The degree of peroxide vulcanization in EPDM rubber varies depending on the specific product being manufactured; some rubber products are produced via non-pressure peroxide vulcanization, while others are processed using pressure-assisted peroxide vulcanization.

Taking the production of sealing strips as an example, most manufacturers use hot‑air vulcanization tunnels for in‑line vulcanization—what we commonly refer to as non‑pressurized vulcanization. This method allows vulcanization to be carried out directly on the production line, offering high productivity and reduced labor costs. By contrast, pressurized vulcanization is typically employed for products with specific pressure‑related requirements or for composite materials. As for the extrusion process of rubber hoses, single‑layer hoses can achieve vulcanization simply by extruding the material on a rubber extruder and then passing it through a hot‑air vulcanization tunnel; after exiting the tunnel, water cooling completes the curing process, yielding the desired product. For certain applications, such as automotive hoses, production involves two rubber extruders operating in tandem: one extrudes the inner layer, while the other forms the outer layer, with intermediate processing steps—such as incorporating reinforcing cords or steel wires—between the layers.

Once the second rubber extruder has completed forming the hose’s structural layers, the product is ready for cutting. After slicing the hose to the required length, it undergoes vulcanization in a vulcanizing tank—a pressurized vulcanization process. Compared with non‑pressurized vulcanization, this method yields hoses that are less prone to delamination and exhibit significantly superior density and burst resistance.

The de‑stone machine for reclaimed rubber manufactured by Hebei Shuangda serves as the pioneering equipment for continuous high‑temperature, atmospheric‑pressure de‑stoning, and is a prerequisite for ensuring stable quality and superior performance in reclaimed rubber products. It enables rubber powder, activators, plasticizers, and other additives to undergo uniform blending within a three‑dimensional spatial structure under precisely controlled conditions. Following agitation by the mixing system, the rubber powder is further plasticized by the plasticizer, significantly enhancing product specifications and stability while reducing energy consumption.

It employs high-temperature, atmospheric-pressure plasticization, electromagnetic heating, a continuous production mode, and an automated control system. Featuring a single-screw split design, it ensures smooth polymer powder flow, uniform heating, stable product performance, safe operation, and ease of use.

Working principle of the rubber de‑stone machine: Based on the “rubber de‑stone reversion” mechanism, the waste rubber powder—premixed with additives according to the formulation—is heated during screw conveyance, enabling it to undergo “reversion and regeneration” under atmospheric pressure and high temperature conditions.

Equipment requirements for the rubber stone-removal machine process:

1. The equipment shall operate stably, and its installation, operation, and maintenance shall be simple and convenient.

2. The heating device operates stably, with a defined temperature rise range and an adjustable, controllable operating temperature.

3. The material is heated uniformly and consistently;

4. Allow sufficient time for the broken stone to be plasticized;

5. A relatively enclosed, plasticized space within the fractured rock mass;

6. Discharge cooling unit.

Features of the rubber stone-removal machine

1. Operates stably, with simple and convenient installation, operation, and maintenance;

2. The electromagnetic heating device operates stably, with a defined temperature rise range and adjustable, controllable operating temperatures; the temperature fluctuation is within ±1.5℃.

3. The outer tube and the helical shaft rotate in opposite directions, ensuring uniform and stable heating of the rubber powder and reducing the heating time.

4. Energy-efficient, highly automated, labor-saving, and low in operating costs;

5. This equipment can operate independently or in parallel, sharing a common feeding and discharging system to meet increased production capacity requirements.

Hebei Shuangda Rubber and Plastics Machinery Co., Ltd. is a modern enterprise that integrates research and development, manufacturing, and sales of complete sets of extrusion equipment 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, as well as production machinery for engineering seals, automotive seals, wire and cable applications, air‑conditioning hoses, braided hoses, automotive hoses, waterstop strips, and related products.