There are 7 steps for Basic process controls for Insulating Firebricks 1. Raw material control 2..Forming 3. Drying 4. Firing 5.Cutting 6. Package 7. Shipping
1. All raw materials should be tested before using at internal or external laboratory
Routine testing includes: particle size analysis, white analysis, chemical analysis, water analysis, specific gravity analysis, viscosity analysis.
Qualified materials will be sent to the warehouse of raw materials and will be recorded the send time to be as the batch of raw material lot number.
2. According to the production of different insulating firebricks, we have a fixed formula for each, and then we confirm the product batch numbers.
Our production batch numbers are identified based on customer orders, different orders have corresponding number while different products will be added the appropriate suffix accordingly , and then transfer to the next processing until the storage.
We will select the corresponding machine for different sizes bricks production, and in this process, we will carefully record the weight of unfired bricks to ensure a reasonable water content and pore structure, and test the viscosity of unfired bricks. The unqualified products will be directly put back as raw materials.
3. The drying process could be divided into the natural drying and manual drying , drying kiln is commonly used to make temperature and humidity uniform throughout the drying process, while achieving the mass production
Unfired insulating firebricks after drying will be weighed again to confirm a reasonable rate of dehydration. if there is any insulating firebricks with a big lack of edge chipping it will be singled out and back to the former step.
4.Tunnel kiln, shuttle kiln, down draft kiln are generally used in the firing of insulating bricks. Generally the maximum firing temperature of tunnel kiln is 1650C.The kilns are all automatically controlled.
Control key points: the density of bricks, the appearance size, shrinkage, thermal shock, sound &shape defects, pores, cracks of surfaces and the internal structures.
Field sampling:
Physical and chemical testing like specific gravity, cold crashing strength, flexural strength, linear change after reheating, thermal shock.
Unqualified products will be crushed.
5. The insulating firebricks after burning will be firstly put into semi-finished products warehouse. The director will appoint corresponding operator and molds according to customers order drawings combined with on-site semi-finished products after an internal review.
On-site inspection will be assigned with full-time staffs, they will make the first inspection and sampling testing.
In this session, the products which have major shortcomings or the ones with big size changing will be crushed. The ones with size deviations will be re-processed.
Company testing standard is the tolerance scope should be within 0.5mm for the size within 250mm, cumulative tolerance of 10 pcs bricks should be not more than 5mm
6. The insulating firebricks will be tested and checked again after cutting before they are sorted to warehouse, the physical and chemical properties will be tested as below,
The density, c.c.s, flexural strength, linear change after reheating, thermal shock, appareance defects like missing angle, lack of edge, surface crack.
Qualified products will be packaged, the packaging with different colors is to distinguish different levels, the weight of standard package does not exceed 15kgs.
We can make customized packaging according to requirements for free.
After sampling, The products which really still have quality problems will be degraded or crushed.
7 We will prepare the goods after receiving customer’s delivery notification along with packing list, the internal test report, third-party test report (such as customer specified)
At the same time we will record the batch number by Internal Quality Control Department to make quality records trackingWe will provide technical support and field service for customers project with insulating firebricks applied.