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Rough / Uneven Surface on EVA Foamed Products Phenomenon Description: The product surface exhibits pitting, granular textures, unevenness, and poor gloss.   Cause Analysis   1. Raw Material Issues: Low EVA melt strength; low surface tension; filler particle size is excessively large or poorly dispersed; presence of impurities in the raw materials.   2. Formulation Issues: Foaming agent particle size is excessively large, leaving behind large residues after decomposition; insufficient lubricant usage; poor melt flowability; excessive use of mold release agents, resulting in surface spotting.   3. Processing Issues: Mold temperature is too low, preventing the melt from flowing sufficiently to fill the mold surface; vulcanization time is too short, resulting in incomplete surface curing; insufficient venting, causing trapped gases to form surface pits; mold opening speed is too fast, causing the surface to be torn or roughened.   4. Equipment Issues: The mold surface is rough, scratched, or rusted; the mold does not close tightly, leaving gaps; the roll gap on the open mixing mill is too wide, resulting in uneven mixing.   5. Solutions Switch to an EVA grade with higher melt strength, or add a small amount of POE to enhance melt strength; use fillers and foaming agents with finer particle sizes (1250 mesh or finer); appropriately increase the dosage of lubricants (such as zinc stearate or stearic acid) to 0.1–0.3 phr; increase the mold temperature by 5–10°C; extend the vulcanization time by 30–60 seconds; increase the frequency of venting cycles to ensure complete gas evacuation; reduce the mold opening speed to prevent surface tearing; and regularly polish the mold surface to remove scratches and rust.

Phenomenon Description: The finished product is thicker/lighter than intended; its density exceeds the standard value, and it feels overly hard with poor elasticity. Root Cause Analysis by Wuxi QuanJinHe Science & Technology Co., Ltd Raw Material Issues The EVA melt flow index (MFI) is too low, resulting in poor flowability and preventing the blowing agent from dispersing evenly. The EVA VA content is too low, limiting the maximum achievable expansion ratio. The raw material has absorbed moisture, resulting in an excessively high water content. Formulation Issues Insufficient dosage of the blowing agent (AC). Excessive dosage of the crosslinking agent (DCP/BIPB), leading to over-crosslinking which prevents gas expansion. Insufficient dosage of the crosslinking agent, preventing the formation of a proper crosslinking network and resulting in gas leakage. Excessive dosage of fillers (calcium carbonate, talc). Process Issues The vulcanization temperature is too low, resulting in incomplete decomposition of the blowing agent. The vulcanization time is too short, meaning the blowing agent did not fully decompose or the crosslinking reaction was not completed. The mold pressure is too high, preventing gas expansion. The number of venting cycles is insufficient, or the venting duration is too short. Equipment Issues The flat-bed vulcanizing press lacks sufficient pressure. The mold temperature is uneven, with certain areas being too cold. Mixing in the internal mixer or open mill was uneven, resulting in poor dispersion of the blowing agent. Solutions Switch to a specialized foaming-grade EVA with a Melt Flow Index (MFI) of 2–6 g/10 min and a VA content of 18–28%. Appropriately increase the dosage of the blowing agent (by 0.2–0.5 phr per adjustment), or switch to a blowing agent with a lower decomposition temperature. Adjust the dosage of the crosslinking agent to the optimal range (typically 0.6–1.2 phr for DCP) to ensure the crosslinking degree falls between 60% and 70%. Increase the vulcanization temperature by 5–10°C, or extend the vulcanization time by 1–2 minutes. Reduce the mold pressure by 10–20% and increase the number of venting cycles by 1–2 times. Extend the mixing time to ensure the blowing agent and crosslinking agent are dispersed evenly. Pre-dry the raw materials before use (at 80°C for 2–4 hours).

We look forward to meeting you at the Canton Fair-Booth: 20.1L06 Main Products: EVA Foaming Press Machines, Composite Hot Press, Rubber Vulcanizing Machines. Wuxi QuanJinHe Science & Technology Co., Ltd.  

Welcome to Chinaplas 2026! Shanghai! China! Dates: April 21–23 Booth No.: 1.1C53 Wuxi QuanJinHe Science & Technology Co., Ltd is a professional manufacturer of EVA Foam Press, rubber vulcanizing machine and all kinds of hot press machine.

As the final chapter of this year comes to a close and a fresh, blank page awaits, we pause to reflect and to hope. The chime of the clock at midnight is more than just a marker of time; it is a universal symbol of renewal, a chance to start anew.   On this beautiful occasion of New Year's Day, I extend my warmest wishes to you and your loved ones.   May the coming year be a canvas of bright opportunities, painted with the vibrant colors of joy, peace, and good health. May you find the courage to pursue your dreams with renewed passion, and the resilience to turn challenges into stepping stones. May your heart be light with laughter, and your days be filled with meaningful connections and simple pleasures.   Let us carry forward the lessons of the past, not as burdens, but as wisdom. Let us greet the future not with uncertainty, but with open arms and optimistic hearts.   Here’s to new beginnings, to shared journeys, and to the unwritten story of the year ahead. May it be your most wonderful chapter yet.   Wishing you a truly Happy and Prosperous New Year!   Wuxi QuanJinHe Science & Technology Co., Ltd.

Several used Rubber Vulcanizing Machines(500Ton & 800Ton) are available for sale. Please contact me if you are interested. Specifications are as follows:  

Transformer Insulation Paperboard Pressing Machine, Transformer Insulation Cardboard Production Line Installing. More than 10 Transformer Insulation Cardboard Production Lines have been produced and sold domestically and internationally.

Dear Customer: To further improve service quality and provide our valued customers with more professional, efficient, and standardized after-sales service, effectively addressing various issues you may encounter during product use, and safeguarding your legitimate rights and interests and ensuring smooth production and operation, we hereby officially announce the following matters regarding after-sales service: I. Service Scope The company's after-sales department fully handles on-site services for all products currently on sale and previously sold, specifically covering four core areas: ✅ Product Installation and Commissioning: Professional technicians will be dispatched to your location to complete product assembly, wiring, and equipment fixing according to installation specifications and on-site conditions; simultaneously, parameter settings, function testing, and performance optimization will be carried out to ensure that the product meets standards and can be put into immediate use. ✅ Equipment Fault Repair: We will respond immediately after receiving a repair request and quickly troubleshoot the fault. Problems that can be solved on-site will be handled immediately; if non-consumable parts need to be replaced, the price and delivery time will be communicated in advance; for complex faults requiring repair at our facility, the repair cycle will be clearly communicated, and the equipment will be returned and commissioned to normal operation promptly after repair. ✅ Professional Technical Support: We will answer questions about product operation, function application, and technical principles through telephone and online communication; for customers' special production needs, we will provide customized technical solutions to assist in optimizing usage processes and improving production efficiency. ✅ Daily Operation and Maintenance Guidance: We provide product maintenance training, guiding staff to master equipment cleaning, component inspection, and regular maintenance methods; we conduct regular follow-up visits to understand usage conditions, provide operation and maintenance suggestions, prevent faults in advance, and extend product service life. II. Service Commitment We make three commitments to you based on the standards of "efficiency, professionalism, and attentiveness": Prompt Response: Within working days, after a customer reports a repair request through official channels, we will proactively contact you within 1 hour to understand the fault details; for urgent faults (such as equipment downtime affecting production), we will arrange for technicians to depart within 24 hours (for special remote areas, the arrival time will be communicated in advance). Professional Operation: All after-sales technicians have undergone rigorous training and assessment, possessing solid professional knowledge and rich practical experience; they strictly follow service procedures and technical specifications, using original factory parts during repairs to ensure equipment performance and stability. Customer Satisfaction: We proactively communicate progress and respect customer opinions during the service process; after the service is completed, we will follow up on customer satisfaction, promptly follow up and resolve any problems raised by customers, and eliminate "inadequate service and unresolved problems." We always adhere to the philosophy of "customer first, service-oriented," and continuously improve our after-sales service system, striving to provide you with higher quality and more attentive service. Thank you for your trust and support in Wuxi Quanjinhe Science & Technology Co., Ltd.!

New Project about EVA foam roll, and this video is testing at customer's factory. This EVA Foaming Machine is used to produce EVA sheet. And EVA sheet can used to make tatami, yoga mats, shoe sole, car mats, prayer mats, sports tools, swimming tools, and so on.

Nice moments at the K Show in Germany. Feel free to contact us if you have any needs for EVA Foaming Machines, Hot Presses, or Rubber Vulcanizing Machines. ----Wuxi QuanJinHe Science & Technology Co., Ltd.

Wuxi Quanjinhe Science & Technology Co.,Ltd will participate in Interfoam China 2025 from Nov.5th to 7th 2025, at Shanghai International Expo Center. We warmly welcome you to visit our booth-E5.E23 at the K Show and look forward to engaging in fruitful discussions with you. We are the professional manufacturer of EVA Foaming Machine. The Foaming Machine including in First Stage Foaming Machine, Secondard Foaming Machine and Supercritical Foaming Machine(Physical Foaming Machine). Our Foaming Machine suitable for EVA, PE, POE, SBR, BR, CR, EPDM and other rubber plastic materials.   

Wuxi Quanjinhe Science & Technology Co.,Ltd will participate in the K Show from Oct.6th to Oct.16th 2025, in Düsseldorf, Germany. We warmly welcome you to visit our booth-3B01 at the K Show and look forward to engaging in fruitful discussions with you. Our main equipment includes: Molding & Foaming Press(suitable for EVA, PE, TPE, EPDM, and other rubber and plastic material ); Rubber Vulcanizing Press; Composite Material Hot Press; Rubber Conveyor Belt Vulcanization and Forming Production Line; and Insulation Paperboard Hot Press.

The 23rd International Exhibition on Rubber Technology. Date: September 17-18-19.   We are looking forward to meeting you at Booth-N2B369.   Wuxi Quanjinhe Science & Technology Co.,Ltd has been established for 30 years, specializing in the research and development of Rubber Vulcanizing Machine, Composite Materials Hot Press Machine and EVA/PE/TPE/EPDM and other rubber & plastic material foaming machines.

1100T EVA PE Foaming Mahcine has been shipped to customer's factory. Our engineers are working hard on the installation on site. This 1100 Ton EVA Foaming Machine can be used for EVA, PE, POE and other plastic rubber materials.

EVA PE Molding Foaming Machine EVA Foaming Machine havs various specifications for different sizes materials, 1*2 meters, 1.2*2.4 meters, 1.2*3 meters, 1.5*3 meters, 1.5*4 meters, etc., and there is a wide range of subsequent additions. With our many years of experience in the manufacturing industry of one-time EVA foaming machine, we can give the most reasonable suggestions, the most reasonable machines and the most suitable products, eliminate invisible waste from the source, and make your project go to market faster.   This time is shipped to our customer in Turkey.

Insulation Cardboard is more and more hot sale around. The power industry: The construction of ultra-high voltage power grids, the increasing demand for transformers and switchgear (especially in emerging markets such as China and Southeast Asia) will drive the demand for insulation cardboard. In the field of new energy: the popularity of wind power, photovoltaic inverters, and energy storage equipment is driving the demand for high-performance insulation materials. Rail transit: The rapid development of high-speed rail and electric vehicles has increased the application of insulating cardboard in electrical equipment.   Wuxi Quanjinhe Science & Technology Co.,Ltd is the professional manufacturer of Insulation cardboard Hot Press machine, we have a big range customers in China. There are also some  At the same time, some foreign insulation cardboard companies are also negotiating business relationships with our company. Welcome insulation cardboard manufacturers from home and abroad to visit and exchange ideas with our company!

    The birth of rubber foam: The earliest form of rubber foam was in 1929, when Eric Owen, a chemist working for Durup Rubber Company, whipped latex in the same way as you made cream for sponge cake. Soon after, the value of what we call polymer foam plastics was reflected, and innovation began to prevail.         Advantages of EVA sole: The sole is made of EVA material. The sole has high elasticity and tension resistance, high toughness, good shock absorption and buffering performance, excellent heat insulation, cold insulation and low-temperature performance, and can withstand severe cold and exposure to sunlight. It has a closed bubble structure, does not absorb water, is moisture-proof, has good water resistance, and is resistant to chemical corrosion such as oil, acid, alkali, etc. It is antibacterial, non-toxic, odorless, and pollution-free.     Types of rubber foam soles: When we look at a pair of shoes, they are likely to contain two different types of foam - open cell foam and closed cell foam. The nature of each foam can vary widely according to the basic ingredients, which can be mixed in different proportions.

Introduction to Supercritical Foaming Technology   In the foaming processing of polymer materials, according to the production mechanism of bubbles, it can be divided into two categories: chemical foaming and physical foaming.   Supercritical foaming is the 1 kind of physical foaming, full name is supercritical fluid microcellular foaming. The physical properties of supercritical fluid are between liquid and gas. Under certain temperature and pressure, it has the properties of gas and liquid. It can diffuse as easily as gas and can be easily infiltrated as liquid. The basic principle of supercritical foaming is to use the dependence of the solubility of gas in the polymer on pressure and temperature, so that the polymer mixture system after supersaturated with supercritical fluid enters a thermodynamically unstable state during the cooling process, inducing the formation of gas nuclei, and then obtaining a microporous structure. Chemical foaming is added to the polymer material in the chemical foaming agent for heating to explain the release of gas and foaming, the whole foaming process is similar to the fermentation of pasta, is a traditional and mature foaming process, is still widely used in the production of ordinary midsole. Compared with traditional chemical foaming, supercritical foaming technology has obvious advantages, which can achieve the two goals of light weight and high elasticity of the midsole at the same time. Supercritical foaming can produce small and uniform bubbles, so that the density of the midsole is lower, thereby reducing the weight of the sneakers and reducing the burden on the user's feet. Supercritical foaming can evenly distribute the bubbles in the midsole material, and the formed buffer structure can effectively absorb the impact, provide better energy feedback, reduce the pressure of joints and muscles, and also improve the compression resistance, so that the midsole is more durable.   The characteristics of supercritical fluid foaming technology include:     Fully utilizing the fast diffusion rate and high solubility of supercritical carbon dioxide in polymers.     During foaming, the polymer is in a semi-solid state, and the melting zone allows for the growth of pores, while the unmelted zone provides melt strength and maintains the pore structure.     Extremely rapid pressure relief induces the formation of a very high nucleation rate, ensuring the formation of a cell structure with micro-nano size and high pore density.     In addition, supercritical foaming does not produce some gases harmful to the environment or human body like chemical foaming, and has the advantages of environmental protection and cleaning.     However, supercritical foaming requires much more equipment and process control than chemical foaming, so the production cost is higher.     At present, there are mainly 4 kinds of raw materials for supercritical foaming: EVA, TPU, TPEE and PEBA.   EVA (ethylene-vinyl acetate) is the earliest application, the most mature, the most extensive foam shoe material, the performance is more common, durability index is relatively backward, after a long time wearing easy to be "flat", thereby reducing the rebound, cushioning performance.   TPU (thermoplastic polyurethane) has excellent rebound performance and strong durability, but its own weight is large, and it will heat up after being subjected to pressure deformation for a long time. TPU is divided into aromatic and aliphatic. Overall, the aliphatic is superior in performance to the aromatic.   TPEE (thermoplastic polyester) can be regarded as an upgraded version of TPU. Generally speaking, it is not much different from TPU in terms of rebound, durability and other indicators, but significantly improved in terms of lightweight indicators.   PEBA (polyether block amide), also known as nylon elastomer, has the highest level of resilience, lightweight performance and durability that does not lose TPU and TPEE. It is the standard midsole of top sneaker. The cost of PEBA is high, and PEBA is commonly used to mix EVA, TPU and other materials for foaming to reduce costs.

Problem 1: Insufficient foaming holes   1. There may be a problem with the quality of the foaming agent. If this happens, we should first check the service life of the foaming agent to see if it is within the service life.   2. It may be that the strength of the rubber material is too low. At this time, we need to check whether the plasticity of the rubber material is within the standard range. If the plasticity is too low, it should be supplemented and mixed to increase the plasticity and increase the number of foaming holes.   3. The rubber material has been placed for too long or in a high temperature place, causing the foaming agent to volatilize. In this case, the rubber material should be reprocessed.   4. The rubber material vulcanizes very quickly. At this time, the formula of the rubber material should be adjusted to coordinate the critical temperature of the vulcanizing agent and the decomposition temperature of the foaming agent so that the speed of the two can cooperate with each other to slow down the vulcanization speed.   Problem 2: Insufficient filling mold   1. The amount of rubber used is insufficient. At this time, the rubber strips should be weighed one by one to ensure that the weight of the rubber material meets the standard.   2. The mold may not be smooth enough or the mold has been used for a long time without corresponding cleaning, so that the rubber is subject to resistance when it flows. In this case, we should find a way to reduce the resistance and enhance the fluidity of the rubber.   Problem 3: The foaming holes are too large or too small and uneven   1. The foaming agent is agglomerated. The solution is to sieve the agglomerated particles, crush the coarser particles, and then mix them thoroughly to make them evenly dispersed.   2. The compound contains too much water or air and other impurities mixed in the rubber. In this case, the excess water in the compound should be removed first, and the air and impurities in the rubber should be fully removed to fully vulcanize them.   3. It may be due to insufficient vulcanization that the phenomenon of continued pores appears after the pattern is formed. At this time, the conditions of the vulcanization process should be adjusted accordingly, and the amount of vulcanizer used should be increased to meet the corresponding standards.   Question 4: Over-vulcanization or under-vulcanization   1. Over-vulcanization generally causes surface discoloration, smaller holes, higher hardness, and cracked edges. The causes are improper operation, too high temperature, too long vulcanization time, or instrument failure. Check whether there are any problems with the valves and instruments, and then strictly follow the operating rules.   2. Under-vulcanization When the vulcanization is insufficient, the internal pressure of the pores is greater than the external pressure after demolding. If the rubber material continues to pore, it will cause low hardness, poor strength, and large deformation at the least; or the holes will burst. Check whether there are any problems with the instruments and valves, and strictly follow the operating rules.   Note: Quality control indicators for foam products (1) Apparent density, the smaller the better; (2) Mechanical strength is generally 0.5-1.6Mpa; (3) Static compression permanent deformation; (4) Hardness; (5) Impact elasticity; (6) Continuous dynamic fatigue; (7) Aging test (70 degrees * 70 hours; 100 degrees * 24 hours); (8) Low temperature test.

EVA PE Foaming machine, Twice Rubber Plastic Foaming machine and Rubber Plastic Extruder are shipped. Wuxi QuanJinHe Science & Technology Co.,Ltd has the experience more than 20 years in rubber and palstic machinery. Our Main Product is EVA PE Rubber Plastic Foaming Machine, Rubber Vulcanizing Mahcine, Hot Press, Conveyor Belt Vulcanizing Line, Conveyor Belt Production Machine and Transformer  Insulation Cardboard Hot Press Machine. If you have any related project, please be free to contact us.