Sidel PET lines installed at Yili China

TWO aseptic complete PET packaging lines, including the Sidel Aseptic Combi Predis™ with dry preform sterilisation technology, have been installed at Yili^[1], the world’s largest liquid dairy producer. The company’s growing sales demonstrate how they manage to be successful in differentiating their brand with the help of premium dairies. In this area, PET packaging can help Yili advance as a business by offering new consumer experiences compared with the traditional carton format while allowing a more flexible production, according to Sidel.

Yili believes in the potential of PET as a packaging material, as it matches the Chinese consumers’ expectations by being user-friendly, shatterproof, re-sealable, and recyclable. It also provides freedom in bottle design to differentiate their dairy brand on the Chinese supermarket shelves. Perhaps more importantly, PET offers great benefits in terms of physical product and food barrier protection, therefore preserving nutritional and sensorial properties of yogurts at all stages – from production, storage, and shipment to distribution. Moreover, the closure tightness adds to PET’s convenience even without the use of aluminium foil.

Side'ls PET packaging line.  

All of these reasons supported the Yili strategic direction to partially switch their production from carton to PET bottles with the aim of introducing innovative packages: a great pioneering move in the Chinese dairy market. As part of this change, the Ambrosial Greek Yogurt, packaged in PET single serve bottles, has been highly popular since its launch. Considering the growing market demand for this premium drinking yogurt, paired with a willingness to innovate the brand, Yili decided to invest in a couple of new aseptic PET packaging lines. This is when Sidel came as the logical choice due to the solid and trustful partnership built between the two companies in the past. The team at Yili appreciated especially Sidel’s insights and inputs on beverage market trends, packaging design, and extensive PET aseptic packaging expertise, all proving instrumental for the leading Chinese dairy brand.

Sidel and Yili collaborated to make sure which type of PET bottles would allow Yili’s yogurts to retain their fresh taste and vitamin content. 

PET barrier qualified for 5-months shelf life

With Sidel’s support, Yili was the first one to bottle Ambrosial Greek Yogurt in PET for ambient distribution – a product which had previously been offered in cartons. Sidel and Yili collaborated to fully qualify the PET barrier properties and make sure which type of PET bottles would allow Yili’s yogurts to retain their fresh taste and vitamin content. This is particularly important as this product’s quality can be easily compromised by the effects of light, oxygen, and temperature. All these considerations justified the requirement for full barrier opaque packaging.

Sidel’s experts in liquid dairies and packaging performed a range of laboratory tests to determine the behaviour of different liquid dairy products (yogurt, UHT white milk) in several PET barrier solutions (PET multi-layers and mono-layer with different rates of TiO₂). The scientists evaluated different caps’ opacity to achieve the optimal light and oxygen barrier and ensure the product’s stability without any alteration in terms of taste or colour. All these analyses confirmed that the combination of approved barrier PET and cap solutions with the Sidel aseptic filling packaging solution will allow reaching a 5-months yogurt shelf life, plus safety throughout the supply chain for distribution at room temperature. The team at Yili was particularly impressed by the technical support given by Sidel in new product development, as well as in the variety of testing methods implemented to qualify the PET barrier solutions.

A single, expert partner across the entire aseptic PET line

Yili acquired two aseptic PET complete lines in the same year both including Sidel and Tetra Pak Processing Systems equipment. Every component was thus centred around one supplier, from process solution to PET packaging assessment, and from equipment definition and delivery to fast ramp-up. The lines, featuring a high-speed production capability to answer the growing Chinese market demand of liquid dairy products for Ready-to-drink (RTD) consumption, also offer Yili the opportunity to move from the traditional wet bottle decontamination technology they were previously using to the Sidel aseptic blow-fill-cap solution, equipped with dry preform and cap sterilisation technologies. For the top liquid dairy producer, this was another decisive factor in choosing Sidel.

Traditional aseptic solutions use peracetic acid, which requires a rinsing of the bottles with chemicals or hot water while the Sidel Aseptic Combi Predis sterilises the preform by injecting hydrogen peroxide (H₂O₂) vapour into the preform, right before the preform heating stage in the oven. This allows Yili to reduce waste and resources while benefitting from a competitive and cost-efficient solution. With no water and almost no use of chemicals for preform decontamination, it also addresses one of the most difficult challenges manufacturers are facing today when it comes to an optimal environmental footprint. In addition to greater production sustainability, it provides high levels of efficiency and bottles’ lightweighting potential, as these bottles do not have the thermal constraints associated with the traditional bottle-rinsing process.

Designed to adapt production for future demands

As Yili plans to diversify their portfolio with more value-added products to create and maintain a sustainable business, they required a versatile production line to vary the recipes of their products. This is why the Sidel Aseptic Combi Predis integrated as part of their complete lines are equipped with specific dosing valves with wider diameter and a low-high speed regulation to get prepared for the future market requirements. To match the increasing consumer demands, Yili recently invested in three new additional aseptic lines with the Sidel Aseptic Combi Predis to enlarge its production capacity.