How to Build a Pet Filled Food Production Line? A Complete Explanation of the Production Process and Supporting Equipment

With the upgrading of pet consumption in China, filled food, with its unique structure of a crispy outer shell and a liquid, nutritious inner core, has become a mainstream high-end product in the pet food market. Currently, many newly built pet food factories and established OEM manufacturers are researching standardized production solutions for filled pet food. Shandong Arrow, with over 30 years of experience in extrusion equipment R&D, combined with practical experience from thousands of implemented projects, has completely broken down the entire production process and supporting equipment for filled food, providing clear production guidance for industry clients.

1. How to Establish a Pet Filled Food Production Line?
A complete Shandong Arrow Machinery fully automated filled food production line includes multiple sequential processes: ingredient preparation → crushing → mixing → extrusion and filling → cutting and shaping → drying → spraying → cooling. The entire set of equipment operates in a fully automated closed-loop system. The outer shell raw materials and filling slurry are processed independently, avoiding common production problems such as material mixing, uneven molding, and filling leakage from the source.
2.What is the Production Process of Pet Filled Food? 
（1）Raw Material Pre-treatment: This is a fundamental step in ensuring the quality of the finished product. Sandwich production requires separate processing of two types of raw materials. The outer skin primarily consists of grain flour, plant starch, animal protein powder, and dietary fiber, while the filling uses animal protein, nutrients, oils, and other liquid materials. Shandong Arrow uses a dedicated hammer mill with adjustable grinding fineness and a fully sealed dust removal structure. This effectively refines clumps of raw materials, removes impurities, and solves problems such as inconsistent particle size and cracking during puffing, fully complying with food production hygiene standards.
（2）Ingredient Mixing: The pulverized dry outer skin material is fed into a twin-shaft mixer, where an independent mixing station is simultaneously set up to prepare the filling liquid slurry. Shandong Arrow's twin-shaft mixer eliminates dead zones, ensuring high material uniformity. It supports automated quantitative feeding, minimizing batching errors. Two independent batching systems allow for quick switching between different product formulas, avoiding cross-contamination of flavors. It is suitable for production lines ranging from 100kg/h to 2000kg/h.
（3）Steam conditioning and twin-screw sandwich puffing process: This is the core process of the entire production line, directly determining the crispness, nutritional maturity, and filling effect of the grains. High-temperature steam fully gelatinizes the outer starch. Shandong Arrow's self-developed twin-screw sandwich puffing unit, utilizing co-extrusion technology, precisely and synchronously injects the filling material during extrusion, forming double-layered granules in one step. The equipment adopts zoned digital temperature control, and the filling injection flow rate is adjustable in real time, enabling stable 24-hour continuous production. It is suitable for high-meat, high-oil premium formulas, significantly reducing the rate of defective products due to core leakage and filling misalignment.
（4）Cutting and shaping process: The semi-finished products after puffing are prone to sticking together and have uneven lengths and dimensions, requiring a granule shaping and separating roller to standardize their shape.
（5）Drying process: Freshly extruded sandwich granules have a moisture content of 18%-22%, making them soft and highly susceptible to mold and spoilage. A multi-layer mesh belt dryer is an essential supporting equipment. Shandong Arrow's drying equipment features segmented constant temperature control and uniform hot air circulation, rapidly reducing material moisture and solidifying the particle structure. This improves the crispness of the grains and significantly extends the shelf life of the finished product.
（6）Seasoning Spraying Process: The dried grains themselves have a mild flavor. The seasoning spraying process is crucial for improving palatability. The powder is sprayed evenly without accumulation, and the seasoning powder adheres firmly to the particle surface without shedding or clumping.
（7）Cooling and Screening Process: The surface temperature of the seasoned particles is relatively high. Direct packaging can lead to moisture absorption and mold growth. Therefore, the production line is equipped with cooling equipment. After sufficient cooling, broken powder and defective products are automatically screened out, consistently improving the finished product qualification rate. 
Finally, a fully automatic quantitative packaging machine completes the weighing, sealing, and coding operations in one integrated process, adapting to mainstream packaging sizes such as 1kg, 5kg, and 10kg, significantly reducing labor input in the workshop.

Leveraging its independent R&D advantages, Shandong Arrow's complete sandwich food production line supports flexible production. By simply changing molds and adjusting the filling flow rate, it can simultaneously produce sandwich cat food, dog food, and functional prescription food. Small production lines (100-300 kg/h) require minimal space and have low investment barriers, making them suitable for start-up processing plants; medium and large-scale high-capacity units are specifically designed for large-scale OEM manufacturers. The entire system is equipped with a PLC intelligent control system, digitally storing all process parameters, allowing for one-click formula switching, and simplifying operation.

3.About Shandong Arrow Machinery
Unlike purchasing individual pieces of equipment piecemeal, choosing Shandong Arrow's one-stop integrated service provides comprehensive support throughout the entire process, including unified factory layout planning, on-site installation and commissioning, and employee training.
With the current high-end sandwich food market experiencing continuous growth, a stable and mature automated production line is the core hardware for companies to create differentiated products and seize market share. Shandong Arrow, a high-tech pet food production equipment manufacturer, possesses numerous industry patents. It can customize entire production lines according to the customer's factory area and target production capacity. Pet food companies with equipment procurement or upgrade needs for existing puffing production lines can leave a message online to inquire and obtain complete process drawings, equipment parameters, and customized quotation solutions.