How to calculate the weight of pp hollow board?
PP hollow board, also known as grid hollow board or corrugated polypropylene sheet, is produced by mixing polypropylene (PP) and polyethylene (PE) raw materials, then extruded and formed through professional hollow‑board production lines. Its unique grid‑shaped cross‑section structure delivers lightweight, high‑strength performance, widely used for turnover boxes, protective packaging, signage, partition panels and many other industrial applications.
When sourcing PP hollow board for projects, many global buyers need to work out board weight for cost estimation, freight calculation and product performance verification. Unlike solid plastic sheets, PP hollow board features hollow grid inner structure, so weight cannot be calculated simply by solid‑plastic density. Below we share practical knowledge and calculation methods for PP hollow board weight.
Core Concept: GSM (Grams Per Square Meter)
For PP hollow board industry, GSM (g/m², grams per square meter) is the most‑used reference index for board weight. GSM represents the weight of one square‑meter hollow‑board sheet. Higher GSM means more raw resin material is used, bringing better stiffness, impact resistance and longer service life, while the product weight and unit cost will increase accordingly.
> Single sheet weight (kg) = Board area (m²) × GSM (g/m²) ÷ 1000
Calculation example:
If you have a hollow‑board sheet sized 2.0m × 1.0m, with 700 GSM:
Area = 2.0 × 1.0 = 2 m²
Single sheet weight = 2 × 700 ÷1000 = 1.4 kg
What affects the weight of PP hollow board
1. GSM / raw material dosage
This is the decisive factor. Even boards with the same thickness can have different GSM, due to different grid structure and resin filling. Two 4 mm hollow boards may be 550 GSM or 800 GSM, with obvious weight and strength gaps.
2. Board thickness
Common thickness range: 2 mm‑8 mm. Normally thicker boards match higher GSM. But thickness alone cannot represent weight; always confirm GSM with your supplier.
3. Additives formulation
Anti‑static, flame‑retardant, UV‑resistant modified hollow boards add functional masterbatch, which will slightly change the finished‑sheet weight.
4. Production tolerance
Actual finished weight has normal production tolerance, generally within ±5%‑8% in regular industry standards.
Two practical ways to get accurate weight
Method 1: Theoretical calculation for quotation and budget
1. Confirm sheet length, width, and GSM from supplier datasheet
2. Calculate sheet area (length × width, unit in meter)
3. Apply formula: Sheet Weight(kg)= Area × GSM ÷ 1000
4. Multiply by total quantity for total cargo weight, for container loading and freight budget.
Method 2: Actual physical weighing (most accurate)
Cut out a 1 m ×1 m sample piece, weigh it directly on electronic scale, you get real‑world GSM value. This method helps you verify whether delivered goods match contract technical specifications.
Common misunderstandings buyers should avoid
- Take thickness alone to judge weight and strength. Same thickness may come with different GSM and actual performance.
- Use solid PP plastic density formula for hollow‑board calculation. Hollow grid void space makes solid‑plastic formulas invalid, and will produce large deviation.
- Ignore weight tolerance. A small weight deviation is normal for mass production.
Practical tips for purchasing
When you inquire for PP hollow‑board sheets or finished hollow‑board turnover boxes, besides dimension and thickness, remember to clearly specify required GSM, functional requirements (anti‑static, UV‑proof etc). This avoids receiving products with insufficient material that cannot meet your loading and turnover demands.
