1. Overview

In mechanical design, a holding / clamping module is a function module that maintains or fixes a target object, tool, jig, mold, transfer body, or working section in a defined position and posture.

If the material handling module moves the target object, and the motion / positioning module guides the target object to a specific position, the holding / clamping module holds the target object so that it does not move from that position.

In other words, the holding / clamping module is the design area that creates the force required to maintain position inside a machine.

For example, in cutting equipment, a clamp is required to prevent the product from shifting during cutting. In filling equipment, guides and holders are required to keep the container stable under the nozzle. In forming equipment, clamping force and clamping structures are required to prevent the mold from opening during operation. In assembly equipment, the part must maintain the correct posture relative to the insertion direction.

A holding / clamping module is not simply a device that “holds something.”
It directly affects positional repeatability, work quality, safety, product damage, working load, cleanability, and maintainability.

Therefore, the holding / clamping module should not be understood as an auxiliary part of the processing / working module. It should be understood as a core design module that stabilizes work quality.

2. Definition

A holding / clamping module is a function module that maintains a target object or machine component in a defined position, posture, reference surface, or contact condition within a mechanical system.

The core purpose of this module can be summarized as follows:

To stably maintain the position and posture of the target object or tool during work.

The holding / clamping module performs the following functions.

Holding and clamping are similar, but there are slight differences.

Therefore, the holding / clamping module is not limited to clamp parts. It includes locating, supporting, fixing, pressing, and reference creation.

3. Role in Mechanical Systems

The holding / clamping module performs the following roles within a mechanical system.

3.1 It Maintains the Target Object Position During Work

Most mechanical operations can be performed reliably only when the target object is in the correct position.

If the product moves during cutting, the cutting position shifts.
If the container shakes during filling, the filling position shifts and the contents may splash.
If the packaging material slips during sealing, sealing defects or leakage may occur.
If a part tilts during assembly, insertion defects or breakage may occur.

If the holding / clamping module is unstable, work quality cannot be stabilized even if the drive module or tooling module is precise.

3.2 It Resists Working Loads

The processing / working module and tooling module apply force to the target object.
Because of this force, the target object may slide, rotate, lift, or deform.

The holding / clamping module must resist these working loads.

Loads to review include:

• Cutting load

• Pressing load

• Insertion load

• Friction load

• Rotational reaction force

• Sealing pressure

• Filling pressure

• Vibration load

• Impact load

• Gravity load

• Eccentric load

The clamping force must be sufficient against the working load. However, if it is excessive, the target object may be crushed or deformed.

Therefore, the important point in a holding / clamping module is not to “hold strongly,” but to hold stably with the necessary amount of force.

3.3 It Creates Positional Repeatability

In repetitive production equipment, the target object must be placed in the same position every cycle.

The holding / clamping module creates repeatable position through reference surfaces, locating pins, stoppers, guides, and clamp pads.

Elements to review include:

• Reference surface position

• Shape of locating pins

• Stopper repeatability

• Clamp contact position

• Clamping force repeatability

• Product insertion direction

• Influence of foreign matter or residue

• Position change after wear

• Response to product dimensional variation

If repeatability is low, the operator must adjust the position every time, and production quality becomes dependent on operator skill.

3.4 It Prevents Product Damage

The holding / clamping module must hold the target object, but it must not damage it.

Food products, packaging materials, thin sheet materials, plastic containers, rubber materials, soft materials, and surface-treated products are especially sensitive to clamping force.

Forms of product damage include:

• Pressure marks

• Crushing

• Tearing

• Deformation

• Surface scratches

• Slip marks

• Wrinkles in packaging material

• Food breakage

• Container deformation

• Surface contamination

Therefore, clamp pad material, contact area, contact position, pressing speed, and pressure control must be reviewed together.

3.5 It Secures Work Safety

If the target object separates during work, safety problems can occur.

For example, if a product separates from a rotary table, material flies out during cutting, or a part slips out during pressing, both the operator and equipment can be at risk.

The holding / clamping module is connected to the following safety functions:

• Prevention of target object separation

• Fall prevention

• Prevention of flying out

• Position holding during work

• Clamp completion confirmation

• Control of unclamping conditions

• Connection with cover interlocks

• Position holding during emergency stop

In vertical axes, rotary devices, high-speed transfer equipment, and cutting equipment, confirmation of the holding state is especially important for safety.

3.6 It Affects Product Changeover and Adjustability

In multi-product equipment, product size and shape often change.
In this case, the adjustability of the holding / clamping module strongly affects productivity.

Elements to review include:

• Clamp position adjustment

• Guide width adjustment

• Stopper position adjustment

• Product height adjustment

• Pad replacement

• Jig replacement

• Scales or reference marks

• Possibility of tool-less adjustment

• Position reproducibility after product changeover

A holding structure that is difficult to change over reduces equipment availability and increases the burden on field operators.

4. Main Types of Holding / Clamping Modules

Holding / clamping modules can be divided into several types according to the fixing method and target object characteristics.

5. Types of Holding / Clamping Methods

5.1 Mechanical Clamping Method

Mechanical clamping fixes the target object using levers, screws, toggle structures, springs, cams, and similar mechanisms.

Typical components include:

• Toggle clamp

• Lever clamp

• Screw clamp

• Cam clamp

• Spring clamp

• Wedge clamp

• V-block

• Fixed jig

Advantages

• The structure is simple.

• It can be used without electricity or compressed air.

• Holding force is stable.

• Field adjustment is easy.

• Cost is relatively low.

Points to Consider

• There may be limitations for automation.

• Holding force may vary depending on operator handling.

• Operator fatigue may occur during repeated work.

• It may not be suitable for high-speed equipment.

• A separate safety confirmation sensor may be required.

Design Review Points

• Holding force

• Operation direction

• Operator accessibility

• Clamp stroke

• Reference surface position

• Product damage

• Repeated position

• Wear

• Replaceability

• Safety confirmation method

5.2 Pneumatic Clamping Method

Pneumatic clamping operates cylinders, grippers, or clamp arms using compressed air.

Typical components include:

• Pneumatic cylinder

• Clamp arm

• Air gripper

• Solenoid valve

• Regulator

• Speed controller

• Reed switch

• Clamp pad

Advantages

• Operation is fast.

• It is easy to apply to automated equipment.

• The structure is relatively simple.

• It is suitable for repeated operation.

• It is easy to connect with clamp completion sensors.

Points to Consider

• Clamping force may change depending on air pressure variation.

• Precise force control is limited.

• Impact may occur.

• Pneumatic piping and valve maintenance are required.

• In food machinery, air quality and lubricant contamination must be considered.

Design Review Points

• Cylinder thrust

• Operating pressure

• Clamp stroke

• Clamp speed

• Pad contact area

• Product damage

• Clamp completion detection

• Air consumption

• Piping location

• Safe release condition

5.3 Hydraulic Clamping Method

Hydraulic clamping uses pressurized oil to create large holding force.

Typical components include:

• Hydraulic cylinder

• Hydraulic clamp

• Hydraulic pump

• Hydraulic valve

• Pressure sensor

• Hydraulic hose

• Clamp block

Advantages

• Large clamping force can be created.

• It is suitable for high-load work.

• It is advantageous for mold fixing, pressing, and heavy object holding.

• Large force can be generated with a compact device.

• Pressure can be maintained.

Points to Consider

• There is a risk of hydraulic oil leakage.

• The system configuration is complex.

• Maintenance is required.

• In food machinery, contamination risk is high.

• It may be affected by temperature changes.

Design Review Points

• Required clamping force

• Operating pressure

• Cylinder bore

• Stroke

• Pressure holding

• Leakage prevention

• Seal life

• Hydraulic hose layout

• Safety valve

• Maintenance accessibility

5.4 Electric Clamping Method

Electric clamping fixes the target object using electric actuators, servo motors, ball screws, electric grippers, and similar devices.

Typical components include:

• Electric actuator

• Servo clamp

• Electric gripper

• Ball screw

• Linear guide

• Force sensor

• Encoder

• Controller

Advantages

• Clamp position can be controlled.

• Clamping force can be controlled.

• Product-specific conditions can be changed by program.

• Pneumatic piping is not required.

• It is advantageous for data collection and quality management.

Points to Consider

• Cost is high.

• Control setup is required.

• Impact loads require caution.

• Waterproof and dustproof protection is required.

• Mechanical damage may occur during overload.

Design Review Points

• Clamping force

• Clamp position

• Repeatability

• Force control method

• Product-specific condition settings

• Sensor feedback

• Overload protection

• Waterproof and dustproof protection

• Maintainability

• Safety stop condition

5.5 Vacuum Holding Method

Vacuum holding holds and maintains the target object using vacuum pressure.

Typical components include:

• Vacuum pad

• Vacuum pump

• Ejector

• Vacuum piping

• Vacuum sensor

• Suction plate

• Filter

• Release valve

Advantages

• It is suitable for flat plates, films, packaging materials, and thin products.

• It does not leave large pressure marks on the product surface.

• It is suitable for fast pickup and transfer.

• A lightweight structure can be created.

• Multiple pads can be combined easily.

Points to Consider

• Holding force decreases if the surface is rough or porous.

• Performance changes if the food surface is wet or sticky.

• Vacuum leakage must be considered.

• Suction failure detection is required.

• Pad material and cleanability must be reviewed.

Design Review Points

• Suction area

• Required vacuum pressure

• Product surface condition

• Pad material

• Pad layout

• Possibility of leakage

• Vacuum sensor

• Release time

• Filter management

• Cleanability

5.6 Jig / Fixture Holding Method

The jig / fixture method places and fixes the target object according to defined reference surfaces and locating elements.

Typical components include:

• Reference surface

• Locating pin

• V-block

• Nest

• Pocket

• Jig plate

• Stopper

• Clamp pad

Advantages

• Positional repeatability is good.

• Product posture can be maintained stably.

• Variation in work quality can be reduced.

• It is suitable for assembly, inspection, and processing work.

• Replaceable jigs can support multiple product variants.

Points to Consider

• It can easily become dedicated to a specific product shape.

• Foreign matter or residue on the reference surface can change the position.

• Position reproducibility after jig replacement is important.

• Pocket structures may become difficult to clean.

• Wear creates positioning error.

Design Review Points

• Reference surface position

• Locating method

• Product insertion direction

• Clamping direction

• Jig replaceability

• Repeatability

• Foreign matter discharge

• Allowable wear range

• Cleaning accessibility

• Product damage

6. Main Design Criteria

The following criteria should be reviewed when designing a holding / clamping module.

6.1 Characteristics of the Target Object

The first factor to review is the characteristics of the target object to be held.

Without understanding the target object characteristics, it is difficult to correctly determine clamping force, contact area, pad material, and reference surface geometry.

6.2 Required Clamping Force

The clamping force must be sufficient to prevent the target object from moving during work.

Review points include:

• Working load

• Friction coefficient

• Target object weight

• Acceleration load

• Cutting reaction force

• Pressing reaction force

• Impact load

• Safety factor

• Possibility of slipping

• Product damage limit

If the clamping force is insufficient, the target object moves. If the clamping force is too large, the product is damaged.

Therefore, clamping force should be determined by considering working load, friction condition, product strength, and quality requirements together.

6.3 Contact Area and Contact Position

In a holding / clamping module, contact area and contact position are very important.

Review points include:

• Clamp pad area

• Contact position

• Reference surface position

• Product centerline

• Load center

• Pressure distribution

• Slip direction

• Product deformation direction

• Interference with tooling

• Cleaning accessibility

If the contact area is too small, pressure marks may occur. If it is too large, cleaning may become difficult or product variation may become harder to handle.

6.4 Positional Repeatability and Reference Surfaces

The holding / clamping module must repeatedly create the same position.

Review points include:

• Clarity of reference surfaces

• Locating pins

• Stopper repeatability

• Clamping direction

• Product insertion direction

• Reference surface wear

• Foreign matter entrapment

• Reproducibility after jig replacement

• Adjustment reference

• Product changeover reference

Positioning is not created by clamping force alone.
Accurate reference surfaces and repeatable contact conditions are also required.

6.5 Product Damage and Deformation

The holding / clamping module must fix the product without damaging it.

Review points include:

• Allowable pressure

• Pressure marks

• Surface scratches

• Crushing

• Tearing

• Slip marks

• Wrinkles in packaging material

• Food breakage

• Clamping speed

• Pad material

For soft products or food products, it may be more important to support them gently over a wide area than to clamp them strongly.

6.6 Release and Discharge Performance

A clamp must release well, just as it must hold well.

Review points include:

• Clamp release time

• Whether the product sticks to the clamp

• Interference with discharge path

• Pad recovery

• Vacuum release time

• Product residue

• Product posture during discharge

• Connection with the next process

If clamp release is unstable, the product may become stuck, fail to move to the next process, or be discharged in an incorrect position.

6.7 Sensors and State Confirmation

The holding / clamping module should be able to confirm the holding state.

Review points include:

• Clamp completion detection

• Clamp release detection

• Product presence detection

• Pressure detection

• Vacuum pressure detection

• Position detection

• Overload detection

• Product separation detection

• Sensor protection

• Interface with the control system

In automated equipment, if work proceeds before clamping is completed, quality defects or safety problems may occur.

6.8 Cleanability and Maintainability

In food machinery in particular, cleanability and maintainability of the holding / clamping module are important.

Review points include:

• Cleanability of product-contact areas

• Gaps where residue remains

• Pad disassembly

• Jig removability

• Prevention of water accumulation

• Prevention of cleaning water ingress

• Separation of lubrication areas

• Corrosion prevention

• Replaceability of wear parts

• Sensor protection

Clamp pads, jigs, reference surfaces, and stoppers directly contact products or easily accumulate residue. Therefore, cleanability should be reviewed from the initial design stage.

7. Interface with Other Modules

The holding / clamping module is closely connected to several function modules.

7.1 Relationship with the Material Handling Module

The material handling module supplies the target object to the holding / clamping position.

Review points include:

• Does the target object enter the clamp position accurately?

• Does the feeding direction match the reference surface?

• Does the product get stuck during insertion?

• Do feeding speed and clamp timing match?

• Is product posture maintained after clamping?

• Is discharge smooth after release?

7.2 Relationship with the Motion / Positioning Module

The motion / positioning module moves the target object to the defined position, and the holding / clamping module maintains that position.

Review points include:

• Does the clamp reference surface match the positioning reference?

• Does the clamp operate after the moving body stops?

• Does clamping force push the object out of position?

• Do the stopper and clamping direction conflict?

• Is the next movement possible after clamp release?

7.3 Relationship with the Processing / Working Module

The processing / working module applies working load to the target object.
The holding / clamping module must maintain the target object position against this load.

7.4 Relationship with the Tooling Module

The tooling module directly contacts the target object and performs the work.
The holding / clamping module must resist the force applied by the tooling.

Review points include:

• Are the tooling action direction and clamping direction appropriate?

• Does the tool interfere with the clamp?

• Does the clamp block tool access?

• Does the target object move under tool load?

• Is the clamp reference maintained after tool replacement?

7.5 Relationship with the Drive Module

The holding / clamping module can be driven by pneumatic, hydraulic, electric, or manual methods.

Review points include:

• Can the drive unit generate the required clamping force?

• Is the clamping speed appropriate?

• Is clamp position control required?

• Is force control required?

• Is the system safe during power failure or air shutoff?

• Is the drive section suitable for the washdown environment?

7.6 Relationship with the Control / Sensing Module

The state of the holding / clamping module should be confirmed by the control system.

Review points include:

• Is there a clamp completion signal?

• Is there a clamp release signal?

• Can product presence be checked?

• Can pressure or vacuum pressure be checked?

• Can work stop when clamping is abnormal?

• Are sensors protected from cleaning water and impact?

7.7 Relationship with the Safety / Protection Module

The holding / clamping module can involve pinch hazards and unexpected motion hazards.

Review points include:

• Can the operator’s hand enter the clamping area?

• Is there a pinch hazard during clamping motion?

• Should clamping motion stop when a cover is opened?

• Can unexpected motion be prevented during manual adjustment?

• Does the target object not fall during emergency stop?

• Does residual air or hydraulic pressure remain?

8. Application in Food Machinery

In food machinery, the holding / clamping module often directly contacts food or is placed near food positioning areas.
Therefore, hygiene, cleanability, product damage prevention, and contamination prevention are very important.

Important conditions for holding / clamping modules in food machinery include the following.

For soft or easily deformable products such as bread, noodles, meat, fruit, and packaging materials, a wide-area, gentle holding structure may be more appropriate than strong clamping.

Also, if there are many gaps in food-contact jigs or clamp pads, raw material may become trapped and cleaning becomes difficult.
Therefore, holding / clamping modules in food machinery must consider not only holding force but also cleanability, drainability, disassembly, and product damage prevention.

9. Common Design Mistakes

Common design mistakes in holding / clamping modules include the following.

9.1 Considering Only Strong Clamping

A large clamping force does not automatically mean good design.
Excessive clamping force can cause product deformation, pressure marks, breakage, and wrinkles in packaging material.

Good clamping design must balance resistance to working load with prevention of product damage.

9.2 Confusing Positioning and Clamping

Clamping is the function of pressing an object. Positioning is the function of locating it against a reference.

If position is created only by clamping force, the position may vary depending on product variation, friction, and foreign matter.
If accurate positioning is required, reference surfaces, locating pins, and stoppers are also required.

9.3 Clamping Direction Does Not Match Working Load

If the working load pushes the product in one direction and the clamping direction does not resist that load, the product will move during work.

The clamping direction should be determined based on the working load, slip direction, and reference surface direction.

9.4 Ignoring Release and Discharge

A clamp must release and discharge well, not only hold well.

If the product sticks to the pad after release, gets caught in the jig, or if the clamp structure interferes with the discharge direction, the machine cycle becomes unstable.

9.5 Reviewing Cleanability and Residue Prevention Too Late

In food machinery, clamp pads, jigs, and stoppers are areas where raw material residue easily accumulates.

If cleanability is reviewed late, gaps, pockets, exposed bolts, and poor drainage often become problems.
Cleanability should be reviewed together with the clamp structure from the initial design stage.

10. Design Checklist

The following questions can be used when designing a holding / clamping module.

10.1 Target Object Review

• What are the shape, size, weight, and strength of the target object?

• Is the product easy to deform, break, or tear?

• Is the surface slippery, wet, or sticky?

• How large is the product dimensional variation?

• Are there food-contact or hygiene requirements?

10.2 Clamping Force Review

• How much force acts on the target object during work?

• Is the clamping force sufficient against the working load?

• Does the clamping force damage the product?

• Are friction conditions stable?

• Have acceleration, impact, and vibration conditions been considered?

10.3 Positioning Review

• Are reference surfaces and reference lines clear?

• Are locating pins or stoppers required?

• Does clamping force push the target object out of position?

• Is repeated position maintained?

• Do foreign matter or residue affect positioning?

10.4 Contact Section Review

• Is the clamp pad area appropriate?

• Does the contact position avoid product damage?

• Is the pad material suitable for the target object?

• Is the contact surface cleanable?

• Is quality maintained after wear?

10.5 Control and Safety Review

• Can clamp completion be detected?

• Can clamp release be confirmed?

• Can work stop if clamping fails?

• Is there a pinch hazard for operators?

• Does the target object not fall or separate during emergency stop?

10.6 Maintenance and Cleaning Review

• Can clamp pads and jigs be replaced easily?

• Can the module be disassembled for cleaning?

• Are there no gaps where residue remains?

• Does cleaning water drain properly?

• Are lubrication areas separated from food-contact areas?

• Is adjustment easy during product changeover?

11. Summary

A holding / clamping module is a core function module that maintains or fixes a target object, tool, jig, mold, or working section in a defined position and posture.

This module may consist of mechanical clamps, pneumatic clamps, hydraulic clamps, electric clamps, vacuum holding devices, magnetic holding devices, jigs, fixtures, stoppers, reference surfaces, and clamp pads.

A holding / clamping module is not simply a device that strongly holds an object.
It is a design area that maintains the target object position during work, resists working loads, creates repeated positions, prevents product damage, and secures safety and productivity.

When designing this module, target object characteristics, required clamping force, contact area, contact position, reference surfaces, positional repeatability, product damage, release and discharge performance, sensors, safety, cleanability, and maintainability must be reviewed together.

The holding / clamping module is also closely connected to the material handling module, motion / positioning module, processing / working module, tooling module, drive module, control / sensing module, and safety / protection module.

In food machinery, food-contact materials, cleaning accessibility, residue prevention, tool-less disassembly, separation of lubrication areas, and product damage prevention become core design requirements.

Therefore, the holding / clamping module should be understood not as a simple fixing device, but as a core design module that determines machine positional stability, work quality, safety, hygiene, and maintainability.