UNIK Moulds Engineered to Reduce Concrete Adhesion for Smoother Demoulding and Faster Cycles
Quanzhou, China – Fujian Unik Mould Technology Co., Ltd., a precision mould manufacturer with over 15 years of industry experience, has placed a central engineering focus on reducing concrete adhesion to mould surfaces. This design priority enables faster cycle times, fewer product defects, and extended tooling life for block producers across 28 countries.
The Demoulding Challenge
Concrete adhesion during demoulding is a persistent issue in block production. When concrete sticks to cavity surfaces, manufacturers face a cascade of problems: cracked block corners, rough surfaces, production stoppages, and rejected products that erode profit margins .
High demoulding resistance stems from several factors. Surface roughness creates friction between concrete and steel. Chemical adhesion can occur between cement paste and untreated mould surfaces . Delayed demoulding timing allows concrete to bond more strongly to cavity walls . Sharp corners and undercuts in mould design trap concrete and prevent clean release .
UNIK addresses each of these factors through material selection, precision machining, and surface engineering.
Surface Finish: The Foundation of Smooth Demoulding
UNIK manufactures all mould cavities with a surface finish of Ra 1.6 or better, with some applications reaching Ra 0.8μm or even Ra 0.4μm . This smooth finish reduces friction between concrete and steel, allowing blocks to release cleanly without sticking.
The surface quality is achieved through a multi-stage precision grinding process following initial CNC milling . The process follows a systematic sequence: rough grinding removes machining marks, fine polishing achieves uniform finish, and mirror finishing delivers a near-mirror surface with roughness values of Ra ≤ 0.4μm when required. A rust-proof coating is then applied to protect the finished surface .
A polished cavity reduces friction and improves block surface finish by up to 30% . It also minimises wear on ejector pins and reduces release agent consumption, lowering operational costs over the mould's lifetime.
Radiused Corners: Eliminating Stress and Adhesion Points
UNIK moulds incorporate 3-5mm radiused corners on all internal cavity edges . This design feature serves a dual purpose: it eliminates the sharp 90-degree corners that act as stress concentration points where concrete adhesion is strongest, and it prevents crack initiation in both the mould and the concrete product .
Blocks produced in moulds without proper corner radius often show cracked or broken corners during demoulding, as the tensile stress concentrates at the sharp edge and exceeds the concrete's green strength during ejection . The radiused corner design is standard across all UNIK moulds, including paver, block, and screen block moulds .
Precision Draft Angles for Clean Ejection
UNIK engineers each mould with a 1.5° draft angle per side . This slight taper on vertical cavity walls allows the cured concrete block to be ejected cleanly without requiring excessive force.
The draft angle reduces undercut stress during hydraulic ejection . Without sufficient draft, blocks can wedge in the cavity, leading to product damage and increased wear on the mould. A properly engineered draft angle is especially critical for complex shapes and deep profiles, where concrete adhesion is more pronounced .
Heat Treatment: Surface Hardness That Resists Wear and Adhesion
Every UNIK mould undergoes a controlled carburizing heat treatment process. This hardens the surface layer to HRC 58-62 while preserving core toughness at HRC 35-40 .
The hard surface resists abrasion from concrete aggregates . As the cavity surface remains smooth and free from scratches, the risk of concrete adhesion is minimised. The tough core absorbs the high-frequency vibration (3,000–4,500 RPM) of modern block machines without cracking, preventing the surface degradation that leads to increased adhesion .
Practical Results: Faster Cycles, Less Waste
The combination of these engineering features delivers measurable operational benefits for block producers.
When demoulding proceeds smoothly, production lines run at full capacity with minimal waste . UNIK's precision-ground cavities and radiused corners reduce sticking, which is the most frequently reported demoulding issue . A consistent demoulding time of 10–15 seconds post-vibration becomes achievable without block damage .
A procurement manager from a Philippine brick plant that has placed multiple UNIK orders commented: "Previous suppliers' moulds showed edge wear at 25,000 cycles. UNIK moulds from the same production period are still running at 85,000 cycles with acceptable tolerance. The heat treatment makes a measurable difference" .
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Conclusion
UNIK moulds are engineered to reduce concrete adhesion through four core design principles: precision-ground cavity surfaces with Ra 1.6 finish or better, radiused corners of 3-5mm to eliminate sharp stress points, 1.5° draft angles per side for clean hydraulic ejection, and carburizing heat treatment that maintains surface hardness while preventing wear-induced roughness. These features work together to deliver smoother demoulding, faster cycle times, and reduced product defects for concrete manufacturers worldwide
About Fujian Unik Mould Technology Co., Ltd.
Established in 2010 and headquartered in Quanzhou, Fujian Province, UNIK specialises in the design and manufacture of high-quality brick machines and precision moulds. The company serves clients in 28 countries, offering solutions for pavers, blocks, curbs, retaining walls, and custom architectural profiles. UNIK holds ISO 9001:2015, CE, and SGS certifications.
For more information:
Fujian Unik Mould Technology Co., Ltd.
Website: www.unikmould.com
Location: Quanzhou, Fujian Province, China
