Tag smh machinery

The Complete Guide to Paper: From Raw Materials to Applications

Have you ever wondered how the paper you use every day is made? What’s the difference between various types of paper? This article will take you through the ins and outs of paper.

1. What Paper Is Made Of: Fibers and Additives Working Together

Main raw materials (plant fibers):

  • Wood, reeds, bamboo
  • Sugarcane bagasse, rice straw, wheat straw
  • Tree bark, cotton, hemp, etc.

Additives:

  • Fillers (e.g., clay, talc): fill gaps between fibers
  • Sizing agents: improve strength and smoothness
  • Dyes: for tinting or coloring – even white paper needs treatment

2. Specialty Papers: Types and Structure of Gold/Silver Cardboard

Gold/Silver Cardboard

TypeComposition
Aluminum foil basedAluminum + backing paper + varnish + print
PET basedFilm + backing paper + varnish + print
HolographicFilm + aluminum + embossing + backing paper + varnish + print

Note: Gold card is made by dyeing silver card (coated with red or yellow pigment), so its adhesion is generally weaker than that of silver card.

3. Paper Quality Evaluation Criteria

Visual quality

  • Uniformity: even distribution of fibers and thickness
  • Cleanliness: surface free from dirt and spots
  • Flatness: smooth and even

Physical properties

  • Squareness, caliper, density
  • Opacity, dirt count
  • Tensile strength, folding endurance, tear resistance

4. Paper Sizes Explained

Packaging formats

  • Sheet-fed: pre-cut by the mill, good flatness
  • Roll: wound on a core
Roll/Sheet-fed

Common sizes

TypeDimensions (mm)Inches
Large format889 × 119435″ × 47″
Standard format787 × 109231″ × 43″
Special formatAny size other than abovee.g., 25″ × 38″

5. Thickness vs. Grammage Reference Tables

Note: 1 “si” (Chinese unit) = 0.01 mm. Values vary by manufacturer and process; for reference only.

Coated paper (art paper)

GrammageThickness (si)
80 gsm5–6
105 gsm7–8
128 gsm10–11
157 gsm12–13
200 gsm16–17
230 gsm19
250 gsm22

Coated board

GrammageThickness (si)
230 gsm22–26
250 gsm26–27
300 gsm30–31
350 gsm35–37

Matte coated paper is about 2 si thicker than gloss coated paper of the same weight.

White card (solid bleached board)

GrammageThickness (si)
230 gsm29–30
250 gsm35
300 gsm40
350 gsm47–48
400 gsm52

White-backed white board / gray board

GrammageThickness (si)
250 gsm white back28
450 gsm white back57
250 gsm gray back28
300 gsm gray back36
350 gsm gray back42
400 gsm gray back49
450 gsm gray back57

Woodfree offset paper

GrammageThickness (si)
70 gsm8
80 gsm9
100 gsm11
120 gsm13
140 gsm16

Kraft paper

GrammageThickness (si)Notes
80 gsm11
120 gsm14
150 gsm16–1818 typical, 16 special
200 gsm22
300 gsm44

6. Practical Conversions and Selection Tips

How to choose:

  1. Brochures: 157–250 gsm coated paper
  2. Business cards: 300–350 gsm coated board or white card – specialty paper for a premium feel
  3. Book interiors: 70–120 gsm woodfree offset paper
  4. Packaging boxes: 250–400 gsm gray board or white card
  5. Envelopes/file folders: 80–150 gsm kraft paper

Thickness reference (everyday items):

  • Standard A4 printer paper: about 8–9 si
  • Typical business card: 30–35 si
  • Hardcover book cover: 40–50 si
  • High-end gift box: over 50 si

With this guide, you now have a solid understanding of paper raw materials, types, specifications, and quality standards. Whether for daily use or professional selection, this knowledge will help you make better decisions.

How Automation Reduces Labor Cost — Without Limiting Output

Labor is one of the largest and most unpredictable costs in paper converting. Wages rise, availability fluctuates, and consistency depends on operator skill.

But cutting labor cost doesn’t have to mean cutting output. Done right, automation restructures production so you get more stability with fewer people.

A4 paper cutting machine

Where Labor Cost Really Comes From

Labor cost isn’t just headcount. It adds up across material handling, sheet counting, packing, palletizing, and machine adjustments. In manual setups, more volume means adding more people – and cost grows with output.

What Automation Actually Replaces

Automation doesn’t simply “remove workers.” It replaces repetitive, variable tasks with controlled, repeatable processes:

  • Continuous sheet feeding and alignment
  • Precise counting and stacking
  • Uniform packing and sealing
  • Pallet transfer

Operators shift from physical handling to supervision. Fewer people per shift, and less dependency on manual coordination.

Stability Is Where Cost Reduction Happens

The biggest impact of automation isn’t fewer workers – it’s more stable production. Manual operations bring inconsistency: varying handling speed, fatigue errors, shift differences. Automation standardizes cycle times and execution, reducing hidden costs like rework, downtime, and waste.

Running at Designed Capacity

Many factories have upstream machines capable of higher speed, but manual downstream packing forces the line to slow down. Automation removes that bottleneck. When cutting, stacking, and packing are synchronized, machines run at stable speed, bottlenecks disappear, and output increases without adding labor. Cost per unit drops because productivity improves.

Reducing Long-Term Labor Pressure

Labor challenges aren’t just cost – they’re also availability and retention. Manual operations need continuous hiring, training, shift coordination. Automation reduces this pressure: fewer operators needed, skill requirements shift to system operation, production becomes less dependent on individual performance. Result: a more scalable, manageable operation.

Flexibility Without Complexity

Modern lines must handle different paper grades, order sizes, and job changes. Manual systems struggle – each change introduces delay and error risk. Automated systems allow parameter-based adjustments: quick format switching, consistent execution, minimal disruption. Better responsiveness without extra labor.

The Role of Equipment

Labor reduction depends on how well the system performs in real conditions. Key factors: stability at speed, consistency across paper types, low downtime, and good integration between stages. Well-designed sheeting, packing, and handling systems let you reduce labor while maintaining or increasing output.

Conclusion

Automation reduces labor cost not by simply cutting headcount, but by restructuring production:

  • From manual coordination to system control
  • From variable output to stable performance
  • From labor-driven capacity to equipment-driven efficiency

The result: lower labor cost, plus a more predictable and scalable operation.

Need to reduce labor cost without losing output?

If you’re evaluating how to cut labor dependency while maintaining production, SMH can help assess your current line and define a practical automation upgrade.

Contact SMH – improve efficiency, reduce manual labor, and stabilize your output.

Why Does Paper Web Drift During Slitting?

In paper converting, web drift is a common issue—but also one of the most costly.

Auto web guide system
Auto web guide system

At the beginning of a run, everything may look stable.

But as speed increases, problems start to show:

the paper slowly shifts to one side

edges no longer align with the knives

slitting width becomes inconsistent

wrinkles or edge damage begin to appear

Many operators try to correct this manually, but the problem often comes back.

That’s because web drift is rarely caused by a single factor—it is usually the result of multiple system imbalances.

  1. Unstable Tension: The Root of Most Drift ProblemsPaper is not a rigid material. It stretches and reacts to force.If tension is not properly controlled:too loose → paper wanders and loses directiontoo tight → paper stretches and pulls unevenlyEven small fluctuations can cause the web to shift sideways over time.In high-speed production, unstable tension becomes the primary trigger for drift.
  2. Lack of Effective Edge GuidingWithout a proper guiding system, the machine has no way to correct position errors.Even if the paper starts centered, small deviations will accumulate:slight misalignment at unwindinguneven roller contactmaterial variationWithout correction, these small errors turn into visible drift.A properly configured edge guiding system continuously detects the paper edge and makes micro-adjustments to keep it aligned.
  3. Guiding and Tension Not Working TogetherMany production lines have both guiding and tension control—but still experience drift.Why?Because the two systems are not synchronized.For example:guiding system corrects position, but tension changes cause new deviationtension system stabilizes force, but guiding reacts too slowlyWhen these systems operate independently, they can even interfere with each other.Stable production requires coordinated control—where guiding and tension respond together.
  4. Mechanical Factors and Alignment IssuesDrift is not always a control problem. It can also come from the machine itself.Common causes include:misaligned rollersuneven wear on componentsinstallation inaccuraciesvibration at certain speedsThese factors create uneven forces across the web, pushing it off its intended path.
  5. Material DifferencesNot all paper behaves the same.Different grades have different:thicknessstiffnesssurface frictionThin or flexible paper is more sensitive to movement.Coated or smooth paper may slip more easily on rollers.If machine parameters are not adjusted to match the material, drift becomes more likely.
  6. Speed Changes and Dynamic ConditionsAt low speed, drift may not be obvious.As speed increases:system response time becomes criticaltension fluctuations amplifysmall alignment errors grow fasterFrequent acceleration and deceleration make the problem worse.Stable high-speed production requires systems that can react in real time.

What Actually Solves the Problem?

There is no single fix.

Stable web tracking comes from a combined system approach:

accurate edge guiding to control position

stable tension control to maintain uniform force

synchronized control logic between both systems

proper mechanical alignment and maintenance

When these elements work together, the paper remains stable—even at high speed.

Conclusion

Paper drift is not just a minor inconvenience—it directly affects product quality, waste, and production efficiency.

Trying to fix it manually or adjusting one parameter at a time often leads to temporary results.

The real solution lies in understanding how different systems interact and ensuring they work as a coordinated whole.

CTA

If your production line still struggles with web drift or unstable slitting results, SMH can help you evaluate the root causes and provide a more stable solution.

Get a tailored web control optimization plan

Contact SMH to improve alignment, reduce waste, and stabilize production

1400J Installed in Japan — Meeting High-Precision Paper Sheeting Standards

In Japan’s paper converting industry, expectations are different. Speed matters – but precision, consistency, and stability matter even more.

A Japanese paper processor recently upgraded with the 1400J paper sheeter from SMH, aiming to improve cutting accuracy and long-run stability for high-quality paper products.

The Challenge: Precision at Scale

The factory runs lightweight coated paper and high-grade printing materials. Their main problems were:

  • Slight deviation in sheet squareness at higher speeds
  • Inconsistent cutting length over long runs
  • Sensitivity to tension and humidity

At lower speeds, these issues were manageable. But as production demand grew, maintaining both speed and precision became difficult.

Why This Is Difficult

Lightweight and coated papers react strongly to tension fluctuation, static electricity, and tiny alignment errors. Even small variations cause visible edge defects, stacking inconsistency, and lower yield in downstream printing. For Japanese customers, these tolerances are not acceptable.

How the 1400J Solved It

The 1400J was configured with:

  • Servo-driven cutting system – consistent length accuracy
  • Optimized frame rigidity – minimal vibration at high speed
  • Integrated tension control – stable web handling
  • Precision alignment system – better sheet squareness

More importantly, it maintains performance over long runs – not just at startup.

Measurable Results

After installation:

  • Cutting consistency improved significantly
  • Production speed increased without quality loss
  • Defect rate reduced
  • Operator intervention decreased

The factory reported a more stable and predictable process, especially for high-grade paper orders.

A Standard, Not Just an Upgrade

In markets like Japan, equipment is judged by real production performance – not just specs. The 1400J delivers stable operation, repeatable accuracy, and adaptability to different paper grades.

Need high-precision sheeting?

If your production requires consistent precision under demanding conditions, SMH can help evaluate your setup and provide a tailored solution.

Contact SMH for a precision-focused configuration plan – improve your production stability.In Japan’s paper converting industry, expectations are different. Speed matters – but precision, consistency, and stability matter even more.

A Japanese paper processor recently upgraded with the 1400J paper sheeter from SMH, aiming to improve cutting accuracy and long-run stability for high-quality paper products.

The Challenge: Precision at Scale

The factory runs lightweight coated paper and high-grade printing materials. Their main problems were:

  • Slight deviation in sheet squareness at higher speeds
  • Inconsistent cutting length over long runs
  • Sensitivity to tension and humidity

At lower speeds, these issues were manageable. But as production demand grew, maintaining both speed and precision became difficult.

Why This Is Difficult

Lightweight and coated papers react strongly to tension fluctuation, static electricity, and tiny alignment errors. Even small variations cause visible edge defects, stacking inconsistency, and lower yield in downstream printing. For Japanese customers, these tolerances are not acceptable.

How the 1400J Solved It

The 1400J was configured with:

  • Servo-driven cutting system – consistent length accuracy
  • Optimized frame rigidity – minimal vibration at high speed
  • Integrated tension control – stable web handling
  • Precision alignment system – better sheet squareness

More importantly, it maintains performance over long runs – not just at startup.

Measurable Results

After installation:

  • Cutting consistency improved significantly
  • Production speed increased without quality loss
  • Defect rate reduced
  • Operator intervention decreased

The factory reported a more stable and predictable process, especially for high-grade paper orders.

A Standard, Not Just an Upgrade

In markets like Japan, equipment is judged by real production performance – not just specs. The 1400J delivers stable operation, repeatable accuracy, and adaptability to different paper grades.

Need high-precision sheeting?

If your production requires consistent precision under demanding conditions, SMH can help evaluate your setup and provide a tailored solution.

Contact SMH for a precision-focused configuration plan – improve your production stability.