News

Trade news

Company news

FAQ

What is the function of a mold temperature controller in rubber extrusion equipment?

The rubber extruder plays a crucial role in the extrusion process of rubber products, enabling extrusion molding. Before processing filled rubber compounds, the extruder’s barrel must first be heated; only when the temperature reaches the desired setpoint can the machine be operated. The equipment responsible for heating the extruder is known as a mold temperature controller. Today, most rubber extruders rely on mold temperature controllers to manage their operating temperatures. When the equipment overheats, the controller sends chilled water through the barrel and screw to cool the system down. Conversely, if the temperature drops too low, the controller increases the heat to bring the equipment back up to the required level. In essence, the mold temperature controller maintains the extruder at a stable, consistent temperature throughout production. By precisely regulating the equipment’s temperature, this system ensures greater accuracy and enhances the overall stability of the extrusion process. Hebei Shuangda Rubber & Plastics Machinery Co., Ltd. is a modern enterprise integrating research, development, manufacturing, and sales of complete sets of extrusion machinery for rubber, silicone, and plastics. The company’s main product lines include rubber extruders, rubber hose extrusion lines, three‑layer composite sealing strip extrusion lines, silicone sealing strip production lines, plastic sealing strip production lines, plastic profile extrusion lines, plastic pipe extrusion lines, elastomer extruders, and other extrusion equipment. Additionally, the company manufactures production equipment for engineering seals, automotive seals, wire and cable applications, air‑conditioning hoses, braided tubes, automotive hoses, waterstop strips, and related products.

2021

05-13

What is the significance of plastic pelletizing machines in the recycling of waste plastics?

The practical significance of recycling and reusing waste plastics goes beyond simple waste management; it carries broader, long-term, and proactive implications, primarily evident in two key areas: 1. The environmental harm caused by discarded plastics. Due to their excellent quality and low cost, plastics are widely used for product packaging, and the majority of these single-use items are thrown away after use, resulting in the well-known “white pollution.” For example, agricultural plastic mulch films have greatly advanced farming practices; however, improper disposal of residual fragments creates an impermeable barrier in the soil, degrading soil quality, hindering root growth and the absorption of water and nutrients, and even leading to soil contamination. Over time, rainwater leaches harmful additives from plastic waste into surface waters—rivers, lakes, and oceans—causing environmental pollution and posing risks to human health. Consequently, China is actively promoting technologies for recycling waste plastics, with plastic recycling pelletizing machines serving as one viable option. Through the processes of collection, cleaning, shredding, and drying, waste plastics can be effectively processed. The relationship between waste plastic recycling and energy resources is significant. Most modern plastics are derived from petroleum, yet China’s oil reserves account for only about 2% of the world’s total. Starting in 1993, China transitioned from a net oil exporter to a net importer, and by 2002 had surpassed Japan to become the world’s second-largest oil consumer. Today, China’s dependence on imported oil has reached nearly 40%. As a result, energy scarcity has become a major obstacle to socioeconomic development, and recycling waste plastics can help alleviate this growing resource shortage to some extent. Currently, China produces vast quantities of plastic products, increasing annually at rates exceeding 10%, generating staggering amounts of waste plastic. However, the current state of waste plastic recycling in China remains concerning, with the majority of such materials still being disposed of through landfilling. In summary, the value of plastic recycling pelletizing machines aligns with the overarching goals of waste plastic recycling, with pelletizing equipment serving as an effective means to achieve this objective. Plastic pelletizing machines are categorized into single-screw extrusion pelletizers and single-screw pelletizers. Single-screw extrusion pelletizers can process plastic films, packaging bags, waste synthetic fibers, greenhouse plastic films, and similar materials, while single-screw pelletizers are suitable for recycling PET bottles (plastic water bottles) and other types of waste plastics. Additional specialized models include PVC pelletizers, cable‑sheath pelletizers, polyvinyl chloride pelletizers, eco‑friendly pelletizing machines, environmentally friendly plastic recycling systems, BOPP film pelletizers, nonwoven fabric pelletizers, LDPE film pelletizers, CPP film pelletizers, composite plastic film pelletizers, PET fiber pelletizers, plastic printing film pelletizers, plastic crushing and washing machines, plastic rinsing equipment, air‑cooled plastic pelletizers, beverage bottle crushing and washing lines, PET plastic cleaning systems, and PET pelletizing machines.

2021

05-16

What functions does a plastic extruder have?

Extrusion Molding The extrusion process proceeds as follows: granular or powdered solid materials are fed into the hopper of an extruder, where they are heated to a viscous‑flow state. Under pressure, the screw inside the barrel rotates, conveying the material forward. The molten material then passes through the die at the head, forming a parison that matches the shape of the die. Next, the parison enters a cooling and shaping unit, acquiring its final form. Finally, the product is cut to length for storage and transportation. The Role of Extrusion Molding in the Plastics Processing Industry 1. Extruded plastic products account for approximately 50% of total plastic production, while extrusion processes themselves comprise about 30% of all plastic molding output. 2. Virtually all thermoplastics, along with some thermosets, can be processed using extrusion equipment. 3. It enables continuous production, high efficiency, broad applicability, and versatile use of a single machine. Advantages of Extrusion Molding 1. Simple equipment requiring low capital investment. 2. Continuous production with high efficiency. 3. High degree of automation, resulting in reduced labor intensity. 4. Easy operation and straightforward process control. 5. Produces uniform, dense products of high quality. 6. Strong material adaptability—suitable for most thermoplastics and a limited range of thermosets. 7. Wide range of applications and multi‑purpose functionality. 8. Compact plant footprint and clean production environment.

2021

05-17

Extrusion Production Process for Silicone Tubing Equipment

The selection of production equipment for silicone tubing depends on the type of tube being manufactured. Silicone tubes are typically formed by extrusion using a silicone extruder; however, since there are various types of silicone tubing, the auxiliary forming equipment required also differs. The most common type is the single‑layer straight silicone tube, which has a relatively simple manufacturing process that mainly involves a silicone extruder and a vulcanization unit. The extruder is designed to suit the specific properties of silicone—generally featuring a short L/D ratio for the screw to minimize energy consumption and facilitate molding. When producing single‑layer silicone tubes, the extruder is usually elevated and fitted with a T‑die, allowing the extruded tube to be formed vertically downward. The extruded tube then passes directly into a vulcanization unit positioned beneath the die. By adjusting the extruder’s output speed, we can synchronize vulcanization with the extrusion process. This method yields tubes with smooth, scratch‑free surfaces, improving yield and making it highly favored by customers. Silicone products are readily vulcanizable; accordingly, we select the length of the vulcanization equipment based on the size of the extruded product. For larger items, we often replace the vertical vulcanization section with a high‑temperature shaping stage, followed by a second pass through a vulcanization chamber. Ultimately, the choice of specific production equipment for silicone tubing depends on the particular requirements of each application. There are many varieties of silicone tubing. In addition to single‑layer straight tubes, there are profiled tubes and specialized single‑layer profiles, which are typically shaped using molds after extrusion. These profiled tubes are then placed in a vulcanization oven for curing. Other types are composite silicone tubes, whose manufacturing processes are more complex and require careful consideration of the product’s structure to determine the appropriate equipment and production methods. For instance, some composite tubes are produced via co‑extrusion using a dual‑die configuration, followed by vulcanization. However, certain tubes feature an intermediate layer; these necessitate two separate silicone extruders operating in-line during production. Such multi‑layer tubes are usually cured in a vulcanization tank, a pressure‑assisted process known as “pressurized vulcanization.” The choice of vulcanization method should be guided by the product’s formulation and structural design.

2021

05-19

What are the production processes and characteristics of silicone extruders?

Extrusion is one of the key methods for shaping silicone rubber. Compared with other forming techniques, extrusion offers the following advantages: it provides a continuous production process with higher efficiency, requires lower investment, and delivers quicker returns. It can produce various products such as hoses, strips, rods, sheets, and hollow components. Extrusion molding is primarily carried out on an extruder. To ensure the molding process proceeds smoothly, an extrusion system typically consists of the following components: 1) Extrusion System: Comprised mainly of the barrel and screw, this system plasticizes the silicone rubber into a viscous flow, which is continuously and precisely extruded through the die by the screw under controlled pressure and rate. 2) Drive System: Supplies the necessary torque and rotational speed to the screw. 3) Heating and Cooling System: Heats and cools the barrel, screw, and die to maintain the extrusion process within the desired temperature range. 4) Die: Shapes the silicone rubber into products with specific geometries and dimensions. 5) Curing Unit: Heats and cures the silicone rubber to produce the final product. Key considerations in extrusion processing include: 1) Screw Speed: Excessive screw speed can lead to overheating of the silicone rubber, causing premature vulcanization and a sticky surface. 2) Die Pressure: Higher die pressure increases backflow while reducing forward flow, potentially resulting in excess material buildup in the barrel; too low a die pressure may prevent the production of correctly sized parts. 3) Feeding Mechanism: Silicone rubber is generally fed cold, so its impact on extrusion temperature is minimal. However, adequate free feeding is crucial; insufficient feeding reduces production efficiency and may cause material shortages. Characteristics of silicone rubber extrusion: 1) The extrudability of silicone rubber is broadly similar to that of conventional rubbers. However, due to its lower green strength, thermal sensitivity, and pronounced stickiness, silicone rubber presents certain challenges during extrusion. 2) For silicone rubber extrusion, a relatively long L/D ratio and a slightly higher compression ratio are recommended. The screw should feature uniform pitch, with a double‑thread design at the discharge end. 3) Silicone rubber is commonly reinforced with precipitated silica. Both the barrel and screw of the extruder should be made from wear‑resistant alloy steel. The expansion rate of extruded silicone rubber is typically low, around 1%. 4) Two‑component peroxide curing systems and platinum catalysts are commonly used. Peroxide systems are cost‑effective and offer good dimensional control, whereas platinum catalysts yield products with higher strength, better transparency, and reduced odor. 5) Gas-phase silica is preferred for extrusion, as precipitated silica tends to form bubbles during the process. Additionally, gas-phase silica provides superior transparency and mechanical strength.

2021

05-22

Overview of the Rubber Hose Extrusion Production Process

Taking EPDM rubber hoses as an example, let’s examine the production process and the equipment involved. Rubber hoses are generally categorized into two types: those with a wire reinforcement layer and those without. The size of the extruder is determined based on the hose’s diameter and wall thickness. Typically, pin‑type rubber extruders are used for producing rubber hoses because they ensure uniform mixing, increase pressure within the screw, and thereby improve product quality. The overall equipment required for manufacturing rubber hoses includes two rubber extruders—one for the inner layer and one for the outer layer. First, the inner layer is extruded: after the rubber has been milled and mixed in a kneader, the rubber compound, cut into sheets, is fed into the first extruder. The rubber is forced through the extrusion barrel to the die head, where it takes its final shape. The extruded hose then moves along a conveyor belt to the knitting machine, which forms the reinforcing mesh. Once knitted, the hose enters the T‑die of the second extruder, where the outer coating is applied, completing the basic structure of the rubber hose. The finished hose is drawn by the first traction unit into a water tank for cooling, then passes through a second water tank containing a release agent. After further traction, it proceeds to the automatic cutting equipment. Hebei Shuangda Rubber & Plastics Machinery Co., Ltd. is a modern enterprise integrating research and development, manufacturing, and sales of complete sets of extrusion machinery for rubber, silicone, and plastics. The company’s main products include rubber extruders, rubber hose extrusion lines, three‑layer composite sealing strip extrusion lines, silicone sealing strip production lines, plastic sealing strip production lines, plastic profile production lines, plastic pipe production lines, elastomer extruders, and other extrusion equipment. Additionally, the company manufactures production equipment for engineering seals, automotive seals, wire and cable applications, air‑conditioning hoses, braided hoses, automotive hoses, waterstop strips, and related products.

2021

05-24

Hebei Shuangda Exhibits at the 2021 China–Hebei International Plastics, Rubber & Packaging Industry Expo.

Hebei Shuangda Rubber & Plastics Machinery Co., Ltd. will be exhibiting at the 2021 China–Hebei International Plastics, Rubber & Packaging Industry Expo, held from June 3 to 5, 2021, at the Hebei Shijiazhuang International Convention and Exhibition Center (No. 9 Heyang Road, Zhengding). Our booth number is Special Hall 20, Hall 6. Our product lineup includes: integrated composite plastic extrusion machines, stainless steel compartment-type lift‑and‑lower water tanks, rotary traction machines, multi‑V‑belt traction machines, and a 150 mm automatic pipe‑cutting and traction integrated machine. We warmly welcome both new and existing customers to visit our booth! Hebei Shuangda Rubber & Plastics Machinery Co., Ltd. is a modern enterprise integrating R&D, manufacturing, and sales of complete sets of extrusion machinery for rubber, silicone, and plastics. Our main products include rubber extruders, rubber hose extrusion lines, three‑layer composite sealing strip extrusion lines, silicone sealing strip production lines, plastic sealing strip production lines, plastic profile production lines, plastic pipe production lines, elastomer extruders, and other extrusion equipment, as well as production machinery for engineering seals, automotive seals, wire and cable applications, air-conditioning hoses, braided tubes, automotive hoses, waterstop strips, and related products.

2021

05-26

Operating Principle and Applications of Rubber Extruders

As a fundamental piece of equipment in the rubber industry, the rubber extruder is one of the key machines that significantly influence product quality and plays a crucial role in the production of tires and rubber goods. Operating principle: The rubber extruder functions by applying heat, pressure, and shear to convert solid plastics into a uniform molten state, which is then conveyed to the next processing stage. The production of the molten material involves blending color masterbatches and other additives, compounding resins, and re‑grinding, among other steps. The concentration and temperature of the finished melt must be uniform, and the pressure must be sufficiently high to extrude the viscous polymer.

2021

05-26

Helical Sleeve Production Line

A spiral protective sleeve is a helical sheath manufactured from materials such as polypropylene (PP), polyethylene (PE), or nylon (PA) using a hot‑state winding and extrusion‑forming process. It serves as a modern alternative to traditional metal spring protectors used for hose protection. Other names for this product include spiral guard, hose protector, and wire protector. Spiral protective sleeves can be produced using reinforced nylon, modified PE, and other plastic materials. The molding processes typically employed include extruding sheet material followed by helical winding, or extruding tubular stock and then shaping it through rotary cutting. Hebei Shuangda Rubber & Plastic Machinery Co., Ltd. is a modern enterprise integrating research, development, manufacturing, and sales of complete sets of extrusion machinery for rubber, silicone, and plastics. The company’s main products include rubber extruders, rubber hose extrusion lines, three‑layer composite sealing strip extrusion lines, silicone sealing strip production lines, plastic sealing strip production lines, plastic profile extrusion lines, plastic pipe extrusion lines, elastomer extruders, and various other extrusion equipment. Additionally, the company provides production equipment for engineering seals, automotive seals, wire and cable applications, air‑conditioning hoses, braided hoses, automotive hoses, waterstop strips, and related products.

2021

05-28

The Importance of Temperature Control in Rubber Extruders

Currently, temperature control in rubber extruders typically operates as a closed-loop system, following a sequence of measurement, adjustment, and set-point regulation. Specifically, the temperature of the controlled process is accurately measured, the deviation from the desired setpoint is determined, and the control action is adjusted to maintain the process temperature within a specified range. The screw of a rubber extruder consists of two main sections: the threaded portion, which serves as the working zone, and the section connected to the drive mechanism. Screws are classified into three types: single-start, double-start, and compound screws. Single-start screws are commonly used for gel filtration, while double-start screws are preferred for extrusion molding, ensuring uniform material discharge. The feed end of a compound screw features a single-start thread configuration, facilitating easier material feeding.

2021

05-31

< 1...858687...93 >