What Causes GRG Components to Crack After Production? How to Completely Prevent It?

What causes GRG components to crack after production? How can it be thoroughly prevented? As a smart manufacturing service provider with nearly 30 years of deep expertise in the field of irregular-shaped building materials, we have received extensive feedback from GRG component application projects, in which post-production cracking is a widespread pain point in the industry, and many projects have experienced schedule delays and cost overruns as a result. Today, drawing on our front-line production and implementation experience, we will systematically break down the core causes of post-production cracking in GRG components and the practical full-process prevention solutions.

I. Breakdown of the Core Causes of Post-Production Cracking in GRG Components 

Many people simply attribute GRG cracking to raw material quality issues. In fact, based on implementation data from nearly a thousand of our projects, the causes of cracking run through the entire chain of raw material ratios, production processes, and later storage—a single oversight at any stage can trigger subsequent cracking problems: 

1. Hidden deviations in raw material ratios: The core raw materials of GRG are gypsum powder, glass fiber, and additives. Many small factories reduce the proportion of high-grade gypsum to cut costs, or the amount of glass fiber added is insufficient or unevenly distributed, which directly results in the overall tensile strength of components falling below standard, making irregular micro-cracks prone to appear during the resting period after production. In addition, inadequate control of the gypsum's initial setting time—setting too quickly means internal stress has no time to release, so internal stress keeps acting after the component is formed—also creates hidden cracking risks. 2. Non-standard production operations: Insufficient mold flatness and uneven application of release agent lead to uneven forces on components during demolding, causing localized hidden cracks. Such hidden cracks are hard to detect during the production stage and often only become visible during storage or transportation. Many manufacturers also demold too early in order to rush schedules, handling components before their overall strength reaches design requirements, which makes structural cracking very likely under external forces. 3. Oversights in later storage and curing: After forming, GRG components need a curing period of about 72 hours in a constant temperature and humidity environment. If the storage environment has large temperature fluctuations or excessively strong ventilation, moisture on the component surface evaporates much faster than inside, resulting in surface drying-shrinkage cracking. In addition, improper stacking, with components left suspended or under pressure for long periods, can also cause cracking under stress.

II. Complete Prevention Solutions for Post-Production Cracking in GRG Components 

Based on our independently developed core processes and implementation verification across multiple landmark projects, avoiding GRG post-production cracking at the root requires building a full-process quality control system from raw material control to factory verification, with clear standard actions at every stage: 1. Upfront raw material control standards: The proportion of high-grade gypsum is fixed at no less than 90%; alkali-resistant glass fiber is used, with the addition amount strictly controlled within the range of 8%-12% of the component's total weight, and a mechanically uniform dispersion process is adopted to avoid localized fiber aggregation. All raw materials must undergo batch testing before warehousing; the gypsum's initial setting time and final setting time must comply with the national GRG industry standard, and non-conforming batches are rejected outright, eliminating ratio deviation problems at the source. 2. Standardized production process control: Molds are made of high-density panels, with flatness verified before each use and errors controlled within 0.5mm; release agent is applied using a uniform spraying process to avoid localized accumulation. Demolding time is strictly controlled—components are only allowed to be demolded after their strength reaches at least 70% of the design strength—and the demolding process uses a multi-point synchronized lifting method to avoid excessive localized stress. 3. Triple factory quality control verification: A triple quality inspection mechanism is established covering raw material warehousing, semi-finished product performance testing, and finished product weather resistance verification before shipment. After components complete curing, micro-cracks are first screened visually by eye, then internal hidden cracks are examined using stress detection equipment, and finally stress tests simulating stacking and transportation are conducted. Only components that pass all inspections are allowed to leave the warehouse. In addition, for the storage and transportation scenarios of different projects, we also provide partners with corresponding storage guidance to avoid cracking problems arising in later stages. This full-process prevention and control solution has already been implemented and verified in GRG decoration projects at multiple theaters and exhibition venues in China, with the post-factory cracking rate of components controlled within 0.1%, far below the industry average.

FAQ: 1. GRG components have no cracks when leaving the factory but crack during transportation—what is going on? In most cases, this is caused by inadequate fixing of components during transportation, with collisions or uneven forces occurring amid bumps. In addition, stacking components in layers exceeding the designed load-bearing capacity can also cause cracking. Reputable manufacturers provide corresponding transportation fixing guidance. 2. Can GRG components with existing micro-cracks still be used normally? If the micro-cracks are on the surface with a depth of no more than 0.1mm, they can be repaired with the same type of gypsum before use. If there are internal hidden cracks or cracks deeper than 1mm, continued use is not recommended to avoid safety hazards after installation. 3. Is the cracking of GRG components related to the project installation stage? Under normal circumstances, insufficient flatness of the base framework or uneven forces at fixing points during installation can also cause cracking. However, such cracking mostly appears after installation is complete; cracking that occurs right after production is basically unrelated to the installation stage.