Center overcame many difficulties and ensured production quality; the Quality Management Center built a comprehensive quality control system to ensure high-quality delivery of products; the Human Resources Center successfully built a complete human resources system to lay a solid foundation for the company's development; the process digitalization team and the financial sales BP team have also made significant progress in their respective fields. The achievement of these achievements is inseparable from the hard work and selfless dedication of every colleague.

‌Looking to the future, we are full of confidence. In 2025, we will continue to uphold the spirit of "anchoring results and attacking hard", and continue to innovate and break through.As a leader in the industry, Delifeng Rock Board will continue to introduce advanced production equipment and technology, strictly control every production link, and ensure that every rock board meets or even exceeds customer expectations. Hai Ruisi Testing Equipment Company will also continue to insist on technological innovation as the driving force, continuously improve its core competitiveness, and provide customers with better testing equipment and services.

1. High design flexibility to meet personalized needs

One of the biggest highlights of rotomolding technology is its high flexibility in product design. Designers can give full play to their creativity without overly considering the difficulty of mold demolding, which provides unlimited possibilities for product innovation.

2. High material utilization and significant cost-effectiveness

During the rotomolding process, plastic powder or liquid can be evenly distributed in the mold, reducing material waste. In addition, the mold making is relatively simple and the cost is low, which makes roto-molded products have significant advantages in cost control.

3. The product has high strength, good durability and is trustworthy

During the molding process of roto-molded products, the plastic material can fully melt and penetrate into every corner of the mold, forming a uniform and dense wall thickness, which enhances the structural strength of the product.

4. Environmentally friendly and sustainable, in line with future trends

With the increasing global awareness of environmental protection, the environmental protection characteristics of roto-molding technology are also increasingly valued. The plastic materials used in the roto-molding process are mostly recyclable thermoplastics, and the waste in the production process can also be recycled and reused, reducing the impact on the environment.

5. High production efficiency, strong adaptability and broad market prospects

The production cycle of the rotomolding process is relatively short, especially in mass production, it can quickly reach economic scale and improve production efficiency. At the same time, the rotomolding equipment is relatively simple, easy to operate and maintain, and has strong adaptability to different materials and products.

Roto-molding and acrylic are two common materials that have different characteristics in many aspects. Here are the differences between roto-molding and acrylic:

1. Material composition:

Roto-molding is a plastic product that is formed by hot pressing or extrusion. Its main component is thermoplastics such as polyethylene. Acrylic is a kind of plexiglass that is synthesized from methyl methacrylate.

2. Appearance:

Roto-molding usually presents a uniform color and smooth surface appearance, and is often used to make some large plastic products such as toys, buckets, etc. Acrylic has high transparency, glass-like luster, and strong permeability. It is often used to make transparent crafts, advertising logos, etc.

3. Texture:

Roto-molding has a softer texture, good toughness, strong wear resistance, and is not easy to deform. Acrylic has a harder texture, stronger brittleness, is not easy to bend and deform, but is also easier to break.

4. Molding method:

Roto-molding is usually formed by hot pressing or extrusion, while acrylic requires complex processing such as injection molding, stretching or extrusion.

5. Application fields:

Due to its good corrosion resistance and toughness, roto-molding is often used for large outdoor plastic products such as stools and tables. Acrylic is often used in artworks, display stands and other fields due to its excellent transparency and glossiness.

6. Cost:

Roto-molding is usually cheaper, with a simple production process and lower cost. Acrylic has a more complicated production process and a relatively high cost.

In general, roto-molding and acrylic have obvious differences in material composition, appearance, texture, molding method, application field and cost. Consumers can make choices based on their specific needs and requirements when choosing to use these two materials.

In the field of plastic processing, rotomolding is like a shining star, standing out among many processes with its unique advantages and wide application. Today, let us explore the secrets, advantages and wonderful applications of rotomolding in various fields.

1. Principle and process of rotomolding

2. Unique advantages of roto-molding process

3. Wide application of rotomolding process

4.Development prospects of rotomolding technology

The plastic fuel tank process has the following basic requirements for its mold:

1. The mold is not easy to deform and bend during repeated heating and cooling.

2. The mold should be equipped with an easy-to-loose clamping mechanism so that the mold can be tightly closed during heating and cooling, and can be easily opened when the product needs to be loaded and unloaded.

3. The design and installation of the mold should be conducive to the relative movement of the airflow around the mold surface.

4. The mold should be equipped with a ventilation pipe to prevent the gas in the mold from expanding due to heat during heating and squeezing out the molten plastic along the mold seam, and to prevent the negative pressure in the mold from causing the mold and the product to deform during cooling.

5. When designing the local structure of the mold, try to avoid deep cavities, deep holes, reinforcing ribs, solid protrusions and other structures.

6. Rotational speed of plastic fuel tank mold Usually, the rotational molding machine uses two adjustable speed motors to power the rotation and swinging motion of the mold around the main axis and the secondary axis.

7. The particle size of polyethylene powder of plastic fuel tank material has an important influence on its melting process.

In today's manufacturing industry, rotomolding equipment is playing an increasingly important role. This efficient, flexible and environmentally friendly manufacturing process is not only widely used in industries such as automobiles, home appliances and aerospace, but is also known as the "manufacturing process that shapes the future" because of its excellent performance and unique advantages.

Rotomolding is a thermoplastic molding process that uses heated plastic profiles to shape in a rotating mold. Compared with traditional injection molding, rotomolding can produce larger and more complex parts at a lower cost. In addition, rotomolded products have the advantages of seamlessness, high strength, corrosion resistance, and aging resistance, making it a substitute for metal and traditional plastic products in many fields.

Core advantages of rotomolding equipment

Flexibility: Rotomolding equipment is suitable for parts of various shapes and sizes, from small parts to large structures, which can be easily achieved. This flexibility enables companies to quickly adapt to market demand and achieve customized production.

Efficient productivity: Rotomolding is superior to traditional injection molding in production efficiency. It can achieve continuous production and reduce the time and cost of mold replacement. In addition, the production cycle of rotomolding equipment is short, which reduces waste in the production process.

Environmental protection: The rotomolding process uses thermoplastics, which can be recycled and reused during the production process, reducing the impact on the environment. At the same time, since no solvents or additives are needed in the production process, it is also more friendly to the health of operators.

Color inspection of rotomolding product is a very important quality control step to ensure that the appearance quality of the product meets the requirements.

The following are the steps for color inspection of rotomolding molds:

1. Preparation: First, you need to prepare a standard color sample, which is customized according to product requirements. It can be a color card or a physical sample.

2. Adjust equipment: Ensure that the inspection equipment is in normal working condition, such as adjustment and inspection of light sources, cameras and other equipment to ensure that color information can be accurately captured.

3. Sampling inspection: Take a certain number of product samples from the production line. The number generally depends on the production batch and product specification requirements.

4. Comparative inspection: Compare the sampled product samples with the standard samples, and detect the color difference by naked eye or using professional color difference instruments.

5. Record data: Record the inspection results, including the color data of each sample, specific difference values ​​and other information, for subsequent reference and analysis.

6. Analysis results: Analyze according to the inspection results, find out the samples with unqualified colors, find out the cause of the problem, and adjust the production process in time.

7. Adjust production: Make necessary adjustments based on the analysis results, such as adjusting the raw material ratio, temperature control, etc., to ensure that the color of the next batch of products meets the requirements.

8. Follow-up: As production progresses, color inspections need to be carried out continuously, and abnormal situations need to be followed up and handled in a timely manner to ensure stable product quality.

There are usually metal inlays on roto-molded products. During roto-molding, the inlay is equivalent to a part of the mold, which increases the wall thickness of the mold here. It is not easy for the end of the inlay to obtain the same temperature as the mold, resulting in poor resin coating on the inlay, and large inlays are more likely to be unevenly coated.

How to solve the poor coating of modified plastics in roto-molded products?

1. Eliminate factors that are not conducive to heat transfer of inlays, so that inlaid metal parts have a good heat transfer structure.

2. Under the premise of meeting the roto-molding conditions and the strength requirements of inlays, the height and volume of the inlay relative to the surface of the product are as small as possible.

3. The depth and width of the anti-rotation and anti-pull grooves on the inlay are suitable for roto-molding requirements.

4. During roto-molding, preheat the inlay according to the actual situation, so as to achieve good results, which is more suitable for roto-molded products with large inlays.

At present, most orders for roto-molded products from abroad directly indicate that linear low-density polyethylene (LLDPE) roto-molding special materials are used for roto-molding. Most of the products are cleaning machine housings of different specifications, lawn mower housings, cargo transport boxes, storage boxes, various mechanical and electronic packaging boxes, double-layer insulation boxes with foam layers inside, auto parts, etc., which have high requirements for roto-molding technology. my country's roto-molding technology and roto-molding mold processing technology have improved rapidly, but there is still a gap in roto-molding product design compared with Europe and the United States.